Change in the surface ANTIGEN of a microorganism. There are two different types. One is a phenomenon, especially associated with INFLUENZA VIRUSES, where they undergo spontaneous variation both as slow antigenic drift and sudden emergence of new strains (antigenic shift). The second type is when certain PARASITES, especially trypanosomes, PLASMODIUM, and BORRELIA, survive the immune response of the host by changing the surface coat (antigen switching). (From Herbert et al., The Dictionary of Immunology, 4th ed)
Variant Surface Glycoproteins, Trypanosoma
Glycoproteins attached to the surface coat of the trypanosome. Many of these glycoproteins show amino acid sequence diversity expressed as antigenic variations. This continuous development of antigenically distinct variants in the course of infection ensures that some trypanosomes always survive the development of immune response to propagate the infection.
Trypanosoma brucei brucei
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Amino Acid Sequence
Bacterial Outer Membrane Proteins
Trypanosoma brucei gambiense
Sequence Analysis, DNA
A disease endemic among people and animals in Central Africa. It is caused by various species of trypanosomes, particularly T. gambiense and T. rhodesiense. Its second host is the TSETSE FLY. Involvement of the central nervous system produces "African sleeping sickness." Nagana is a rapidly fatal trypanosomiasis of horses and other animals.
An acute infection characterized by recurrent episodes of PYREXIA alternating with asymptomatic intervals of apparent recovery. This condition is caused by SPIROCHETES of the genus BORRELIA. It is transmitted by the BITES of either the body louse (PEDICULUS humanus corporis), for which humans are the reservoir, or by soft ticks of the genus ORNITHODOROS, for which rodents and other animals are the principal reservoirs.
The measurement of infection-blocking titer of ANTISERA by testing a series of dilutions for a given virus-antiserum interaction end-point, which is generally the dilution at which tissue cultures inoculated with the serum-virus mixtures demonstrate cytopathology (CPE) or the dilution at which 50% of test animals injected with serum-virus mixtures show infectivity (ID50) or die (LD50).
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
The asymmetrical segregation of genes during replication which leads to the production of non-reciprocal recombinant strands and the apparent conversion of one allele into another. Thus, e.g., the meiotic products of an Aa individual may be AAAa or aaaA instead of AAaa, i.e., the A allele has been converted into the a allele or vice versa.
A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)
Malaria caused by PLASMODIUM FALCIPARUM. This is the severest form of malaria and is associated with the highest levels of parasites in the blood. This disease is characterized by irregularly recurring febrile paroxysms that in extreme cases occur with acute cerebral, renal, or gastrointestinal manifestations.
Thin, hairlike appendages, 1 to 20 microns in length and often occurring in large numbers, present on the cells of gram-negative bacteria, particularly Enterobacteriaceae and Neisseria. Unlike flagella, they do not possess motility, but being protein (pilin) in nature, they possess antigenic and hemagglutinating properties. They are of medical importance because some fimbriae mediate the attachment of bacteria to cells via adhesins (ADHESINS, BACTERIAL). Bacterial fimbriae refer to common pili, to be distinguished from the preferred use of "pili", which is confined to sex pili (PILI, SEX).
Hemagglutination Inhibition Tests
Equine Infectious Anemia
Lipid-protein complexes involved in the transportation and metabolism of lipids in the body. They are spherical particles consisting of a hydrophobic core of TRIGLYCERIDES and CHOLESTEROL ESTERS surrounded by a layer of hydrophilic free CHOLESTEROL; PHOSPHOLIPIDS; and APOLIPOPROTEINS. Lipoproteins are classified by their varying buoyant density and sizes.
An infectious disease caused by a spirochete, BORRELIA BURGDORFERI, which is transmitted chiefly by Ixodes dammini (see IXODES) and pacificus ticks in the United States and Ixodes ricinis (see IXODES) in Europe. It is a disease with early and late cutaneous manifestations plus involvement of the nervous system, heart, eye, and joints in variable combinations. The disease was formerly known as Lyme arthritis and first discovered at Old Lyme, Connecticut.
Repetitive Sequences, Nucleic Acid
Sequences of DNA or RNA that occur in multiple copies. There are several types: INTERSPERSED REPETITIVE SEQUENCES are copies of transposable elements (DNA TRANSPOSABLE ELEMENTS or RETROELEMENTS) dispersed throughout the genome. TERMINAL REPEAT SEQUENCES flank both ends of another sequence, for example, the long terminal repeats (LTRs) on RETROVIRUSES. Variations may be direct repeats, those occurring in the same direction, or inverted repeats, those opposite to each other in direction. TANDEM REPEAT SEQUENCES are copies which lie adjacent to each other, direct or inverted (INVERTED REPEAT SEQUENCES).
Sequence Homology, Amino Acid
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Influenza A virus
The type species of the genus INFLUENZAVIRUS A that causes influenza and other diseases in humans and animals. Antigenic variation occurs frequently between strains, allowing classification into subtypes and variants. Transmission is usually by aerosol (human and most non-aquatic hosts) or waterborne (ducks). Infected birds shed the virus in their saliva, nasal secretions, and feces.
Sensitive assay using radiolabeled ANTIGENS to detect specific ANTIBODIES in SERUM. The antigens are allowed to react with the serum and then precipitated using a special reagent such as PROTEIN A sepharose beads. The bound radiolabeled immunoprecipitate is then commonly analyzed by gel electrophoresis.
A genus of protozoa that comprise the malaria parasites of mammals. Four species infect humans (although occasional infections with primate malarias may occur). These are PLASMODIUM FALCIPARUM; PLASMODIUM MALARIAE; PLASMODIUM OVALE, and PLASMODIUM VIVAX. Species causing infection in vertebrates other than man include: PLASMODIUM BERGHEI; PLASMODIUM CHABAUDI; P. vinckei, and PLASMODIUM YOELII in rodents; P. brasilianum, PLASMODIUM CYNOMOLGI; and PLASMODIUM KNOWLESI in monkeys; and PLASMODIUM GALLINACEUM in chickens.
The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.
Infectious Anemia Virus, Equine
A species of LENTIVIRUS, subgenus equine lentiviruses (LENTIVIRUSES, EQUINE), causing acute and chronic infection in horses. It is transmitted mechanically by biting flies, mosquitoes, and midges, and iatrogenically through unsterilized equipment. Chronic infection often consists of acute episodes with remissions.
A species of gram-negative, aerobic BACTERIA. It is a commensal and pathogen only of humans, and can be carried asymptomatically in the NASOPHARYNX. When found in cerebrospinal fluid it is the causative agent of cerebrospinal meningitis (MENINGITIS, MENINGOCOCCAL). It is also found in venereal discharges and blood. There are at least 13 serogroups based on antigenic differences in the capsular polysaccharides; the ones causing most meningitis infections being A, B, C, Y, and W-135. Each serogroup can be further classified by serotype, serosubtype, and immunotype.
Rec A Recombinases
A family of recombinases initially identified in BACTERIA. They catalyze the ATP-driven exchange of DNA strands in GENETIC RECOMBINATION. The product of the reaction consists of a duplex and a displaced single-stranded loop, which has the shape of the letter D and is therefore called a D-loop structure.
Cell-surface components or appendages of bacteria that facilitate adhesion (BACTERIAL ADHESION) to other cells or to inanimate surfaces. Most fimbriae (FIMBRIAE, BACTERIAL) of gram-negative bacteria function as adhesins, but in many cases it is a minor subunit protein at the tip of the fimbriae that is the actual adhesin. In gram-positive bacteria, a protein or polysaccharide surface layer serves as the specific adhesin. What is sometimes called polymeric adhesin (BIOFILMS) is distinct from protein adhesin.
Sequence Homology, Nucleic Acid
Gene Expression Regulation
One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.
Enzyme-Linked Immunosorbent Assay
An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.
Polymerase Chain Reaction
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Borrelia burgdorferi Group
Gram-negative helical bacteria, in the genus BORRELIA, that are the etiologic agents of LYME DISEASE. The group comprises many specific species including Borrelia afzelii, Borellia garinii, and BORRELIA BURGDORFERI proper. These spirochetes are generally transmitted by several species of ixodid ticks.
Blood-sucking acarid parasites of the order Ixodida comprising two families: the softbacked ticks (ARGASIDAE) and hardbacked ticks (IXODIDAE). Ticks are larger than their relatives, the MITES. They penetrate the skin of their host by means of highly specialized, hooked mouth parts and feed on its blood. Ticks attack all groups of terrestrial vertebrates. In humans they are responsible for many TICK-BORNE DISEASES, including the transmission of ROCKY MOUNTAIN SPOTTED FEVER; TULAREMIA; BABESIOSIS; AFRICAN SWINE FEVER; and RELAPSING FEVER. (From Barnes, Invertebrate Zoology, 5th ed, pp543-44)
Viral Envelope Proteins
Layers of protein which surround the capsid in animal viruses with tubular nucleocapsids. The envelope consists of an inner layer of lipids and virus specified proteins also called membrane or matrix proteins. The outer layer consists of one or more types of morphological subunits called peplomers which project from the viral envelope; this layer always consists of glycoproteins.
