Mononuclear Phagocyte System
Complement System Proteins
Blood Bactericidal Activity
Endocarditis, Subacute Bacterial
Complement Pathway, Alternative
Complement Pathway, Classical
Serum Amyloid P-Component
Receptors, Complement 3b
2-Deoxyglucose selectively inhibits Fc and complement receptor-mediated phagocytosis in mouse peritoneal macrophages II. Dissociation of the inhibitory effects of 2-deoxyglucose on phagocytosis and ATP generation. (1/1165)Macrophages incubated in 2-deoxy-D-glucose (2-dG)-containing medium showed a marked decrease in cellular ATP content, and were unable to ingest IgG- and complement-coated erythrocytes via the corresponding membrane receptors for these ligands. However, the inhibitory effects of 2-dG on Fc- and C3 receptor-mediated phagocytosis were not a consequence of lowered macrophage ATP levels since addition of glucose or mannose to the culture medium restored the capacity of the macrophages to ingest IgG- and C3-coated particles without increasing ATP levels. These results indicate that Fc- and C3 receptor-mediated phagocytosis (opsonin dependent) differs qualitatively from the ingestion of latex and zymosan particles (opsonin independent); they suggest that the same regulatory molecules govern the responses of phagocytic cells to signals initiated by both the Fc and C3 receptors. The possibility that these molecules are regulated by glycosylation is discussed. (+info)
Influenza A virus accelerates neutrophil apoptosis and markedly potentiates apoptotic effects of bacteria. (2/1165)Neutrophils are recruited into the airway in the early phase of uncomplicated influenza A virus (IAV) infection and during the bacterial superinfections that are a significant cause of morbidity and mortality in IAV-infected subjects. In this report, we show that IAV accelerates neutrophil apoptosis. Unopsonized Escherichia coli had similar effects, although apoptotic effects of opsonized E coli were greater. When neutrophils were treated with both IAV and unopsonized E coli, a marked enhancement of the rate and extent of neutrophil apoptosis occurred as compared with that caused by either pathogen alone. Treatment of neutrophils with IAV markedly increased phagocytosis of E coli. Simultaneous treatment of neutrophils with IAV and E coli also elicited greater hydrogen peroxide production than did either pathogen alone. IAV increased neutrophil expression of Fas antigen and Fas ligand, and it also increased release of Fas ligand into the cell supernatant. These findings may have relevance to the understanding of inflammatory responses to IAV in vivo and of bacterial superinfection of IAV-infected subjects. (+info)
Role of antibody and complement in opsonization of group B streptococci. (3/1165)A requirement for the classic complement pathway in opsonization of group B streptococci was observed by using both a chemiluminescence and a radiolabeled bacterial uptake technique. The classic pathway increased levels of opsonization for types Ia and II stock and wild strains and for some type III wild strains. In contrast, other type III wild strains and the type III stock strain had accelerated kinetics of uptake in the presence of an intact classic pathway, but the level of opsonization was unchanged from that with antibody alone. We could not demonstrate a significant role for the alternative pathway in opsonizing stock or wild strains of group B streptococci. Futhermore, electrophoretic and complement consumption analysis by hemolytic titration failed to reveal alternative pathway activation by the majority of strains of this group. Therapy aimed at supplying opsonins for these organisms will require the presence of type-specific antibody. (+info)
Type-specific opsonophagocytosis of group A Streptococcus by use of a rapid chemiluminescence assay. (4/1165)A whole-blood chemiluminescence (CL) assay was developed to determine the presence of type-specific opsonic antibodies against group A streptococcus (GAS). Convalescent sera with high bactericidal activities against an M-1 serotype were used to opsonize different M-types of GAS. CL responses were monitored for 20 min, and results were expressed as integral counts/minute per phagocyte. CL responses of phagocytes incubated with M-1 GAS opsonized with homologous (M-1) serum were significantly higher than responses of phagocytes incubated with heterologous (M-3) GAS. Adsorption of convalescent serum against the homologous, but not the heterologous, strain markedly reduced the CL response, demonstrating type specificity. The CL assay showed a high correlation with the indirect bactericidal test (r=0.90). In conclusion, this CL assay is a rapid, highly sensitive, specific, and reproducible method for quantifying type-specific opsonic antibodies against GAS and will be a useful tool for future clinical, basic science, and epidemiological studies. (+info)
