Cytotoxic effect of the thoracic-duct-lymph incubated on lymphocytes

It was found that lymphocytes cultured in the medium containing chyle were remarkably suppressed in responding to phytohemagglutinin as compared with the control culture without the fluid. This suppressive effect on the cell type seemed likely to be induced by cytotoxic substance produced from the fluid incubated. Various lipids were separated from the incubated-chyle by thin-layer and gas-liquid chromatographies and then their cytotoxic activity to the lymphocytes was examined. These experimental results suggested that unsaturated free fatty acids, made possibly from chylomicron by lipoprotein lipase, had a capability to cause lymphocytolysis. The patho-physiological and immunological significance of the cytotoxic products was discussed.