Role of Teleost Fish B Cell Subsets in Innate and Adaptive Immunity Against Pathogens

University Of Pennsylvania, Philadelphia PA

Investigators

Abstract

B cells are responsible for antibody production in vertebrate immune systems. Recent studies in Dr. Sunyer's laboratory have produced the unexpected finding that unlike mammalian B cells, B cells in bony fish have potent phagocytic and bactericidal capacities. His lab has also found a novel B cell lineage expressing exclusively surface IgT immunoglobins. Importantly, the IgT system has been found to be specialized in mucosal immune responses. The overarching goal of this new project is to use two complementary trout-pathogen models (Yersinia ruckeri and Ceratomyxa shasta) to test whether IgT and IgM responses are compartmentalized into mucosal and systemic sites, respectively, and to analyze the specific contributions of IgT+ and IgM+ B cell subsets in the development of an innate inflammatory response during the course of infection. Rainbow trout will be infected with these two pathogens and innate and adaptive immune B cell responses will be measured during the course of infection. The responses will include the capacity of these B cells to internalize and kill the pathogens, and their ability to produce a range of pro-inflammatory and anti-inflammatory cytokines. It is expected that IgT+ B cells will play an important role in mucosal responses whereas IgM+ B cell will play a key role in systemic responses. It is expected that both B cell subsets will play a significant role in the development of pro- and anti-inflammatory responses. This project will continue the training of underrepresented minorities in this laboratory as well as the training of one postdoctoral fellow. On a broader level, the studies proposed here will benefit society by contributing to the aquaculture industry since better knowledge of the fish immune system is essential to develop new therapeutic agents and vaccines to prevent fish diseases.