Chrysanthemum virus B: antibodies to structural protein in mammals and Mg2(+)-dependent reverse-transcriptase activity.

Human plasma has been found to contain antibodies reacting with the structural protein of chrysanthemum virus B (CV-B) and about 10 times less intensively with the structural protein of another carlavirus, the potato virus M. It has been shown that the antibodies bind to CV-B through their F(ab)2 fragments. No reaction with proteins of other plant viruses or retroviruses was observed. Antibodies reacting with CV-B protein are also present in the plasma of green monkey, goat, rabbit, and mouse, their level being somewhat lower than in man. In addition, Mg2(+)-dependent reverse transcriptase activity reaching maximum at 37 degrees C was detected in the CV-B preparations. It is suggested that humans and the mammals in question developed antibodies to CV-B which could enter into some enzymatic reactions at the body temperature.