HIV type 2 gp36 [GST]

Human immunodeficiency virus type 1 (HIV-1) transmembrane glycoprotein 41 (gp41) contains an immunosuppressive domain (Env amino acids 583-599). Previous studies by us and others using recombinant soluble gp41 (rsgp41; amino acids 539-684) and immunosuppressive peptide (1SP; a gp41 peptide, amino acids 583-599) have shown that HIV-1 gp41 by the immunosuppressive domain could bind to several proteins on human T, B and monocyte cell lines, and also to normal human peripheral blood mononuclear cells. In this study we demonstrated that HIV-1 rsgp41 could inhibit spontaneous cell proliferation of human T cell lines H9 and Jurkat, B cell lines Raji and Daudi, monocyte cell line U937, but could not inhibit cell proliferation of human fibroblast cell line HEF and green monkey kidney cell line Cos-1. HIV-1 rsgp41 could inhibit also concanavalin A (Con A)-, phytohaemagglutinin (PHA)- and tetanus toroid (TT)-induced cell proliferation of normal human peripheral blood lymphocytes, with 50% inhibition at a concentration of 8 mu M, but could not inhibit pokeweed mitogen (PWM)-induced lymphocyte proliferation. Furthermore, recombinant soluble gp36 of HIV-2 like HIV-1 rsgp41 could inhibit Con A-, but not PWM-induced lymphocyte proliferation. These results indicate that HIV-1 gp41-induced inhibition of proliferation is selective in so far as the effect of PWM is not altered while the effects of several other stimuli are.

The HIV/AIDS pandemic is primarily caused by HIV-1. Another virus type, HIV-2, is found mainly in West African countries. We hypothesized that population migration and mobility in Africa may have facilitated the introduction and spreading of HIV-2 in Mozambique. The presence of HIV-2 has important implications for diagnosis and choice of treatment of HIV infection. Hence, the aim of this study was to estimate the prevalence of HIV-2 infection and its genotype in Maputo, Mozambique. HIV-infected individuals (N = 1,200) were consecutively enrolled and screened for IgG antibodies against HIV-1 gp41 and HIV-2 gp36 using peptide-based enzyme immunoassays (pepEIA). Specimens showing reactivity on the HIV-2 pepEIA were further tested using the INNO-LIA immunoblot assay and HIV-2 PCR targeting RT and PR genes. Subtype analysis of HIV-2 was based on the protease gene. After screening with HIV-2 pepEIA 1,168 were non-reactive and 32 were reactive to HIV-2 gp36 peptide. Of this total, 30 specimens were simultaneously reactive to gp41 and gp36 pepEIA while two samples reacted solely to gp36 peptide. Only three specimens containing antibodies against gp36 and gp105 on the INNO-LIA immunoblot assay were found to be positive by PCR to HIV-2 subtype A. The proportion of HIV-2 in Maputo City was 0.25% (90%CI 0.01-0.49). The HIV epidemic in Southern Mozambique is driven by HIV-1, with HIV-2 also circulating at a marginal rate. Surveillance program need to improve HIV-2 diagnosis and consider periodical survey aiming to monitor HIV-2 prevalence in the country.