Pseudomonas aeruginosa outer-membrane protein F epitopes are highly immunogenic in mice when expressed on a plant virus. (5/1165)A synthetic peptide (peptide 10) representing a surface-exposed, linear B cell epitope from outer-membrane (OM) protein F of Pseudomonas aeruginosa was shown previously to afford protection in mice from P. aeruginosa infection. This peptide was expressed in tandem with the protein F peptide 18 on each of the two coat proteins of cowpea mosaic virus (CPMV). The chimaeric virus particles (CVPs) expressing the peptides on the S (small) coat protein (CPMV-PAE4) and L (large) coat protein (CPMV-PAE5) were used to immunize mice. Following subcutaneous immunization in Freund's and QuilA adjuvants, CPMV-PAE4 induced antibodies predominantly against peptide 18, whereas CPMV-PAE5 produced antibodies exclusively against peptide 10, indicating that the site of peptide expression on CPMV influences its immune recognition. The anti-peptide antibodies elicited by CPMV-PAE5 were predominantly of the IgG2a isotype, indicating a highly polarized TH1-type response. The peptide-specific IgG2a strongly recognized the whole F protein, but more importantly, recognized protein F in all seven Fisher-Devlin immunotypes of P. aeruginosa. Furthermore, the peptide-specific IgG2a in CVP/QS-21 adjuvant-immunized mice was shown to bind complement and to augment phagocytosis of P. aeruginosa by human neutrophils in vitro. The ability of CPMV-PAE5 to induce P. aeruginosa-specific opsonic IgG2a gives it potential for further development as a protective vaccine against P. aeruginosa. (+info)
Participation of cofilin in opsonized zymosan-triggered activation of neutrophil-like HL-60 cells through rapid dephosphorylation and translocation to plasma membranes. (6/1165)We studied the roles of cofilin, an actin-binding phosphoprotein, in superoxide production of neutrophil-like HL-60 cells triggered by opsonized zymosan (OZ). OZ caused dephosphorylation of cofilin as well as a transient increase of F-actin. Both reactions were complete within 30 s. Okadaic acid (OA) magnified the OZ-triggered O2--production 3.3-fold at 1 microM, but inhibited it completely at 5 microM. We used these critical concentrations to study the effects of OA on changes in phosphorylation and intracellular localization of cofilin. The OZ-induced dephosphorylation of cofilin was inhibited by 5 microM OA but not by 1 microM OA. Subcellular fractionation and immunoblotting revealed that 1 microM OA increased cofilin on the phagosomal membranous fraction but 5 microM OA decreased it. At 1 microM, OA increased translocation of p47phox to membranes, which may explain in part the enhancing effect of 1 microM OA. Confocal laser scanning microscopy showed that: (i) Cofilin diffused throughout the cytosol of resting cells, but accumulated at the plasma membranes forming phagocytic vesicles in activated cells. (ii) At 1 microM, OA had little effect on the OZ-evoked translocation of cofilin, whereas 5 microM OA suppressed it completely. (iii) OA alone, which could not trigger the phagocytic respiratory burst, did not cause any change in the distribution of cofilin at such concentrations. Furthermore, in a superoxide-producing cell-free system employing membranous and cytosolic fractions, affinity-purified anti-cofilin antibody showed an enhancing effect. These results suggest that cofilin participates in the superoxide production of the OZ-activated phagocytes through dephosphorylation and translocation. The roles of cofilin in the activated leukocytes will be discussed. (+info)
Relationship between cell surface carbohydrates and intrastrain variation on opsonophagocytosis of Streptococcus pneumoniae. (7/1165)Streptococcus pneumoniae undergoes spontaneous phase variation between a transparent and an opaque colony phenotype, the latter being more virulent in a murine model of sepsis. Opaque pneumococci have previously been shown to express lower amounts of C polysaccharide (cell wall teichoic acid) and in this study were shown to have a higher content of capsular polysaccharide by immunoelectron microscopy. This report then examined the relationship between expression of these two cell surface carbohydrate structures and their relative contribution to the increased virulence