The major focus of the Division of Immunology is AIDS-related research, including AIDS pathogenesis, analysis of mechanisms of protective immunity induced by SIV vaccines, and the development of new immune-based therapeutic strategies for AIDS. In addition, the Division conducts research on basic topics in immunology such as T cell turnover and hematopoietic stem cells.

Analysis of protective immunity in macaques immunized with live attenuated SIV strains, one of the most effective vaccine approaches in primates, has evolved as a leading experimental model in which to study protective immunity against primate lentiviruses. Prior publications from our laboratory have demonstrated that attenuated SIV vaccines are able to induce vigorous and durable cellular immune responses and to protect against mucosal challenge. Ongoing research is focused on defining the role of CD8+ and CD4+ T cell responses in protective immunity and analyzing mucosal immune responses induced by attenuated SIV.

Genetic modification of hematopoietic stem cells has the potential to provide effective treatments for a variety of diseases, including AIDS. Studies in nonhuman primates offer a valuable opportunity to test and refine approaches to introduce genes into hematopoietic stem cells prior to human clinical trials. Notable accomplishments of our research effort over the past several years include establishment of an in vitro system to support T cell differentiation, the first demonstration that introduction of viral inhibitory genes into CD34+ hematopoietic cells can block HIV or SIV replication in T cells derived from transduced cells, and identification of a previously unrecognized CD34 - negative hematopoietic stem cell population in macaques. Current research is analyzing the ability of novel vectors and inhibitory genes to protect CD4+ T cells and macrophages from viral infection in monkeys.