Quantification of HIV-1-specific T-cell responses at the mucosal cervicovaginal surface

Objective: To characterize HIV-1 specific cellular immune responses at muco sal surfaces using a rapid, sensitive enzyme-linked immune-spot (ELISPOT) t echnique. Design: Cervicovaginal mononuclear cells obtained from cytobrush and cervic ovaginal ravage were assessed for production of interferon-gamma (IFN-gamma ) in response to stimulation by HIV-1 antigens. HIV-1 specific responses we re compared in a cross-sectional study of two HIV-l-positive patient groups : women not currently on antiretroviral therapy with peripheral CD4 cell co unts >250 x 10(6)/l (n=12); and women on highly active antiretroviral thera py (HAART) (n = 9). Methods: Mononuclear cells from peripheral blood or cervicovaginal specimen s were assessed in an ELISPOT assay for responses to HIV-1 antigens express ed by recombinant vaccinia viruses. This assay detects primarily CD8 T cell s and shows good correlation with MHC class I tetramer staining of cytotoxi c T lymphocytes. Results: HIV-1 specific IFN-gamma spot-forming cells were detected in cervi covaginal samples of one out of nine women (11%) on HAART and five out of 1 2 women (42%) not currently on HAART. In peripheral blood mononuclear cells , HIV-1 specific IFN-gamma spot-forming cells were significantly more numer ous in women not currently on HAART than in women on HAART (P = 0.009). In most cases, antigens recognized by mucosal T cells were also recognized by PBMC; however, there were exceptions. Conclusions: HIV-l-specific antigen-reactive T cells may be detected in rou tine, noninvasive gynecological specimens. The results suggest that cervico vaginal HIV-1-specific T cells may be less numerous in individuals on HAART than in those not on HAART, as shown previously for HIV-l-specific cytotox ic T lymphocytes in the peripheral blood. (C) 2000 Lippincott Williams & Wi lkins.