Effect of Fas/FasL interaction on CD8+ T cell differentiation in vitro

Author(s)

Marcela Bittar Araujo Lima

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2023-02-09

Examining board members

Joao Gustavo Pessini Amarante Mendes; Bruna Cunha de Alencar Bargieri; Alexandre de Castro Keller; Jamile Ramos da Silva

• Advisor: Joao Gustavo Pessini Amarante Mendes

Abstract

One scientific essential approach that has been central to the study of CD8 + T cell biology and role during immune responses, is the better understanding of death/survival mechanisms of these cells. During the contraction phase, death of antigen-specific T cells can be achieved by activation-induced cell death (AICD) that occurs upon ligation of Fas and FasL, both expressed by activated T cells. This interaction trimerizes Fas, resulting in the recruitment of Fas-associated death domain (FADD) adaptor protein and the caspases-8 and/or -10, creating the Death-induced signaling complex (DISC). Then, DISC activates caspase-8 or 10 that initiate a cascade leading to apoptosis. The knowledge and manipulation of death/survival mechanisms could improve T cells killing skills, optimizing cancer immunotherapies and prevention methods of virus infections. Following this idea, the project studied the effect of death/survival molecules, such as Fas and FasL, in CD8 + T cell activation and differentiation in vitro. In this study, we first standardized fresh CD8 + T cell isolation from spleens of wild-type (WT) mice and analyzed the activation, and differentiation of these cells towards the Tc0 (activation-only control), Tc1, and Tc2 subsets by Multicolor Flow Cytometry (MFC) and Real-Time Polymerase Chain Reaction (qPCR), later applying the same evaluation on FasL-deficient mice (gld). Last, we assessed Tc0, Tc1, and Tc2 activation, and differentiation betweenWT and gld mice by MFC. Our results showed that efficient isolation, activation and differentiation in both mice lineages were achieved. Overall, FasLdeficiency does not interfere with the activation, differentiation, and effector activity of CD8 + T cells. (AU)

• FAPESP's process: 20/06564-7 - Effect of Bim and Fas/FasL interaction on CD8+ T cell differentiation In vitro.
• Grantee: Marcela Bittar Araujo Lima
• Support Opportunities: Scholarships in Brazil - Master