title: Heterogeneity in the differentiation and function of CD8⁺ T cells.
abstract: It is well established that CD8(+) T cells constitute an important branch of adaptive immunity contributing to clearance of intracellular pathogens and providing long-term protection. These functions are mostly fulfilled by the best characterized subpopulation of CD8(+) T cells, the cytotoxic T lymphocytes (also called Tc1 cells), owing to their ability to kill infected cells and to secrete cytokines such as interferon-γ and tumor necrosis factor-α. However, there is growing evidence for alternative CD8(+) T cell fates influencing CD4(+) T-cell-mediated responses in the context of allergy, autoimmunity and infections. Thus, like subpopulations of CD4(+) T cells, also CD8(+) T cells under particular conditions acquire the expression of interleukin (IL)-4, IL-5, IL-9, IL-13, IL-17 or suppressive activity and thereby influence immune responses. The process of CD8(+) T-cell differentiation is dictated by antigen strength, co-stimulatory molecules and cytokines. These environmental cues induce transcription factors further specifying CD8(+) T-cell decision into Tc1, Tc2, Tc9, Tc17 or CD8(+) T regulatory fate. Here, we discuss our current understanding about functional diversity of effector CD8(+) T cells and contribution of transcription factors to this process.
authors.affiliation: Institute for Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Hans-Willi
authors.initials: HW
authors.lastname: Mittrücker
authors.forename: Alexander
authors.initials: A
authors.lastname: Visekruna
authors.forename: Magdalena
authors.initials: M
authors.lastname: Huber
mesh_terms: D056704:Adaptive Immunity; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis; D005786:Gene Expression Regulation; D006801:Humans; D007156:Immunologic Memory; D008213:Lymphocyte Activation; D051379:Mice; D015398:Signal Transduction; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D016207:Cytokines