B-1 cells role in the differentiation, proliferation and suppressor activity of regulatory T cells

• Grant number: 14/14506-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2014
• End date: July 31, 2015
• Field of knowledge: Biological Sciences - Immunology - Cellular Immunology
• Principal Investigator: Mario Mariano
• Grantee: Karina Alcantara de Lima
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

Studies have shown that B-1 cells, the major B cells population in pleural and peritoneal cavity, play a role in immune systems cells regulation, in particular macrophages and both effector and regulatory (reg) T cells. Furthermore, Xid mice (B-1 cells- deficient mice), are more susceptible to infections disease, suggesting a down-regulation of effectors cells by B-1 cells. Preliminary data obtained in our laboratory demonstrated that Xid mice show a lower number of T cells in the peritoneal cavity and when B-1 cells are transferred to these mice, the number of Treg cells increases. This study aims to investigate the involvement of B-1 cells in the differentiation, proliferation and suppressor activity of Treg cells. For this purpose, cells populations of peritoneal cavity, spleen and thymus of BALB/c (WT) and BALB/Xid mice are analyzed, by flow citometry. In vitro, differentiation and proliferation assays are performed with purified naïve T cells from spleen of WT and Xid mice, in the presence or absence of B-1 cells purified from peritoneal cavity of WT mice. Also, suppression and proliferation assays are performed with Treg cells generate in vitro or obtained ex vivo. All of the results are evaluated by two-way ANOVA, with superior 95% reliability.