EFFECT OF A STAPHYLOCOCCUS EPIDERMIDIS-EXTRACTED SLIME FACTOR ON HUMAN NATURAL-KILLER-CELL ACTIVITY

A slime factor produced by Staphylococcus epidermidis was a complex gl ycoconjugate extracted by the phenol extraction method. The potential stimulatory or inhibitory capacity of the phenol-extracted slime (PES) was tested on human natural killer cell cytotoxic activity. Various c oncentrations of the PES preparation were incubated with the effector cells 30 min before and during the assay period. The PES factor inhibi ted natural killer cell cytotoxic activity at a concentration of 250 m u g/ml and at higher concentrations (p < 0.05). The inhibition of natu ral killer cell cytotoxic activity may probably be related to the comp lex composition of the slime substance.