of opaque variants. Comparison of genetically related strains showed that the differential content of capsular polysaccharide did not affect the amount of teichoic acid as measured by a capture enzyme-linked immunosorbent assay (ELISA). In contrast, when the teichoic acid structure was altered by replacing choline in the growth medium with structural analogs, the quantity of capsular polysaccharide as measured by a capture ELISA was decreased, demonstrating a linkage in the expression of the two surface carbohydrate structures. A standardized assay was used to assess the relative contribution of cell surface carbohydrates to opsonophagocytosis. The opaque variants required 1.2- to 30-fold more immune human serum to achieve 50% opsonophagocytic killing than did related transparent variants (types 6B and 9V). The opsonophagocytic titer was proportional to the quantity of capsular polysaccharide rather than teichoic acid. The major factor in binding of the opsonin, C-reactive protein (CRP), was also the amount of capsular polysaccharide rather than the teichoic acid ligand. Only for the transparent variant (type 6B), which bound more CRP, was there enhanced opsonophagocytic killing in the presence of this serum protein. Increased expression of capsular polysaccharide, therefore, appeared to be the major factor in the decreased opsonophagocytic killing of opaque pneumococci. (+info)
Avidity as a determinant of the protective efficacy of human antibodies to pneumococcal capsular polysaccharides. (8/1165)Antibodies reactive with capsular polysaccharides are considered the principal mediators of immunity against invasive diseases caused by Streptococcus pneumoniae. In this study, we tested the hypothesis that anti-pneumococcal capsular polysaccharide (PPS) antibody avidity can influence protective efficacy. We measured the avidities of individual adult postvaccination immunoglobulin G2 (IgG2) antibodies to PPS serotypes 6B and 23F and examined the relationship between avidity and opsonophagocytic and mouse-protective activities. The avidities of PPS 6B- and PPS 23F-specific IgG2 antibodies ranged from 6 to 31 nM-1 and from 3 to 20 nM-1, respectively. We observed an inverse correlation between the magnitude of avidity and the amount of antibody required to protect mice against lethal bacteremia caused by serotype 6B pneumococci. Similarly, higher-avidity antibodies were more effective than lower-avidity antibodies in vitro in mediating complement-dependent opsonophagocytosis of both 6B and 23F pneumococci. These data suggest that in adults, PPS antibodies are sufficiently polymorphic to possess biologically significant variations in avidity. We conclude that avidity functions as an important determinant of anticapsular antibody protective efficacy against pneumococci. (+info)
Subacute bacterial endocarditis is caused by bacteria such as Streptococcus or Staphylococcus, which can enter the body through a variety of means, including dental procedures, skin infections, or injected drug use. The bacteria can then colonize on the heart valves and cause inflammation and damage.
Symptoms of subacute bacterial endocarditis may include fatigue, fever, joint pain, and skin lesions. In addition, people with subacute bacterial endocarditis may experience heart murmurs, swelling in the legs or abdomen, and difficulty breathing.
If you suspect that you or someone else may have subacute bacterial endocarditis, it is important to seek medical attention immediately. The condition can be diagnosed through a variety of tests, including echocardiography, blood cultures, and imaging studies. Treatment typically involves antibiotics to eradicate the infection, as well as supportive care to manage symptoms and prevent complications. In some cases, surgery may be necessary to repair or replace damaged heart valves. With prompt and appropriate treatment, most people with subacute bacterial endocarditis can recover fully, but delays in diagnosis and treatment can lead to serious complications, including heart failure, stroke, and death.
The most common form of this disease is Meningococcal Group B (MenB). Symptoms often develop within hours or days after exposure, but can be nonspecific, such as fever, headache, and muscle aches.
Early signs that are more specific and suggestive of the diagnosis include neck stiffness, confusion, seizures, and rash. Diagnosis is by culture or PCR of a sterile site. Treatment consists of antibiotics that cover Neisseria meningitidis, which should be initiated promptly after recognition of the signs and symptoms.
