title: Human suppressor T cell clones lack CD28.
abstract: Previously we showed that certain T cell lines and clones from a lepromatous leprosy patient displayed a dose-dependent suppression of the proliferation of autologous T cells to Mycobacterium leprae (M. leprae) but not mitogen or an unrelated antigen. The latter cells were also cloned and did not display this suppressive activity, were CD4+ and proliferated vigorously to M. leprae presented by autologous HLA-DR molecules. We shall refer to these cells as T helper (Th) cells. Most of the suppressive T cell clones (Ts) were also CD4+ and also proliferated to M. leprae presented by HLA-DR, but much less strongly than Th cells. In this study we report on our search for (a) the mechanism of this apparently antigen-specific suppression by T cells, and (b) a possible phenotypic difference between Th and Ts clones. The two main conclusions are that Ts clones possess a lytic machinery, but that M. leprae-specific suppression and cytotoxicity can be clearly dissociated, and that the only phenotypic difference between Th and Ts is the presence of the CD28 marker on Th and its absence on Ts clones.
authors.affiliation: Department of Immunohaematology and Blood Bank, University Hospital, Leiden, The Netherlands.
authors.forename: S G
authors.initials: SG
authors.lastname: Li
authors.forename: T H
authors.initials: TH
authors.lastname: Ottenhoff
authors.forename: P
authors.initials: P
authors.lastname: Van den Elsen
authors.forename: F
authors.initials: F
authors.lastname: Koning
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.forename: T
authors.initials: T
authors.lastname: Mak
authors.forename: R R
authors.initials: RR
authors.lastname: De Vries
mesh_terms: D015703:Antigens, CD / Q000032:analysis*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis* / Q000096:biosynthesis; D018106:CD28 Antigens; D017252:CD3 Complex; D002999:Clone Cells; D005434:Flow Cytometry; D006801:Humans; D015439:Leprosy, Borderline / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D009166:Mycobacterium leprae / Q000276:immunology*; D010641:Phenotype; D011948:Receptors, Antigen, T-Cell / Q000096:biosynthesis; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D018106:CD28 Antigens; D017252:CD3 Complex; D011948:Receptors, Antigen, T-Cell