Two distinct porcine natural killer lytic trigger molecules as PNK-E/G7 molecular complex.
PNK-E and G7 mAbs regulate porcine NK and ADCC activities by binding to distinct NK function-associated trigger molecules on porcine NK cells. Previous work demonstrates that PNK-E mAb binds to a 205-kDa tetrameric molecule composed of two 47-kDa peptides and two 50-kDa peptides and G7 mAb binds to a distinct 40-kDa heterodispersed monomeric peptide on porcine NK cells. The data presented herein demonstrate that all PNK-E+ PBLs are G7+ and all G7+ PBLs are PNK-E+ indicating that the PNK-E and G7 molecules are coexpressed by porcine NK cells. Bound G7 mAb blocks subsequent binding of PNK-E mAb but not the converse. Bound F(ab')2 G7 mAb abrogates the ability of whole PNK-E mAb to enhance NK activity but bound F(ab')2 PNK-E mAb has no affect on G7 mAb enhancement of NK activity. PNK-E mAb enhanced NK activity is inhibited by binding of F(ab')2 G7 mAb even though whole PNK-E mAb remains bound. However, bound F(ab')2 PNK-E mAb has no affect on G7 mAb-enhanced NK activity. When PNK-E and G7 mAbs were tested alone and together in NK assays, comparable levels of enhancement were observed. PNK-E and G7 hybridomas express surface mAb through which NK cells bind and specifically lyse these hybridomas. Lysis of PNK-E and G7 hybridomas is inhibited by pretreatment of PBLs with F(ab')2 G7 mAb. These data indicate a physical association between the PNK-E and G7 molecules on NK cells and suggest that the G7 molecule is external to the PNK-E molecule.
Wierda
W G
WG
Department of Microbiology and Immunology, University of Health Sciences, Chicago Medical School, North Chicago, Illinois 60064.
Johnson
B D
BD
Dato
M E
ME
Kim
Y B
YB
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002469:Cell Separation; D002499:Centrifugation, Density Gradient; D003602:Cytotoxicity, Immunologic; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011971:Receptors, Immunologic / Q000737:chemistry* / Q000502:physiology; D013552:Swine; D013556:Swine, Miniature; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D007140:Immunoglobulin Fab Fragments; D011971:Receptors, Immunologic