A novel antigen (H47 Ag) on human lymphocytes involved in T cell activation.
Surface molecules involved in human T cell activation were investigated using a newly developed monoclonal antibody (H47 mAb). H47 antigen (Ag) recognized by H47 mAb was expressed on approximately 10% of resting T cells (mostly CD4-CD8+), 30% of phorbol 12-myristate 13-acetate (PMA)-activated T cells (both CD4+CD8- and CD4-CD8+), and most NK, B cells, and monocytes in the peripheral blood mononuclear cells (PBMC). H47 mAb respectively immunoprecipitated a 100 or 120-kD molecular weight (MW) membrane protein of T cells and monocytes under nonreducing or reducing conditions, suggesting that H47 Ag consists of a single polypeptide that has intramolecular disulfide bonds. H47 mAb significantly enhanced PMA-induced proliferation of PBMC in a monocyte-independent fashion. H47 mAb, however, failed to enhance T cell proliferation induced by anti-CD3 mAb, anti-CD2 mAb, or phytohemagglutinin (PHA). H47 mAb also enhanced PMA-induced interleukin-2 receptor (IL-2R) expression and IL-2 synthesis, but did not induce a change in intracellular free calcium ([Ca2+]i) of T cells. These results suggest that H47 Ag is a new membrane molecule involved in PMA-induced T cell activation.
Hirohashi
N
N
Department of Immunology, Kurume University School of Medicine, Fukuoka, Japan.
Nakao
M
M
Kubo
K
K
Yamada
A
A
Shichijo
S
S
Hara
A
A
Sagawa
K
K
Itoh
K
K
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D000954:Antigens, Surface / Q000502:physiology*; D002118:Calcium / Q000097:blood; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology*; D051379:Mice; D009000:Monocytes / Q000276:immunology; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis; D011990:Receptors, Transferrin / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D011990:Receptors, Transferrin; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium