Limits...
Itk and Fyn make independent contributions to T cell activation.

Liao XC, Littman DR, Weiss A - J. Exp. Med. (1997)

Bottom Line: Itk is a member of the Btk/Tec/Itk family of nonreceptor protein tyrosine kinases (PTKs), and has been implicated in T cell antigen receptor (TCR) signal transduction.Lck and Fyn are the Src-family nonreceptor PTKs that are involved in TCR signaling.These data support the notion that Itk and Fyn both make independent contributions to TCR-induced T cell activation.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, Howard Hughes Medical Institute, University of California, San Francisco, California 94143, USA.

ABSTRACT
Itk is a member of the Btk/Tec/Itk family of nonreceptor protein tyrosine kinases (PTKs), and has been implicated in T cell antigen receptor (TCR) signal transduction. Lck and Fyn are the Src-family nonreceptor PTKs that are involved in TCR signaling. To address the question of how these members of different families of PTKs functionally contribute to T cell development and to T cell activation, mice deficient for both Itk and either Lck or Fyn were generated. The Itk/Lck doubly deficient mice exhibited a phenotype similar to that of Lck-deficient mice. The phenotype of the Itk/Fyn doubly deficient mice was similar to that of Itk deficient mice. However the Itk/Fyn doubly deficient mice exhibited a more severe defect in TCR-induced proliferation of thymocytes and peripheral T cells than did mice deficient in either kinase alone. These data support the notion that Itk and Fyn both make independent contributions to TCR-induced T cell activation.

Show MeSH
Impaired proliferative responses upon TCR stimulation of  Itk−Fyn− thymocytes and splenocytes. (A) Thymocytes from +, itk−/−,  fyn−/−, and itk−/−fyn−/− mice were stimulated with anti-CD3 at indicated  concentrations in the presence of PMA (1 ng/ml) for 48 h. Cell proliferation was measured by [3H]thymidine incorporation after an additional 16 h.  The genotypes of mice are as indicated: I, itk; F, fyn. Standard deviations  for triplicate samples are shown as error bars along the y axis. (B) Splenocytes from +, itk−/−, fyn−/−, and itk−/−fyn−/− mice were stimulated with  anti-CD3 at indicated concentrations in the presence of PMA (1 ng/ml)  for 48 h. Cell proliferation was measured by [3H]thymidine incorporation  after an additional 16 h. The genotypes of mice are as indicated in A.  Standard deviations for triplicate samples are shown as error bars along the  y axis. Data are representative of two independent experiments.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2199174&req=5

Figure 2: Impaired proliferative responses upon TCR stimulation of Itk−Fyn− thymocytes and splenocytes. (A) Thymocytes from +, itk−/−, fyn−/−, and itk−/−fyn−/− mice were stimulated with anti-CD3 at indicated concentrations in the presence of PMA (1 ng/ml) for 48 h. Cell proliferation was measured by [3H]thymidine incorporation after an additional 16 h. The genotypes of mice are as indicated: I, itk; F, fyn. Standard deviations for triplicate samples are shown as error bars along the y axis. (B) Splenocytes from +, itk−/−, fyn−/−, and itk−/−fyn−/− mice were stimulated with anti-CD3 at indicated concentrations in the presence of PMA (1 ng/ml) for 48 h. Cell proliferation was measured by [3H]thymidine incorporation after an additional 16 h. The genotypes of mice are as indicated in A. Standard deviations for triplicate samples are shown as error bars along the y axis. Data are representative of two independent experiments.

Mentions: To address whether Itk and Fyn make independent contributions to the processes that lead to T cell activation, thymocytes and splenocytes were prepared from Itk/Fyn doubly deficient mice and compared with those from mice lacking either kinase alone in TCR-mediated proliferative responses. Thymocytes lacking either Fyn or Itk consistently showed a reduction in proliferation to anti-CD3 mAb over a broad dose range when compared to control Itk+ Fyn+ thymocytes (Fig. 2 A), consistent with previous studies (9, 10). Interestingly, thymocytes lacking both Itk and Fyn exhibited a much more severe proliferative defect, detectable over all doses of anti-CD3 mAb used. These results suggest that both Fyn and Itk contribute to the proliferative response induced by TCR stimulation in thymocytes.