Genetic and antigenic variation of capsid protein VP7 of serotype G1 human rotavirus isolates. (1/863)The deduced amino acid sequences of the outer capsid protein, VP7, of serotype G1 rotavirus clinical isolates collected over a 6 year period (1990-1995) in Melbourne, Australia, were examined. Phylogenetic analysis characterized the sequences into two discrete clusters representing two of the four global lineages of human G1 VP7 proteins. Antigenic characterization using a panel of serotype G1-specific neutralizing monoclonal antibodies classified lineage II isolates (1990-1993) as monotype G1a while lineage I isolates were classified as monotype G1b (1993-1995). Examination of the sequences of the neutralization epitope regions of VP7 revealed a particular amino acid substitution at residue 94 in region A (Asp --> Ser/Thr) that correlated with lineage and monotype designation. Our results indicated that temporal genetic variation of the VP7 of serotype G1 rotaviruses was associated with changes in the antigenicity of these isolates. (+info)
The major immunogenic epitopes of Epstein-Barr virus (EBV) nuclear antigen 1 are encoded by sequence domains which vary among nasopharyngeal carcinoma biopsies and EBV-associated cell lines. (2/863)Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1) is a protein expressed consistently in EBV-infected cells and EBV-associated malignant tissues. A panel of monoclonal antibodies (MAbs) was generated against the C terminus of EBNA-1 and evaluated for the detection of EBNA-1 in different cell lines. The epitopes recognized were mapped. Since sequence variations of EBNA-1 have been reported in nasopharyngeal carcinoma (NPC) tissues and in infected healthy individuals, the ability of these MAbs to recognize a recombinant protein derived from an NPC biopsy was also analysed. MAb 4H11 appeared to react with EBNA-1 sequences from different sources, whereas MAbs 5C11, 5F12 and 8F6 failed to recognize a recombinant EBNA-1 protein cloned from an NPC patient. Using different recombinant EBNA-1 fragments in an immunoblot format, this study demonstrates that the domain bounded by amino acids 408 and 498 is very immunogenic in mice in that epitopes in this region are recognized by various MAbs. Amino acid sequences of EBNA-1 were also deduced from nucleotide sequences amplified from three Burkitt's lymphoma cell lines, two spontaneous lymphoblastoid cell lines, two NPC biopsies and one NPC hybrid cell line, NPC-KT, and compared to the sequence from B95-8. The amino acid sequence of EBNA-1 in Akata is almost identical to that in an NPC biopsy, except for amino acid 585. The results of this study indicate that the immunogenic epitopes of EBNA-1 are highly variable. (+info)
Antigenic variation in malaria: a 3' genomic alteration associated with the expression of a P. knowlesi variant antigen. (3/863)Antigenic variation of malaria parasites was discovered in P. knowlesi, using a schizont-infected cell agglutination (SICA) assay to detect variant antigens expressed at the surface of infected erythrocytes. Later studies utilizing stable clones, Pk1(A+) and its direct derivative, Pk1(B+)1+, showed that SICA[+] clones express distinct parasite-encoded antigens of approximately 200 kDa. Here we identify a P. knowlesi variant antigen gene and cDNA and demonstrate that it encodes the 205 kDa variant antigen expressed by B+ parasites. This gene belongs to a multigene family, which we term SICAvar. Its ten-exon structure with seven cysteine-rich coding modules is unique compared to P. falciparum var genes. Further, we highlight a 3' genomic alteration that we predict is related to SICAvar gene switching. (+info)
Phase variations of the Mycoplasma penetrans main surface lipoprotein increase antigenic diversity. (4/863)Mycoplasma penetrans is a recently identified mycoplasma, isolated from urine samples collected from human immunodeficiency virus (HIV)-infected patients. Its presence is significantly associated with HIV infection. The major antigen recognized during natural and experimental infections is an abundant P35 lipoprotein which, upon extraction, segregates in the Triton X-114 detergent phase and is the basis of M. penetrans-specific serological assays. We report here that the P35 antigen undergoes spontaneous and reversible phase variation at high frequency, leading to heterogeneous populations of mycoplasmas, even when derived from a clonal lineage. This variation was found to be determined at the transcription level, and although this property is not unique among the members of the class Mollicutes, the mechanism by which it occurs in M. penetrans differs from those previously described for other Mycoplasma species. Indeed, the P35 phase variation was due neither to a p35 gene rearrangement nor to point mutations within the gene itself or its promoter. The P35 phase variation in the different variants obtained was concomitant with modifications in the pattern of other expressed lipoproteins, probably due to regulated expression of selected members of a gene family which was found to potentially encode similar lipoproteins. M. penetrans variants could be selected on the basis of their lack of colony immunoreactivity with a polyclonal antiserum against a Triton X-114 extract, strongly suggesting that the mechanisms involved in altering surface antigen expression might allow evasion of the humoral immune response of the infected host. (+info)
Molecular and functional analysis of a conserved CTL epitope in HIV-1 p24 recognized from a long-term nonprogressor: constraints on immune escape associated with targeting a sequence essential for viral replication. (5/863)It has been hypothesized that sequence variation within CTL epitopes leading to immune escape plays a role in the progression of HIV-1 infection. Only very limited data exist that address the influence of biologic characteristics of CTL epitopes on the emergence of immune escape variants and the efficiency of suppression HIV-1 by CTL. In this report, we studied the effects of HIV-1 CTL epitope sequence variation on HIV-1 replication. The highly conserved HLA-B14-restricted CTL epitope DRFYKTLRAE in HIV-1 p24 was examined, which had been defined as the immunodominant CTL epitope in a long-term nonprogressing individual. We generated a set of viral mutants on an HX10 background differing by a single conservative or nonconservative amino acid substitution at each of the P1 to P9 amino acid residues of the epitope. All of the nonconservative amino acid substitutions abolished viral infectivity and only 5 of 10 conservative changes yielded replication-competent virus. Recognition of these epitope sequence variants by CTL was tested using synthetic peptides. All mutations that abrogated CTL recognition strongly impaired viral replication, and all replication-competent viral variants were recognized by CTL, although some variants with a lower efficiency. Our data indicate that this CTL epitope is located within a viral sequence essential for viral replication. Targeting CTL epitopes within functionally important regions of the HIV-1 genome could limit the chance of immune evasion. (+info)
Spontaneous regression of primary autoreactivity during chronic progression of experimental autoimmune encephalomyelitis and multiple sclerosis. (6/863)Experimental autoimmune encephalomyelitis (EAE) is a widely used animal model for multiple sclerosis (MS). EAE is typically initiated by CD4(+) T helper cell type 1 (Th1) autoreactivity directed against a single priming immunodominant myelin peptide determinant. Recent studies have shown that clinical progression of EAE involves the accumulation of neo-autoreactivity, commonly referred to as epitope spreading, directed against peptide determinants not involved in the priming process. This study directly addresses the relative roles of primary autoreactivity and secondary epitope spreading in the progression of both EAE and MS. To this end we serially evaluated the development of several epitope-spreading cascades in SWXJ mice primed with distinctly different encephalitogenic determinants of myelin proteolipid protein. In a series of analogous experiments, we examined the development of epitope spreading in patients with isolated monosymptomatic demyelinating syndrome as their disease progressed to clinically definite MS. Our results indicate that in both EAE and MS, primary proliferative autoreactivity associated with onset of clinical disease invariably regresses with time and is often undetectable during periods of disease progression. In contrast, the emergence of sustained secondary autoreactivity to spreading determinants is consistently associated with disease progression in both EAE and MS. Our results indicate that chronic progression of EAE and MS involves a shifting of autoreactivity from primary initiating self-determinants to defined cascades of secondary determinants that sustain the self-recognition process during disease progression. (+info)
Antigenic heterogeneity of the hepatitis C virus NS4 protein as modeled with synthetic peptides. (7/863)The effect of sequence heterogeneity on the immunologic properties of two strong antigenic regions of the hepatitis C virus (HCV) NS4 protein was studied by using a set of 443 overlapping 20-mer synthetic peptides. One antigenic region comprising the cleavage site between NS4a and NS4b (region 5-1-1) was modeled with peptides derived from 73 different known sequences, representing HCV genotypes 1-6. The other antigenic region, designated region 59 and located at the C-terminus of the NS4b protein, was modeled with peptides from 7 known sequences representing genotypes 1-3. All peptides were tested for antigenic reactivity by enzyme immunoassay with a panel of anti-HCV-positive serum specimens representing genotypes 1-5. The data demonstrated that immunoreactive peptides fell into two groups. One group, represented by N-terminal peptides, demonstrated genotype-independent immunoreactivity; the other group, from the central part of region 5-1-1, showed strict genotype specificity. Nineteen peptides from the genotype-independent group strongly immunoreacted with a wide range of serum samples containing antibodies to all 5 HCV genotypes. Twenty-five peptides from the genotype-specific group were found to strongly react with serum containing antibodies only to the genotype from which the peptides were derived. Similar to the N-terminal part of region 5-1-1, peptides derived from region 59 did not show genotype-specific immunoreactivity. Some peptides derived from the central part of region 59 showed very strong and broad antigenic reactivity. Thus, after examining two antigenic regions of the NS4 protein, we identified short sequences that can be used for the efficient detection of either genotype-independent or genotype-specific HCV antibodies. (+info)
Structural and evolutionary inference from molecular variation in Neisseria porins. (8/863)The porin proteins of the pathogenic Neisseria species, Neisseria gonorrhoeae and Neisseria meningitidis, are important as serotyping antigens, putative vaccine components, and for their proposed role in the intracellular colonization of humans. A three-dimensional structural homology model for Neisseria porins was generated from Escherichia coli porin structures and N. meningitidis PorA and PorB sequences. The Neisseria sequences were readily assembled into the 16-strand beta-barrel fold characteristic of porins, despite relatively low sequence identity with the Escherichia proteins. The model provided information on the spatial relationships of variable regions of peptide sequences in the PorA and PorB trimers and insights relevant to the use of these proteins in vaccines. The nucleotide sequences of the porin genes from a number of other Neisseria species were obtained by PCR direct sequencing and from GenBank. Alignment and analysis of all available Neisseria porin sequences by use of the structurally conserved regions derived from the PorA and PorB structural models resulted in the recovery of an improved phylogenetic signal. Phylogenetic analyses were consistent with an important role for horizontal genetic exchange in the emergence of different porin classes and confirmed the close evolutionary relationships of the porins from N. meningitidis, N. gonorrhoeae, Neisseria lactamica, and Neisseria polysaccharea. Only members of this group contained three conserved lysine residues which form a potential GTP binding site implicated in pathogenesis. The model placed these residues on the inside of the pore, in close proximity, consistent with their role in regulating pore function when inserted into host cells. (+info)
Antigenic variation | Article about antigenic variation by The Free Dictionary
Looking for antigenic variation? Find out information about antigenic variation. Alteration of an antigen on the surface of a microorganism; may enable a pathogenic mocroorganism to evade destruction by the hosts immune system Explanation of antigenic variation
Cesarean delivery and the risk-benefit calculus. Influenza vaccine--outmaneuvering antigenic shift and drift. Estimating the...
Cesarean delivery and the risk-benefit calculus. Influenza vaccine--outmaneuvering antigenic shift and drift. Estimating the number of potential organ donors in the United States
Antigenic variation - Wikipedia
Different virus families have different levels of ability to alter their genomes and trick the immune system into not recognizing. Some viruses have relatively unchanging genomes like paramyxoviruses while others like influenza have rapidly changing genomes that inhibit our ability to create long lasting vaccines against the disease. Viruses in general have much faster rate of mutation of their genomes than human or bacterial cells. In general viruses with shorter genomes have faster rates of mutation than longer genomes since they have a faster rate of replication. It was classically thought that viruses with an RNA genome always had a faster rate of antigenic variation than those with a DNA genome because RNA polymerase lacks a mechanism for checking for mistakes in translation but recent work by Duffy et al. shows that some DNA viruses have the same high rates of antigenic variation as their RNA counterparts. Antigenic variation within viruses can be categories into 6 different ...
Many evolutionarily distant pathogenic organisms have evolved similar survival strategies to evade the immune responses of their hosts. These include antigenic variation, through which an infecting organism prevents clearance by periodically altering the identity of proteins that are visible to the immune system of the host1. Antigenic variation requires large reservoirs of immunologically diverse antigen genes, which are often generated through homologous recombination, as well as mechanisms to ensure the expression of one or very few antigens at any given time. Both homologous recombination and gene expression are affected by three-dimensional genome architecture and local DNA accessibility2,3. Factors that link three-dimensional genome architecture, local chromatin conformation and antigenic variation have, to our knowledge, not yet been identified in any organism. One of the major obstacles to studying the role of genome architecture in antigenic variation has been the highly repetitive ...
Pazopanib | kinase inhibitor tool compounds for pharmacological validation
The immune response to is understood, but its extensive antigenic variability and resistance to check are thought to permit it to evade destruction from the hosts immune defenses. relationships during infectious disease are believed of as two-way reactions conventionally, that of the sponsor against the vice and pathogen versa, with the results dependent on which prevails ultimately. We suggest that should result in novel restorative strategies and facilitate fresh methods to vaccine advancement. Introduction The immune system response to gonorrhea, an specifically human std due to possesses a fantastic convenience of antigenic variation concerning the majority of its main surface constructions, including its lipooligosaccharide, pili, porin, and opacity (Opa) proteins, that are subject to different mechanisms of stage variant and recombinatorial gene manifestation, compounded by regular horizontal gene transfer (evaluated in research 3). Furthermore, utilizes several systems for inhibiting the ...
Influenza and Respiratory Care - Google Libros
Respiratory infections constitute a major public health concern. The goal of this book is to share knowledge on the best advances in influenza and influenza-like viral infections, and new molecular-based diagnostic methods that discern the antigenic shift enabling viruses to constantly evolve and elude the host immune response. Co-infections, co-morbidities, persistently meager anti-flu vaccination coverage, and infection complications are dealt with. The chapters also further insight into such topics as the effects of sex hormones, and socioeconomic and anthropometric measures on respiratory and immune functions underlying the severity of asthma and respiratory allergy. Psychological functioning in respiratory disorders, taking into account quality of life, illness acceptance, and depressive symptoms is also reviewed as it is all too often underestimated by healthcare providers. The book is intended for clinicians, researchers, students, and all other actors in health-related issues.
2009 H1N1 Swine Flu Epidemic | Science Buzz
Influenza A viruses circulate in humans, birds, and pigs. Occasionally, different influenza A viruses can infect a single host at the same time. This often happens in places where humans and animals live in close contact. The genetic material of the viruses gets mixed up, creating an entirely new virus. (This process is called antigenic shift or viral reassortment.) If the new virus makes people sick and is transmitted easily from person to person, an influenza pandemic can occur.. Thats what happened in the spring of 2009: the virus thats making the news right now has genes from flu viruses that normally circulate in pigs in Europe and Asia as well as avian (bird) and human genes.. ...
Microbiology Term Paper Free Short Essay Example
More Influenza Essay Topics.. In that year, H2N2 viruses circulated, followed by H3N8 in 1900, H1N1 in 1918, H2N2 in 1957, H3N2 in 1968, and H1N1 in 1977, with the latest antigenic shift being in 2009 with the H1N1 virus. This shows the emergence of the H1N1 strain of the virus was in 1918. The reason that these were major pandemics back then was because of the lack of treatments. The virus was unchecked as it spread throughout the population causing mass death. There are treatments available now that can alleviate the effects of the virus and save the lives of those infected by the swine flu.. The H1N1 virus cannot be treated by the use of antibiotics. Antibiotics are used to treat bacterial infections and issues and are therefore useless when fighting a virus. However there are ways to alleviate the pains that are caused by the virus. Common symptoms of the H1N1 virus include: body aches, cough, diarrhea, sore throat, vomiting, chills, fever, fatigue, runny nose and headaches. Common over the ...
Section Sub Zero: h1n1???
this is the host shift of the influenza A H1N1...if you can see, there are a red line is a connection between human and pig, so you can think for yourselves about that. take a look at the antigenic shift, and then you will understand the virus better...this make no sense, but it will make a big change ...
