7th Conference - Abstract 389

Single-Cell Analysis of Cytokine (IL-2, IL-4, IFN-g) and Beta Chemokine (MIP-1a, MIP-1b, RANTES) Production by CD4+ (CD8-) and CD8+ T-Lymphocytes from HIV-1-Infected Long-Term Nonprogressors and Progressors

S. E. WILSON*¹, J. C. KUNICH¹, C.-W. LEE², K. SCHREIBER¹, M. PROPST¹, and H. W. SHEPPARD¹. ¹California Dept. of Hlth. Services, Berkeley, CA; and ²Sch. of Publ. Hlth., Univ. of California at Berkeley

Much evidence suggests that HIV-1 specific CD8+ CTL and secreted suppressive factors play a central role in controlling HIV-1 infection and disease progression. HIV-1 specific CD8+ CTL activity has been found to correlate with the production of IFN-g, whereas CD8+ mediated anti-viral suppressive effects are predominantly mediated by the b-chemokines RANTES, MIP-1a and MIP-1b. In this study we used intracellular staining flow cytometric methodology to investigate mitogen-induced b chemokine (RANTES, MIP-1a and MIP-1b) and cytokine (IL-2, IL-4 and IFN-g) production by CD3+ gated CD4+ (CD8-) and CD8+ T-cell subsets in healthy controls (n=11) versus HIV-1 infected long-term non-progressors (LTNP) who had stable CD4 cell counts (>415 mm³, n=11) for at least 14 years and typical progressors (TP) stratified by CD4 counts (<500, n=10; >500, n=10). Multiparametric analysis indicated that healthy controls and LTNP showed similar levels of IL-2 and MIP-a and MIP-1b production by both CD4+ and CD8+ T-cell subsets. CD8+ T-cells from LTNP produced elevated levels of IFN-g when compared to TP <500 CD4 mm³>500 and controls. In contrast, marked RANTES production occurred spontaneously in both CD4 and CD8 T-cells following culture of PBMC from controls and HIV-1 infected donors in media alone. Spontaneous RANTES levels were detectable at 6h and peaked at 24h and were significantly down-regulated following PMA-stimulation. Notably, spontaneous RANTES production by CD8+ T cells was significantly elevated in LTNP versus healthy controls.

Key Words: cellular immunity, chemokines, cytokines