YopM Plague Vaccine Component: Immunogenicity, Protectiveness, and Mode of Action

摘要

The plague virulence protein YopM was studied for immunogenicity, protectiveness,importance of its thrombin-binding, and its localization in infected tissue culture. YopM is highly immunogenic in mice, and human convalescent plague sera contain antibodies to YopM. However, YopM is not a good candidate for a subunit vaccine because it is not protective by either active or passive immunization. Further study is merited to determine whether diagnostic probes for Yersinia pestis could be based on yopM. In the cellular response to Y. pestjs infection of naive mice against plague, 0DB T cells were more important than were CD4 T cells, a finding with large implications for the pathogenesis of plague and for future efforts to improve the plague vaccine. Site-directed mutagenesis of yopM yielded mutants with normal thrombin-binding but that were as avirulent as a Y. pestis strain lacking Y6pM altogether, suggesting that thrombin-binding is not YopM's function in the pathogenesis of plague. YopM is mostly targeted into the cytosol of eukaryotic cells when Y. pestis adheres to them. There, YopM traffics in association with a vesicular pathway and enters the nucleus. This raises the possibility that YopM manipulates host gene expression.