ACTIVE IMMUNIZATION WITH RECOMBINANT V-ANTIGEN FROM YERSINIA-PESTIS PROTECTS MICE AGAINST PLAGUE

The gene encoding V antigen from Yersinia pestis was cloned into the p lasmid expression vector pGEX-5X-2. When electroporated into Escherich ia coli JM109, the recombinant expressed V antigen as a stable fusion protein with glutathione S-transferase. The glutathione S-transferase- V fusion protein was isolated from recombinant E. coli and cleaved wit h factor Xa to yield purified V antigen as a stable product Recombinan t V antigen was inoculated intraperitoneally into mice and shown to in duce a protective immune response against a subcutaneous challenge wit h 3.74 x 10(6) CFU of virulent Y. pestis. Protection correlated with t he induction of a high titer of serum antibodies and a T-cell response specific for recombinant V antigen. These results indicate that V ant igen should be a major component of an improved vaccine for plague.