1985 Volume 38 Issue 5 Pages 305-309
The formation of intranuclear inclusion body (IB) in feline lung cell line cells by mink enteritis virus (MEV) was inhibited nonspecifically by bovine serum. The mechanism of the inhibition of IB and the nature of the inhibitor were examined. Commercially available calf serum (CS) inhibited the formation of IB remarkably, but the inhibitory activity of fetal calf serum (FCS) was weak. The inhibitory activity of CS decreased remarkably after treatment with one of ethyl ether, trypsin, receptor-destroying enzyme, and potassium periodate, but not with kaolin, acetone, or heparin.
The inhibitory activity of CS was observed in the IgG and other pooled fractions. In FCS it was observed in the IgG fraction only. The inhibitor was absorbed by normal tissue culture cells, but did not combine with viral particles. Therefore, it was deduced that the inhibitor attached itself to the surface of the cell, thereby preventing the penetration of the virus. This inhibitor was considered to be different from those which nonspecifically inhibited the hemagglutination of MEV, and which were persent in both CS and FCS.
