Costimulatory signals and viral immunity

Abstract

Costimulation plays a pivotal role in T-cell activation, since engagement of the T-cell receptor in the absence of costimulatory signals can lead to T-cell anergy. The B7-CD28/CTLA4 costimulatory pathway can provide a potent costimulatory signal. This article focuses on the B7-CD28/CTLA4 pathway, reviewing aspects of costimulation relevant to the development of anti-viral immune responses and summarizing vaccination strategies employing costimulatory molecules. In addition, this article discusses the importance of regulated expression of costimulatory molecules and describes how viruses can modulate the expression of costimulatory molecules, which may contribute to immune dysfunction.