The Department of Microbiology and Immunology is proud to announce that Regina Antonetti, Graduate Research Assistant, has been awarded a National Institutes of Health F31 NRSA Predoctoral Fellowship Award titled: "Epigenetic regulation of Plasmodium-specific CD4 T cells." Ms. Antonetti is a PhD Candidate in the Interdisciplinary Graduate Program in Immunology under the mentorship of Dr. Noah Butler from the Department of Microbiology.

Project Summary

During infection, CD4 T cells differentiate into functionally distinct subsets that position the host to fight infection and ameliorate disease. Regulation of gene expression through epigenetic programming is one way that CD4 T cells differentiate and function to provide effective protection and memory development during primary and secondary infections. During malaria, CD4 T cells, specifically T follicular helper (Tfh) cells and Type 1 helper (Th1) cells, are crucial for initiating humoral immune and cellular responses, respectively. However, CD4 T cell function and recall responses are suboptimal during Plasmodium infection, which contributes to non-sterilizing immunity to malaria. In this project, the applicant will investigate how gene expression profiles and programming of anti-malarial CD4 helper T cells are regulated by epigenetic mechanisms. The applicant’s new preliminary data show that deletion of DNA demethylases results in lack of protection against Plasmodium parasite infection and an impairment in generating a germinal center response. Despite their inability to orchestrate humoral immunity, these cells exhibit a Tfh-like phenotype. While these data demonstrate an obvious role for DNA demethylation in CD4 T cell differentiation and function, the loci that these enzymes govern and the precise molecular mechanisms that contribute to these striking phenotypes are not known. This project addresses these knowledge gaps and will utilize in vivo, ex vivo, and in vitro techniques to identify the mechanisms by which DNA demethylation governs CD4 T cell function, such as co-stimulation, cytokine production, migration, and activation. The proposed research will reveal new information about CD4 T cell biology. Aim 1 of this proposal will investigate how DNA demethylation in Plasmodium-specific CD4 T cells impacts their function. Genetically modified mice (temporal deletion of target genes) facilitates examination of cytokine production, B cell-T cell interactions, and chemotaxis. Aim 2 interrogates the role of DNA demethylases in TCR activation and signal transduction and will identify the proteins within TCR signaling pathways that are impacted. Plasmodium-specific CD4 T cells from conditional knockout mice will be examined via western blot, phospho-flow cytometry, calcium flux, and functional avidity assays. These studies will advance the field of CD4 T cell biology by revealing the epigenetic mechanisms that govern differentiation and function during infection. Successful completion of this project will engage the applicant in specialized techniques, collaboration, and scientific discussion, making the applicant well-versed in a variety of techniques and different branches of immunology and preparing for her future career in academic research.