Williams, Amanda

Abstract We identified the lowest composition necessary to generate a vaccination adjuvant that promotes a Treg response following immunization in mice and named it “complete tolerogenic adjuvant.” This novel adjuvant may allow us to utilize the well-established “antigen plus adjuvant” method of vaccination to induce Treg cell-mediated antigen-specific immunosuppression. The minimal composition is dexamethasone, rapamycin, and monophosphoryl lipid A with the following mass ratios: 8:20:3. We have demonstrated why immunosuppressive and immunogenic substances are both required for the formation of genuine adjuvants for Treg cells by dissecting the roles of each of these components during vaccination. Currently, research is ongoing in our group to begin to assess the usefulness of this adjuvant for antigen immunization in murine models of human autoimmune/inflammatory diseases. Specifically, we are evaluating the tolerogenic efficacy of this adjuvant for vaccination regimen targeting the apolipoprotein B antigen, using the ApoE−/− mouse model of atherosclerosis. These studies are expected to help drive the development of further, perhaps more effective, complete tolerogenic adjuvants that could be used to create a plethora of new, novel vaccines for treating immunological illnesses. Master program and NIH grant

Our understanding of tissue-resident memory T (T RM ) cell biology has been largely developed from acute infection models in which antigen is cleared and sterilizing immunity is achieved. Less is known about T RM cells in the context of chronic antigen persistence and inflammation. We investigated factors that underlie T RM maintenance in a kidney transplantation model in which T RM cells drive rejection. In contrast to acute infection, we found that T RM cells declined markedly in the absence of cognate antigen, antigen presentation, or antigen sensing by the T cells. Depletion of graft-infiltrating dendritic cells or interruption of antigen presentation after T RM cells were established was sufficient to disrupt T RM maintenance and reduce allograft pathology. Likewise, removal of IL-15 transpresentation or of the IL-15 receptor on T cells during T RM maintenance led to a decline in T RM cells, and IL-15 receptor blockade prevented chronic rejection. Therefore, antigen and IL-15 presented by dendritic cells play nonredundant key roles in CD8 T RM cell maintenance in settings of antigen persistence and inflammation. These findings provide insights that could lead to improved treatment of chronic transplant rejection and autoimmunity.