Buffering deleterious polymorphisms in highly constrained parts of HIV-1 envelope by flexible regions
AbstractBackgroundCovariation is an essential process that leads to coevolution of parts of proteins and genomes. In organisms subject to strong selective pressure, coevolution is central to keep the balance between the opposite requirements of antigenic variation and retention of functionality. Being the viral component most exposed to the external environment, the HIV-1 glycoprotein gp120 constitutes the main target of the immune response. Accordingly its more external portions are characterised by extensive sequence heterogeneity fostering constant antigenic variation.ResultsWe report that a single polymorphism, present at the level of the viral population in the conserved internal region C2, was sufficient to totally abolish Env functionality when introduced in an exogenous genetic context. The prominent defect of the non-functional protein is a block occurring after recognition of the co-receptor CCR5, likely due to an interference with the subsequent conformational changes that lead to membrane
TWiP 161: All I need is a bit of skin | This Week in Parasitism
The TWiPsters solve the case of the Brazilian Immigrant With Heart Problems, and describe how genome organization controls trypanosome antigenic variation.
ANALYSIS OF THE MECHANISMS OF ACTION - Enercel | Nature AdvancedEnercel | Nature Advanced
The numerous cases which were treated showed a positive clinical response in greater or lesser degree. The earliest cases were studied intensively and were readied for publication.. The tumors that responded to a greater degree to our treatment, as was expected, are the ones with the greatest degree of undifferentiation; because of their antigenic characteristics and because of the greater degree of dissimilarity between them and the genotypes and antigenic characteristics of normal cells, they have more probability of eliciting an efficient immunologic response.. Histological studies which were made give us certain possible mechanisms of action which correlate with the clinical response obtained.. Microscopic studies showed the almost complete delimitation of the tumoral areas by connective-vascular structures which seem to have diverse morphologies according to their proximity to the tumor and the level of their chronological development, having at first a thick endothelial wall with ...
Reverse immunodynamics: a new method for identifying targets of protective immunity
Despite a dramatic increase in our ability to catalogue variation among pathogen genomes, we have made far fewer advances in using this information to identify targets of protective immunity. Epidemiological models predict that strong immune selection can cause antigenic variants to structure into g …
Eosinophil Granule Proteins Summary Report | CureHunter
Eosinophil Granule Proteins: Proteins found in EOSINOPHIL granules. They are primarily basic proteins that play a role in host defense and the proinflammatory actions of activated eosinophils.
Antigenic Variability - Medical Dictionary online-medical-dictionary.org
Change in the Surface Antigen of a microorganism. There are two different types. One is a phenomenon, especially associated with Influenza Viruses, where they undergo spontaneous variation both as slow Antigenic drift and sudden emergence of new strains (Antigenic shift). The second type is when certain Parasites, especially trypanosomes, Plasmodium, and Borrelia, survive the immune response of the host by changing the surface coat (Antigen switching). (From Herbert et al., The Dictionary of Immunology, 4th ed ...
Health Book: May 2010
Influenza A virus can mutate in two ways: antigenic drift or adaptive mutation, whereby the existing antigen transformed and antigenic shift or mutation of the mating process of two or more kinds of antigens. Antigenic drift, causing a small mutations in the flu virus from year to year, which attacks the human immune system but not completely. In contrast, the new H1N1 strain emerged in a way antigenic shift in pigs in Mexico ...
Browsing publications of theresearch group Single Cell Analysis ([HIRI] SIGA) by Authors
Many evolutionarily distant pathogenic organisms have evolved similar survival strategies to evade the immune responses of their hosts. These include antigenic variation, through which an infecting organism prevents clearance by periodically altering the identity of proteins that are visible to the immune system of the host1. Antigenic variation requires large reservoirs of immunologically diverse antigen genes, which are often generated through homologous recombination, as well as mechanisms to ensure the expression of one or very few antigens at any given time. Both homologous recombination and gene expression are affected by three-dimensional genome architecture and local DNA accessibility2,3. Factors that link three-dimensional genome architecture, local chromatin conformation and antigenic variation have, to our knowledge, not yet been identified in any organism. One of the major obstacles to studying the role of genome architecture in antigenic variation has been the highly repetitive ...
3. Drifting and Shifting | ATrain Education
To successfully infect a person, the influenza virus must develop ways to evade a persons immune system. Viruses do this through evolutionary processes called antigenic drift and antigenic shift. Influenza type A viruses undergo both kinds of changes, while influenza type B and C viruses change only by the gradual process of antigenic drift.Antigenic Drift: Continual Small
Antigenic variation in Schistosoma - Kingston University Research Repository
Schistosomes have an outer tegument that protects them from the host immune system. Parasite antigens expressed on or within the surface layer of the tegument have been suggested to be potential vaccine targets such as tetraspanin 23 (TSP23). Little is known about the evolution and diversity of tegumental antigens, an important consideration given that vaccines are being designed and are failing. Moreover, these antigens, including TSP23, are in direct contact with the host immune system, and so accelerated and adaptive evolution may be occurring. Species of Schistosoma infect a variety of definitive hosts. The way in which these hosts are shaping the evolution of antigens across different species of Schistosoma needs investigating. Much attention has been focussed on the production of an effective multi-species vaccine against the schistosomes, and there has been little success in absolute clearance or even establishment of continued immune memory post-infection. The aim of this study was ...
Vax2 | Role of NK1 and NK2 receptors in mouse gastric mechanical activity
Supplementary MaterialsQuantitative Recognition of Weak D Antigen Variations in Bloodstream Typing Using SPR - Supplementary Material 41598_2017_1817_MOESM1_ESM. response device (RU) is certainly reported ( 100?RU). Unbound harmful cells are eluted ( 100 directly?RU). Weak D cells had been detected between a variety of 180C580?RU, because of a lower appearance of antigens. Partial D cells, category D VI, had been also positively discovered (352C1147?RU), similar compared to that of normal D antigens. The recognition of two classes of weaker D variations was attained for the very first time using this completely regenerable SPR system, starting up a fresh avenue to displace the existing GS-1101 inhibitor database subjective and arbitrary options for quantifying bloodstream group antibody-antigen connections. Introduction Mismatching incompatible blood types can lead to a haemolytic transfusion reaction, the severity of which can range from moderate to fatal1. Therefore, accurate and reliable ...
Epidemics in Competition: Partial Cross-Immunity<...
TY - JOUR. T1 - Epidemics in Competition. T2 - Partial Cross-Immunity. AU - Andreasen, Viggo. PY - 2018. Y1 - 2018. N2 - The competition between two pathogen strains during the course of an epidemic represents a fundamental step in the early evolution of emerging diseases as well as in the antigenic drift process of influenza. The outcome of the competition, however, depends not only on the epidemic properties of the two strains but also on the timing and size of the introduction, characteristics that are poorly captured by deterministic mean-field epidemic models. We describe those aspects of the competition that can be determined from the mean-field models giving the range of possible final sizes of susceptible hosts and cumulated attack rates that could be observed after an epidemic with two cross-reacting strains. In the limit where the size of the initial infection goes to zero, the possible outcomes lie on a (one dimensional) curve in the outcome space.. AB - The competition between two ...
Citation tools | Infection and Immunity
Brunham, R C, F A Plummer, and R S Stephens. Bacterial antigenic variation, host immune response, and pathogen-host coevolution.. Infection and Immunity 61.6 (1993): 2273-2276. Web. 19 Jan. 2020. ...
10-07 Culture Exists 2 - Culture exists Three sources of variation Much variation is not environmental Much variation not due...
View Notes - 10-07_Culture_Exists_2 from ANTHRO 186P at UCLA. Culture exists Three sources of variation Much variation is not environmental Much variation not due to institutions w w Cultures
M. tuberculosis T cell epitope analysis reveals paucity of antigenic variation and identifies rare variable TB antigens - edoc
Pathogens that evade adaptive immunity typically exhibit antigenic variation. By contrast, it appears that although the chronic human tuberculosis (TB)-causing pathogen Mycobacterium tuberculosis needs to counter host T cell responses, its T cell epitopes are hyperconserved. Here we present an extensive analysis of the T cell epitopes of M. tuberculosis. We combined population genomics with experimental immunology to determine the number and identity of T cell epitope sequence variants in 216 phylogenetically diverse strains of M. tuberculosis. Antigen conservation is indeed a hallmark of M. tuberculosis. However, our analysis revealed a set of seven variable antigens that were immunogenic in subjects with active TB. These findings suggest that M. tuberculosis uses mechanisms other than antigenic variation to evade T cells. T cell epitopes that exhibit sequence variation may not be subject to the same evasion mechanisms, and hence vaccines that include such variable epitopes may be more ...
Evaluation of mechanisms that may generate DNA lesions triggering antigenic variation in African trypanosomes - Enlighten:...
Antigenic variation by variant surface glycoprotein (VSG) coat switching in African trypanosomes is one of the most elaborate immune evasion strategies found among pathogens. Changes in the identity of the transcribed VSG gene, which is always flanked by 70-bp and telomeric repeats, can be achieved either by transcriptional or DNA recombination mechanisms. The major route of VSG switching is DNA recombination, which occurs in the bloodstream VSG expression site (ES), a multigenic site transcribed by RNA polymerase I. Recombinogenic VSG switching is frequently catalyzed by homologous recombination (HR), a reaction normally triggered by DNA breaks. However, a clear understanding of how such breaks arise-including whether there is a dedicated and ES-focused mechanism-is lacking. Here, we synthesize data emerging from recent studies that have proposed a range of mechanisms that could generate these breaks: action of a nuclease or nucleases; repetitive DNA, most notably the 70-bp repeats, providing ...
Strong Positive Selection and Recombination Drive the Antigenic Variation of the PilE Protein of the Human Pathogen Neisseria...
TY - JOUR. T1 - Strong Positive Selection and Recombination Drive the Antigenic Variation of the PilE Protein of the Human Pathogen Neisseria meningitidis. AU - Andrews, T. Daniel. AU - Gojobori, Takashi. PY - 2004/1/1. Y1 - 2004/1/1. N2 - The PilE protein is the major component of the Neisseria meningitidis pilus, which is encoded by the pilE/pilS locus that includes an expressed gene and eight homologous silent fragments. The silent gene fragments have been shown to recombine through gene conversion with the expressed gene and thereby provide a means by which novel antigenic variants of the PilE protein can be generated. We have analyzed the evolutionary rate of the pilE gene using the nucleotide sequence of two complete pilE/pilS loci. The very high rate of evolution displayed by the PilE protein appears driven by both recombination and positive selection. Within the semivariable region of the pilE and pilS genes, recombination appears to occur within multiple small sequence blocks that lie ...
Tracking the In Vivo Dynamics of Antigenic Variation in the African Tr by Monica R. Mugnier
Trypanosoma brucei, a causative agent of African sleeping sickness in humans and nagana in animals, constantly changes its dense variant surface glycoprotein (VSG) coat to avoid elimination by the immune system of its mammalian host, using an extensive repertoire of dedicated genes. Although this process, referred to as antigenic variation, is the major mechanism of pathogenesis for T. brucei, the dynamics of VSG expression in T. brucei during an infection are poorly understood. In this thesis, I describe the development of VSG-seq, a method for quantitatively examining the diversity of expressed VSGs in any population of trypanosomes. Using VSG-seq, I monitored VSG expression dynamics in vivo during both acute and chronic mouse infections. My experiments revealed unexpected diversity within parasite populations, and the expression of as much as one-third of the functional genomic VSG repertoire after only one month of infection. In addition to suggesting that the host-pathogen interaction in T.
Switches in expression of Plasmodium falciparum var genes correlate with changes in antigenic and cytoadherent phenotypes of...
Plasmodium falciparum expresses on the host erythrocyte surface clonally variant antigens and ligands that mediate adherence to endothelial receptors. Both are central to pathogenesis, since they allow chronicity of infection and lead to concentration of infected erythrocytes in cerebral vessels. Here we show that expression of variant antigenic determinants is correlated with expression of individual members of a large, multigene family named var. Each var gene contains copies of a motif that has been previously shown to bind diverse host receptors; expression of a specific var gene correlated with binding to ICAM-1. Thus, our findings are consistent with the involvement of var genes in antigenic variation and binding to endothelium.
Patricia Totten | University of Washington - Department of Global Health
Research in the Totten group focuses on the molecular biology, pathogenesis, and disease associations of the recently discovered STD pathogen, Mycoplasma genitalium. Their finding that this bacterium can persist for months, if not years, in infected women lead to our hypothesis that this pathogen evades the host immune response in part by antigenically varying two of its immunogenic surface-exposed proteins. Supporting this hypothesis, they have shown that the sequences of the genes encoding these proteins evolve using reciprocal recombination with non-coding homologous DNA distributed throughout its minimal chromosome. Further, contrary to the accepted wisdom that this bacterium contains few regulatory genes, they have shown that recombination leading to antigenic variation is regulated at the transcriptional, post-transcriptional, and translational levels. The novel recombination and regulatory mechanisms of antigenic variation, the biologic significance of the resulting antigenic variants, ...