Prevention with vaccines is recommended for infants at 2 months of age; boosters are given at 4 months, 6 months, and 12 to 15 months of age.
The disease is primarily transmitted through inhalation of infected particles, such as dust or aerosols, which contain the bacterium. People working in close contact with animals, such as veterinarians and farmers, are at higher risk of contracting Q fever.
Symptoms of Q fever typically develop within 2-3 weeks after exposure and may include fever, headache, fatigue, muscle pain, and respiratory symptoms such as cough and shortness of breath. In severe cases, the infection can spread to the heart, liver, and other organs, leading to life-threatening complications.
Diagnosis of Q fever is based on a combination of clinical findings, laboratory tests, and epidemiological investigations. Laboratory confirmation of the disease requires the isolation of Coxiella burnetii from blood or other bodily fluids.
Treatment of Q fever typically involves antibiotics, which can effectively cure the infection if administered early. However, treatment is not always necessary for mild cases, and some people may recover without any treatment.
Prevention of Q fever primarily involves avoiding exposure to infected animals or their tissues, as well as practicing good hygiene practices such as wearing personal protective equipment (PPE) when handling animals or their tissues. Vaccination is also available for high-risk groups, such as veterinarians and farmers.
Overall, Q fever is an important zoonotic disease that can cause significant illness in humans and a range of animal species. Prompt diagnosis and appropriate treatment are critical to preventing complications and ensuring effective management of the disease.
Thioester-containing protein 1
Proteins produced and secreted by the liver
List of MeSH codes (D12.776)
List of MeSH codes (D12.776.124)
Surfactant protein D
Adaptive immune system
Classical complement pathway
Serum amyloid A1
Outline of immunology
Index of immunology articles
Signaling lymphocytic activation molecule
Polyclonal B cell response
DeCS 2006 - Changed terms
NIH Guide: ONTOGENY OF PERINATAL HOST DEFENSES
Pediatric Pneumonia: Practice Essentials, Background, Pathophysiology
Nanomaterials | Free Full-Text | Tailored Magnetic Multicore Nanoparticles for Use as Blood Pool MPI Tracers
JCI - Kidney injury molecule-1 is a phosphatidylserine receptor that confers a phagocytic phenotype on epithelial cells
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SPON2 - Early...
Opsonization- Definition, Mechanism, Opsonins, Examples
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Pharos : Target Details - SPON2
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NDF-RT Code NDF-RT Name
NDF-RT Code NDF-RT Name
Research Festival | Intramural Research Program | National Institutes of Health
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DailyMed - ENJAYMO- sutimlimab-jome injection, solution, concentrate
Many coupled with the complexity and diversity of - Free Reviews Examples
- Targeting can be achieved by coating orconjugating the carrier with affinity reagents such as nucleic acids, peptides,antibodies, or others that bind specific cell receptor proteins, nucleic acids,or polysaccharides. (wallaceandjames.com)
- However, γδ T cells are not MHC restricted and seem to be able to recognise whole proteins rather than requiring peptides to be presented by MHC molecules on antigen presenting cells. (wikidoc.org)
- Proteins that bind to particles and cells to increase susceptibility to PHAGOCYTOSIS , especially ANTIBODIES bound to EPITOPES that attach to FC RECEPTORS. (nih.gov)
- Complement permits the efficient labelling of bacteria with opsonins, supports phagocytosis, and facilitates phagocyte recruitment to the site of infection through the production of chemoattractants. (bath.ac.uk)
- It binds directly to bacteria and their components and functions as an opsonin for macrophage phagocytosis of bacteria. (nih.gov)
- An opsonin is any molecule that enhances phagocytosis by marking an antigen for an immune response or marking dead cells for recycling. (microbenotes.com)
