CD38 expression on mouse T cells: CD38 defines functionally distinct subsets of alpha beta TCR+CD4-CD8- thymocytes

• Published in: International immunology Vol. 7; no. 2; p. 213
• Main Authors: Bean, A G, Godfrey, D I, Ferlin, W G, Santos-Argumedo, L, Parkhouse, M E, Howard, M C, Zlotnik, A
• Format: Journal Article
• Language: English
• Published: England 01-02-1995
• Subjects: ADP-ribosyl Cyclase; ADP-ribosyl Cyclase 1; Animals; Antigens, CD - biosynthesis; Antigens, CD - immunology; Antigens, Differentiation - biosynthesis; Antigens, Differentiation - immunology; CD3 Complex - immunology; Cells, Cultured; Flow Cytometry; Male; Membrane Glycoproteins; Mice; Mice, Inbred BALB C; Receptors, Antigen, T-Cell, alpha-beta - biosynthesis; Receptors, Antigen, T-Cell, alpha-beta - immunology; T-Lymphocyte Subsets - classification; Thymus Gland - cytology; Thymus Gland - immunology
• ISSN: 0953-8178
• DOI: 10.1093/intimm/7.2.213

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.