Study identifies key protein enabling plague bacteria to evade mammalian immune system
Researchers found that a lipoprotein called SlyB helps Yersinia pestis bacteria resist the mammalian immune system at body temperature, particularly during bubonic plague infection. The protein is essential for surviving neutrophil attacks in lymph nodes but is not needed for flea colonization or septicemic plague. The discovery reveals how plague bacteria have evolved specific mechanisms to establish infection in mammals while maintaining their natural cycle in fleas.
A new study published on bioRxiv demonstrates that the outer membrane lipoprotein SlyB plays a critical role in Yersinia pestis pathogenesis by enabling the bacteria to tolerate immune stress in mammalian hosts. Using phylogenetic analysis and infection models in rodents and fleas, researchers showed that SlyB was under negative selective pressure during plague bacteria evolution, suggesting its importance was refined over time. The protein is specifically required for resisting neutrophil-mediated antimicrobial activity during lymph node colonization in bubonic plague, but is dispensable in septicemic plague and flea infection. This temperature-dependent function—critical at mammalian body temperature (37°C) but not at lower arthropod temperatures—reflects how plague bacteria have adapted to their dual-host lifecycle. The findings connect SlyB function to the bacteria's lipopolysaccharide structural changes, providing insight into the molecular mechanisms underlying bubonic plague establishment.
What's missing
The study does not discuss potential therapeutic applications of targeting SlyB, nor does it address whether SlyB inhibition might be viable as a treatment strategy for plague infections.
What different sources said
- bioRxivCenter
Yersinia pestis lipoprotein SlyB promotes plague pathogenesis via envelope stress tolerance
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