Andrea Sant, Ph.D.

Our research seeks to understand the elements in vivo that dictate the selective specificities and effector functions of CD4 T cells during protective immune responses to pathogenic organisms, with a particular commitment overcoming the challenges associated with protective immunity to influenza virus. We are heavily focused on the role that CD4 T cells play in immunity to influenza virus because of the multiplicity of contributions that they make in protective immunity to influenza, including help for high affinity antibody production, enhancement of CD8 T cell expansion, function and memory, acceleration of the early innate response to infection and direct tissue localized cytotoxicity.

The influenza-specific CD4 T cell repertoire in humans is established through periodic exposures to infection and vaccination that each lead to distinct signatures of CD4 T cell memory. Our data suggests that the CD4 T cell repertoire specific for influenza viruses are highly variable in abundance, specificity and functionality. It is our hypothesis that deficits in particular subsets of CD4 T cells recruited into the response are associated with less robust or effective antibody responses and diminished protection mediated by the cellular components of the adaptive immune response. Accordingly, our laboratory seeks to develop and analyze improved strategies for human vaccination and to the development of molecular strategies to both foster protective immunity in the host and to dissect both predictors and correlates of protective immunity to vaccines and virus infections.