The Abl tyrosine kinases have been implicated in the regulation of cell proliferation, survival, adhesion, and migration. Targeted deletion of c-Abl in mice has revealed a role for this protein in B and T cell development and function. The c-Abl-deficient mice exhibit splenic and thymic atrophy and lymphopenia, and B lymphocytes isolated from c-Abl knockout mice have increased susceptibility to apoptosis following growth factor withdrawal. We have shown that splenic B cells from c-Abl knockout mice exhibit a reduced proliferative response to B cell receptor (BCR) stimulation, and that c-Abl binds to and phosphorylates the BCR co-receptor CD19. The c-Abl kinase exhibits functional redundancy during mouse development with Arg, an Abl-related tyrosine kinase. Single loss of c-Abl or Arg produces viable mice, but homozygous loss of both kinases results in embryonic lethality with the embryos displaying cytoskeletal abnormalities and apoptosis in multiple tissues. The Arg tyrosine kinase is highly expressed in thymus and spleen, and may compensate for loss of c-Abl in these tissues. A role for Abl kinases in lymphocyte signaling is further supported by our recent finding that inhibiting the activities of the Abl kinases in T cells markedly inhibits T cell receptor (TCR)-dependent proliferation, IL-2 production, transcription of the IL-2 promoter, and tyrosine phosphorylation of a subset of proteins critical for TCR signaling. We hypothesize that Abl family kinases regulate proliferative, survival, and cytoskeletal responses downstream of immunoreceptors in B and T cells.
Two specific aims are proposed: 1) to define the mechanisms employed by the Abl kinases to regulate proliferation, survival, cytoskeletal reorganization, and integrin-mediated adhesion downstream of TCR engagement, and identify the critical Abl targets in these processes, and 2) to define the mechanisms whereby c-Abl regulates the proliferative response to BCR stimulation through identification of critical Abl targets and upstream regulators, as well as to examine whether loss of Arg exacerbates the c-Abl dependent B cell phenotypes. Results from the proposed experiments will provide mechanistic explanations for the defective B and T cell phenotypes induced by loss of Abl kinases in mice, and wilt reveal novel signaling pathways modulated by these kinases in normal lymphocytes and under pathological conditions elicited by loss or deregulation of Abl kinase function.
| Khatri, Aaditya; Wang, Jun; Pendergast, Ann Marie (2016) Multifunctional Abl kinases in health and disease. J Cell Sci 129:9-16 |
| Wang, Jun; Pendergast, Ann Marie (2015) The Emerging Role of ABL Kinases in Solid Tumors. Trends Cancer 1:110-123 |
| Trampont, Paul C; Zhang, Li; Giles, Amber J et al. (2015) ShcA regulates thymocyte proliferation through specific transcription factors and a c-Abl-dependent signaling axis. Mol Cell Biol 35:1462-76 |
| Chislock, Elizabeth M; Pendergast, Ann Marie (2013) Abl family kinases regulate endothelial barrier function in vitro and in mice. PLoS One 8:e85231 |
| Chislock, Elizabeth M; Ring, Colleen; Pendergast, Ann Marie (2013) Abl kinases are required for vascular function, Tie2 expression, and angiopoietin-1-mediated survival. Proc Natl Acad Sci U S A 110:12432-7 |
| Greuber, Emileigh K; Pendergast, Ann Marie (2012) Abl family kinases regulate Fc?R-mediated phagocytosis in murine macrophages. J Immunol 189:5382-92 |
| Gu, Jing Jin; Lavau, Catherine P; Pugacheva, Elena et al. (2012) Abl family kinases modulate T cell-mediated inflammation and chemokine-induced migration through the adaptor HEF1 and the GTPase Rap1. Sci Signal 5:ra51 |
| Ryu, Jae Ryun; Echarri, Asier; Li, Ran et al. (2009) Regulation of cell-cell adhesion by Abi/Diaphanous complexes. Mol Cell Biol 29:1735-48 |
| Gu, Jing Jin; Ryu, Jae Ryun; Pendergast, Ann Marie (2009) Abl tyrosine kinases in T-cell signaling. Immunol Rev 228:170-83 |
| Gu, Jing Jin; Zhang, Nu; He, You-Wen et al. (2007) Defective T cell development and function in the absence of Abelson kinases. J Immunol 179:7334-43 |
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