Our laboratory has two main areas of research focus. The first studies the mechanisms whereby a family of oligosaccharides that are biologically conserved on viral, bacterial and parasitic worms, as well as on a number of cancers, tumors and in human milk, drive immune suppression and biasing of CD4+ T cell responses to Th2-type. The sugars belong to the Lewis family, and activate "suppressor" macrophages and B1-B cells in vivo and dendrtitic cells in vitro. Sugar elicited suppressor macrophages inhibit anti-CD3 activation of naïve CD4+ and CD8+ T cells and we are examining the suppressive mechanisms. Because these sugars drive potent anti-inflammatory and Th2-type responses, we tested their ability to prevent or treat the Th1-based autoimmune diseases psoriasis and inflammatory bowel disease and found that they prevent both diseases and also can reverse disease in animals. Treatment of human PBMCs or bronchoalveolar macrophages also suppresses HIV-1 replication, thus we are examining the mechanism by which this occurs.
The second area of interest in the lab is the development of vaccines for infectious diseases of the tropics. Our work has focused on the human helminth parasite Schistosoma mansoni. To date we have produced recombinant, synthetic peptide and DNA vaccines that are protective against challenge in vivo. DNA vaccines are currently being evaluated as veterinary anti-transmission vaccines in China. We are also involved in modifying existing HIV-1 CTL based vaccines by incorporating dendritic cell targeting proteins. Lastly, we are developing a novel anti-HIV-1 vaccine that is based on viral envelope oligosaccharides which are conserved across strains and clades, and are the targets of neutralizing monoclonal antibodies.