Bovine and mouse serum βinhibitors of influenza A viruses are annose-binding lectins

Abstract

Normal bovine and mouse sera contain a ponent, termed β inhibitor, that inhibits the infectivity and agglutinating activity of influenza A viruses of the H1 and subtypes. To investigate the nature of the interaction of β itors with influenza A viruses we isolated a mutant of the Mem71H-BelN (H3N1) that could grow in the presence of vine serum. The mutant virus was resistant to hemagglutiion inhibition by mouse serum as well as by bovine serum d had undergone changes in the receptor-binding and the genic properties of its hemagglutinin (HA) molecule. Sequence analysis of the HA genes of parent and mutant viruses ealed a single nucleotide change in the mutant, resulting in substitution Thr → A..