Abstract
Members of the suppressor of cytokine signaling (SOCS) family were discovered as negative regulators of cytokine signaling by inhibition of the Janus kinase-signal transducer and activator of transcription (Jak-STAT) pathway. Among them, cytokine-induced Src homology 2 (SH2) protein (CIS) was found to inhibit the interleukin 3- and erythropietin-mediated STAT5 signaling pathway. However, involvement of SOCS proteins in other signaling pathways is still unknown. This study shows that the expression of CIS is selectively induced in T cells after T cell receptor (TCR) stimulation. In transgenic mice, with selective expression of CIS in CD4 T cells, elevated CIS strongly promotes TCR-mediated proliferation and cytokine production in vitro, and superantigen-induced T cell activation in vivo. Forced expression of CIS also prolongs survival of CD4 T cells after TCR activation. Molecular events immediately downstream from the TCR are not changed in CIS-expressing CD4 T cells, but activation of mitogen-activated protein (MAP) kinase pathways by TCR stimulation is significantly enhanced. Together with the increased MAP kinase activation, a direct interaction of CIS and protein kinase Ctheta was also demonstrated. These results suggest that CIS is one of the important regulators of TCR-mediated T cell activation. The functions of CIS, enhancing TCR signaling and inhibiting cytokine signaling, may be important in the regulation of immune response and homeostasis.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Animals
-
CD4-Positive T-Lymphocytes / cytology
-
CD4-Positive T-Lymphocytes / enzymology
-
CD4-Positive T-Lymphocytes / immunology*
-
CD4-Positive T-Lymphocytes / metabolism*
-
Carrier Proteins / biosynthesis
-
Cell Survival / immunology
-
Cells, Cultured
-
Cytokines / physiology*
-
DNA-Binding Proteins*
-
Enzyme Activation / immunology
-
Gene Expression Regulation / immunology
-
Genes, Immediate-Early / immunology
-
Immediate-Early Proteins / biosynthesis
-
Immediate-Early Proteins / genetics
-
Immediate-Early Proteins / physiology*
-
Isoenzymes / metabolism
-
Lymphocyte Activation* / genetics
-
Mice
-
Mice, Transgenic
-
Mitogen-Activated Protein Kinases / metabolism
-
Protein Biosynthesis
-
Protein Kinase C / metabolism
-
Protein Kinase C-theta
-
Receptors, Antigen, T-Cell / physiology*
-
Repressor Proteins*
-
Suppressor of Cytokine Signaling 1 Protein
-
Suppressor of Cytokine Signaling 3 Protein
-
Suppressor of Cytokine Signaling Proteins
-
Trans-Activators*
-
Transcription Factors*
-
src Homology Domains / genetics
-
src Homology Domains / physiology*
Substances
-
Carrier Proteins
-
Cytokines
-
DNA-Binding Proteins
-
Immediate-Early Proteins
-
Isoenzymes
-
Receptors, Antigen, T-Cell
-
Repressor Proteins
-
Socs1 protein, mouse
-
Socs2 protein, mouse
-
Socs3 protein, mouse
-
Suppressor of Cytokine Signaling 1 Protein
-
Suppressor of Cytokine Signaling 3 Protein
-
Suppressor of Cytokine Signaling Proteins
-
Trans-Activators
-
Transcription Factors
-
cytokine inducible SH2-containing protein
-
Prkcq protein, mouse
-
Protein Kinase C
-
Protein Kinase C-theta
-
Mitogen-Activated Protein Kinases