Infection of CD8+ T lymphocytes by Influenza virus

Author(s)

Brenda Cristina Vitti

• Document type: Master's Dissertation
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC)
• Defense date: 2023-09-21

Examining board members

Eurico de Arruda Neto; Renato Santana de Aguiar; Fabiani Gai Frantz

• Advisor: Eurico de Arruda Neto

Abstract

Influenza viruses are responsible for acute infections of the upper and lower respiratory tract, a disease known as the flu. Estimates indicate that millions of cases of acute respiratory disease are caused by Influenza virus infection, resulting in about 200,000 deaths annually. CD8+ T lymphocytes play a fundamental role in adaptive immunity, acting in the elimination of intracellular pathogens through the induction of apoptotic programs in infected cells, promoting viral clearance. The infection of CD8+ T lymphocytes by the Influenza virus is a surprising phenomenon and raises questions about the possible effects of this infection on the effector function of lymphocytes. Thus, through an in vitro infection model, the present study sought to better understand the characteristics and consequences of this infection in CD8+ T lymphocytes. For this, CD8+ T lymphocytes were isolated from samples of tonsils and peripheral blood by the negative selection method and then infected with the Influenza virus. The findings presented in this study reveal that tonsillar and peripheral blood-derived CD8+ T lymphocytes are susceptible to infection by the Influenza virus in vitro, but with low permissiveness. The susceptibility of CD8+ T lymphocytes to infection varies between individuals. IAV infection promotes a significant increase in the expression of cytokines IFN-α, IFN-β, IL-2, IL-6 and IL-10, which also varies in intensity according to the individual. However, changes in the expression of the T-bet transcription factor and granzyme B effector protein, important effector molecules of CD8+ T lymphocytes, are not observed. (AU)

• FAPESP's process: 21/05869-1 - Influenza virus infection of TCD8+ lymphocytes
• Grantee: Brenda Cristina Vitti
• Support Opportunities: Scholarships in Brazil - Master