In HIV infection, virus-specific CD4 T cells are preferentially infected and depleted. Surprisingly little is known about the role and functions of these cells, nor is it understood how HIV-specific CD4 T cell responses can be induced without risking an increase in viral targets. The Streeck laboratory therefore focuses on several different areas of basic CD4 T cell immunobiology and specific aspects of CD4 T cell activity that are especially relevant to HIV infection and vaccine design. In particular, we are actively pursuing the following research areas:

• Understanding the role of HIV-specific T follicular helper cells in the induction of broadly neutralizing antibodies;
• Understanding of direct cytotoxic roles of HIV-specific CD4 T cells;
• Identification of factors that influence the susceptibility of CD4 T cells to HIV infection;
• Assessment of HIV-specific CD4 T cell immunodominance patterns and HLA class II restriction; and
• Assessment of CD4 T cell mediated factors involved in enhancement of cytolytic activity of HIV-specific CD8 T cells.

Much of this work is technically challenging, and requires the creative use of innovative techniques and new technologies. Together, these project areas comprise a comprehensive program designed not only to understand the basic anti-viral functions of CD4 T cells, but also to determine the ways in which these responses can be harnessed for future vaccine design.