Spectrum of Human Cytomegalovirus Complement-Fixing Antigens

Abstract

Summary The antigenic properties of two strains of monkey cytomegalovirus (CMV) were analyzed and compared with several human CMV strains. Analysis of the strains was made possible by utilization of selective cross-reactive sera obtained from African green monkeys recently taken into captivity. A uni-directional cross of complement-fixing (CF) reactivity was demonstrated in that certain monkey sera reacted with both monkey and some, but not all, human CMV strains; however, human sera reacted only with human CMV. In contrast, the serum neutralization reactions with these two systems were species specific; monkey sera neutralized only simian CMV strains and human sera neutralized only human CMV strains. Monkey sera which contained CF antibodies against simian CMV gave a spectrum of reactivity when tested with five different strains of human CMV. About 90% of these monkey sera reacted with human CMV strain AD-169 but none reacted with strain C-87. Approximately 50% of these sera reacted with strains BC-13 and L-38E and 25% reacted weakly with the Davis strain. It was concluded that the various human CMV strains possess overlapping mosaics of CF antigens which can be differentiated with sera obtained from monkeys naturally infected with simian CMV.