The B-cell antigen receptor (BCR) produces a calcium-dependent signal which is required for both B-cell proliferation and apoptotic receptor editing during antigen driven humoral immune responses. This calcium signal is generated by a mechanism which involves inositol-1,4,5- trisphosphate (IP3) production driven at least in part by the D3- phosphoinositide PtdIns-3,4,5-P3 through the action of TEC family tyrosine kinases. The importance of the PtdIns-3,4,5-P3/TEC kinase pathway is underscored by the modulation of this pathway negatively by the inhibitory receptor Fc[gamma]RIIb l for the purpose of feedback control of B-cell proliferation and antibody production, and by the interruption of this pathway by mutations in BTK which cause the inherited B-cell irnmunodeficiency X-linked agammglobulinemia (XLA). Tec kinase signaling mechanisms have been shown in two different systems to involve a direct interaction between TEC PH domains and PtdIns-3,4,5-P3, and phosphorylation of PLCgamma2 by the kinase domains. However two other TEC domains also appear to be required for TEC signaling function: the Tec homology (TH) doman and the SH2 domain, and what these domains do during TEC signaling is currently unknown. This grant will use the B-cell predominant TEC kinase BTK as a prototype to pursue two lines of investigation aimed at extending and refining our understanding of the mechanisms of TEC kinase function during the B-cell receptor calcium signal: I) Analysis of the role of the BTK TH domain in BTK-dependent PLC- activation; and II) Analysis of the role of the BTK SH2 domain in BTK-dependent PLCgamma2 activation.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
7R01AI045901-06
Application #
6730639
Study Section
Experimental Immunology Study Section (EI)
Program Officer
Miller, Lara R
Project Start
2000-04-01
Project End
2006-03-31
Budget Start
2004-04-01
Budget End
2006-03-31
Support Year
6
Fiscal Year
2004
Total Cost
$232,500
Indirect Cost
Name
Seattle Children's Hospital
Department
Type
DUNS #
048682157
City
Seattle
State
WA
Country
United States
Zip Code
98105
Bailey, Adam L; Lauck, Michael; Ghai, Ria R et al. (2016) Arteriviruses, Pegiviruses, and Lentiviruses Are Common among Wild African Monkeys. J Virol 90:6724-6737
Scharenberg, Andrew M; Humphries, Lisa A; Rawlings, David J (2007) Calcium signalling and cell-fate choice in B cells. Nat Rev Immunol 7:778-89
Liu, Ping; Scharenberg, Andrew M; Cantrell, Doreen A et al. (2007) Protein kinase D enzymes are dispensable for proliferation, survival and antigen receptor-regulated NFkappaB activity in vertebrate B-cells. FEBS Lett 581:1377-82
Matthews, Sharon A; Liu, Ping; Spitaler, Martin et al. (2006) Essential role for protein kinase D family kinases in the regulation of class II histone deacetylases in B lymphocytes. Mol Cell Biol 26:1569-77
Song, Yumei; Dayalu, Rashmi; Matthews, Sharon A et al. (2006) TRPML cation channels regulate the specialized lysosomal compartment of vertebrate B-lymphocytes. Eur J Cell Biol 85:1253-64