Absence of both Sos‐1 and Sos‐2 in peripheral CD4+ T cells leads to PI3K pathway activation and defects in migration. Issue 8 (5th June 2015)

• Record Type: Journal Article
• Authors: Guittard, Geoffrey; Kortum, Robert L.; Balagopalan, Lakshmi; Çuburu, Nicolas; Nguyen, Phan; Sommers, Connie L.; Samelson, Lawrence E.
• Is Part Of: European journal of immunology. Volume 45:Issue 8(2015:Aug.)
• Page Start: 2389
• Page End: 2395
• Publication Date: 2015-06-05
• Subjects: Immunology -- Periodicals; 616.079
• DOI: 10.1002/eji.201445226
• Languages: English
• ISSNs: 0014-2980

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Sos‐1 and Sos‐2 are ubiquitously expressed Ras‐guanine exchange factors involved in Erk‐MAP kinase pathway activation. Using mice lacking genes encoding Sos‐1 and Sos‐2, we evaluated the role of these proteins in peripheral T‐cell signaling and function. Our results confirmed that TCR‐mediated Erk activation in peripheral CD4⁺ T cells does not depend on Sos‐1 and Sos‐2, although IL‐2‐mediated Erk activation does. Unexpectedly, however, we show an increase in AKT phosphorylation in Sos‐1/2dKO CD4⁺ T cells upon TCR and IL‐2 stimulation. Activation of AKT was likely a consequence of increased recruitment of PI3K to Grb2 upon TCR and/or IL‐2 stimulation in Sos‐1/2dKO CD4⁺ T cells. The increased activity of the PI3K/AKT pathway led to downregulation of the surface receptor CD62L in Sos‐1/2dKO T cells and a subsequent impairment in T‐cell migration.</p> </abstract>