Role of the Vibrio cholerae Matrix Protein Bap1 in Cross-Resistance to Antimicrobial Peptides

PLoS Pathogens

Annika E. Sjöström¹  Dharmesh Sabharwal¹  Bernt Eric Uhlin¹  Fatemeh Damghani¹  Sun Nyunt Wai¹  Marylise Duperthuy¹ 

[1] Department of Molecular Biology, The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden

关键词: Vibrio cholerae;    Outer membrane proteins;    Extracellular matrix proteins;    Immune serum;    Vesicles;    Binding analysis;    Bacteria;    Protein domains;   

DOI  :  10.1371/journal.ppat.1003620

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Outer membrane vesicles (OMVs) that are released from Gram-negative pathogenic bacteria can serve as vehicles for the translocation of effectors involved in infectious processes. In this study we have investigated the role of OMVs of the Vibrio cholerae O1 El Tor A1552 strain in resistance to antimicrobial peptides (AMPs). To assess this potential role, we grew V. cholerae with sub-lethal concentrations of Polymyxin B (PmB) or the AMP LL-37 and analyzed the OMVs produced and their effects on AMP resistance. Our results show that growing V. cholerae in the presence of AMPs modifies the protein content of the OMVs. In the presence of PmB, bacteria release OMVs that are larger in size and contain a biofilm-associated extracellular matrix protein (Bap1). We demonstrated that Bap1 binds to the OmpT porin on the OMVs through the LDV domain of OmpT. In addition, OMVs from cultures incubated in presence of PmB also provide better protection for V. cholerae against LL-37 compared to OMVs from V. cholerae cultures grown without AMPs or in presence of LL-37. Using a bap1 mutant we showed that cross-resistance between PmB and LL-37 involved the Bap1 protein, whereby Bap1 on OMVs traps LL-37 with no subsequent degradation of the AMP.

【 授权许可】

CC BY