Activation of natural killer cells by the mAb YTA-1 that recognizes leukocyte function-associated antigen-1.
The mAb YTA-1, which brightly stains CD3-CD16+ large granular lymphocytes (LGL)/natural killer (NK) cells and CD8+ T cells by immunofluorescence, is specific for leukocyte function-associated antigen (LFA)-1. Some mAbs recognizing the LFA-1 alpha chain (CD11a) or LFA-1 beta chain (CD18) inhibited the binding of YTA-1 to peripheral blood mononuclear cells. YTA-1 mAb could be chemically cross-linked to 170 and 96 kDa molecules, whose molecular weights correspond to those of LFA-1 alpha and beta respectively. YTA-1 bound to COS-7 cells co-transfected with CD11a and CD18 cDNAs, but not to untransfected cells. Reactivities of YTA-1 to K562 cells transfected with LFA-1 alpha and beta (CD11a/CD18) cDNAs and to CHO cells transfected with Mac-1 (CD11b/CD18) or p150, 95 (CD11c/CD18) cDNAs strongly suggest that YTA-1 recognizes either LFA-1 alpha or an epitope formed by a combination of LFA-1 alpha and beta. Treatment of fresh CD3-CD16+ LGL with YTA-1 augmented cytolytic activity and induced proliferation. F(ab')2 fragments of YTA-1 augmented NK cytotoxicity, indicating that the NK activating signal was transmitted through LFA-1 without involvement of Fc gamma receptor III. In contrast, the other mAbs against LFA-1 could not activate NK cells. These results collectively indicate that YTA-1 recognizes a unique epitope of LFA-1, which is involved in activation of fresh NK cells.
Sugie
K
K
Department of Late Effect Studies, Radiation Biology Center, Kyoto University, Japan.
Nakamura
K
K
Teshigawara
K
K
Diamond
M S
MS
Springer
T A
TA
Nakamura
Y
Y
Leonard
W J
WJ
Uchida
A
A
Yodoi
J
J
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000937:Antigen-Antibody Reactions; D017252:CD3 Complex / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology* / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C
D000911:Antibodies, Monoclonal; D017252:CD3 Complex; D016169:Lymphocyte Function-Associated Antigen-1