A New Host-Virus System.

Abstract
A new host-virus system is described. The virus is the WS strain of Type A influenza virus, and the host cell is the Ehrlich ascitic carcinoma of mice. The virus was adapted to culture in this tissue and has been maintained through 38 serial passages. The growth characteristics during a single passage have been described. The first increase in infectious titer occurs in the interval of 4 to 6 hrs. after inoculation of the virus, and the maximum titer, 10-6.5, is obtained by 28 to 30 hrs. Associated with the multiplication of this virus is a loss of viability of the host cell. The effect of this phenomenon on the course of development of an established ascitic tumor has been followed. The infected cell culture showed a marked aggregation and a decrease in extracellular fluid by 2 days after inoculation with virus. By the 7th day after the addition of the virus, the tumor bearing mice appeared normal. On sacrificing these animals only small aggregates of cells could be found in the peritoneal cavity. The importance of this new host-virus system as a tool for the study of the mechanism of viral multiplication is discussed.