British Library EThOS: Investigation of the distribution, antigenic variation and the biological role of phase variation of the...
Neisseria meningitidis is the major cause of bacterial meningitis worldwide. The genome of this pathogen contains >40 phase variable loci whose expression is regulated by tandem DNA repeat tracts. Majority of these loci encode OMPs, which are potential targets for host innate and adaptive immune responses. An analysis for the distribution, frequency and role of PV of these genes is relevant in determining their virulence association and suitability as a future vaccine candidate. The project investigated the combined distribution, frequency and PV status of two important genes, hpuAB and hmbR, in disease (n=221) and carriage (n=305) isolates. Strains with both genes or only hmbR were present at similar frequencies among disease isolates as compared with carriage isolates. However, >90 % of isolates from CC5, CC8 and CC11 (CCs with the highest disease to carriage ratios) contained both genes. Strains with only hpuAB gene were under-represented among disease isolates, possibly due to the receptor ...
Fondation Recherches 3R / 3R Info Bulletins / Generic in-vitro assays for immunological correlates of protection against foot...
Vaccination against foot-and-mouth disease (FMD) represents an essential element in controlling and combating outbreaks, which can otherwise have disastrous consequences such as during the FMD outbreak in the UK in 2001. This is pertinent to regions in large parts of the developing world in which the FMD virus (FMDV) is endemic, as well as during an epidemic in FMDV-free areas such as Europe. Nevertheless, successful vaccination against FMDV requires selection of the appropriately matching vaccine strain providing protection against a particular circulating field virus. This problem originates from the existence of seven known serotypes of FMDV, with which a high antigenic variation of the virus is observed. In addition, subtypical antigenic variation within a serotype is under constant evolutionary change due to the high mutation rate of FMDV. For these reasons, continuous vaccine testing and modification in the light of recent antigenic changes to the virus is required. Traditionally, vaccines ...
darcoda at telerama.lm.com (S. Frog) wrote: , , , Hi, and all that. , , Im not sure if this is the proper place to raise this question, , and forgive me if it isnt, but I have a question about the flu. , Actually, three questions: , Is the flu a retrovirus? , If it isnt a retrovirus, do I have a faulty definition of what a , retrovirus is? , Lastly, is it true that the flu has only been around for like a , hunred years or so? And that it mutated from something else, which is , why human has so little resistence to it when the influenza epidemic , roared through just after world war I? , , , Thanks. :) , , , , , S. Frog , -- , , , .. The agent which causes many cases of the flu is called influenza. It is a member of the Orthomyxoviridae. These viruses have a segmented, single stranded RNA genome. Their segmented genome enables them to undergo a special kind of mutation (actually it is segment reassortment) called antigenic shift, which causes the pandemics in human medicine. Many species ...
Why are parasite contingency genes often associated with telomeres? - Lancaster EPrints
Contingency genes are common in pathogenic microbes and enable, through pre-emptive mutational events, rapid, clonal switches in phenotype that are conducive to survival and proliferation in hosts. Antigenic variation, which is a highly successful survival strategy employed by eubacterial and eukaryotic pathogens, involves large repertoires of distinct contingency genes that are expressed differentially, enabling evasion of host acquired immunity. Most, but not all, antigenic variation systems make extensive use of subtelomeres. Study of model systems has shown that subtelomeres have unusual properties, including reversible silencing of genes mediated by proteins binding to the telomere, and engagement in ectopic recombination with other subtelomeres. There is a general theory that subtelomeric location confers a capacity for gene diversification through such recombination, although experimental evidence is that there is no increased mitotic recombination at such loci and that sequence ...
Biology-Online • View topic - Bio Research Paper Writing
In addition to avoiding destruction by modulating DNA-Repair pathways, viruses also alter other aspects of the cells defense such as cell surface markers. CMV and adenoviruses decrease the expression of a cells MHC recognition markers which decreases the ability of the immune system to respond to infections that is highly characteristic of the immune system in senescence (DNA-Damage-Response np). One factor is the loss of the CD28 marker; when CD28 isnt expressed, antigen-presenting cells like macrophages no longer recognise the T cell and thus arent able to alert the immune cell to danger (de Grey 207). Some viruses like HIV are able to prevent detection from the immune system by restricting the expression of virus antigens as well as having wide antigen variation (DNA-damage-response). Furthermore, there are viruses that modify other signaling pathways that lead affects lymphocyte and macrophage (which is an anti-gen presenting cell) functions that lead to immunosupression ...
Then is this host specific antigenic variation due to different subspecies of P.carinii infecting their particular favorite flavor of host? Or is there one P.carinii changing its disguise to suit its situation (Like the elusive pimpernel)? Do the authors of this splendid sounding article offer an explanation? My library doesnt carry that journal. Doesnt carry much of anything not relating to engineering, actually. Regards Simon ______________________________ Reply Separator _________________________________ Subject: RE: Re: P.carinii Author: [email protected] at Internet Date: 11/12/98 7:14 PM Host species-specific antigenic variations have been reported, according to the article I cited. Pigs are not dogs are not rats are not people! -----Original Message----- From: [email protected] [SMTP:[email protected]] Sent: Thursday, November 12, 1998 12:27 PM To: [email protected] Subject: Re: P.carinii Forgive my stupidity, but wont any antibody to P.carinii label ...
Browsing Peter Agre by Author Saboori, A M
A Mr 32,000 integral membrane protein has previously been identified on erythrocytes bearing the Rh(D) antigen and is thought to contain the antigenic variations responsible for the different Rh phenotypes. To study it on ...
Pile loom - NAKADA AKIHIKO
There is provided an apparatus capable of maintaining a pile warp tension at a desired value even under a high speed operation of a pile loom in a pile warp tension controller of the pile loom. The pi
Ayurvedic Piles Medicine Vs Piles Surgery. Which is Better? - Pfree.in
There arent too many options if you want to root piles out completely. Perhaps in that context surgery is one of the best bets. But that too, there is no foolproof guarantee that you will never have it.
Speculations on the Origin and Future of H1N1 | Mark Thornton M.D
5/4/2009 10:24:08 PM Flu viruses change slightly from year to year. This is called antigenic drift. This is what the committee that determines what the
Antigenic Variation between Human Respiratory Syncytial Virus Isolates | Microbiology Society
Summary Three hybridoma antibodies, prepared against the RSN-2 strain of human respiratory syncytial (RS) virus, have been used to identify antigenic variation between 41 isolates of RS virus collected from widely separated geographical regions over a period of 29 years. One antibody was directed against an antigenic site on the virus fusion protein, VP70. This site was shared by 21 virus isolates tested and its recognition by the antibody was sensitive to the presence of 2-mercaptoethanol. The remaining two antibodies used react against the virus phosphoprotein, VPP32. Two independent sites were recognized on VPP32 by these antibodies. One antibody reacted with all of the virus isolates screened while the second reacted with only 21 out of the 41 virus isolates. On the basis of the variable epitope, two antigenic types of human RS virus were identified. The distribution of each antigenic group among 28 RS virus isolates from the Grampian Region, north-east Scotland, collected between 1982 and 1984 was
Plasmodium falciparum var gene expression is modified by host immunity | PNAS
As with other infectious diseases, much discussion has been generated in the past about whether the malaria parasite population is structured into strains that have variable virulence (27). PfEMP1 presents us with a scenario in which a repertoire of molecules that play a central role in the host-parasite interaction, both through cytoadherence and immunogenicity, appear to be functionally and genetically differentiated within every parasite genome (13, 28), potentially giving each parasite line the ability to alter its pathogenicity depending on the combination of selection pressures experienced within the host (29). However, there is no direct evidence for links between the structure of the PfEMP1 antigen repertoire and a role for PfEMP1 in parasite immune evasion and pathogenicity.. A frequently cited study supporting a link between group A var expression and parasite virulence is based on the in vitro selection of a lab-adapted parasite isolate using pooled serum from semi-immune children ...
Uderstanding the basis of strain-restricted immunity to theileria parva - University of Edinburgh Research Explorer
Cattle can be immunised against the disease by infection with live parasites and simultaneous drug treatment, but the immunity induced by one parasite strain is not effective against all other strains. Use of a mixture of 3 parasite strains for vaccination has been found to give broad protection. This vaccine has been used locally with some success, but widespread application has been hindered by difficulties in production and distribution. The antigenic composition of the vaccine is poorly defined and there remain questions as to whether the content of parasite strains is optimal for obtaining robust immunity. More recently, antigens recognised by the protective cellular immune responses have been identified, with the aim of investigating their potential for developing a subunit vaccine. Preliminary evidence indicates that several of these antigens vary between parasite strains. Hence, understanding antigenic variability in T. parva is a key issue both for improving the current live vaccine and ...
Profiling MHC II immunopeptidome of blood‐stage malaria reveals that cDC1 control the functionality of parasite‐specific CD4 T...
In malaria‐endemic areas, a nagging issue is the failure of naturally exposed individuals to develop sterile long‐lasting protective immunity. This may be due to several factors including the stage specificity of parasite antigen expression, the antigenic variability among field parasites, and the profound immune dysregulation caused by pre‐erythrocytic and erythrocytic stages (Renia & Goh, 2016; Scholzen & Sauerwein, 2016; Van Braeckel‐Budimir et al, 2016). These factors could also contribute to explain why despite tremendous investments and years of research, progress on the vaccination front has been only modest. Clinical efficacy of the most advanced subunit vaccine candidate against P. falciparum (RTS,S) is limited and quickly wanes over time (Olotu et al, 2016). Hopes are emerging from whole attenuated sporozoite vaccination strategies (Sissoko et al, 2017), but the disappointing RTS,S results combined with the fact that vaccine research on P. vivax is only beginning (Tham et al, ...
Structural studies of two rhinovirus serotypes complexed with fragments of their cellular receptor | The EMBO Journal
Human rhinoviruses (HRVs), a genus of the Picornaviridae family, are the most frequent etiological agents of common colds (Rueckert, 1996). Rhinoviruses are small, icosahedral viruses, with an average diameter of 300 Å and a molecular mass of ∼8.5 × 106 Da. They are composed of a protein shell that encapsidates a single, positive RNA strand of ∼7000 bases. The capsid is built from 60 copies each of four viral proteins. The three larger proteins, VP1, VP2 and VP3 (∼250 amino acids, 30 kDa each), form the external surface of the virus, whereas VP4 (70 amino acids, 6 kDa) is an internal protein located at the interface between the capsid and genome (Rossmann et al., 1985).. With ,100 different serotypes identified to date, HRVs exhibit remarkable antigenic variability. To produce infection, HRVs must first attach to a cellular receptor. The major group of HRVs, consisting of ∼90 serotypes, utilizes the cell surface glycoprotein, intercellular adhesion molecule‐1 (ICAM‐1), as its ...
Permalien vers Post-doctoral position in the Trypanosome Molecular Biology group
Interested in discovering how trypanosomes undergo antigenic variation? If the answer is yes - we have a postdoctoral position available in the Trypanosome Molecular Biology group with Lucy Glover. In our group we study how the trypanosomes control expression of the variant surface glycoprotein from the fly to the mammalian host, and the the role of DNA repair and recombination in antigenic variation and immune evasion in African trypanosomes We are located in the Department of Parasites and Insect Vectors at the Institute Pasteur in Paris, which provides an excellent international scientific environment and state-of-the-art core facilities including high throughput sequencing, and imaging technologies.. ...
PLOS Computational Biology: Inference of Genotype-Phenotype Relationships in the Antigenic Evolution of Human Influenza A (H3N2...
Author Summary The molecular evolution of any organism is described by changes in the genotype resulting from genetic drift or selection to maintain or establish fitness under the given environmental conditions. Identification of phenotype-defining changes and their distinction from (near-) neutral (hitchhikers) ones is a fundamental challenge in genome research. The standard approach involves time- and cost-intensive mutation experiments, which are typically low throughput, due to their experimental nature. We have developed a computational method for the inference of phenotypic impact of genotypic changes that is applicable to any system, within or across species, where homologous genetic sequences and associated pairwise phenotype distances are available. We demonstrate the accuracy of our method by application to the human influenza A (H3N2) virus. This exemplary system is of particular interest, as recognizing changes in the antigenic phenotype and a viral strains capability to evade pre
Silymarin flavonolignans are well-known agencies that possess antioxidative typically, anti-inflammatory, and hepatoprotective...
