[Cytotoxic activity and activation ability of Syrian hamster NK cells isolated in the Percoll density gradient].

Natural killer cells possessing cytotoxic activity (CTA) and the ability to be activated by an interferon inductor and Newcastle disease virus, were isolated from blood, spleen and bone marrow of Syrian hamsters in the discontinuous Percoll density gradient. According to morphological criteria these cells were identified as large granular lymphocytes (LGL). The largest amount of LGL was isolated in the fraction containing 52-55% Percoll. CTA of cells from this fraction was the highest as compared to nonfractionated control or cells from other Percoll fractions. Effective (3-fold) activation of bone marrow cells isolated in the fraction of 49% Percoll with initially low CTA suggests that this Percoll fraction contains noncytotoxic precursors of NK cells.