EFFECT OF ENDOTOXIN ON CELLS AND ON THEIR RESPONSE TO INFECTION BY POLIOVIRUSES

Abstract

The effect of lipopolysaccharide on HeLa-S3, HeLa-Gey, Chang-liver, Maben, and L strain mouse fibroblasts was studied. The liminal dose of endotoxin for the human epithelial cell strains was approximately 250 [mu]g/ml, and their order of sensitivity to endotoxin was: Chang-liver, HeLa-Gey, HeLa-S3, and Maben, the latter being the most resistant. Endotoxin at concentrations exceeding 100 [mu]g/ml was cytotoxic to the L strain of mouse fibroblasts and caused them to markedly agglutinate. Cytotoxic response of cells to endotoxin was not characterized by cell lysis, but by distinctive nuclear changes. In an attempt to demonstrate the metabolic induction of the latent infection of cell cultures by a noncytopathic variant of poliovirus, endotoxin was added to maximal subliminal concentration to cell cultures totally, partially, or fully susceptible to virus. Endotoxin caused a slight but consistent accelerative cytopathic response of cells to infection by cytopathic poliovirus, but failed to induce cytopathic response to infection by submoderate (noncytopathic) poliovirus. Although endotoxin slightly suppressed yields of poliovirus from cells, it did not affect the plating efficiency of virus on cell monolayers.