The expanding B7 superfamily: increasing complexity in costimulatory signals regulating T cell function

AJ Coyle, JC Gutierrez-Ramos - Nature immunology, 2001 - nature.com
Nature immunology, 2001nature.com
Upon encounter with specific antigen, naïve T helper precursor (THP) cells become
activated. This event is regulated not only by engagement of the T cell receptor (TCR) with
peptide presented in the context of major histocompatibility complex (MHC) class II
molecules but by a number of costimulatory signals. CD28 engagement by B7-1 and B7-2
on resting THP cells provides a critical signal for initial cell cycle progression, interleukin 2
production and clonal expansion. However, largely as a consequence of the unraveling of …
Abstract
Upon encounter with specific antigen, naïve T helper precursor (T H P) cells become activated. This event is regulated not only by engagement of the T cell receptor (TCR) with peptide presented in the context of major histocompatibility complex (MHC) class II molecules but by a number of costimulatory signals. CD28 engagement by B7-1 and B7-2 on resting T H P cells provides a critical signal for initial cell cycle progression, interleukin 2 production and clonal expansion. However, largely as a consequence of the unraveling of the human genome, it is becoming clear that B7-1 and B7-2 are part of a larger family of related counter-receptors that play an essential role in regulating the fate of primed, rather then resting, T H P cells. These molecules play an important sequential role and act, together with B7-1–and B7-2–primed T cells, in the acquisition of effector function and/or tolerance induction.
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