Effect of heat shock on Epstein-Barr virus and cytomegalovirus expression

The effect of heat shock was investigated on lymphoblastoid cell lines Raji and P3HR1 harbouring Epstein-Barr virus (EBV) genomes, and on Vero cells abortively infected with human cytomegalovirus (HCMV). A heat shock at 44 degrees C for 10 min induced the appearance of EBV early antigens in Raji cells and increased the percentage of cells expressing EBV viral capsid antigens in P3HR1 cells. Heat shock performed on Vero cells just before HCMV infection resulted in an approximately fourfold increase in the number of cells exhibiting early nuclear antigens, and in the appearance of HCMV-induced Fc receptors.