title: Cell division-associated expression of an epitope, KH17, on early developing thymocytes.
abstract: A newly established monoclonal antibody, KH17, detects a unique epitope temporarily expressed on early developing CD3-thymocytes confined to a cycling stage. KH17 is detectable on a part of CD4-CD8-,CD4-CD8+, and CD4+CD8+ cells, but not on CD4+CD8- thymocytes. By four-color flow cytometry analysis using KH17, we were able to define the heterogeneity of immature CD4-CD8- thymocytes by the expression of KH17 and IL-2R. In Thy-1-congeneic bone marrow chimeras, the appearance of KH17-IL-2R+ thymocytes preceded the increase of KH17+IL-2R- cells. The antibody could also divide CD3-CD4-CD8+ cells into two subpopulations, KH17+ and KH17-, which showed a continuum. In the fetal thymus there was a rapid and dramatic increase of KH17-CD4+CD8+ thymocytes concomitant with a decrease of KH17+CD4-CD8+ thymocytes in later gestation days. KH17 is not expressed on resting peripheral T cells, but is expressed on a large proportion of Con A-activated blastic spleen cells. The KH17 molecules precipitated from Con A-activated spleen cells were 55 and 75 kd polypeptides, but different from IL-2R subunits.
authors.affiliation: Department of Immunology, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sano
authors.forename: H
authors.initials: H
authors.lastname: Kishimoto
authors.forename: H
authors.initials: H
authors.lastname: Karasuyama
authors.forename: Y
authors.initials: Y
authors.lastname: Asano
authors.forename: T
authors.initials: T
authors.lastname: Tada
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism*; D002454:Cell Differentiation; D002455:Cell Division; D000939:Epitopes / Q000378:metabolism; D005333:Fetus / Q000166:cytology / Q000276:immunology; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology; D007700:Kinetics; D051379:Mice; D008810:Mice, Inbred C57BL; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000939:Epitopes; D015375:Receptors, Interleukin-2