ABSTRACT
Analysis by radioimmunoprecipitation of serum samples from 27 different human immunodeficiency virus type 1 (HIV-1)-infected individuals residing in Chile showed that the sera of 26% of these individuals also react with glycoprotein gp125 of HIV type 2 (HIV-2). This cross-reaction seems to reflect a qualitative difference among infected individuals, because the titer of antibodies against gp120 of HIV-1 in the cross-reacting samples did not differ significantly from that in the non-cross-reacting samples. Most of the HIV-1-seropositive sera, including many that did not react with gp125 of HIV-2, reacted with gp140, the precursor of HIV-2 glycoproteins. The observed cross-reactions allowed us to distinguish three groups of HIV-1-infected individuals: (i) those whose sera react with both gp140 and gp125, (ii) those whose sera react with gp140, and (iii) those whose sera react with neither of these glycoproteins. The possible cause and significance of these differences is under study.
Subject(s)
HIV Infections/immunology , HIV-1/immunology , HIV-2/immunology , Retroviridae Proteins/immunology , Cross Reactions , Gene Products, env/immunology , Glycoproteins/immunology , Glycoproteins/isolation & purification , HIV Antibodies , Humans , Protein Precursors/immunology , Radioimmunoprecipitation Assay , Retroviridae Proteins/isolation & purification , env Gene Products, Human Immunodeficiency VirusABSTRACT
Sera of supposedly healthy blood donors were screened for the presence of anti HTLV-I p24 antibodies, and HLA typing for A, B, C and DR antigens was performed for 68 seropositive subjects and 92 seronegative controls. HLA phenotypes of the two groups were not significantly different but the level of the antibody response was related to the antigens of the HLA-B (P = 0.02) and -C loci (P = 0.003). Subjects with HLA-B12 or -B21 antigens had lower titres than the others. Subjects with HLA-Cw2 or -Cw7 antigens had higher titres than the others, but only the difference between HLA-B12 positive and negative subjects (P = 0.002) remained significant at the alpha = 0.10 level if the classical, although conservative, Bonferroni procedure was used to correct for the number of comparisons performed.
Subject(s)
HIV Seropositivity/immunology , HLA Antigens/analysis , HTLV-I Antibodies/analysis , Adult , HIV Antigens/immunology , HIV Core Protein p24 , HLA-B Antigens/analysis , HLA-C Antigens/analysis , Humans , Martinique , Retroviridae Proteins/immunologyABSTRACT
Monoclonal antibodies were raised against the gag proteins of a British isolate of the human immunodeficiency virus (HIV), CBL-1. Seven of the monoclonal antibodies recognized HIV gag-coded proteins of 55,000 mol. wt. (p55) and 24,000 mol. wt. (p24), three recognized p55/p18 and three p18 alone. Cross-competition assays suggested that at least two independent epitopes exist on the p24 cleaved from the p55 precursor, whereas a cluster of closely related epitopes was recognized by the p55/p18 and p18 antibodies. The panel of monoclonal antibodies was then used to compare by immunofluorescence the expression of gag-encoded antigenic determinants on HIV isolates from different geographical locations. Minor changes in epitope expression were observed in isolates from the U.S.A. and Haiti with the most notable changes being detected in isolates from Zaire, Tanzania and Uganda.