Cd79a, also known as Igα, is a crucial signaling component of the preB cell receptor (preBCR) [1]. The BCR, composed of surface-bound Ig and a heterodimeric signaling unit of CD79A and CD79B, is essential for B cell development, function, and survival signals like tonic signaling. It is involved in pathways related to B cell activation and differentiation [3].

In a Cd79a-Cre;Tsc1ff mouse model (Cd79a-Tsc1 KO), Cre-mediated Tsc1 depletion driven by the Cd79a promoter activated mTORC1 exclusively along the distal nephron from embryonic day 16. Cysts appeared in the distal nephron at 1 week of age, and mice developed definite polycystic kidney disease (PKD) by 4 weeks. This shows that Cd79a-driven mTORC1 overactivation in developing distal tubules disrupts morphogenesis, which may be essential for cystogenesis [2]. In pediatric B-cell precursor acute lymphoblastic leukemia, down-regulation of CD79a in murine xenograft models hampers the engraftment of leukemia cells, especially in the central nervous system (CNS), indicating its role in CNS-infiltration and-relapse [1].

In conclusion, Cd79a is vital for B cell-related functions and is involved in important biological processes. Mouse models such as the Cd79a-Tsc1 KO and murine xenograft models with CD79a down-regulation have revealed its role in PKD and pediatric B-cell precursor acute lymphoblastic leukemia, respectively. These models contribute to understanding the mechanisms of related diseases and may provide directions for treatment strategies.

References:

1. Lenk, Lennart, Carlet, Michela, Vogiatzi, Fotini, Alsadeq, Ameera, Schewe, Denis M. 2021. CD79a promotes CNS-infiltration and leukemia engraftment in pediatric B-cell precursor acute lymphoblastic leukemia. In Communications biology, 4, 73. doi:10.1038/s42003-020-01591-z. https://pubmed.ncbi.nlm.nih.gov/33452446/

2. Tran Nguyen Truc, Linh, Matsuda, Satoshi, Takenouchi, Akiko, Yoshizawa, Katsuhiko, Tsukaguchi, Hiroyasu. 2023. Mechanism of cystogenesis by Cd79a-driven, conditional mTOR activation in developing mouse nephrons. In Scientific reports, 13, 508. doi:10.1038/s41598-023-27766-2. https://pubmed.ncbi.nlm.nih.gov/36627370/

3. Huse, Kanutte, Bai, Baoyan, Hilden, Vera I, Wälchli, Sébastien, Myklebust, June H. . Mechanism of CD79A and CD79B Support for IgM+ B Cell Fitness through B Cell Receptor Surface Expression. In Journal of immunology (Baltimore, Md. : 1950), 209, 2042-2053. doi:10.4049/jimmunol.2200144. https://pubmed.ncbi.nlm.nih.gov/36426942/