Browsing by keyword "Genes, nef"
Now showing items 1-2 of 2
-
HIV-1-specific CD8+ T cell responses and viral evolution in women and infantsCD8+ T lymphocyte responses play an important role in controlling HIV-1 replication but escape from CD8+ T cell surveillance may limit the effectiveness of these responses. Mother-to-child transmission of CD8+ T cell escape variants may particularly affect CD8+ T cell recognition of infant HIV-1 epitopes. In this study, amino acid sequence variation in HIV-1 gag and nef was examined in five untreated mother-infant pairs to evaluate the potential role of CD8+ T cell responses in the evolution of the viral quasispecies. Several CD8+ T cell escape variants were detected in maternal plasma. Evaluation of infant plasma viruses at 1-3 mo documented heterogeneity of gag and nef gene sequences and mother-to-child transmission of CD8+ T cell escape variants. Infant HLA haplotype and viral fitness appeared to determine the stability of the escape mutants in the infant over time. Changes in CD8+ T cell epitope sequences were detected in infants' sequential plasma specimens, suggesting that infants are capable of generating virus-specific CD8+ T cell responses that exert selective pressures in vivo. Altogether, these studies document that HIV-1-specific CD8+ T cell responses contribute to the evolution of the viral quasispecies in HIV-1-infected women and their infants and may have important implications for vaccine design.
-
Silent human immunodeficiency virus type 1 infection: a rare occurrence in a high-risk heterosexual populationA group of 58 heterosexual female partners (FP) of human immunodeficiency virus type 1 (HIV-1)-seropositive hemophiliacs was studied by conventional diagnostic methods such as enzyme-linked immunosorbent assay (ELISA) and Western blot analysis to examine whether any had acquired HIV-1 infection through sexual transmission. A subset of 29 FP were asked to answer a detailed questionnaire concerning their health, use of "safer sex" techniques, and other risk factors for HIV-1 infection. They also had additional blood drawn for CD4 cell analysis, viral cultures, nef, gag, and env immunoblots, and polymerase chain reaction (PCR) analysis to assess the occurrence of "silent" HIV-1 infection in a high-risk seronegative population. Among the 58 FP, three were found to be HIV-1-seropositive on first testing, with no new seroconversions occurring with subsequent testing in the remaining 55. Two seropositive FP had the additional testing and were found to have positive viral cultures, as well as positive PCR results. All of the seronegative FP (n = 24) who had additional testing were negative in viral culture, had negative immunoblots, and had no HIV-1 nucleic acid sequences detected by PCR. Thus, in this population, silent HIV-1 infection appears to be a rare occurrence and antibody testing seems to correlate with the more sensitive techniques of PCR and viral cultures.
