Crosslinking of the CD5 antigen on human T cells induces functional IL2 receptors.
CD5 is a 67-kDa antigen that is expressed on the membrane of the majority of human T cells, and on a subset of B cells. Previous studies have demonstrated that anti-CD5 monoclonal antibodies (mAb) can provide a helper signal for T cell activation through the TCR/CD3 complex. We now demonstrate that when CD5 is crosslinked by immobilized anti-CD5 mAb in the absence of other activating stimuli, the T cells proliferate in response to recombinant interleukin 2 (rIL2) (but not to rIL4). Four different anti-CD5 mAb (anti-Leu1, 10.2, anti-T1, and OKT1) had a similar effect. IL2 responsiveness could be induced with immobilized anti-CD5 mAb in cultures of purified T cells, but was enhanced by the addition of monocytes, by monocyte culture supernatant, or by the combination of IL1 and IL6. Staining with an anti-IL2 receptor (p55) mAb demonstrated expression of IL2 receptors on about 10% of the anti-CD5-stimulated T cells. Both virgin (CD45RA+) and memory (CD45RO+) T cells were responsive. Our data provide further evidence for the involvement of CD5 in T cell activation.
Department of Internal Medicine and Pathophysiology, University of Leuven Faculty of Medicine, Belgium.
J
J
Verwilghen
R
R
Vandesande
P
P
Vandenberghe
J L
JL
Ceuppens
D000328:Adult; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000502:physiology*; D000943:Antigens, Differentiation / Q000502:physiology*; D018956:CD5 Antigens; D003432:Cross-Linking Reagents; D003470:Culture Media; D016207:Cytokines / Q000502:physiology; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000502:physiology; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000502:physiology; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis*; D013601:T-Lymphocytes / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D018956:CD5 Antigens; D003432:Cross-Linking Reagents; D003470:Culture Media; D016207:Cytokines; D007376:Interleukin-2; D015375:Receptors, Interleukin-2