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HIV-Specific CD4+ T Cells Are Maintained in Untreated Patients with or without Proliferative Responses to HIV Antigens A. C. MCNEIL*, W. L. SHUPERT, J. A. MICAN, and M. CONNORS. NIAID/NIH, Bethesda, MD The HIV specific CD4+ T cell response was investigated in two cohorts of patients with similar CD4+ T cell counts. Group A (n=14) includes a unique cohort of long term non-progressors (LTNP) with strong proliferative responses to p24 antigen and less than 1000 copies of viral RNA/ml plasma. Group B includes a cohort of patients with similar CD4+ T cell counts but without significant proliferative responses to p24 antigen. CD4+ T cell responses to p55, p24, p17, and gp160 antigens were studied by conventional proliferation assays and flow cytometric detection of intracellular IFN-g and IL-2. Group A had very high levels of proliferation to p55(Dcpm 1,797-34,671) and p24(Dcpm 2,586-57,803) and p17(124-6,630). No significant proliferation was observed in Group B to p55, p24, or p17. No significant proliferation to gp160 was found in either group. The frequency of antigen specific memory CD4+ T cells in Group A was not significantly higher than those in Group B for either p55(0.21 vs 0.12, p=0.23) or p24(0.15 vs 0.07, p=0.07). In many cases similar frequencies of antigen specific CD4+ T cells were observed in patients in Group A with proliferative responses as those in Group B without proliferative responses. These data indicate that HIV specific CD4+ T cells are maintained even in patients with similar CD4+ T cell counts without proliferative responses to HIV antigens. Further, they suggest the early loss of proliferative responses occurs by mechanisms that suppress such responses rather than by deletion of antigen specific CD4+. Key Words: cytokine, non-progressor, proliferation |
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© 7th
Conference on Retroviruses and Opportunistic Infections, |