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Involvement of p21ras activation in T cell CD69 expression
D D'Ambrosio1, D A Cantrell, L Frati
1Department of Experimental Medicine, University of Rome La Sapienza, Italy.
European Journal of Immunology
|March 1, 1994
Summary
Ras proteins play a key role in T cell activation. Constitutively active ras induced CD69 expression, while inhibiting ras blocked T cell receptor signaling, indicating ras
Area of Science:
- Immunology
- Molecular Biology
- Cell Signaling
Background:
- Early activation antigen CD69 is crucial for T cell responses.
- p21ras proteins are key regulators in cellular signaling pathways.
Purpose of the Study:
- To investigate the role of p21ras in the induction of CD69 expression in T cells.
- To elucidate the involvement of ras signaling in T cell receptor (TcR)/CD3-mediated activation.
Main Methods:
- Jurkat T cells were transfected with constitutively active v-Ha-ras or dominant-negative c-Ha-ras-N17 mutants.
- Ras activation was assessed by immunoprecipitation of GTP-bound forms.
- AP-1 reporter gene transactivation was measured.
- CD69 surface expression was analyzed following TcR/CD3 stimulation.
Main Results:
- Expression of constitutively active v-Ha-ras induced CD69 expression on Jurkat T cells.
- Active ras was confirmed by GTP-binding and AP-1 transactivation.
- Dominant-negative c-Ha-ras-N17 inhibited ras activation upon TcR/CD3 triggering.
- Inhibition of ras signaling markedly reduced TcR/CD3-mediated CD69 induction.
Conclusions:
- Ras proteins are central mediators of CD69 expression in T cells.
- Ras signaling is essential for T cell receptor/CD3-induced CD69 upregulation.
- These findings highlight the critical role of ras in T cell activation pathways.