FRED H. BIXBY
FELLOWSHIP PROGRAM
Mentor Research Interests

Melissa Robbiani (Pope), Ph.D.

Dendritic cells (DCs) are an important type of white blood cell* that coordinates the activation of immune responses against pathogens, including HIV. Because they are positioned at the body surfaces that HIV must cross to enter the body, DCs are critical to the earliest (innate) and later (adaptive) immune responses mounted against HIV. However, HIV is able to exploit DCs (especially those at the body surfaces), overwhelming the immune system to establish infection. Understanding the intricacies of DC–HIV interplay and how this drives HIV growth (particularly in the presence of T cells) is a major focus of our work and is critical for understanding how HIV establishes infection and developing strategies to prevent HIV spread.

• Researchers in our lab study the roles of DCs in the immune responses occurring at the body surfaces during HIV infection and how these are affected by other pathogens (e.g., HSV-2, Candida albicans) that can exacerbate HIV spread (and vice versa). Methods to boost DC function (through TLR-mediated activation) also are being tested in order to strengthen the immune responses against HIV.
• We are also exploring ways to prevent DC-driven infection through microbicides with colleagues at the Population Council as well as outside collaborators. These studies are carried out using extensive in vitro immunologic and virologic assays, as well as in vivo work in macaques. We have ongoing collaborations with researchers within the United States, Australia, Austria, Germany, and Switzerland.

* Ralph Steinman, recipient of a 2007 Lasker Medical Research Award for the discovery of DCs, http://www.laskerfoundation.org/

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