Silymarin flavonolignans are well-known agencies that possess antioxidative typically, anti-inflammatory, and hepatoprotective features. predictive, additional in vitro and in vivo research would be essential to confirm the antiviral impact. 2.2. Influenza A Pathogen Influenza A pathogen (IAV) is an extremely contagious pathogen and a respected reason behind mortality and morbidity internationally. Influenza pandemics and epidemics pose a significant threat to both individual and pet populations. Although effective vaccines can be found against IAV, these vaccines should be frequently updated because of the ability from the pathogen to induce regular antigenic drift and periodic antigenic shifts to its envelope glycoproteins. Furthermore, just few IAV antiviral therapeutics have already been clinically accepted and currently used including neuraminidase inhibitors  as well as the newer inhibitor of cap-dependent endonuclease . As a result, continuous id of novel healing strategies to ...
Genetic basis of Neisseria gonorrhoeae lipooligosaccharide antigenic variation. | Journal of Bacteriology
Thank you for sharing this Journal of Bacteriology article.. NOTE: We request your email address only to inform the recipient that it was you who recommended this article, and that it is not junk mail. We do not retain these email addresses.. ...
Ronald C. Montelaro, PhD | Center for Vaccine Research | University of Pittsburgh
The primary focus of the Montelaro lab is to elucidate the intricate interactions between viral pathogens and host immune responses to determine the mechanisms by with host immunity contributes to protection and disease and to serve as a basis for the development of effective vaccines. A particular interest of the lab is to develop effective strategies to overcome the challenge of natural viral antigenic variation that has evolved as a common complication to the development of effective vaccines to important viral diseases, including those related to biodefense and emerging infectious diseases. Systems currently under investigation include HIV-1 and related animal lentiviruses (SHIV, SIV, and EIAV). Studies in these systems include investigation of the nature and role of antigenic variation during infection, the development of novel assays to characterize virus-specific innate, humoral, and cellular immune responses, and the design of engineered immunogens for effective vaccination against ...
Identification of nuclear proteins that interact differentiall...
Identification of nuclear proteins that interact differentially with Plasmodium falciparum var gene promoters.: The Plasmodium falciparum virulence factor PfEMP
Novel Strategy Could Yield More Precise Seasonal Flu Vaccine
A novel strategy to predict the antigenic evolution of circulating influenza viruses and more precisely anticipate seasonal flu strains has been developed.
Behavior of Laterally Loaded Piles: I-Single Piles
Behavior of Laterally Loaded Piles: I-Single Piles. An analysis is presented for the horizontal displacement and rotation of a vertical pile subjected to lateral loading and moment, and situated in an ideal elastic mass. Influence factors are presented for a wide range of pile flexibilities and length-to-diameter ratios, for both free-head and fixed-head piles. Comparisons between the elastic solutions and the corresponding solutions obtained from the subgrade reaction theory show that the latter considerably overestimates the displacement and rotation of the pile, but gives a reasonable estimate of the moments in the pile. The elastic analysis is extended to include the effect of local yield between the soil and the pile; the load-displacement relationship for relatively flexible piles is found to be markedly influenced by local yield. The characteristics of behavior indicated by the theoretical solutions agree reasonably well with those reported from measurements on full-scale piles.
Gambal, Hamid, Osko and Leon India - Новости Ставрополя и Ставропольского края
Yet crucial advances in toxicology also occurred within other NIH laboratories, led during pioneers such as Bernard Brodie and Julius Axelrod and later continued at hand investigators such as JR Mitchell, D Jollow and JR Gillette. There are assorted institutes all across the world, which gather genome data, for benchmark, to discover why united treatment in regard to a genetic malady helps one untiring, but shows no or less to all intents on another. This substance inferior intimacy, lower communications, and much fights discount dapoxetine 90mg with mastercard erectile dysfunction at age 25. J Biol Chem 270:7241В-7250 Prucca CG, Slavin I, Quiroga R, Elias EV, Rivero FD, Saura A, Carranza PG, Luj?n HD (2008) Antigenic variation in Giardia lamblia is regulated by RNA interference. As infants fit more expressive, they jeopardy wound from falls down stairs and afar chairs, tables, and other structures. Its an surprising process, this on-going detoxification of your consistency order cialis 10mg ...
Puzzle 92. A pile of prime-spheres
Problems & Puzzles: Puzzles Puzzle 92. A pile of prime-spheres Days ago my friend Enoch Haga and me starting puzzling each other to construct a pile of balls (a tetrahedron) with the following properties: a) every ball contains a distinct prime, b) each prime-ball must be the sum of the prime numbers contained in the three balls from the immediate inferior level and in contact with the mentioned prime-ball. Can you imagine a pile of balls? A new friend of these pages, Chuck Henry, kindly and quickly provided several beautiful photos generated by him that should help to visualize a pile of balls like the one we are talking about. Please click here 1 and here 2 (*). Question: Get the least solution for a pile of n levels, for n=5, 6 & 7. ...
Institut de Chimie de Nice UMR 7272 - Publications/brevets
M. Soriani, P. Petit, R. Grifantini, R. Petracca, G. Gancitano, E. Frigimelica, F. Nardelli, C. Garcia, S. Spinelli, G. Scarabelli, S. Fiorucci, R. Affentranger, M. Ferrer-Navarro, M. Zacharias, G. Colombo, L. Vuillard, X. Daura and G. Grandi. Exploiting antigenic diversity for vaccines design : the Chlamydia ArtJ paradigm. J. Biol. Chem, 2010, 285, 30126-30138. ...
What is Piles? Causes, Piles Symptoms and Piles Treatments - News Web BD
There are numerous possible causes of piles. In fact, they are not nervous and not hazardous. If youre on the lookout for piles remedy or strategies to do
Piles Treatment in Jaipur | Piles Surgeon in Jaipur, Rajasthan
Piles disease is very painful, to reduce piles we are suggest best Specialist & Surgeon Doctor Kapileshwar Vijay, who provide best piles treatment in jaipur.
Are Piles Bad?
Are Piles Bad? Lets face it, the pain experienced by people due to piles is bad and embarrassing. Nobody wants to talk about pooping, pain, and discomfort around the anus. According to statistics, 80% of adults over the age of 40 experience piles.
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Are Piles Soft?
Are Piles Soft? Did you see any soft bumps or lumps in your anus? Well, they are most likely piles. External and prolapsed internal piles are usually soft, moist grapes around your anal opening. They may cause itching and pain during passing stool.
Useful Tips For The Treatment of Piles - Medicine Health
Useful Tips For The Treatment of Piles. Piles are considered to be one of the common problems, a number of people are endurance from. Dealing with..
Bleeding in the Toilet? Perhaps You Have Piles? | HubPages
Piles or hemorrhoids are a very common condition that most people suffer. It creates much discomfort and pain especially when going to the toilet. Learn more about piles here.
What are Some Effective Remedies for Piles? | CRH ORegan System
What are some effective remedies for piles? If youre looking for piles treatment options, youve come to the right place. Read more here.
Questionnaire / Movax
The MOVAX side grip pile driver is based on MOVAXs Modular System and thus capable of handling a wide variety of piles [linkki]. In order to select the correct arms, clamps and pads information is needed about the main type of piles to be driven, but also whether there is a need to drive also other type of piles, now or in the future ...
The effect of vitamin D deficiency and vitamin D supplementation on the risk of cardiovascular diseases
Studies revealed an association between vitamin D deficiency and the frequency of cardiovascular diseases and their risk factors. This review is aimed at summarizing evidence for the association of vitamin D deficiency and vitamin D supplementation with the risk of cardiovascular diseases. The...
Many of the proteins known to show antigenic or phase variation are related to virulence. Antigenic variation in bacteria is ... shows that some DNA viruses have the same high rates of antigenic variation as their RNA counterparts. Antigenic variation ... making it one of the mechanisms of antigenic escape. It is related to phase variation. Antigenic variation not only enables the ... Antigenic variation may be classified into two types, antigenic drift that results from a change in few amino acids and ...
Tet methylcytosine dioxygenase 2
... a role in antigenic variation?". Nucleic Acids Research. 12 (10): 4153-70. doi:10.1093/nar/12.10.4153. PMC 318823. PMID 6328412 ...
Scherf, Artur; Lopez-Rubio, Jose Juan; Riviere, Loïc (October 2008). "Antigenic Variation in Plasmodium falciparum". Annual ... Guizetti, Julien; Scherf, Artur (May 2013). "Silence, activate, poise and switch! Mechanisms of antigenic variation in". ... Cross, George A. M. (April 1996). "Antigenic variation in trypansosomes: Secrets surface slowly". BioEssays. 18 (4): 283-291. ... "The large diverse gene family var encodes proteins involved in cytoadherence and antigenic variation of plasmodium falciparum- ...
Plasmodium falciparum erythrocyte membrane protein 1
Scherf A, Lopez-Rubio JJ, Riviere L (2008). "Antigenic variation in Plasmodium falciparum". Annual Review of Microbiology. 62 ( ... Kyes SA, Kraemer SM, Smith JD (September 2007). "Antigenic variation in Plasmodium falciparum: gene organization and regulation ... "The large diverse gene family var encodes proteins involved in cytoadherence and antigenic variation of Plasmodium falciparum- ... This variation gives rise to different types of PfEMP1. The DBL-CIDR combination in a particular type of PfEMP1 protein is ...
This is called antigenic variation. An example is HIV, which mutates rapidly, so the proteins on its viral envelope that are ... The B cell then displays these antigenic peptides on its surface MHC class II molecules. This combination of MHC and antigen ... Welling GW, Weijer WJ, van der Zee R, Welling-Wester S (September 1985). "Prediction of sequential antigenic regions in ... Fc receptor Immune system receptors Immunostimulator Neuroimmune system Original antigenic sin - when the immune system uses ...
Antigenic variation of Latinamerican rotavirus. Structural studies of the rotavirus inner capsid. Gene sequence of some ... Puerto Manzano, F; Avendano, L; Esparza, J; Caul, EO (Dec 1984). "Antigenic variation in Latin American human pararotaviruses ( ...
World Health Organization (1972). "ANTIGENIC VARIATION IN INFLUENZA A VIRUSES". Weekly Epidemiological Record. 47: 381. hdl: ... Through April 1972, little antigenic difference from the original Hong Kong virus was noted on the whole among circulating ...
Russell J. Howard
Thirteen years of his group's malaria research on antigenic variation in malaria culminated in the first molecular cloning of ... Howard, R. J.; Barnwell, J. W.; Kao, V. (1 July 1983). "Antigenic variation of Plasmodium knowlesi malaria: identification of ... Howard, RJ (13 November 1984). "Antigenic variation of bloodstage malaria parasites". Philosophical Transactions of the Royal ... to the molecular pathogenesis of human cerebral malaria and the role of parasite antigenic variation and infected cell ...
Hong Kong flu
It became apparent once the extent of antigenic variation in the virus was recognized that a new vaccine would be needed to ... World Health Organization (1972). "ANTIGENIC VARIATION IN INFLUENZA A VIRUSES". Weekly Epidemiological Record. 47: 381. hdl: ... The virus was descended from H2N2 (which caused the Asian flu pandemic in 1957-1958) through antigenic shift, a genetic process ... The novel virus was thereafter designated H3N2, indicating its partial similarity to H2N2 but also its antigenic distinction. ...
Variant surface glycoprotein
Barry JD, McCulloch R (2001). "Antigenic variation in trypanosomes: enhanced phenotypic variation in a eukaryotic parasite". ... The antigenic variation causes cyclical waves of parasitemia, which is one of the characteristics of Human African ... Periodic antigenic variation - the VSG coat undergoes frequent stochastic genetic modification-'switching'-allowing variants ... This antigenic variation creates cyclical waves of parasitemia characteristic of Human African Trypanosomiasis. Antigen ' ...
Kinetoplast DNA and Antigenic Variation. Krips Repro b.V., Netherlands. "Jan Hoeijmakers, CV (as of the end of 2013)". Archived ... Kinetoplast DNA and Antigenic Variation . At Erasmus University Rotterdam, as a member of Dirk Bootsma's group in the Institute ... in which he clarified the molecular mechanism of the antigen variation of trypanosomes. He uncovered the structure and main ...
van der Woude MW, Bäumler AJ (2004). "Phase and antigenic variation in bacteria". Clin Microbiol Rev. 17 (3): 581-611. doi: ... Wisniewski-Dyé F, Vial L (2008). "Phase and antigenic variation mediated by genome modifications". Antonie van Leeuwenhoek. 94 ... It involves the variation of protein expression, frequently in an on-off fashion, within different parts of a bacterial ... In this form of phase variation. The promoter region of the genome can move from one copy of a gene to another through ...
