Th1/Th2 shift in HIV lymph nodes: no contribution of CD6o cells

An expansion of CD8+60+ cells with Th2 type helper function has been observed in HIV-infected individuals. A Th1/Th2 shift in late HIV infection might be related to the functional activity of this subset. Our objective was to test the ability of lymph node (LN) lymphocytes to produce cytokines of the Th1 and Th2 type.

LN cells were stimulated with PMA in the presence of ionomycin and brefeldin A. After surface staining for CD4, CD8 and CD60 and intracellular staining for interferon gamma (IFNgamma), interleukin 2 (IL-2) or IL-4 and IL-10, the percentage of cytokine producing lymphocytes (CPL) was determined by flow cytometry. LN of nine individuals in the early stage of HIV infection were compared to late stage patients.

CD4+ subset: in early stages of HIV infection the percentage of Th1 CPL was 1.9 times higher than that of Th2 CPL. In late stages of infection the Th1 responding cells were not found more frequently than Th2 ceLLs. CD8+ subset: no Th1/Th2 shift was detected during early or late stages of HIV infection. CD60+ subset: a maximum of 32.1 +/- 7.8% of double positive cells of the CD8+60+ type produced Th2 type cytokines. A small percentage (< 8%) of CD60+ cells also produced Th1 cytokines. No shift in the cytokine production was seen in early or late stages of infection.

At single cell level a shift in cytokine production in LN cells can only be detected in the CD4+ subset. Thus, the CD60+ subset does not seem to contribute to the putative Th1/Th2 shift attributed to the immunopathogenesis of HIV-induced destruction of the immune system.