title: Expression and functional role of CD23 on T cells.
abstract: We have found that approximately 10%-15% of tonsil, but not peripheral blood, T cells express the CD23 antigen following activation with 12-O-tetradecanoylphorbol 13-acetate (TPA), phytohemagglutinin (PHA) or recombinant interleukin 4. The proliferative response of tonsil T cells is significantly increased when CD23 monoclonal antibodies (mAb) are present in the cultures. In contrast, no such proliferative augmentation is seen when peripheral blood T cells are cultured in this way. Supernatant (SN) of Epstein-Barr Virus-transformed B lymphoblastoid cell lines (EBVLCL), is found to have a similar co-stimulatory effect on the proliferation of tonsil T cells to that seen with CD23 mAb. This effect is greatly diminished by preclearing SN with CD23 mAb. Similarly, SN from a CD23+ L cell transfectant augments the proliferative response of tonsil T cells to both TPA and PHA. The CD23 molecule expressed by TPA-driven T cell blasts appears identical in size to the 45-kDa glycoprotein present on EBVLCL and activated B cells. In contrast, a 42-kDa molecule is observed when CD23 is precipitated from T cells activated with PHA. The results presented here demonstrate that CD23 is expressed on activated tonsil, but not peripheral blood T cells and plays a role, via the binding of CD23 mAb and CD23+ material, present in EBVLCL and CD23+ transfectant SN, in the regulation of T cell proliferation in response to mitogens such as PHA and TPA.
authors.affiliation: I.C.R.F. Human Tumour Immunology Group, Courtauld Institute of Biochemistry, London, GB.
authors.forename: R J
authors.initials: RJ
authors.lastname: Armitage
authors.forename: L K
authors.initials: LK
authors.lastname: Goff
authors.forename: P C
authors.initials: PC
authors.lastname: Beverley
mesh_terms: D000276:Adjuvants, Immunologic / Q000502:physiology; D000911:Antibodies, Monoclonal / Q000502:physiology; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis* / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects; D014066:Palatine Tonsil / Q000032:analysis / Q000276:immunology; D010835:Phytohemagglutinins; D011961:Receptors, Fc / Q000032:analysis* / Q000276:immunology; D017455:Receptors, IgE; D012995:Solubility; D013601:T-Lymphocytes / Q000032:analysis / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate
chemical_list: D000276:Adjuvants, Immunologic; D000911:Antibodies, Monoclonal; D000944:Antigens, Differentiation, B-Lymphocyte; D010835:Phytohemagglutinins; D011961:Receptors, Fc; D017455:Receptors, IgE; D013755:Tetradecanoylphorbol Acetate