The role of T follicular helper cells in T helper cell fate decisions, function, and plasticity

• Applicant: Professor Dr. Dirk Baumjohann
• Subject Area: Immunology
• Term: from 2014 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 252623821

T helper (Th) cells orchestrate the cellular and humoral immune response to various pathogens. Different subsets of Th cells have been characterized based upon their functional properties. Among these, T follicular helper (Tfh) cells provide help to B cells for efficient antibody production. Not surprisingly, dysregulated Tfh cells can cause autoimmunity and allergies. Recently, Tfh cells have also emerged as central intermediaries of other Th cell-mediated immune responses that involve the generation of certain effector and memory Th cells. However, the precise relationship between Tfh and other Th cell subsets remains unknown. MicroRNAs (miRNAs) are small endogenously expressed RNAs that regulate gene expression. Importantly, there is growing evidence that miRNAs are also critical modulators of Th cell differentiation and function. The proposed studies address the central hypothesis that Tfh cells represent important constituents of both humoral and cellular immunity. We will combine cellular and molecular immunology techniques and state-of-the-art genomic approaches to answer fundamental questions about Th cell differentiation and plasticity, including the role of miRNAs and transcription factors in regulating adaptive immune responses. It is anticipated that a better understanding of how Tfh cells are regulated on the molecular level and how Tfh cells contribute to Th cell fate decisions will yield important insights into the rational design of drugs and therapies that target Tfh cells in autoimmune diseases or boost their function in vaccine settings.

• DFG Programme: Independent Junior Research Groups