Reduction in immunoreactivity of varicella-zoster virus proteins induced by mycoplasma contamination.

During the study of protein differences between several strains of varicella-zoster virus (VZV), two of the strains were found to be contaminated with Mycoplasma hyorhinis. Polyacrylamide gel electrophoresis showed fourteen extra bands present in MRC5 fibroblasts infected with these strains compared to other strains of VZV. A more striking difference was observed when infected cultures were used as antigens in immunoblotting. Certain viral proteins, corresponding in molecular weight to the viral glycoproteins, showed greatly reduced immunoreactivity. Experimental contamination of a mycoplasma-free strain of VZV with the glucose fermenting M. hyorhinis produced similar effects on immunoreactivity, while contamination with the arginine-hydrolysing M. orale produced no detectable effects. Given these data, it appears likely that the glucose-fermenting species induced significant changes in the VZV glycoproteins, possibly by depletion of sugars or interference in glycosylation pathways. The implications of this are discussed.