Acute effects of ethanol on biosynthesis and glycosylation of IgGl(kappa) antibody molecules in cultured P3/X63-Ag8 myeloma cells.

Protein synthesis in cultured P3/X63-Ag8 mouse myeloma cells was inhibited by acute exposure to ethanol. However, the synthesis of IgGl antibody, as a percentage of total protein synthesis, increased slightly. Experiments using actinomycin D suggest that the overall inhibition of protein synthesis by ethanol occurs at the translational level. Following an L-[35S]methionine pulse, cultured P3/X63-Ag8 cells contained one light antibody polypeptide and two heavy antibody polypeptides. One of these heavy chains was shown to be the unglycosylated precursor of the other, mature molecule. Only the glycosylated polypeptide is a normal constituent of secreted IgGl antibody. The glycosylation of the immature heavy chains occurred more rapidly during a 1-hr isotopic pulse in cells exposed to ethanol (0.1 v/v % and above), than in unexposed control cells. The observed effects of ethanol on antibody glycosylation may be related to the increased susceptibility of alcoholic patients to infections. Ethanol may also affect the synthesis of other glycoproteins in myeloma cells and other tissues.