VIRAL-INFECTIONS AND IGM ANTO-ANTIBODIES TO CYTOPLASMIC INTERMEDIATE FILAMENTS

Abstract

Of 113 sera from patients with infectious hepatitis, chickenpox, measles and mumps, 74 reacted with smooth muscle and cytoplasmic filaments in cultured fibroblasts and neuroblastoma. Of 85 control sera, 5 reacted in this way. That the cytoplasmic structures are intermediate filaments was suggested by their rearrangement into coils of perinuclear filaments in colchicine- or vinblastine-treated fibroblasts but not in cytochalasin B-treated cells. The identity of these structures was confirmed by the demonstration that the same structures reacted with the post-viral sera and a rabbit and human anti-intermediate filament antibody [Ab]. Immunoabsorption studies showed that 27 out of 32 positive sera were neutralized by skeletin, the intermediate filament protein from smooth muscle. In all but 1 of the sera, the Ab was Ig[immunoglobulin]M. Ab titers fell in the 2nd specimen in 11 of 14 pairs of acute and convalescent sera. The association between viral infections and auto-Ab suggests that production of Ab to intermediate filaments may be initiated by viruses.