Correlation between canine NK cell mediated cytotoxicity and radical production

We investigated the relationship between natural killer (NK) mediated cytotoxicity and radical production in canine peripheral blood lymphocytes (PBLs). Canine NK cell mediated cytotoxicity, measured by 51Cr release assay, was found to be the highest in the T-cell (Thymus cell) subpopulation which partitioned into the 35–40% percoll fraction by centrifugation through a discontinuous gradient. Radical production showed a similar tendency in luminol-dependent chemiluminescence (CL) assay. Furthermore, enrichment of large granular lymphocytes (LGL) was observed in the cell fraction from the same percoll density. These results suggest that NK cell mediated cytotoxicity is related to radical production in canines.