The Jak family tyrosine kinase Jak3 is required for IL-2 synthesis by naive/resting CD4+ T cells

UMMS Affiliation

Department of Pathology

Publication Date


Document Type



Animals; Biological Transport; CD4-Positive T-Lymphocytes; DNA-Binding Proteins; Interleukin-2; Interphase; Janus Kinase 3; *Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Transgenic; NFATC Transcription Factors; Nuclear Proteins; Protein-Tyrosine Kinases; Transcription Factors


Life Sciences | Medicine and Health Sciences


The Jak family tyrosine kinase, Jak3, is involved in signaling through cytokine receptors using the common gamma-chain. Mice deficient in Jak3 have mature T cells, all of which have an activated/memory cell phenotype but are unresponsive to in vitro stimulation. Due to this activated phenotype, it has been impossible to determine whether Jak3 plays a role in the responsiveness of naive/resting T cells. To circumvent this difficulty, we generated naive/resting Jak3-negative T cells by two genetic approaches. After stimulation, these cells failed to produce significant amounts of IL-2. Although no signaling defect could be detected, we did find that naive/resting Jak3-negative T cells have substantially reduced levels of the transcription factor NF-AT1 and moderately reduced levels of c-Jun and c-Fos. On the basis of these data, we propose that Jak3-dependent cytokine signals may be required to maintain the normal levels of basal transcription factors required for immediate responsiveness to Ag activation.


J Immunol. 1999 Nov 15;163(10):5411-7.

Journal/Book/Conference Title

Journal of immunology (Baltimore, Md. : 1950)

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