title: CD38 expression on mouse T cells: CD38 defines functionally distinct subsets of alpha beta TCR+CD4-CD8- thymocytes.
abstract: We have examined CD38 expression on mouse lymphocytes using the rat mAb NIM-R5 and demonstrate that CD38 expression is restricted to approximately 8% of thymocytes. Although CD38 is absent from the majority of CD4+CD8- and CD4-CD8+ T cells, we detected a strong correlation between CD38 expression and alpha beta+CD4-CD8- T cells in the thymus, with nearly 80% of alpha beta TCR+CD4-CD8- thymocytes being CD38+. Using heat stable antigen (HSA) and CD38, we divided alpha beta+CD4-CD8- thymocytes into four subsets: HSA+CD38-, HSA-CD38hi, HSA-CD38low and HSA-CD38-. Two established characteristics of alpha beta TCR+CD4-CD8- cells, bias towards V beta 8.2 TCR expression and high levels of IL-4 production, were used to establish a possible relationship between the above thymocyte subsets. Our present data show that the HSA+CD38- subset is not biased towards V beta 8.2 TCR expression whereas the HSA-CD38- subset does show this bias (approximately 47%). Neither of these subsets make IL-4 upon CD3 mediated stimulation. In contrast, the CD38+ subsets are heavily biased toward V beta 8.2 expression and produce large amounts of IL-4 upon stimulation, particularly the CD38low cells. Taken together, these data suggest that these four subsets represent various stages of a possible differentiation pathway for alpha beta TCR+CD4-CD8- cells, with the HSA+CD38- subset being the most immature while the HSA-CD38low subset is the most functionally mature. These characteristics support the view that alpha beta TCR+CD4-CD8- T cells represent an independent lineage with a distinct, but as yet obscure, role in immunity.
authors.affiliation: DNAX Research Institute of Molecular and Cellular Biology, Inc., Palo Alto, CA 94304, USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Bean
authors.forename: D I
authors.initials: DI
authors.lastname: Godfrey
authors.forename: W G
authors.initials: WG
authors.lastname: Ferlin
authors.forename: L
authors.initials: L
authors.lastname: Santos-Argumedo
authors.forename: M E
authors.initials: ME
authors.lastname: Parkhouse
authors.forename: M C
authors.initials: MC
authors.lastname: Howard
authors.forename: A
authors.initials: A
authors.lastname: Zlotnik
mesh_terms: D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis* / Q000276:immunology; D000943:Antigens, Differentiation / Q000096:biosynthesis* / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D002478:Cells, Cultured; D005434:Flow Cytometry; D008297:Male; D008562:Membrane Glycoproteins; D051379:Mice; D008807:Mice, Inbred BALB C; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000145:classification*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D017252:CD3 Complex; D008562:Membrane Glycoproteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D036541:ADP-ribosyl Cyclase; C498155:Cd38 protein, mouse; D051997:ADP-ribosyl Cyclase 1