Immunocharacterization of cytotoxic and regulatory T lymphocytes in oral and oropharyngeal squamous cell carcinoma associated or not with human papillomavirus

• Grant number: 20/05780-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2020
• End date: May 31, 2021
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Jorge Esquiche León
• Grantee: Thalia Carvalho de Almeida dos Santos
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The squamous cell carcinoma (SCC) of the head and neck region (HNSCC) represents a serious problem in public health, due to its high incidence and risk of mortality. Oral SCC (OSCC) is related to smoking and drinking; while oropharyngeal SCC (OPSCC) shows a frequent association with human papillomavirus (HPV) infection. Several studies show that the prognosis of OPSCC is better than OSCC; and still, relevantly, OPSCC HPV + has a better prognosis than OPSCC HPV-. However, its cellular and/ or molecular mechanisms, including the participation of HPV, are not well understood. The immunological mechanisms in the tumor microenvironment, emphasizing the relationship between carcinogenic and immune cells, can help in understanding the pathogenesis of these tumors. In this context, regulatory T lymphocytes (Tregs) are cells that regulate immune tolerance and modulate immunosuppressive responses, while cytotoxic T lymphocytes (CTLs) are considered effector cells with antitumoral and antiviral properties. Thus, understanding the balance between Tregs and CTLs in OSCC and OPSCC is essential. The purpose of this work is to evaluate by immunohistochemistry and in situ hybridization, the balance between Tregs and CTLs in OSCC (n= 20; 10 HPV + and 10 HPV-) and OPSCC (n= 20; 10 HPV + and 10 HPV-), aiming to understand the participation of the adaptive immune system in the pathogenesis of these tumors and to establish clinic pathological correlations.