title: T cell development in a major histocompatibility complex class II-deficient patient.
abstract: In this report we show that the major histocompatibility complex (MHC) class II-negative thymus of a bare lymphocyte syndrome (BLS) patient contains a reduced CD4+ CD8- T cell population when compared to thymocytes derived from a MHC class II-expressing thymus. Of these CD4+ CD8- BLS thymocytes, approximately only one third co-expressed the CD3 antigen, moreover at a lower expression level when compared to control thymocytes. This suggests a partial maturation of the CD4+ CD8- T cells in the absence of MHC class II expression. Among the BLS thymocytes, CD4+ CD8+ thymocytes could easily be detected. Noteworthy, the number of CD4- CD8+ thymocytes was significantly increased. CD4+ CD8- T cells could also be found among the BLS peripheral blood mononuclear cells, albeit at reduced numbers. Despite the absence of peripheral MHC class II expression, the majority of these CD4+ CD8- T cells co-expressed the CD45RO marker. In the BLS patient, thymocytes as well as peripheral CD4+ CD8- T cells were not restricted in the use of the available T cell receptor (TcR) V gene family pool. However, the lack of detectable levels of thymic and peripheral MHC class II antigen expression in the BLS patient had altered the CD4-skewing patterns of TcR V gene families which were present in normal individuals. In conclusion, the lack of MHC class II expression in the BLS patient does not completely inhibit the CD4+ CD8- T cell development.
authors.affiliation: Department of Immunohematology and Blood Bank, University Hospital Leiden, The Netherlands.
authors.forename: M C
authors.initials: MC
authors.lastname: van Eggermond
authors.forename: G T
authors.initials: GT
authors.lastname: Rijkers
authors.forename: W
authors.initials: W
authors.lastname: Kuis
authors.forename: B J
authors.initials: BJ
authors.lastname: Zegers
authors.forename: P J
authors.initials: PJ
authors.lastname: van den Elsen
mesh_terms: D015704:CD4 Antigens; D016827:CD8 Antigens; D002454:Cell Differentiation; D002648:Child; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D005810:Multigene Family; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000473:pathology; D014158:Transcription, Genetic
chemical_list: D015704:CD4 Antigens; D016827:CD8 Antigens; D000949:Histocompatibility Antigens Class II; D016693:Receptors, Antigen, T-Cell, alpha-beta