- The term opsonization refers to the capacity of antibodies and complement components (as well as other proteins) to coat dangerous antigens that can then be recognized by antibodies or complement receptors on phagocytic cells. (microbenotes.com)
- The complement system is composed of over 30 proteins that improve the ability of antibodies and phagocytic cells to fight invading organisms. (microbenotes.com)
- We have found that FX acts as a defense for Ad virions against plasma opsonins, shielding the virions from attack by natural antibodies and complement. (nih.gov)
- The opsonins act as markers or tags that allow recognition by the immune system of the body. (microbenotes.com)
- Once activated, they divide rapidly and secrete small proteins called cytokines that regulate or "help" the immune response. (wikidoc.org)
- Many of those proteins are additionally rec- fire ants are more prevalent in the hols and esters) is released from the ognized as international by the human immune southeast. (xiangyunxitong.com)
- Search of new therapeutic tools requires the discovery and biochemical characterization of new potential targets among the bacterial proteins essential for the survival and virulence. (pasteur.fr)
- In this work, we determined the solution structure of adenylate kinase (AK) from Mycobacterium tuberculosis (AKmt), a protein of 181 residues that was found to be essential for bacterial survival. (pasteur.fr)
- This action results in reactivation of AMP-ACTIVATED PROTEIN KINASE activity and downstream signaling aimed at decreased metabolism. (nih.gov)
- HN - 2022 FX - Quality of Health Care MH - AMP-Activated Protein Kinase Kinases UI - D000091162 MN - D8.811.913.696.620.682.700.74 MN - D12.776.476.563.74 MS - Protein Serine-threonine kinases that phosphorylate the 63-kDa subunit of AMP-ACTIVATED PROTEIN KINASES. (nih.gov)
- A class of intracellular signaling proteins that were originally identified as inhibitors of ANGIOSTATIN activity. (nih.gov)
- HN - 2022 BX - ADP Ribosylation Factor 6 BX - ARF6 Protein MH - Aerosolized Particles and Droplets UI - D000088342 MN - D20.65 MS - A suspension of tiny particles or liquid droplets ( (nih.gov)
- This is the mechanism of identifying invading particles (antigens ) by the use of specific components called opsonins. (microbenotes.com)
- The most critical heat-labile opsonin, and perhaps the most essential opsonin of all, is C3b (C3b is the fragment of C3 that binds to particles when C3 is cleaved by a C3-convertase). (microbenotes.com)
- The dictum 'like cures like' can be understood by considering the mimicry between the antigens present on the invading pathogen and the antigens present on the proteins in the selected homeopathic medicine. (baholafoundation.org)
- Integrins are heterodimeric integral membrane proteins composed of an alpha subunit and a beta subunit that function in cell surface adhesion and signaling. (assaygenie.com)
- HN - 2022 BX - Adolescent Motherhood BX - Teen Mothers BX - Teenage Mothers FX - Pregnancy in Adolescence MH - ADP-Ribosylation Factor 6 UI - D000089982 MN - D8.811.277.40.330.300.400.100.50 MN - D12.776.157.325.515.100.550 MN - D12.776.476.338.400.100.50 MS - A member of GTP-binding protein of the large ras superfamily involved in regulation of membrane trafficking by modulating ENDOCYTOSIS and ACTIN CYTOSKELETON remodeling. (nih.gov)
- The important components of this system are various cell membrane-associated proteins such as complement receptor 1 (CR1), complement receptor 2 (CR2), and decay accelerating factor (DAF). (medscape.com)
- is caused by cytoskeletal or red cell membrane protein defects. (slideshare.net)
- Dying cells also expose ligands that bind initiator molecules of the various complement pathways, so that complement activation and opsonin deposition on the dead cell surface may enhance phagocytotic clearance ( 1 , 8 ). (frontiersin.org)
- MBL) can also be recruited by the pentraxins C-reactive protein (CRP) and pentraxin 3 (PTX3), which themselves bind to dying cells via various ligands ( 8 , 10 ). (frontiersin.org)
- Genes that encode the proteins of complement components or their isotypes are distributed throughout different chromosomes, with 19 genes comprising 3 significant complement gene clusters in the human genome. (medscape.com)
