Transient infectivity and heterokaryon formation in hamster cell cultures inoculated with cell-associated stocks of Marek’s disease virus and herpesvirus of turkeys

Virus infectivity persisted for up to 10 serial passages in primary hamster kidney (HK) cultures inoculated with cell-associated Marek’s disease virus (MDV) or herpesvirus of turkeys (HVT). However, the direct correlation of infectivity with the persistence of at least 10⁶ inoculum cells/culture, the ablation of infectivity by treatment with cytotoxic anti-avian cell antibody, and the failure to infect HK cultures with high doses of cell-free MDV or HVT strongly indicated that infection was solely associated with inoculum-derived avian cells. Heterokaryons containing avian and hamster nuclei as well as viral antigens were observed in HK cultures inoculated with virus-infected avian cells, but the function of these heterokaryons in viral replication was uncertain. It was concluded that HK cells did not support persistent infection with, and were probably refractory to, the strains of MDV and HVT used.