Human T cell activation. IV. T cell activation and proliferation via the early activation antigen EA 1.
A new mAb G38 was generated against purified EA 1, an early activation antigen. In immunoprecipitation, it was reactive with the same complex precipitated by the initial anti-EA 1 mAb P8. mAb G38 augmented PMA-induced proliferation of PBMC. It was shown to be mitogenic for purified T cells in collaboration with PMA in a dose-dependent manner. This effect was independent of monocytes and other accessory cells. mAb G38 augmented PMA-induced IL-2-R expression. In conjunction with PMA, it induced IL-2 synthesis and secretion. Its effects on IL-2-R and IL-2 expression were documented at both protein and mRNA levels. Both anti-EA 1 mAbs did not induce Ca2+ influx by themselves in PMA-treated T cells. However, the addition of second anti-mouse Ig antibodies induced readily detectable increases in [Ca2+]i. Ca2+-mediated pathways may be utilized as the transduction signal mechanisms. mAb Leu-23 was shown to be reactive with EA 1. mAb Leu-23 was also mitogenic for T cells in the presence of PMA. These findings provide evidence for a functional role for EA 1 in T cell activation and proliferation.
Nakamura
S
S
Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City 73104.
Sung
S S
SS
Bjorndahl
J M
JM
Fu
S M
SM
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D002118:Calcium / Q000378:metabolism; D002455:Cell Division; D000939:Epitopes / Q000276:immunology; D006801:Humans; D007163:Immunosorbent Techniques; D007376:Interleukin-2 / Q000096:biosynthesis / Q000235:genetics; D037181:Lectins, C-Type; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D000099192:CD69 Antigens
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D002118:Calcium; D000939:Epitopes; D007376:Interleukin-2; D037181:Lectins, C-Type; D012333:RNA, Messenger; D013755:Tetradecanoylphorbol Acetate; D000099192:CD69 Antigens