CD8+ T-Cell Gamma Interferon Production Specific for Human Immunodeficiency Virus Type 1 (HIV-1) in HIV-1-Infected Subjects

摘要

The CD8+-T-cell response to human immunodeficiency virus type 1 (HIV-1) is considered to be important in host control of infection and prevention of AIDS. We have developed a single-cell enzyme immunoassay (enzyme-linked immunospot assay) specific for gamma interferon (IFN-γ) production stimulated by either autologous B-lymphoblastoid cell lines (B-LCL) infected with vaccinia virus vectors expressing HIV-1 proteins or synthetic peptides representing known HIV-1 CD8+ cytotoxic T-lymphocyte (CTL) epitopes. Single-cell IFN-γ production stimulated by HIV-1 Gag-, Pol-, and Env-expressing B-LCL was a reliable measure of HIV-1-specific T-cell immunity in peripheral blood CD8+ T cells from HIV-1 infected individuals. This method was more sensitive than stimulation of IFN-γ by direct infection of the cultures with HIV-1–vaccinia virus vectors. Comparable results were found for IFN-γ production in CD8+ T cells from HIV-1-negative, cytomegalovirus (CMV)-seropositive, healthy donors stimulated with B-LCL expressing the CMV pp65 lower matrix protein. HIV-1 peptides were immunodominant for both CD8+ single-cell IFN-γ production and CTL precursor frequencies. The number of cells producing IFN-γ decreased in individuals with late-stage HIV-1 infection and was temporally enhanced during combination antiretroviral therapy with two reverse transcriptase nucleoside inhibitors and a protease inhibitor.