title: Intracellular signals of T cell costimulation.
abstract: Ligation of T cell receptor (TCR) alone is insufficient to induce full activation of T lymphocytes. Additional ligand-receptor interactions (costimulation) on antigen presenting cells (APCs) and T cells are required. T cell costimulation has been shown to be essential for eliciting efficient T cell responses, involving all phases during T cell development. However, the mechanisms by which costimulation affects the function of T cells still need to be elucidated. In recent years, advances have been made in studies of costimulation as potential therapies in cancer, infectious disease as well as autoimmune disease. In this review, we discussed intracellular costimulation signals that regulate T cell proliferation, cell cycle progression, cytokine production, survival, and memory development. In general, the pathway of phosphoinositide-3 kinase (PI3K)/protein kinase B (PKB, also known as Akt)/nuclear factor kappaB (NF-kappaB) might be central to many costimulatory effects. Through these pathways, costimulation controls T-cell expansion and proliferation by maintenance of survivin and aurora B expression, and sustains long-term T-cell survival and memory development by regulating the expression of bcl-2 family members.
authors.affiliation: Department of Microbiology and Immunology and Penn State Cancer Institute, the Pennsylvania State University College of Medicine, 500 University Dr, Hershey, PA 17033, USA. jus35@psu.edu
authors.forename: Jianxun
authors.initials: J
authors.lastname: Song
authors.forename: Fengyang Tylan
authors.initials: FT
authors.lastname: Lei
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Xiong
authors.forename: Rizwanul
authors.initials: R
authors.lastname: Haque