Apoptotic cell death in lymphocytes can be triggered by activation signals transmitted through cell surface receptors and utilizing signal transduction pathways which are shared with mitogenic programs. The susceptibility of cells to activation-induced cell death is dependent on both the maturation stage and previous activation history of a lymphocyte. The bcl-2 gene product, a mitochondrially targeted protein which inhibits apoptotic death, is another important determinant of cell survival. The detailed understanding of the interaction between these components of an apoptotic pathway in B lymphocytes, signal transduction following sIgM crosslinking, developmental stage, and endogenous inhibitors of cell death is the overall goal of this proposal. Knowledge of important intracellular events leading to self tolerance in B lymphocytes is relevant to human autoimmune diseases and broader problems of premature cell deaths in various cell lineages, many of which appear to involve activation pathways. Bcl-2 function is pivotal in understanding mechanisms of apoptotic death, and we have proposed that bcl-2 functions in a cellular antioxidant pathway. Mice with homozygous deletions of the bcl-2 gene have phenotypes of oxidant injury and accelerated apoptosis. Our previous findings of oxygen free radical-mediated damage as a necessary step i lymphocyte apoptosis will be extended to models of activation-induced death in murine cell lines and immature B lymphocytes. Downregulation of bcl-2 levels and function appear to be important determinants of susceptibility to cell death in many systems. The requirements for bcl-2 mRNA and protein synthesis and degradation in this model and compared to mature B lymphocytes resistant to activation-induced death and the potential interaction of bcl-2 with bax and bcl-x will be determined. Finally, the delayed commitment to cell death will be examined by comparing effects on duration of intracellular signals as a potential decision point for entry into apoptotic versus mitotic programs.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Program Projects (P01)
Project #
5P01GM042508-08
Application #
5212147
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
8
Fiscal Year
1996
Total Cost
Indirect Cost
Craxton, A; Chuang, P I; Shu, G et al. (2000) The CD40-inducible Bcl-2 family member A1 protects B cells from antigen receptor-mediated apoptosis. Cell Immunol 200:56-62
Law, C L; Ewings, M K; Chaudhary, P M et al. (1999) GrpL, a Grb2-related adaptor protein, interacts with SLP-76 to regulate nuclear factor of activated T cell activation. J Exp Med 189:1243-53
Ostrowski, J; Trzeciak, L; Kolodziejski, J et al. (1998) Increased constitutive activity of mitogen-activated protein kinase and renaturable 85 kDa kinase in human-colorectal cancer. Br J Cancer 78:1301-6
Hashimoto, A; Okada, H; Jiang, A et al. (1998) Involvement of guanosine triphosphatases and phospholipase C-gamma2 in extracellular signal-regulated kinase, c-Jun NH2-terminal kinase, and p38 mitogen-activated protein kinase activation by the B cell antigen receptor. J Exp Med 188:1287-95
Graves, J D; Gotoh, Y; Draves, K E et al. (1998) Caspase-mediated activation and induction of apoptosis by the mammalian Ste20-like kinase Mst1. EMBO J 17:2224-34
Jiang, A; Craxton, A; Kurosaki, T et al. (1998) Different protein tyrosine kinases are required for B cell antigen receptor-mediated activation of extracellular signal-regulated kinase, c-Jun NH2-terminal kinase 1, and p38 mitogen-activated protein kinase. J Exp Med 188:1297-306
Craxton, A; Shu, G; Graves, J D et al. (1998) p38 MAPK is required for CD40-induced gene expression and proliferation in B lymphocytes. J Immunol 161:3225-36
Cornall, R J; Cyster, J G; Hibbs, M L et al. (1998) Polygenic autoimmune traits: Lyn, CD22, and SHP-1 are limiting elements of a biochemical pathway regulating BCR signaling and selection. Immunity 8:497-508
Ostrowski, J; Florio, S K; Denis, G V et al. (1998) Stimulation of p85/RING3 kinase in multiple organs after systemic administration of mitogens into mice. Oncogene 16:1223-7
Graves, J D; Draves, K E; Craxton, A et al. (1998) A comparison of signaling requirements for apoptosis of human B lymphocytes induced by the B cell receptor and CD95/Fas. J Immunol 161:168-74

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