Cell-free varicella-zoster virus in tissue culture

Abstract
Infected human thyroid tissue cultures have been found to yield free V-Z virus on ultrasonic disintegration and some virus is also present in the fluid phase of intact tissue cultures, while the yield of virus from infected human amnion cells is very low and no free virus is found in the fluid phase. Thyroid cultures are more susceptible to infection with V-Z virus, and the infected cultures are a better source of complement-fixing antigen, than are amnion cultures.The lack of free virus in infected amnion tissue cultures cannot be attributed to protection by interferon. It also seems likely that if any infectious virus were released it would be more likely to be adsorbed to normal cells than to be inactivated, but as no secondary foci appear in amnion monolayers we conclude that infective virus is not released into the medium.It is suggested that the virus in thyroid cells is present in a more complete form than that in amnion cells.We are grateful to Dr R. M. Rawcliffe of Birkenhead General Hospital and Dr F. Whitwell of Broadgreen Hospital, Liverpool, for arranging the supply of thyroid tissue.