Acquired Immunodeficiency Syndrome: Cohen S

Chien PC, Chen D, Chen PD, Tuen M, Cohen S, Migueles SA, Connors M, Rosenberg E, Malhotra U, Gonzalez C, Hioe CE. · Department of Pathology, New York University School of Medicine, and Veterans Affairs New York Harbor Healthcare System, New York, New York 10010, USA. · J Infect Dis. · Pubmed #14976603 No free full text.

Abstract: BACKGROUND: Antibodies to the CD4-binding domain (CD4bd) of human immunodeficiency virus type 1 (HIV-1) glycoprotein 120 (gp120) inhibit gp120 antigen presentation to CD4 T cells. These findings imply that the presence of anti-CD4bd antibodies might contribute to the dearth of envelope-specific T helper responses observed in most HIV-1-positive patients. In the absence of these antibodies, however, anti-envelope T helper responses might be maintained. METHODS: We used ELISA to evaluate the levels of anti-CD4bd antibodies in rare HIV-1-positive patients who exhibit envelope-specific lymphoproliferation. Subsequently, we examined the contribution of anti-CD4bd antibodies to disease progression by comparing anti-CD4bd antibody levels in 3 cohorts of HIV-1-positive patients with distinct rates of disease progression. RESULTS: Although most HIV-1-positive individuals produce anti-CD4bd antibodies, 77% of patients with envelope-specific lymphoproliferation have undetectable anti-CD4bd antibody levels. Moreover, comparison of the 3 HIV-1-positive cohorts revealed that individuals with long-term nonprogression have significantly lower anti-CD4bd antibody titers than do those with rapid or slow progression. Unlike immunoglobulin G (IgG) from rapid progressors, IgG from nonprogressors had no suppressive effects on glycoprotein (gp) 120-specific T cell proliferation. CONCLUSIONS: Low anti-CD4bd antibody levels are associated with the absence of disease progression. A number of HIV-1-positive individuals without these antibodies also appear to sustain gp120-specific T helper responses needed to help control the infection.

Cohen S, Tuen M, Hioe CE. · Veteran Affairs New York Harbor Healthcare System and Department of Pathology, New York University School of Medicine, New York, New York 10010, USA. · AIDS Res Hum Retroviruses. · Pubmed #14585210 No free full text.

Abstract: HIV-specific CD4+ T cell responses, in particular to the HIV envelope antigen gp120, are often undetectable in the peripheral blood of HIV-infected individuals. The failure to detect these cells poses a significant impediment to studying the T cell populations that are considered to be essential for controlling HIV infection and has led to speculation that these cells are entirely depleted during HIV infection. This study was designed to test whether gp120-specific CD4+ T cells exist in HIV-infected subjects and can be expanded from peripheral blood mononuclear cells by in vitro stimulation with the gp120 antigen, allowing better characterization of these cells. Although gp120-specific T cell responses were barely observed in patient cells ex vivo before antigenic stimulation, CD4+ T cells specific for gp120 were successfully propagated from the blood of each asymptomatic chronically HIV-infected subject studied. The dominant epitopes recognized by gp120-specific CD4+ T cells from these HIV-infected subjects were mapped to well-conserved sites in the C1 and C2 domains of gp120. Two CD4+ T cell lines recognizing these two regions were subsequently established. The CD4+ T cell lines proliferated and produced interferon gamma in response to the specific epitopes, and the responses were MHC class II restricted. These T cell lines also exhibited cross-reactivity with gp120 from T cell line-adapted HIV-1 strains IIIB and MN, as well as with gp120 from primary isolates SF33 (subtype B), CA1 (subtype A), and CA10 (subtype A/E). The data demonstrate that CD4+ T cells specific for gp120 are not entirely depleted from the peripheral blood of chronically HIV-infected subjects; these cells are present in low numbers but can be expanded after antigenic stimulation in vitro.

DuMont KA, Rapkin BD, Smith MY, Correa A, Palmer S, Cohen S. · Department of Psychology, New York University, New York 10003, USA. · Am J Community Psychol. · Pubmed #10234803 No free full text.

Abstract: This study evaluates the relationship between the social climate from different services and the personal goal-directed activities of 224 individuals with AIDS. The study's results supported the main hypothesis that "recipient" and "participatory" service involvement uniquely influence personal goal-directed activities, even after considering individuals with AIDS' physical symptoms, psychological distress, income, and recruitment site. Income and involvement with participatory services were both positively related to the amount of personal goal-directed activity. Longitudinal analyses suggest that personal initiative contributes to the subsequent amount of personal goal-directed activities a person pursues. These results suggest further examination of factors contributing to the selection of different service types and of the processes underlying the relationship between participatory services and positive outcomes for clients with AIDS.