- They play a role in cell signaling pathways such as those involving G-PROTEINS and the HIPPO-SIGNALING PATHWAY. (nih.gov)
- FH, FHR-1, and FHR-5 bound to both plasmid DNA and human genomic DNA, where both FHR proteins inhibited FH-DNA interaction. (frontiersin.org)
- In case of HIV-1 infection, the interaction with extracellular viral Tat protein seems to enhance angiogenesis in Kaposi's sarcoma lesions. (assaygenie.com)
- In the case of ultra-diluted homeopathic medicines devoid of any drug molecule, it has been suggested that in the absence of drug-protein interaction, protein-protein interaction leads to the conformational modulation of protein molecules, where allosteric communication and synchronization of vibrating of the protein molecules play key roles. (baholafoundation.org)
- The classical pathway is triggered by interaction of the Fc portion of an antibody (immunoglobulin [Ig] M, IgG1, IgG2, IgG3) or C-reactive protein with C1q. (medscape.com)
- Protein Serine-threonine kinases that phosphorylate the 63-kDa subunit of AMP-ACTIVATED PROTEIN KINASES. (nih.gov)
- SPON2, also known as spondin-2, is a cell adhesion protein that promotes adhesion and outgrowth of hippocampal embryonic neurons. (nih.gov)
- Cell adhesion protein that promotes adhesion and outgrowth of hippocampal embryonic neurons. (nih.gov)
- Kidney injury molecule-1 (KIM-1 or TIM-1) is an immunoglobulin superfamily cell-surface protein not expressed by cells of the myeloid lineage but highly upregulated on the surface of injured kidney epithelial cells. (jci.org)
- FHR-1 and FHR-5 bound to late apoptotic and necrotic cells and recruited monomeric C-reactive protein and pentraxin 3, and vice versa . (frontiersin.org)
- Fe/Mg-Modified Carbonate Apatite with Uniform Particle Size and Unique Transport Protein-Related Protein Corona Efficiently Delivers Doxorubicin into Breast Cancer Cells. (omicsdi.org)
- Here, we modified the nano-carrier by partially substituting Ca2+ with Mg2+ and Fe3+ into a basic lattice structure of CA, forming Fe/Mg-carbonate apatite (Fe/Mg-CA) NPs with the ability to mitigate self-aggregation, form unique protein corona in the presence of serum and efficiently deliver doxorubicin (DOX), an anti-cancer drug into breast cancer cells. (omicsdi.org)
- In other cases, the only evidence of a flare is a laboratory test showing a low white blood cell or platelet count or protein in the urine, for example. (nih.gov)
- Notably, these pentraxins may also recruit soluble complement regulators, such as factor H (FH) and C4b-binding protein (C4BP), which in turn limit excessive complement activation on the surface ( 11 - 14 ). (frontiersin.org)
- Recently multiple groups have shown that the major adenovirus capsid protein (hexon) has a high-affinity binding site for coagulation Factor X (FX) and that FX plays a central role in the ability of Ad vectors to transduce the liver. (nih.gov)
- The FH-related (FHR) proteins share common ligands with FH, due to their homology with this complement regulator, but they lack the domains that mediate the complement inhibitory activity of FH. (frontiersin.org)
- It is C3b that binds to the surface of the particle and serves as an opsonin. (microbenotes.com)
- Here it is proposed that homeopathy is a form of protein-based immunotherapy and the immunogenic proteins exist in the microbial lysates, which are present in the homeopathic medicines. (baholafoundation.org)
- The drugs in the homeopathic medicines modulate the conformations and, in essence, the immunogenicity of the proteins present in the medicines. (baholafoundation.org)
- As compared to other crystallographic structures of free form AKs, AKmt is more compact, with the AMP(bd) domain closer to the CORE of the protein. (pasteur.fr)
- They have a red- coloured iron containing complex protein called hemoglobin. (physicscatalyst.com)
- Primary function of lymphocytes is to produce anti- bodies & opsonins . (physicscatalyst.com)
- The first member of the Angiopoietin-like protein family to be discovered. (nih.gov)
- The protein has a central CORE domain, composed of a five-stranded parallel beta-sheet surrounded by seven alpha-helices, and two peripheral domains, AMPbd and LID. (pasteur.fr)