POLYKARYOCYTOSIS INDUCED BY VIRUSES

Abstract

The conditions required for the induction of polykaryocytes by herpes simplex virus and measles virus and some properties of these multinucleated cells suggest that they arise by fusion of functioning cells differing in some phenotypic characteristic. It is postulated that polykaryocyte-inducing viruses cause some disturbance in cells manifest in an altered cell membrane. The altered membrane of the infected cell fuses with membranes of uninfected cells giving rise to a polykaryo-cyte. True polykaryocytes arise after the fused cells do not participate equally in the process of fusion as evident from the fact that uninfected cells which lost capacity to initiate polykaryocytes may still fuse with a polykaryocyte initiated in another cell. The mechanism by which viruses induce polykaryocytes is not understood. Attention has been drawn to the fact that a variety of other, nonviral agents induce "foreign body giant cells" or Langhans-type giant cells which resemble the polykaryocytes and true polykaryocytes, respectively, characterized in this communication.