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  • Proteins
  • Variation in R5 Env proteins can also influence the ability of a virus to utilize various levels of CD4 and CCR5 found on different cell types, such as macrophages and T cells ( 23 , 25 , 64 , 67 , 89 , 95 ). (pubmedcentralcanada.ca)
  • Four classes of membrane proteins are known in virus and cell fusion. (nih.gov)
  • Class I virus-cell fusion proteins (fusogens) are α-helix-rich prefusion trimers that form coiled-coil structures that insert hydrophobic fusion peptides or loops (FPs or FLs) into membranes and refold into postfusion trimers. (nih.gov)
  • Serum adsorptions with recombinant Env proteins. (nih.gov)
  • The term IA antigens used to refer only to the proteins encoded by the IA genes in the mouse, but is now used as a generic term for any class II histocompatibility antigen. (healthmatics.info)
  • Its identification may point to functionally important regions of a gene and is thus of potential interest to protein engineers who alter proteins to produce new functions. (genetics.org)
  • The following five Env proteins were used: trimeric SF162 gp140 (open circles), trimeric ΔV2 gp140 (filled triangles), monomeric ΔV2 gp140 (filled circles), monomeric SF162 gp120 (filled squares), and HxB2 gp41 (open inverted triangles). (nih.gov)
  • HIV-1 Env gp140 (native or uncleaved molecules) or gp120 monomeric proteins elicit relatively poor B-cell responses which are short-lived. (duke.edu)
  • gp120
  • We demonstrate that an HIV-1 variant containing a G367R substitution within the CD4 binding site of gp120 was non-infectious as free virus in culture but was infectious when infected cells were co-cultured with certain T cell lines or when cells were transfected by a relevant proviral plasmid. (nih.gov)
  • The human immunodeficiency virus type 1 (HIV-1) glycoprotein gp160 is processed into the transmembrane subunit (TM) gp41 and the nonconvalently linked gp120 glycoprotein, which binds to the CD4 receptor and chemokine coreceptor molecules. (asm.org)
  • Previous studies in which this cytoplasmic tail had been deleted partially or entirely have suggested that it is important for virus infectivity and incorporation of the gp120-gp41 glycoprotein complex into virions. (asm.org)
  • Only one anti-gp120 MAb (an anti-V3 MAb) displayed cross-neutralizing activity, which was influenced by the type of V1 loop present on the target heterologous viruses. (nih.gov)
  • glycoprotein
  • During synthesis and export of protein, the majority of the human immunodeficiency virus type 1 (HIV-1) Env glycoprotein gp160 is retained in the endoplasmic reticulum (ER) and subsequently ubiquitinated and degraded by proteasomes. (asm.org)
  • To prove that these two elements act similarly in the homologous context of the Env glycoprotein, we generated a synthetic gp160 gene with synonymous codons, the transcripts of which are not retained within the nucleus. (asm.org)
  • Previous studies demonstrated that the majority of the Env glycoprotein is intracellularly retained and remains endoglycosidase H (Endo H) sensitive ( 31 , 32 , 53 , 69 ). (asm.org)
  • Glycoprotein surface expression, however, not only depends on ER-mediated quality control and the retention of misfolded or disassembled Env in the ER but also involves subsequent steps, including Golgi export and internalization of surface-expressed Env ( 58 ). (asm.org)
  • The transmembrane (TM) glycoprotein gp41 of human immunodeficiency virus type 1 possesses an unusually long (∼150 amino acids) and highly conserved cytoplasmic region. (asm.org)
  • Substitution of the arginines (residues 839 and 846) with glutamates also reduced infectivity, but without a noticeable decrease in the amount of glycoprotein incorporated into virus produced from infected T cells. (asm.org)
  • The decreased infectivity of mutants with truncated cytoplasmic tail regions was postulated to be due in some cases to reduced glycoprotein incorporation into virus particles ( 12 , 38 ). (asm.org)
  • Interferon-γ enzyme-linked immunosorbent spot assay Responses to Env Following DNA/ polylactide coglycolide (PLG) Priming and Oligomeric, V2-deleted Glycoprotein Boosting. (nih.gov)
  • This demonstrates that receptor binding to the outer envelope glycoprotein induces certain conformational changes which are common to all of these viruses and others which are restricted to cell line-passaged isolates of HIV-1. (ox.ac.uk)
  • infectivity
  • Differences in viral infectivity by cell-associated G367R viruses were determined by the type of target cell employed, regardless which type of donor cell was used. (nih.gov)
  • With the exception of a mutation deleting amino acids QGL, all of the constructs resulted in decreased infectivity of the progeny virus both in a single-round infectivity assay and in a multiple-infection assay in H9 and CEM×174 cells. (asm.org)
  • subpopulations
  • Our results suggest that the HIV-1 env subpopulations detectable in the peripheral blood are produced by cells with similar life spans and are not genetically isolated within particular cell types. (pubmedcentralcanada.ca)
  • The frequency of utilization of the different V H gene families (upper panel), D H (middle) and J H (lower) gene families across the different B cell subpopulations (indicated above pie charts) is shown. (nih.gov)
  • Sera
  • Sera from rabbits primed with the HXB-2 Env DNA were, for the most part, type-specific for neutralization of IIIb. (umassmed.edu)
  • Nucleic Acid
