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Updated: Aug 1, 2026

Generation of Human CD40-activated B cells
Published on: October 17, 2009
OX40 promotes Bcl-xL and Bcl-2 expression and is essential for long-term survival of CD4 T cells
P R Rogers1, J Song, I Gramaglia
1Division of Immunochemistry, La Jolla Institute for Allergy and Immunology, San Diego, CA 92121, USA.
Abstract:
It is important to understand which molecules are essential for long-lived immunity. We show that OX40 (CD134) is required with CD28 for the survival of CD4 T cells following antigen-driven expansion. In contrast to CD28-/- T cells, which show defects early, OX40-/- T cells are relatively unimpaired in IL-2 production, cell division, and expansion. However, OX40-/- T cells fail to maintain high levels of Bcl-xL and Bcl-2 4-8 days after activation, and undergo apoptosis. Conversely, OX40 stimulation promotes Bcl-xL and Bcl-2 and suppresses apoptosis. Moreover, retroviral transduction of OX40-/- T cells with Bcl-xL or Bcl-2 reverses their survival defect. Thus, a temporal relationship exists between CD28 and OX40, with OX40 being a critical regulator of antigen-driven T cell survival.
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