Important questions about antigenic variation are also relevant for such research areas as developing a vaccine against HIV and ... Antigenic variation is common among pathogenic organisms. These include the agents of malaria, gonorrhea, and sleeping sickness ... through antigenic variation. Essentially, the pathogen stays one step ahead of antibodies by changing its surface proteins. ... which is sufficient to create a new antigenic "identity" for the organism. Antibodies in the blood that are binding to and ...
Prucca CG, Slavin I, Quiroga R, Elias EV, Rivero FD, Saura A, Carranza PG, Lujan HD (2008). "Antigenic variation in Giardia ... 2008). "Antigenic variation in Giardia lamblia is regulated by RNA interference". Nature. 456 (7223): 750-4. Bibcode:2008Natur. ... called antigenic variation). Gillin's work reveals why Giardia infections are extremely persistent and prone to recur. In ... Svärd SG, Meng TC, Hetsko ML, McCaffery JM, Gillin FD (1998). "Differentiation-associated surface antigen variation in the ...
Cassava mosaic virus
Harrison B & Robinson D (1999). Natural genomic and antigenic variation in whitefly-transmitted geminiviruses (begomoviruses). ... There is variation in the literature on this score, however, with other sources citing a 4-hour acquisition time and 4-hour ... Little to no infection occurs after three months, and variation in spread was due to change in temperature, radiation and ...
The virulence factor that M. penetrans displays is antigenic variation, the ability to exchange or switch antigens against ... Horino, A.; Sasaki, Y.; Sasaki, T.; Kenri, T. (2003-01-01). "Multiple Promoter Inversions Generate Surface Antigenic Variation ... penetrans antigenic variation. Mycoplasma penetrans has been shown to hinder p53, a tumor suppressing gene that aids in ... In M. penetrans, this promoter region can undergo reversible inversion, allowing for variation in antigen production and, thus ...
All are antigenic and all exhibit antigenic variation (see below). The pili exhibit the most variation. The pili, Opa proteins ... pilin antigenic variation in the pathogenic Neisseria: Pilin antigenic variation". Molecular Microbiology. 81 (5): 1136-1143. ... Phase variation is similar to antigenic variation, but instead of changes at the genetic level altering the composition of ... Pili are varied by antigenic variation, but also phase variation. Frameshifts occur in both the pilE and pilC genes, ...
Its most prevalent mechanism is its ability to evade recognition by antibodies through antigenic variation. This is achieved ... One cause of antigenic escape is that a pathogen's epitopes (the binding sites for immune cells) become too similar to a ... However, variation of this coat can lead to antibodies being unable to recognize and eliminate the antigen. In addition to this ... Antigenic escape, immune escape, immune evasion or escape mutation occurs when the immune system of a host, especially of a ...
"Transient cross-reactive immune responses can orchestrate antigenic variation in malaria". Nature. 429 (6991): 555-558. Bibcode ... "The generation of influenza outbreaks by a network of host immune responses against a limited set of antigenic types". ...
Morrison LJ, Marcello L, McCulloch R; Marcello; McCulloch (December 2009). "Antigenic variation in the African trypanosome: ...
Unfortunately, vaccines are not effective with Chagas disease due to antigenic variation. This pathogen causes damage to the ... but vaccines can not be used due to antigenic variation. Amoebozoa are characterized by the use of pseudopodia ...
William A. Haseltine
Clements, JE; Pedersen FS; Narayan O; Haseltine WA (1980). "Genomic Changes Associated with Antigenic Variation of Visna Virus ... Terwilliger, EF; Langhoff E; Gabuzda D; Haseltine W; Haseltine, W. A. (1991). "Allelic variation in the effects of nef on HIV-1 ...
Barrett, Pastoret & Taylor 2006, p. 24 Chen J, Deng YM (2009). "Influenza virus antigenic variation, host antibody production ... Other viruses change more slowly as mutations in their genes gradually accumulate over time, a process known as antigenic drift ...
Biswas B, Vemulapalli R, Dutta SK (August 1998). "Molecular basis for antigenic variation of a protective strain-specific ... Strain variation among isolates can be determined by identifying surface antigens or by performing whole-genome sequencing. ... Molecular analysis surface antigens has found significant genetic and phenotypic variation in strains of N. risticii, these ... Chaichanasiriwithaya W, Rikihisa Y, Yamamoto S, Reed S, Crawford TB, Perryman LE, Palmer GH (December 1994). "Antigenic, ...
A DNA transposition mechanism for antigenic variation in African trypanosomes (9) (10) (11) (12). Transsplicing as an essential ... Bitter W, Gerrits H, Kieft R, Borst P. The role of transferrin-receptor variation in the host range of Trypanosoma brucei. ... J, a new base in the DNA of trypanosomes and related parasites (30) (31). Variation in the transferrin receptor allows African ...
Similar to HIV-escape, cancer can escape the immune system's detection by antigenic variation. As the immunodominant epitope is ... Immunodominance is the immunological phenomenon in which immune responses are mounted against only a few of the antigenic ... That is, despite multiple allelic variations of MHC molecules and multiple peptides presented on antigen presenting cells, the ...
Antigenic variation prevents the development of cross immunity to the various strains of O. tsutsugamushi. An infected ... As of 2009, more than 20 different strains have been established in humans based on antigenic variation using serological tests ... "Demonstration of antigenic and genotypic variation in Orientia tsutsugamushi which were isolated in Japan, and their ... DNA analyses have shown that the GroES and GroEL genes are indeed present in O. tsutsugamushi with slight variation in ...
Many genes involved in antigenic variation are located in the subtelomeric regions of the chromosomes. These are divided into ...
Dai Q, Restrepo BI, Porcella SF, Raffel SJ, Schwan TG, Barbour AG (June 2006). "Antigenic variation by Borrelia hermsii occurs ...
Among its virulence factors are its capsule, endotoxins, siderophores, antimicrobial resistance and antigenic phase variation. ...
A hypothesis for the origin of this genetic variation states that the host-defense system responsible for silencing foreign DNA ... Bookmarking Original antigenic sin, immunological imprinting Metabolic imprinting Ferguson-Smith AC (July 2011). "Genomic ... Natural selection for genomic imprinting requires genetic variation in a population. ...
... antigenic variation of the VlsE surface protein, inactivating key immune components such as complement, and hiding in the ... Is it a new tick borne disease or Lyme disease variation?". Brazilian Journal of Medical and Biological Research. 40 (4): 443- ...
Carrell RW, Jeppsson JO, Laurell CB, Brennan SO, Owen MC, Vaughan L, Boswell DR (July 1982). "Structure and variation of human ... Consequently, carbamylated A1AT is currently being developed as an antigenic biomarker for RA. The protein was initially named ... "NM_001127701.1(SERPINA1):c.1096G>A (p.Glu366Lys)". ClinVar Genomic variation as it relates to human health. U.S. National ... as an antigenic target of anti-CarP antibodies in patients with rheumatoid arthritis". Journal of Autoimmunity. 80: 77-84. doi: ...
Spanish flu research
The ability of various influenza strains to show species-selectivity is largely due to variation in the hemagglutinin genes. ... genetic drift and antigenic shift - in viruses in poultry and swine which the fort bred for local consumption. Though initial ...
Enormous antigenic variation in Orientia tsutsugamushi strains is now recognized, and immunity to one strain does not confer ... A vaccine developed for one locality may not be protective in another, because of antigenic variation. This complexity ... 2003). "Short report: variation in the 56-kD type-specific antigen gene of Orientia tsutsugamushi isolated from patients in ... Kang JS, Chang WH (1999). "Antigenic relationship among the eight prototype and new serotype strains of Orientia tsutsugamushi ...
1510 influenza pandemic
Flu became more widely referred to as coqueluche and coccolucio in France and Sicily during this pandemic, variations of which ... in which cross-species infections trigger antigenic shift and create new strains of flu human beings have little immunity to. ...
"Periodic variation in side-chain polarities of T-cell antigenic peptides correlates with their structure and activity". ... DeLisi, C.; Berzofsky, J. A. (1985). "T-cell antigenic sites tend to be amphipathic structures". Proceedings of the National ...
This displaces the antigenic peptide away from the TCR and circumvents the normal mechanism for T-cell activation. The ... Arcus VL, Proft T, Sigrell JA, Baker HM, Fraser JD, Baker EN (May 2000). "Conservation and variation in superantigen structure ... 2003). "Identification of the Antigenic Epitopes in Staphylococcal Enterotoxins A and E and Design of a Superantigen for Human ... "High-frequency intracellular infection and erythrogenic toxin A expression undergo phase variation in M1 group A streptococci ...
In wild birds, within-subtype antigenic variation appears to be limited but has been observed in poultry. Antigenic shift is a ... Two key processes that influenza viruses evolve through are antigenic drift and antigenic shift. Antigenic drift is when an ... Antigenic drift occurs in all influenza species but is slower in B than A and slowest in C and D. Antigenic drift is a major ... ICV and IDV experience a slower rate of antigenic evolution than IAV and IBV. Because of this antigenic stability, relatively ...
Type A influenza vaccine
There are 18 and 11 subtypes of hemagglutinin and neuraminidase respectively which allow variations of the virus surface ... "Inhibition of virus-induced hemolysis with monoclonal antibodies to different antigenic areas on the hemagglutinin molecule of ...
PAL labeling can be confusing to consumers, especially as there can be many variations on the wording of the warning. PAL is ... Other formulas, based on free amino acids, are the least antigenic and provide complete nutritional support in severe forms of ... However, for the soybean proteins known to trigger allergic reactions, there is more variation from strain to strain than ... Hypoallergenic infant formulas can be based on proteins partially predigested to a less antigenic form. ...
There is little geographical variation, with some minor local differences in the amount of orange on the belly. In 1915, ... In 1966, a paramyxovirus with some antigenic similarity to Newcastle disease was isolated from the brain of a turquoise parrot ... Observations at Chiltern in Victoria indicated seasonal variation in flock size, with turquoise parrots foraging in groups of 5 ...
In 1965 and 1972, several groups characterized how P. knowlesi antigenic variation contributed to immune evasion and chronic ...
... is a kind of genetic variation in viruses, arising from the accumulation of mutations in the virus genes that ... Antigenic drift occurs in both influenza A and influenza B viruses. (Confusion can arise with two very similar terms, antigenic ... Antigenic drift is this continuous process of genetic and antigenic change among flu strains. In human populations, immune ( ... Antigenic drift should not be confused with antigenic shift, which refers to reassortment of the virus' gene segments. As well ...
Development of a vaccine has been complicated by the ongoing evolution of resistant strains and antigenic variation (the ...
Glenny A, Pope C, Waddington H, Wallace U (1926). "The antigenic value of toxoid precipitated by potassium alum". J Pathol ... significant variations in the efficacy of different batches of the same vaccine were correctly assumed to be caused by ... Because immune systems have evolved to recognize these specific antigenic moieties, the presence of an adjuvant in conjunction ...
Hepatitis B virus
The virus is divided into four major serotypes (adr, adw, ayr, ayw) based on antigenic epitopes present on its envelope ... and forty subgenotypes according to overall nucleotide sequence variation of the genome. The genotypes have a distinct ...
An interesting variation of this idea is the use of genetically modified cells that can produce custom-tailored ribozymes. This ... Vaccination involves the introduction (i.e. via injection) of a small amount of typically inactivated or attenuated antigenic ... Moreover, the major difficulty in developing vaccines and anti-viral drugs is due to viral variation. The emergence of ... This effect, called the quasispecies model, results in immense variation in any given sample of virus, and gives the ...
"Loss-of-function variations within the filaggrin gene predispose for atopic dermatitis with allergic sensitizations". The ... "Citrulline is an essential constituent of antigenic determinants recognized by rheumatoid arthritis-specific autoantibodies". ...
While most strains are beneficial, there are significant phenotypic variations among strains, even those that share >99% of ... especially because it is versatile not only in its antigenic and pathogenic behaviors, but also in its cell morphology. C. ... "Genomic variation landscape of the human gut microbiome". Nature. 493 (7430): 45-50. Bibcode:2013Natur.493...45S. doi:10.1038/ ...
However, the antigenic cross-reactivity among these two representatives within the genus Respirovirus may explain why SeV ... This difference results in different neuraminidase conformations around the receptor binding site and variations in ... The virus genome has high similarity with human parainfluenza virus 1 (HPIV-1) and the two viruses share common antigenic ... Human parainfluenza virus type 1, also shares common antigenic determinants with SeV and triggers the generation of cross- ...
The severity and variation in symptoms correlates with the region the case develops in. This could be due to climatic factors ... ORF2 encode the structural proteins, which are -at least- VP26, VP29 and VP32, the most antigenic and immunogenic of these ... Royuela E, Sánchez-Fauquier A (January 2010). "Molecular cloning, expression and first antigenic characterization of human ...
