Induction of human T cell proliferation by a monoclonal antibody to CD5.
A mouse mAb, TS 43, which recognized the human CD5 molecule, was found to induce the proliferation of human peripheral blood T cells. TS 43 mAb precipitated from 125I-radiolabeled T cells a 67-kDa band, which comigrated with the 67-kDa band precipitated by the anti-CD5 mAb OKT1. Preclearing of cell lysates with OKT1 mAb abolished the capacity of TS 43 mAb to precipitate radiolabeled material from T cell lysates. Furthermore, a mouse T cell hybridoma transfected with human CD5 was stained by TS 43 mAb. T cell proliferation mediated by TS 43 mAb was monocyte dependent, and was accompanied by IL-2R expression and by IL-2 synthesis. T cell activation by TS 43 mAb involved a rise in intracellular calcium level (CA2+)i and was dependent on the expression of the TCR/CD3 complex because no rise in (Ca2+)i was observed in a TCR-beta-deficient Jurkat T cell mutant. This study indicates that CD5 should be added to the list of surface molecules that can signal T cells to proliferate.
Spertini
F
F
Division of Immunology, Children's Hospital, Boston, MA 02115.
Stohl
W
W
Ramesh
N
N
Moody
C
C
Geha
R S
RS
D000911:Antibodies, Monoclonal / Q000276:immunology*; D015703:Antigens, CD / Q000276:immunology*; D000943:Antigens, Differentiation / Q000276:immunology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology; D017252:CD3 Complex; D018956:CD5 Antigens; D002118:Calcium / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D015375:Receptors, Interleukin-2 / Q000276:immunology; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D018956:CD5 Antigens; D007376:Interleukin-2; D011948:Receptors, Antigen, T-Cell; D015375:Receptors, Interleukin-2; D002118:Calcium