Association of human cytomegalovirus (HCMV) with mink and rabbit lung cells.

The association of human cytomegalovirus with mink and rabbit lung cells was studied. Strain AD-169 was used which was free of Mycoplasma and other contaminating agents. It was found to be incapable of productively infecting mink lung cells. Infection appeared to be initiated but aborted at an early stage. This was indicated by indirect immunofluorescence, assays of culture supernatants and cell lysates for infectious virus, electron microscopy of ultra-thin sections of infected cells, labelling of virus and viral DNA with 3H-thymidine and assay of virally-induced DNA polymerase at various times after infection. On the other hand, using these methods. AD-169 was found to infect rabbit lung cells, the virus being produced in low amounts over a period of up to one month after infection. At this time, focal areas of infection were still apparent and 15 per cent of the cells expressed nuclear viral antigens as shown by immunofluorescence. The viral genome was assumed to have become latent in some rabbit cells with a few being capable of producing infectious virus.