INEFFICIENT TERMINATION OF ANTIGEN RESPONSES IN NF-ATP-DEFICIENT MICE

In order to elucidate the role of NF-ATp, one of the most prominent me mbers of family of NF-AT transcription factors In peripheral T lymphoc ytes, in T cell activation and differentiation Ne created NF-ATp-defic ient mice by gene targeting. Such NF-ATp(-/-) mice are burn and appear to develop a normal immune system. Apart from clear-cut defects in th e synthesis of mRNAs for Th2-type lymphokines, such as IL-4, IL-5, IL- 10 and IL-13, in primary and secondary stimulations of spleen cells in vitro, of a distinct impaired deletion of V beta 11(+)/CD4(+) T lymph ocytes from these mice was detected after superantigen injection. More over, NF-ATp(-/-) mice older than 6 weeks show an 2-5 fold increase in number of lymphocytes. This is correlated with an increased expressio n of activation markers CD44 and CD69 and decreased expression of CD62 .