[Interaction of the Sindbis virus and Rauscher and Friend leukoviruses in primary cultures and subcultures of mouse fibroblasts in the early stages of persistence].

The interaction between Friend and Raucher leukoviruses and Sindbis togavirus was studied in primary cultures of mouse fibroblasts and subcultures passaged for 77 days. In primary cultures, two types of virus interactions were observed: neutralism and interference. In interference, the release of the infectious Sindbis virus from the cells is blocked. According to electron microscopic observations, its reproduction terminates by formation of virus nucleocapsid. The blocking of the togavirus maturation is stable in primary cultures but reversible upon subcultivation of the cells infected with oncorna- and togavirus. Rauscher and Sindbis viruses are capable of joint persistence in subcultures with a gradual decrease of the infectivity of togavirus and the leukemogenic activity of oncornavirus.