Itk and Fyn make independent contributions to T cell activation.

Liao XC, Littman DR, Weiss A - J. Exp. Med. (1997)

Impaired proliferative responses upon TCR stimulation of  Itk−Fyn− thymocytes and splenocytes. (A) Thymocytes from +, itk−/−,  fyn−/−, and itk−/−fyn−/− mice were stimulated with anti-CD3 at indicated  concentrations in the presence of PMA (1 ng/ml) for 48 h. Cell proliferation was measured by [3H]thymidine incorporation after an additional 16 h.  The genotypes of mice are as indicated: I, itk; F, fyn. Standard deviations  for triplicate samples are shown as error bars along the y axis. (B) Splenocytes from +, itk−/−, fyn−/−, and itk−/−fyn−/− mice were stimulated with  anti-CD3 at indicated concentrations in the presence of PMA (1 ng/ml)  for 48 h. Cell proliferation was measured by [3H]thymidine incorporation  after an additional 16 h. The genotypes of mice are as indicated in A.  Standard deviations for triplicate samples are shown as error bars along the  y axis. Data are representative of two independent experiments.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2199174&req=5

Figure 2: Impaired proliferative responses upon TCR stimulation of Itk−Fyn− thymocytes and splenocytes. (A) Thymocytes from +, itk−/−, fyn−/−, and itk−/−fyn−/− mice were stimulated with anti-CD3 at indicated concentrations in the presence of PMA (1 ng/ml) for 48 h. Cell proliferation was measured by [3H]thymidine incorporation after an additional 16 h. The genotypes of mice are as indicated: I, itk; F, fyn. Standard deviations for triplicate samples are shown as error bars along the y axis. (B) Splenocytes from +, itk−/−, fyn−/−, and itk−/−fyn−/− mice were stimulated with anti-CD3 at indicated concentrations in the presence of PMA (1 ng/ml) for 48 h. Cell proliferation was measured by [3H]thymidine incorporation after an additional 16 h. The genotypes of mice are as indicated in A. Standard deviations for triplicate samples are shown as error bars along the y axis. Data are representative of two independent experiments.
Mentions: To address whether Itk and Fyn make independent contributions to the processes that lead to T cell activation, thymocytes and splenocytes were prepared from Itk/Fyn doubly deficient mice and compared with those from mice lacking either kinase alone in TCR-mediated proliferative responses. Thymocytes lacking either Fyn or Itk consistently showed a reduction in proliferation to anti-CD3 mAb over a broad dose range when compared to control Itk+ Fyn+ thymocytes (Fig. 2 A), consistent with previous studies (9, 10). Interestingly, thymocytes lacking both Itk and Fyn exhibited a much more severe proliferative defect, detectable over all doses of anti-CD3 mAb used. These results suggest that both Fyn and Itk contribute to the proliferative response induced by TCR stimulation in thymocytes.

Bottom Line: Itk is a member of the Btk/Tec/Itk family of nonreceptor protein tyrosine kinases (PTKs), and has been implicated in T cell antigen receptor (TCR) signal transduction.Lck and Fyn are the Src-family nonreceptor PTKs that are involved in TCR signaling.These data support the notion that Itk and Fyn both make independent contributions to TCR-induced T cell activation.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, Howard Hughes Medical Institute, University of California, San Francisco, California 94143, USA.

ABSTRACT
Itk is a member of the Btk/Tec/Itk family of nonreceptor protein tyrosine kinases (PTKs), and has been implicated in T cell antigen receptor (TCR) signal transduction. Lck and Fyn are the Src-family nonreceptor PTKs that are involved in TCR signaling. To address the question of how these members of different families of PTKs functionally contribute to T cell development and to T cell activation, mice deficient for both Itk and either Lck or Fyn were generated. The Itk/Lck doubly deficient mice exhibited a phenotype similar to that of Lck-deficient mice. The phenotype of the Itk/Fyn doubly deficient mice was similar to that of Itk deficient mice. However the Itk/Fyn doubly deficient mice exhibited a more severe defect in TCR-induced proliferation of thymocytes and peripheral T cells than did mice deficient in either kinase alone. These data support the notion that Itk and Fyn both make independent contributions to TCR-induced T cell activation.

Show MeSH