Activated Akt promotes increased resting T cell size, CD28-independent T cell growth, and development of autoimmunity and lymphoma.

Published

Journal Article

The mechanisms that regulate basal T cell size and metabolic activity are uncertain. Since the phosphatidylinositol-3 phosphate kinase (PI3 K) and Akt (PKB) pathway has been shown in model organisms to regulate both cell size and metabolism, we generated transgenic mice expressing a constitutively active form of Akt (myristoylated Akt, mAkt) in T cells. Naive transgenic T cells were enlarged and had increased rates of glycolysis compared to control T cells. In addition, mAkt transgenic T cells resisted death-by-neglect upon in vitro culture. Upon activation, mAkt-transgenic T cells were less dependent than control cells on costimulation through CD28 and could both grow rapidly and secrete cytokines in the absence of CD28 ligation. In addition, transgenic expression of mAkt led to the accumulation of CD4 T cells and B cells with age. Many aged mAkt-transgenic mice also developed autoimmunity with immunoglobulin deposits on kidney glomeruli and displayed increased incidence of lymphoma. Together, these data show that Akt activation is sufficient to increase basal T cell size and metabolism. Enhancement of T cell metabolism by Akt and more rapid CD28-independent T cell growth may contribute to the accumulation of excess immune cells and the development of lymphoma and autoimmunity.

Full Text

Duke Authors

Cited Authors

  • Rathmell, JC; Elstrom, RL; Cinalli, RM; Thompson, CB

Published Date

  • August 2003

Published In

Volume / Issue

  • 33 / 8

Start / End Page

  • 2223 - 2232

PubMed ID

  • 12884297

Pubmed Central ID

  • 12884297

International Standard Serial Number (ISSN)

  • 0014-2980

Digital Object Identifier (DOI)

  • 10.1002/eji.200324048

Language

  • eng

Conference Location

  • Germany