Characterization of specific T follicular helper cell upon sensitization with Ovalbumin associated with different adjuvants

Abstract

T Follicular helper cells (Tfh) are a population of CD4+ T lymphocytes, essential for the generation of high affinity humoral response, since they have a unique ability to interact with B cells and promote germinal centers (CG).In CG, the interaction of Tfh with B cells leads to immunoglobulin isotype exchange, affinity maturation, and generation of memory B cells. Therefore, understanding the different signals generated by Tfh cells and their influence on the change to the different isotypes is fundamental for understanding the generation of humoral response.Therefore, in addition to the influence of classical T helper cells (Th) and their classical subtypes (Th1, Th2 and Th17) for isotype change, Tfh cells have an influence not yet fully understood.Toll-like receptor agonists (TLRs) are considered Th1/Th17 adjuvants, however it has already been shown that the addition of TLR during allergic sensitization may induce a change in antibodies production without inducing a polarization of the effector Th response.Our hypothesis is that TLR has the ability to modify the production of cytokines by Tfh cells and that these cytokines would be associated with the change of humoral response presented by the animals.Therefore, the present project aims to understand the model used in the Professor Graça´s laboratory, to determine the cytokine production profile of Tfh cells specific for OVA in different conditions of intranasal sensitization.