AEGiS-15IAC: Maintenance of CD4+ T help in HIV-2 infected Senegalese patients.

15th International AIDS Conference

Bangkok, Thailand - July 11-16, 2004

Maintenance of CD4+ T help in HIV-2 infected Senegalese patients.

Int Conf AIDS 2004 Jul 11-16; 15:(abstract no. MoOrA1004)

Zheng NN, Kiviat NB, Sow SP, Diall-Agne H, Robinson AD, McElrath MJ
University of Washington, Seattle, United States

BACKGROUND: Virus-specific CD4+ T helper cells are important in generating functional CD8+ T cell memory. HIV-2 infection is typically less virulent than HIV-1 infection, possibly permitting the host to mount a more effective, sustained T cell immune response. Our previous study in a cohort of HIV-2 infected individuals in Senegal showed that 48% of them had HIV-2-specific, Interferon-gamma (IFN-γ)-secreting CD4+ T cells. By contrast, HIV-1-specific CD4+ T cell help was uncommonly detected in HIV-1 infection. In this study we further investigated the T helper profiles in these Senegalese patients.

METHODS: PBMC were isolated from anticoagulated blood from 9 HIV-2 infected individuals and stimulated for 6 hour with HIV-2 15-mers, either singly or in pools, subsequently treated with brefeldin A, and then reacted with fluorescent mAb for intracellular cytokine staining. IFN-γ, IL-2 and TNF-a production was measured in CD3+CD4+ and CD3+CD8+ cells by seven-color flow cytometry using a LSRII cytometer.

RESULTS: HIV-2-specific CD8+ and CD4+ IFN-γ-secreting T cells were detected in 9 and 8 individuals, respectively. The CD4+ helper responses, primarily specific for HIV-2 Gag, included both IFN-γ and IL-2 secretion in 5 of the 8 patients, and secretion of both cytokines by the same cells was commonly observed. In addition, distinct cytokine profiles were noted upon stimulation with SEB, with higher frequencies of IL-2 in all HIV-2 infected patients.

CONCLUSIONS: Patients with HIV-2 infection are more likely to maintain CD4+ T helper function than those with HIV-1 infection. In addition, preservation of IL-2 as well as IFN-γ secretion occurs in HIV-2 infection. Further studies are needed to determine if the broader functional helper profile is associated with improved clinical disease.

Keywords: AEGIS, HIV-2, Antigens, CD4, Tumor Necrosis Factors, HIV-1, CD4-Positive T-Lymphocytes, HIV Infections, Interleukin-2, CD8-Positive T-Lymphocytes, Antigens, CD8, Interferon Type II, T-Lymphocytes, T-Lymphocytes, Helper-Inducer, Cytokines, Senegal, Humans, immunology

040711
MoOrA1004