  • Viruses have evolved by borrowing and modifying cellular genes to become extremely efficient at nucleic acid delivery to different cell types, avoiding at the same time immunosurveillance by an infected host. (news-medical.net)
  • type
  • The ability of HIV containing an env G367R mutation in cell-free and cell-associated viruses to cause infection and to revert to wild-type was measured using several T cell lines. (nih.gov)
  • G367R, that can compromise infection by cell-free virus but less severely by cell-associated virus and that does so in a cell type-dependent manner. (nih.gov)
  • Infection with human immunodeficiency virus type 1 (HIV-1) is typically established by one or a few variants that give rise to an initially homogeneous viral population ( 12 , 19 , 38 , 45 ). (pubmedcentralcanada.ca)
  • These concepts became more sharply focused with the identification of the human immunodeficiency virus type 1 (HIV-1) and the recognition that it can infect a critical cell involved in the regulation of the immune response of humans, namely, the CD4 + T lymphocyte. (springer.com)
  • NB100-64802 does not recognize Feline Leukaemia Virus (FeLV), Feline Herpes Virus (FHV) type 1, Feline Coronavirus or Feline Calicivirus. (novusbio.com)
  • Neutralizing
  • HIV-1 envelopes from two series of primary isolates (from Swedish patients 5 and 6), from JR-FL and BaL (prototypic monocyte/macrophage tropic viruses) and from HXB-2 (a prototypic T-cell-line-adapted virus), have been screened for their ability to elicit neutralizing antibody to HIV-1. (umassmed.edu)
  • Our results highlight the low immunogenic potential of the HIV-1 Env and demonstrate that different Envs have different potentials to raise low titer neutralizing antibody. (umassmed.edu)
  • cells
  • Mutations in the env gene of HIV may be able to exert a differential influence on viral transmission ability in regard to cell-free and cell-associated viral forms.The persistence of defective forms can potentially lead to the emergence of virulent forms.The heterogeneity of cell types that constitute the HIV reservoir can contribute to viral variability, even among similar types of cells. (nih.gov)
  • p24 production in MT2, MT4 and SupT1 cells after infection by G367R virus that had been pseudotyped with VSV-G viruses in the presence of IL2, PMA or ionomycin. (nih.gov)
  • Contrary to expectations, we found that IL2 was able to inhibit the reversion of G367R virus in MT2 cells at the same concentration used to maintain T lymphocyte growth (Figure 6a) without affecting cell viability, while it only slightly inhibited cell-free wt HIV by about 2 fold (data not shown). (nih.gov)
  • Again, there was no growth or reversion of G367R in MT4 cells, suggesting that a different mechanism of reversion of G367R may be involved in different cells.However, PMA and ionomycin inhibited the reversion of G367R virus in both MT2 and SupT1 cells (Figure 6b). (nih.gov)
  • Using heteroduplex tracking assays targeting the highly variable V3 or V4-V5 regions of the HIV-1 env gene in eight subjects, we found that all detectable coexisting HIV-1 variants in the peripheral blood generally decayed at similar rates during the initiation of HAART, suggesting that all of the variants were produced by cells with similar life spans. (pubmedcentralcanada.ca)
  • Single human B cells were sorted from bone marrow and periphery of humanized NOD/SCID γc(null) (hNSG) mice at 8-10 months post engraftment with human cord blood-derived CD34(+) stem cells. (nih.gov)
  • Earlier studies focused on the direct infection of CD4 + cells by HIV-1 as the primary mechanism underlying the pathogenesis of the acquired immunodeficiency syndrome (AIDS). (springer.com)
  • We hypothesized that Env engagement of the CD4 receptor on T-helper cells results in anergic effects on T-cell recruitment and consequently a lack of strong, robust, and durable B-memory responses. (duke.edu)
  • responses
  • Env responses are shown at 2 weeks following the completion of DNA/PLG priming (day 70) and 2 weeks after receipt of the first and second protein boosts (days 182 and 287, respectively). (nih.gov)
  • exposure
  • The percentage of the CD3 + /CD4 + population expressing either cytokine following exposure to Env peptides is depicted. (nih.gov)
  • For human populations, candidates include genes mediating adaptations to UV exposure or pathogens, such as malaria. (genetics.org)
  • Variation
  • In applying this test to several thousand human-chimpanzee gene orthologs, I show that such variation clusters are not generally caused by relaxed selection. (genetics.org)
  • mice
  • Human B-cell ontogeny in humanized NOD/SCID γc(null) mice generates a diverse yet auto/poly- and HIV-1-reactive antibody repertoire. (nih.gov)
  • Sorting criteria of human B cell subsets from humanized NOD/SCID γc null (hNSG) mice. (nih.gov)
  • Analysis of the human immunoglobulin V H repertoire in hNSG mice. (nih.gov)
  • leukocyte antigen
  • Although there is mounting evidence that these escape pathways are broadly consistent among individuals with similar human leukocyte antigen (HLA) class I alleles, previous population-based studies have been limited by the inability to simultaneously account for HIV codon covariation, linkage disequilibrium among HLA alleles, and the confounding effects of HIV phylogeny when attempting to identify HLA-associated viral evolution. (ox.ac.uk)
  • synonymous
  • Specifically, the ratio N / S of the number of nonsynonymous ( N ) to synonymous ( S ) changes per gene, or the ratio K a / K s of the fraction of nonsynonymous ( K a ) to synonymous changes ( K s ) per nonsynonymous and synonymous site, can give an indication of positive selection. (genetics.org)