Modulation of tumor cell susceptibility to humoral immune killing through chemical and physical manipulation of cellular lipid and fatty acid composition.
Line-10 tumor cells cultured for 24 hr in lecithin-rich normal human plasma or with synthetic lecithin showed a 5- to 8-fold increase in their lecithin:sphingomyelin mole ratio without being affected in their total lipid content or cholesterol:phospholipid mole ratio. These cells were more sensitive to killing by antibody plus complement (C) than untreated controls. Line-10 cells that underwent a homogeneously catalyzed hydrogenation reaction were reduced 6-fold in their content of unsaturated fatty acid compared to controls; the lipid content of these cells was largely unaffected. These cells were more resistant to antibody-C mediated killing than controls. These modifications in cellular lipid and fatty acid composition could be reversed when the cells were recultured for 24 hr in serum-containing tissue culture medium; the cells regained control levels of susceptibility to antibody-C killing at this time. These results suggest that by manipulating the lipid or fatty acid composition of a tumor cell, either indirectly by changing the lipid composition of the environment in which the cell resides or by directly altering the chemical nature of a cellular lipid constituent, the susceptibility of the cell to humoral immune killing can be modulated.
D000818:Animals; D000917:Antibody Formation; D002478:Cells, Cultured; D002784:Cholesterol / Q000097:blood; D005227:Fatty Acids / Q000378:metabolism*; D006168:Guinea Pigs; D006801:Humans; D007111:Immunity, Cellular; D050356:Lipid Metabolism; D008113:Liver Neoplasms / Q000276:immunology*; D008297:Male; D009374:Neoplasms, Experimental / Q000276:immunology*; D010713:Phosphatidylcholines / Q000494:pharmacology; D010743:Phospholipids / Q000097:blood; D014280:Triglycerides / Q000097:blood
D005227:Fatty Acids; D010713:Phosphatidylcholines; D010743:Phospholipids; D014280:Triglycerides; D002784:Cholesterol