PMID: 8955177Dec 15, 1996Paper

Preferential involvement of Go and Gz proteins in mediating rat natural killer cell lysis of allogeneic and tumor target cells

The Journal of Immunology : Official Journal of the American Association of Immunologists
A A MaghazachiB Rolstad

Abstract

IL-2-activated NK cells from PVG rats potently lyse target cells expressing allo-MHC class I determinants. Here, we investigated the role that G proteins play in mediating this activity. Pretreatment of NK cells with pertussis toxin (PT) or cholera toxin (CT) inhibited NK cell killing of tumor (YAC-1 or P815), and allogeneic target cells. ADP ribosylation assay revealed that PT ADP ribosylates a 39-kDa G protein, whereas CT ADP ribosylates a 45 to 47-kDa G protein in PVG NK cell membranes. Membranes prepared from intoxicated NK cells with either PT or CT lost their ability to incorporate [32P]NAD. These membranes possess Gi, Go, Gs, and Gz as demonstrated by immunoblot analysis. However, Gq was not clearly detected by this method. IL-2-activated NK cells were permeabilized with streptolysin O. Permeabilized cells incorporated Abs to Gi, Go, Gz, Gs, and Gq as determined by flow cytometric analysis. When Abs to Go or Gz, but not to Gi, Gs, or Gq, were incorporated inside permeabilized NK cells, a significant reduction in the lysis of tumor or allo-MHC target cells was observed, suggesting that Go and Gz play important roles in transducing the signals necessary to lyse target cells. Our results show for the first time a role for G...Continue Reading

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