Detection of natural killer cells in Japanese quails

Spleen cells of normal quails exhibited cytotoxicity on normal embryo cells as well as on virus- and chemically transformed cells. Spleen cells responsible for the destruction of target cells were shown to be non-adherent lymphoid cells which lack surface immunoglobulin and are resistant to the treatment with anti-thymocyte serum and complement. Spleen cells of quails which were injected with chicken amniotic fluid (ChAmF) showed no cytotoxic activity. Furthermore, the addition of ChAmF-treated spleen cells abolished the cytotoxic activity of untreated spleen cells. These results indicated the presence of a spleen-cell population in normal quails compatible with mammalian natural killer (NK) cells and the induction of suppressor cells directed to the NK cells by administration of ChAmF.