GENETIC-ANALYSIS OF TYROSINE KINASE FUNCTION IN B-CELL DEVELOPMENT

B lymphopoiesis is regulated by multiple signals from stromal cell con tact, soluble cytokines, antigen, and T helper cells. In vitro and bio chemical experiments have implicated tyrosine kinases as key component s of many of these signaling pathways. Genetic analysis of the role of these tyrosine kinases has been facilitated by recent advances in tra nsgenic and gene targeting technology as well as by the identification of the genetic basis of several human and murine immune deficiencies. This review discusses the effect of gain and loss of function mutatio ns of selected tyrosine kinases and their regulators and substrates on B cell development and function.