Variations in these factors could lead to different strengths of immune response toward the newly formed antigenic determinant ...
However, due to the amino acid variation between different proteins, molecular mimicry should not happen from a probability ... Molecular mimicry is thus occurring between two recognized peptides that have similar antigenic surfaces in the absence of ... "Similar antigenic surfaces, rather than sequence homology, dictate T-cell epitope molecular mimicry". Proceedings of the ... which leads to the expression of novel receptor specificity through V region gene rearrangements which will create variation in ...
Current Trends Antigenic Variation of Recent Influenza A(H3N2) Viruses
Antigenic variation has always complicated influenza vaccine formulation. The occurrence of viruses that exhibit antigenic ... Current Trends Antigenic Variation of Recent Influenza A(H3N2) Viruses Analysis of recent influenza A(H3N2) viruses indicates ... This response confirms the existence of antigenic variation in recent virus isolates. Vaccinees in all age groups developed ... Although antigenic variants differ in some epitopes on the hemagglutinin, they also share other common hemagglutinin epitopes. ...
Browsing Meeting reports by Subject "Antigenic Variation"
Browsing by Subject "Antigenic Variation"
Figure 2 - Canine Influenza Virus A(H3N2) Clade with Antigenic Variation, China, 2016-2017 - Volume 25, Number 1-January 2019 -...
Canine Influenza Virus A(H3N2) Clade with Antigenic Variation, China, 2016-2017 Yanli Lyu1, Shikai Song1, Liwei Zhou1, Guoxia ... Canine Influenza Virus A(H3N2) Clade with Antigenic Variation, China, 2016-2017. ... Antigenic cartograph representative of hemagglutinin inhibition (HI) titers of canine influenza viruses, China, 2009-2017, ... showing antigenic groups A-C. Map was generated by using AntigenMap 3D (http://sysbio.cvm.msstate.edu/software/AntigenMap) and ...
1202.4290v1] The effects of symmetry on the dynamics of antigenic variation
Using the example of a model of antigenic variation in malaria, we show how many of the observed dynamical regimes can be ... Title:The effects of symmetry on the dynamics of antigenic variation. Authors:K. B. Blyuss ... an important role is played by the structure of antigenic variants associated with a pathogen. ... explained in terms of the symmetry of interactions between different antigenic variants. The results of this analysis are quite ...
Antigenic variation among strains of the New Jersey serotype of vesicular stomatitis virus.<...
Antigenic variation among strains of the New Jersey serotype of vesicular stomatitis virus. American journal of veterinary ... Tesh, R. B. / Antigenic variation among strains of the New Jersey serotype of vesicular stomatitis virus. In: American journal ... Antigenic variation among strains of the New Jersey serotype of vesicular stomatitis virus. / Tesh, R. B. ... Tesh, R. B. (1979). Antigenic variation among strains of the New Jersey serotype of vesicular stomatitis virus. American ...
Relapsing Fever Workup: Approach Considerations, Laboratory Studies, Imaging Studies
The MRN complex promotes DNA repair by homologous recombination and restrains antigenic variation in African trypanosomes -...
We conclude that MRN promotes stringent homologous recombination at subtelomeric loci and restrains antigenic variation. ... and is especially important for recombination of the subtelomeric variant surface glycoprotein during antigenic variation. ... The MRN complex promotes DNA repair by homologous recombination and restrains antigenic variation in African trypanosomes Ann- ... We conclude that MRN promotes stringent homologous recombination at subtelomeric loci and restrains antigenic variation. ...
Gonococcal Arthritis: Practice Essentials, Pathophysiology and Etiology, Epidemiology
Canine Influenza Virus A(H3N2) Clade with Antigenic Variation, China, 2016-2017 - Volume 25, Number 1-January 2019 - Emerging...
Canine Influenza Virus A(H3N2) Clade with Antigenic Variation, China, 2016-2017. Emerging Infectious Diseases. 2019;25(1):161- ... Canine Influenza Virus A(H3N2) Clade with Antigenic Variation, China, 2016-2017 On This Page ... Canine Influenza Virus A(H3N2) Clade with Antigenic Variation, China, 2016-2017. Volume 25, Number 1-January 2019 ... Canine Influenza Virus A(H3N2) Clade with Antigenic Variation, China, 2016-2017. ...
Population structuring of multi-copy, antigen-encoding genes in Plasmodium falciparum
Empirical comparison of patterns of genetic variation at antigenic and neutral sites supports this role for immune selection in ... The model explicitly considers the extensive diversity of multi-copy genes that undergo antigenic variation via sequential, ... Keywords: Other; Plasmodium falciparum; antigenic diversity; epidemiological dynamics; immune selection; parasite population ... structures the parasite population into a subset of coexisting dominant repertoires of var genes whose degree of antigenic ...
Stability and bifurcations in a model of antigenic variation in malaria. - Peter Medawar Building for Pathogen Research
We examine the properties of a recently proposed model for antigenic variation in malaria which incorporates multiple epitopes ... We examine the properties of a recently proposed model for antigenic variation in malaria which incorporates multiple epitopes ... Algorithms, Animals, Antibody Formation, Antigenic Variation, Computer Simulation, Cross Reactions, Epitopes, Humans, Immune ...
Structural and serological evidence for a novel mechanism of antigenic variation in foot-and-mouth disease virus - CAMS Oxford...
Plasmodium falciparum antigenic variation. Mapping mosaic var gene sequences onto a network of shared, highly polymorphic...
... structure of the sequences and their division into subgroups may reflect the conflicting problems of maximizing antigenic ... Plasmodium falciparum antigenic variation. Mapping mosaic var gene sequences onto a network of shared, highly polymorphic ... Plasmodium falciparum antigenic variation. Mapping mosaic var gene sequences onto a network of shared, highly polymorphic ... Amino Acid Sequence, Animals, Antigenic Variation, Antigens, Protozoan, Child, Conserved Sequence, Humans, Malaria, Falciparum ...
HIV Envelope Glycoform Heterogeneity and Localized Diversity Govern the Initiation and Maturation of a V2 Apex Broadly...
Thieme E-Journals - Journal of Laboratory Physicians / Abstract
Mutations in SARS-CoV-2 Leading to Antigenic Variations in Spike Protein: A Challenge in Vaccine Development. Praveen Kumar ... The significant variations in the predicted epitopes showing high antigenicity were A348V, V367F and A419S in receptor binding ... One of the major reasons attributed to this variation is genetic mutation. Therefore, we aimed to predict the mutations in the ... Conclusion S protein is the major target for vaccine development, but several mutations were predicted in the antigenic ...
Advanced Search Results - Public Health Image Library(PHIL)
Predicting Antigenicity of Influenza A Viruses Using biophysical ideas | Scientific Reports
... provides important insights into the evolutionary mechanisms underpinning viral antigenic variations, and helps to understand ... Prediction of antigenic relationships among influenza viruses is useful for designing (or updating the existing) influenza ... In this study, we present a simple and physically interpretable model that can predict antigenic relationships among influenza ... Antigenic variations of influenza A viruses are induced by genomic mutation in their trans-membrane protein HA1, eliciting ...
Publication Year: 2018 / Subject: elderly and children / Subject term: children / Text Availability: Citation in PubAg - PubAg...
Norovirus; animal models; antigenic variation; bioengineering; capsid; children; clinical trials; coat proteins; elderly; ... spatial variation; spring; summer; temporal variation; toxicity; vinyl acetate; volatile organic compounds; winter; Taiwan. ... However, it is still unclear whether temperature variation within the same day, that is diurnal temperature range (DTR), is ... 5. Change in the efficacy of influenza vaccination after repeated inoculation under antigenic mismatch: A systematic review and ...
Computational design of a new chimeric protein for sero-diagnosis of Mycoplasma hominis - Gazzetta Medica Italiana - Archivio...
Malaria parasite interactions with the human host Pouniotis D S, Proudfoot O, Minigo G, Hanley J L, Plebanski M - J Postgrad Med
Antigenic variation in Plasmodium falciparum:mechanisms and consequences. Curr Opin Microbiol 1999;2:420-5. [PUBMED] [FULLTEXT] ... mechanisms which include clonal antigenic variation and altered peptide ligand (APL) antagonism. Despite extensive efforts ... Identification of conserved antigenic components for a cytotoxic T lymphocyte-inducing vaccine against malaria. Lancet 1995;345 ... persistence of malaria infections within populations is the ability of the parasites to undergo repeated antigenic variation.[2 ...
Publications at this Location : USDA ARS
Influenza Vaccine Composition for the 1989-90 Season
However, over time there may be enough antigenic variation (antigenic drift) within the same subtype that infection or ... Antigenic variation occurs with influenza B viruses, although no subtypes are known to exist. For these reasons, major ... Antigenic analysis of type A(H1N1) viruses from outbreaks indicates that most strains are closely related to the U.S. vaccine ... The antigenic characteristics of current strains provide the basis for selecting virus strains included in each years vaccine. ...
This antigenic variation associated with the surface exposed PfEMP-1 allows the parasite to evade the immune system. However, ... For example, P. falciparum exhibits an antigenic variation that allows it to stay one step ahead of the immune system. In ... Click here for more on knobs, receptors/ligands, and antigenic variation.. Early observations of the pathology of cerebral ... This, along with antigenic variation and polymorphisms in many Plasmodium antigens, could explain the slow development of ...
Pertussis resurgence: waning immunity and pathogen adaptation - two sides of the same coin | Epidemiology & Infection |...
For example, antigenic variation may diminish the efficacy of antibodies, or affect T-cell recognition and memory. Changes in ... These changes include antigenic divergence with vaccine strains and increased production of pertussis toxin. Antigenic ... Characterization of the key antigenic components of pertussis vaccine based on outer membrane vesicles. Vaccine, Vol. 32, Issue ... Studies on prn variation in the mouse model and comparison with epidemiological data. PLoS One 2011; 6: e18014.CrossRefGoogle ...
Seminal Plasma Initiates a Neisseria gonorrhoeae Transmission State - Kölner UniversitätsPublikationsServer
Plasmodium falciparum uses antigenic variation to evade host immunity, including vaccine-induced immunity.1,2 The protective ... They cannot measure antibody function, and seroreactivity to any one of the large number of antigenic variants on an array does ... array represents an enabling technology that will make it possible to evaluate antibody responses to large numbers of antigenic ...
Laboratory guidelines: Canadian Pandemic Influenza Preparedness: Planning Guidance for the Health Sector - Canada.ca
Antigenic characterization: Monitoring antigenic variation as the influenza season progresses is an important part of the ... including antiviral resistance and antigenic variation. Laboratories equipped to readily determine the genome sequence will be ... as viral isolates are required for antigenic characterization to monitor for potential antigenic drift and antiviral resistance ... Because the NML has the technical capacity for antigenic characterization and is required to conduct surveillance reporting to ...
