Research

Publications
Title: Conserved Role of mTORC1 Signaling in B Cell Immunity in Teleost Fish
First author: Cao, Jia-feng; Ding, Li-guo; Wang, Qing-chao; Han, Guang-kun; Qin, Da-cheng; Cheng, Gao-feng; Dong, Zhao-ran; Mu, Qing-jiang; Kong, Wei-guang; Liu, Xia; Yu, Yong-yao; Xu, Zhen
Journal: JOURNAL OF IMMUNOLOGY
Years: 2022
Volume / issue: /
DOI: 10.4049/jimmunol.2200280
Abstract: Mammalian studies have demonstrated that B cell immune responses are regulated by mechanistic target of rapamycin complex 1 (mTORC1) signaling. Teleost fish represent the oldest living bony vertebrates that contain bona fide B cells. So far, whether the regulatory mechanism of mTORC1 signaling in B cells occurred in teleost fish is still unknown. In this study, we developed a fish model by using rapamycin (RAPA) treatment to inhibit mTORC1 signaling and demonstrated the role of mTORC1 signaling in teleost B cells. In support, we found inhibition of mTORC1 signaling by RAPA decreased the phagocytic capacity, proliferation, and Ig production of B cells. Critically, Flavobacterium columnare induced specific IgM binding in serum, and these titers were significantly inhibited by RAPA treatment, thus decreasing Ab-mediated agglutination of F. columnare and significantly increasing the susceptibility of fish upon F. columnare reinfection. Collectively, our findings elucidated that the mTORC1 pathway is evolutionarily conserved in regulating B cell responses, thus providing a new point for understanding the B cells functions in teleost fish.