title: Functional heterogeneity of human effector CD8+ T cells.
abstract: Effector CD8(+) T cells are believed to be terminally differentiated cells having cytotoxic activity and the ability to produce effector cytokines such as INF-γ and TNF-α. We investigated the difference between CXCR1(+) and CXCR1(-) subsets of human effector CD27(-)CD28(-)CD8(+) T cells. The subsets expressed cytolytic molecules similarly and exerted substantial cytolytic activity, whereas only the CXCR1(-) subset had IL-2 productivity and self-proliferative activity and was more resistant to cell death than the CXCR1(+) subset. These differences were explained by the specific up-regulation of CAMK4, SPRY2, and IL-7R in the CXCR1(-) subset and that of pro-apoptotic death-associated protein kinase 1 (DAPK1) in the CXCR1(+) subset. The IL-2 producers were more frequently found in the IL-7R(+) subset of the CXCR1(-) effector CD8(+) T cells than in the IL-7R(-) subset. IL-7/IL-7R signaling promoted cell survival only in the CXCR1(-) subset. The present study has highlighted a novel subset of effector CD8(+) T cells producing IL-2 and suggests the importance of this subset in the homeostasis of effector CD8(+) T cells.
authors.affiliation: Center for AIDS Research, Kumamoto University, Kumamoto, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takata
authors.forename: Takuya
authors.initials: T
authors.lastname: Naruto
authors.forename: Masafumi
authors.initials: M
authors.lastname: Takiguchi
mesh_terms: D000328:Adult; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D002470:Cell Survival / Q000235:genetics / Q000276:immunology; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000235:genetics / Q000276:immunology*; D064550:Death-Associated Protein Kinases; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D006801:Humans; D007376:Interleukin-2 / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D015851:Interleukin-7 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D008565:Membrane Proteins; D020411:Oligonucleotide Array Sequence Analysis; D020395:Receptors, Interleukin-7 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D023062:Receptors, Interleukin-8A / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology / Q000378:metabolism
chemical_list: D051017:Apoptosis Regulatory Proteins; D007376:Interleukin-2; D015851:Interleukin-7; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D020395:Receptors, Interleukin-7; D023062:Receptors, Interleukin-8A; C485561:SPRY2 protein, human; C579096:DAPK1 protein, human; D064550:Death-Associated Protein Kinases; C517683:CAMK4 protein, human; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases