Previous Article | Next Article ![]()
Infection and Immunity, May 2009, p. 1807-1816, Vol. 77, No. 5
0019-9567/09/$08.00+0 doi:10.1128/IAI.01162-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Department of Microbiology, University of Chicago, Chicago, Illinois 60637
Received 17 September 2008/ Returned for modification 26 October 2008/ Accepted 5 February 2009
Yersinia pestis is perhaps the most feared infectious agent due to its ability to cause epidemic outbreaks of plague disease in animals and humans with high mortality. Plague infections elicit strong humoral immune responses against the capsular antigen (fraction 1 [F1]) of Y. pestis, and F1-specific antibodies provide protective immunity. Here we asked whether Y. pestis generates mutations that enable bacterial escape from protective immunity and isolated a variant with an IS1541 insertion in caf1A encoding the F1 outer membrane usher. The caf1A::IS1541 insertion prevented assembly of F1 pili and provided escape from plague immunity via F1-specific antibodies without a reduction in virulence in mouse models of bubonic or pneumonic plague. F1-specific antibodies interfere with Y. pestis type III transport of effector proteins into host cells, an inhibitory effect that was overcome by the caf1A::IS1541 insertion. These findings suggest a model in which IS1541 insertion into caf1A provides for reversible changes in envelope structure, enabling Y. pestis to escape from adaptive immune responses and plague immunity.
Published ahead of print on 23 February 2009.
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»