Flow Cytometry Study of T Cell Responses to HIV Vaccines

Assays for HIV-specific human CD4 and CD8 T cell immunity are needed in order to evaluate the immune response to HIV vaccines. Such assays should be robust, reproducible, and amenable to high throughput analysis of clinical specimens. Cytokine flow cytometry (CFC) assays can reliably and specifically detect human CD4 and CD8 T cell responses to AIDS-related opportunistic infections, including those caused by cytomegalovirus, Mycobacterium tuberculosis, the Mycobacterium avium complex, cryptococcus, and human papillomavirus. The purpose of this study is to devise and evaluate a similar CFC assay for the detection and quantitation of CD4 and CD8 T cell responses against HIV.

This study will evaluate a "Gag-IFNg CFC" assay by comparing the results of this assay with results from other assays of immune phenotype and function in long-term nonprogressors, untreated patients with progressive HIV disease, and recipients of candidate HIV vaccines. The study will also examine HIV-specific immune responses in HIV infected individuals who appear to exhibit significant immune protection from HIV disease.

Participants in this study will be drawn from other studies currently underway. As a part of those studies, participants will have regular blood tests. Blood samples from those studies will be used in this study. No participants will be directly enrolled in this study.