StrainsMalariaEpitopesImmunityTrypanosomesDiversityTrypanosomaPlasmodiumVariants of influenzaH3N2DriftVariabilitySurface glycoproteinHemagglutininVirusesPathogenInhibitionSerotypeDifferencesVariantImmuneAntibodiesIsolatesAntigenShiftLociTitersGeneticsHumansGenesGenetic variationsInterindividualBiologyVirusSignificantAnalysisStructure
- Analysis of recent influenza A(H3N2) viruses indicates antigenic drift from the previously prevalent strains A/Mississippi/1/85 and A/Leningrad/360/86. (cdc.gov)
- Antigenic variation among strains of the New Jersey serotype of vesicular stomatitis virus. (utmb.edu)
- however, by plaque-reduction neutralization method, slight antigenic differences were observed between the Hazelhurst and the three other strains. (utmb.edu)
- Dive into the research topics of 'Antigenic variation among strains of the New Jersey serotype of vesicular stomatitis virus. (utmb.edu)
- Antigenic analysis of type A(H1N1) viruses from outbreaks indicates that most strains are closely related to the U.S. vaccine strain, A/Taiwan/1/86. (cdc.gov)
- However, over time there may be enough antigenic variation (antigenic drift) within the same subtype that infection or vaccination with one strain may not induce immunity to distantly related strains of the same subtype. (cdc.gov)
- The antigenic characteristics of current strains provide the basis for selecting virus strains included in each year's vaccine. (cdc.gov)
- These changes include antigenic divergence with vaccine strains and increased production of pertussis toxin. (cambridge.org)
- Because about 75 percent of Shigella infections in developing countries are caused by Shigella sonnei, the lack of antigenic variation within this species makes it difficult to discriminate between strains. (cdc.gov)
- Understanding the amount of genetic variation and the relatedness of strains helps us appreciate the way the organism is changing and interpret our laboratory findings to track and control the spread of infections. (cdc.gov)
- Recently isolated FMDV strains showed high genetic variations from locally used vaccine strains in the major antigenic sites of VP1 region. (mendeley.com)
- Individual strains may show antigenic drift, presumably generating new serotypes over time. (creative-biolabs.com)
- One is a phenomenon, especially associated with INFLUENZA VIRUSES , where they undergo spontaneous variation both as slow antigenic drift and sudden emergence of new strains (antigenic shift). (bvsalud.org)
- Using the example of a model of antigenic variation in malaria, we show how many of the observed dynamical regimes can be explained in terms of the symmetry of interactions between different antigenic variants. (arxiv.org)
- Stability and bifurcations in a model of antigenic variation in malaria. (ox.ac.uk)
- We examine the properties of a recently proposed model for antigenic variation in malaria which incorporates multiple epitopes and both long-lasting and transient immune responses. (ox.ac.uk)
-  An important reason for the persistence of malaria infections within populations is the ability of the parasites to undergo repeated antigenic variation. (jpgmonline.com)
-  There is evidence of the suppression and evasion of parasite-specific responses during acute malaria: mechanisms which include clonal antigenic variation and altered peptide ligand (APL) antagonism. (jpgmonline.com)
- Although antigenic variants differ in some epitopes on the hemagglutinin, they also share other common hemagglutinin epitopes. (cdc.gov)
- The significant variations in the predicted epitopes showing high antigenicity were A348V, V367F and A419S in receptor binding domain (RBD). (thieme-connect.com)
- Conclusion S protein is the major target for vaccine development, but several mutations were predicted in the antigenic epitopes of S protein across all genomes available globally. (thieme-connect.com)
- It tracks the dynamics of all unique var repertoires in a population of hosts, and shows that even under high levels of sexual recombination, strain competition mediated through cross-immunity structures the parasite population into a subset of coexisting dominant repertoires of var genes whose degree of antigenic overlap depends on transmission intensity. (nih.gov)
- This large variation is probably due to different definitions of immunity and different vaccines included in these studies. (cambridge.org)
- Immunoglobulin gamma marker (GM) and kappa marker (KM) allotypes, hereditary antigenic determinants of gamma and kappa chains, respectively, have been shown to be associated with immunity to a variety of self and nonself antigens, but their possible contribution to immunity to the tumor-associated antigens epidermal growth factor receptor (EGFR) and EGFR variant (v)III has not been evaluated. (cdc.gov)
- VEX1 controls the allelic exclusion required for antigenic variation in trypanosomes. (lshtm.ac.uk)
- Allelic exclusion underpins antigenic variation and immune evasion in African trypanosomes. (lshtm.ac.uk)
- Trypanosomes develop as extracellular parasites and escape the host immune response by means of a sophisticated process of antigenic variation. (biomedcentral.com)
- The model explicitly considers the extensive diversity of multi-copy genes that undergo antigenic variation via sequential, mutually exclusive expression. (nih.gov)
- Empirical comparison of patterns of genetic variation at antigenic and neutral sites supports this role for immune selection in structuring parasite diversity.DOI:http://dx.doi.org/10.7554/eLife.00093.001. (nih.gov)
- The mosaic structure of the sequences and their division into subgroups may reflect the conflicting problems of maximizing antigenic diversity and minimizing epitope sharing between variants while maintaining their host cell binding functions. (ox.ac.uk)
- Many of these glycoproteins show amino acid sequence diversity expressed as antigenic variations. (harvard.edu)
- Each RVA genomic segment has extensive variability, which may reflect in antigenic diversity of the respective proteins, mainly VP7 and VP4 proteins that comprise the outer layer. (bvsalud.org)
- Homologous recombination dominates as the major form of DNA repair in Trypanosoma brucei, and is especially important for recombination of the subtelomeric variant surface glycoprotein during antigenic variation. (archives-ouvertes.fr)
- A yeast-endonuclease-generated DNA break induces antigenic switching in Trypanosoma brucei. (harvard.edu)
- Plasmodium falciparum antigenic variation. (ox.ac.uk)
Variants of influenza1
- Editorial Note: In 1987, the World Health Organization Collaborating Centers for Influenza (Atlanta and London), in conjunction with National Influenza Centers in several countries in Asia and Oceania, detected antigenic variants of influenza A(H3N2). (cdc.gov)
- Analysis of about 50 recently isolated A(H3N2) viruses from Asia, Oceania, and the United States indicates a spectrum of antigenic specificity, with many isolates having reaction patterns intermediate between A/Leningrad/360/86 and A/Sichuan/2/87. (cdc.gov)
- The occurrence of viruses that exhibit antigenic drift from the vaccine strain has on occasion resulted in diminished vaccine efficacy, such as the failure of A/Port Chalmers/1/73 to protect against A/Victoria/3/75 (2). (cdc.gov)
- In 1972, vaccine containing A/Aichi/2/68 reduced cases of influenza by 60% in an outbreak caused by the antigenic drift variant A/England/42/72 (3), and, in 1977, A/Victoria/3/75 vaccine protected adults from A/Texas/1/77 infection with 80% efficacy (4). (cdc.gov)
- Significant protection from illness may also be induced by the neuraminidase surface glycoprotein (5,6), which has shown less evidence of antigenic drift. (cdc.gov)
- This causes antigenic variation in infectious agents and a high interindividual variability in the human response to the vaccine. (scielo.br)
- In addition, the antigenic changes described occurred in the hemagglutinin surface glycoprotein. (cdc.gov)
- Still other factors, such as the capacity of a strain to spread in the population, can emerge independently from changes in the antigenic properties of the hemagglutinin. (cdc.gov)
- Antigenic cartograph representative of hemagglutinin inhibition (HI) titers of canine influenza viruses, China, 2009-2017, showing antigenic groups A-C. Map was generated by using AntigenMap 3D ( http://sysbio.cvm.msstate.edu/software/AntigenMap ) and HI data shown in Table 2 . (cdc.gov)
- Although repeated exposure to influenza H3 induced the so-called "original antigenic sin" phenomena in hemagglutination inhibition assay titers against exposure to viruses later on, the ferret antibodies showed gradually enhanced avidity for different H3/hemagglutinin. (infectiousdiseaseadvisor.com)
- Antigenic variations of influenza A viruses are induced by genomic mutation in their trans-membrane protein HA1, eliciting viral escape from neutralization by antibodies generated in prior infections or vaccinations. (nature.com)
- Prediction of antigenic relationships among influenza viruses is useful for designing (or updating the existing) influenza vaccines, provides important insights into the evolutionary mechanisms underpinning viral antigenic variations, and helps to understand viral epidemiology. (nature.com)
- In this study, we present a simple and physically interpretable model that can predict antigenic relationships among influenza A viruses, based on biophysical ideas, using both genomic amino acid sequences and experimental antigenic data. (nature.com)
- Prediction of antigenic relationships (similar or variant) among influenza viruses is useful in designing (or updating the existing) effective influenza vaccines, provides important insights into the evolutionary mechanisms that underpin their antigenic variations due to the pressure of natural selection imposed by the neutralizing antibodies 10 , and helps to understand the epidemiology of these pathogens. (nature.com)
- Antigenic variation occurs with influenza B viruses, although no subtypes are known to exist. (cdc.gov)
- Antigenic variation is displayed by a number of important pathogenic viruses. (creative-biolabs.com)
- The extent of cross-reactive ferret antibodies induced by repeated exposure to influenza H3 also increased, and antigenic variations between influenza H3 viruses characterized by ferret antisera decreased as the number of exposures increased. (infectiousdiseaseadvisor.com)
- This rise in antibody avidity inversely correlated with reduced antigenic differences among H3 viruses characterized. (infectiousdiseaseadvisor.com)
- In the studies of dynamics of pathogens and their interactions with a host immune system, an important role is played by the structure of antigenic variants associated with a pathogen. (arxiv.org)
- One of the many fascinating features of this unique pathogen is an elaborate system for antigenic variation, whereby the sequence of the surface-bound lipoprotein VlsE is continually modified through segmental gene conversion events. (jbc.org)
- Antigenic variation as the pathogen passes through an entire host population rather than just a single host. (bvsalud.org)
- The antigenic relationships of the human and swine IAV were investigated by hemagglutination inhibition (HI) assays using panels of post-infection ferret and swine antisera raised against representative human and swine IAV (see Appendix Table 1 and S2). (cdc.gov)
- Shigella sonnei only has one antigenic variant we call a serotype, while the other Shigella species each have many serotypes which helps distinguish one strain from another within a species. (cdc.gov)
- Interference among the three attenuated poliovirus serotypes was minimized with a 'balanced- formulation' vaccine, and serologic responses after IPV were optimized by adjusting the antigenic content of each inactivated poliovirus serotype. (who.int)
- It is concluded that these antigenic differences are insufficient to warrant reclassification of vesicular stomatitis virus--New Jersey into two distinct subtypes, as has been recently proposed. (utmb.edu)
- Differences in the antigenic makeup of meningococcal clonal complexes (cc) ( 11 ) likely influence reported disparities in spatiotemporal spread. (cdc.gov)
- Nancy Strockbine] Shigella sonnei is one of four species of Shigella that are recognized for historical and medical reasons and are classified on the basis of biochemical and antigenic differences. (cdc.gov)
- T. brucei sequentially expresses immunologically distinct Variant Surface Glycoproteins (VSGs), its major surface antigen, to evade the host's immune response, and Dr. Li's lab has demonstrated that telomeres play critical roles in regulating this antigenic variation process in T. brucei . (csuohio.edu)
- Antigenic divergence will affect both memory recall and the efficacy of antibodies, while higher levels of pertussis toxin may increase suppression of the innate and acquired immune system. (cambridge.org)
- Additionally, recent advances in immunogenetics and genomics should help in the understanding of the influence of genetic factors on the interindividual and interpopulation variations in immune responses to vaccines, and could be useful for developing new vaccine strategies. (scielo.br)
- Among them are the direct and indirect suppression of host immune signals, phase and antigenic variation, escaping recognition by host complement proteins, and seclusion into immune privileged sites. (isbn.nu)
- A primary basis of antigenic variation is a selection of virus mutants by antibodies. (creative-biolabs.com)
- This response confirms the existence of antigenic variation in recent virus isolates. (cdc.gov)
- Antigenic variation refers to the observation that different isolates of a single virus species may show variable cross-reactivity when tested with a standard serum. (creative-biolabs.com)
- In addition, the geometric mean titers were higher to the homologous A/Leningrad/360/86 antigen than to the antigenic variants A/Sichuan/2/87 or A/Victoria/7/87. (cdc.gov)
- Studies conducted in the Brazilian Mid-West have shown a temporal variation in the predominance of certain G and P genotypes, characterizing the occurrence of an antigenic shift (Cardoso et al. (bvsalud.org)
- We conclude that MRN promotes stringent homologous recombination at subtelomeric loci and restrains antigenic variation. (archives-ouvertes.fr)
- We describe two tandem repeat loci, designated 'TR6' and 'TR10', which display extensive sequence variation that may be useful for sequence-based strain typing. (biomedcentral.com)
- Vaccinees in all age groups developed titers of 40 or more to A/Leningrad/360/86 with greater frequency than they did to the new antigenic variants (Table 2). (cdc.gov)
- Genetics is the study of genes , heredity , and the variation of organisms , as well as the medical practice of diagnosing, treating, and counseling patients with genetic disorders . (wikipedia.org)
- Vaccine development faces major difficulties partly because of genetic variation in both infectious organisms and humans. (scielo.br)
- and National Institute for complicating interpretation of variation in fi m genes. (cdc.gov)
- Efforts to estimate the prevalence of genetic variations underpinning the antigenic expression are emerging. (biorxiv.org)
- The aim of the present investigation was to determine whether the interindividual variation in endogenous antibody responsiveness to EGFR and EGFRvIII is associated with particular GM, KM, and Fcgamma receptor (FcgammaR) genotypes and whether antibody levels were associated with the overall survival of patients with glioblastoma. (cdc.gov)
- The variation may be manifest in different ways depending on the virus' natural biology. (creative-biolabs.com)
- The formulation of the vaccine is reviewed annually to take account of the antigenic variation of the virus. (alcohol.gov.au)
- Eastern) are not subject to significant antigenic variation. (who.int)
- A spatially slowly moving clone with multiple-locus variable-number tandem repeat analysis type 19, ST42, and antigenic profile B:P1.7-2,4:F1-5 was responsible for the outbreak. (cdc.gov)
- A review of surveys conducted to date reveals considerable variation in both the choice and use of survey methods and in the assumptions made in the analysis and interpretation of findings. (who.int)
- I'm interested in how telomere-binding proteins define the chromatin structure at the chromosome ends and how they influence antigenic variation. (uni-wuerzburg.de)