Impact of 4 Lactobacillus plantarum capsular polysaccharide clusters on surface glycan composition and host cell signaling

Microbial Cell Factories

Research

Richard van Kranenburg¹  Nico Taverne²  Jerry M Wells²  Roger S Bongers³  Michiel Wels³  Iris I van Swam³  Michiel Kleerebezem⁴  Peter A Bron⁵  Daniela M Remus⁶ 

[1] Purac, P.O. Box 20, 4200 AA, Gorinchem, The Netherlands;TI Food & Nutrition, Nieuwe Kanaal 9A, 6709 PA, Wageningen, The Netherlands;Host-Microbe Interactomics Group, Wageningen University, De Elst 1, 6708 WD, Wageningen, The Netherlands;TI Food & Nutrition, Nieuwe Kanaal 9A, 6709 PA, Wageningen, The Netherlands;NIZO food research, Kernhemseweg 2,, 6718 ZB, Ede, The Netherlands;TI Food & Nutrition, Nieuwe Kanaal 9A, 6709 PA, Wageningen, The Netherlands;NIZO food research, Kernhemseweg 2,, 6718 ZB, Ede, The Netherlands;Host-Microbe Interactomics Group, Wageningen University, De Elst 1, 6708 WD, Wageningen, The Netherlands;TI Food & Nutrition, Nieuwe Kanaal 9A, 6709 PA, Wageningen, The Netherlands;NIZO food research, Kernhemseweg 2,, 6718 ZB, Ede, The Netherlands;Kluyver Centre for Genomics of Industrial Fermentation, P.O. Box 5057, 2600 GA, Delft, The Netherlands;TI Food & Nutrition, Nieuwe Kanaal 9A, 6709 PA, Wageningen, The Netherlands;NIZO food research, Kernhemseweg 2,, 6718 ZB, Ede, The Netherlands;Laboratory for Microbiology, Wageningen University, Dreijenplein 10, 6703 HB, Ede, The Netherlands;

关键词: Lactobacillus plantarum;    Probiotic;    Surface polysaccharides;    Host cell signaling;    TLR2 activation;   

DOI  :  10.1186/1475-2859-11-149

 received in 2012-08-28, accepted in 2012-11-08,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundBacterial cell surface-associated polysaccharides are involved in the interactions of bacteria with their environment and play an important role in the communication between pathogenic bacteria and their host organisms. Cell surface polysaccharides of probiotic species are far less well described. Therefore, improved knowledge on these molecules is potentially of great importance to understand the strain-specific and proposed beneficial modes of probiotic action.ResultsThe Lactobacillus plantarum WCFS1 genome encodes 4 clusters of genes that are associated with surface polysaccharide production. Two of these clusters appear to encode all functions required for capsular polysaccharide formation (cps2A-J and cps4A-J), while the remaining clusters are predicted to lack genes encoding chain-length control functions and a priming glycosyl-transferase (cps1A-I and cps3A-J). We constructed L. plantarum WCFS1 gene deletion mutants that lack individual (Δcps1A-I, Δcps2A-J, Δcps3A-J and Δcps4A-J) or combinations of cps clusters (Δcps1A-3J and Δcps1A-3I, Δcps4A-J) and assessed the genome wide impact of these mutations by transcriptome analysis. The cps cluster deletions influenced the expression of variable gene sets in the individual cps cluster mutants, but also considerable numbers of up- and down-regulated genes were shared between mutants in cps cluster 1 and 2, as well as between mutant in cps clusters 3 and 4. Additionally, the composition of overall cell surface polysaccharide fractions was altered in each mutant strain, implying that despite the apparent incompleteness of cps1A-I and cps3A-J, all clusters are active and functional in L. plantarum. The Δcps1A-I strain produced surface polysaccharides in equal amounts as compared to the wild-type strain, while the polysaccharides were characterized by a reduced molar mass and the lack of rhamnose. The mutants that lacked functional copies of cps2A-J, cps3A-J or cps4A-J produced decreased levels of surface polysaccharides, whereas the molar mass and the composition of polysaccharides was not affected by these cluster mutations. In the quadruple mutant, the amount of surface polysaccharides was strongly reduced. The impact of the cps cluster mutations on toll-like receptor (TLR)-mediated human nuclear factor (NF)-κB activation in host cells was evaluated using a TLR2 reporter cell line. In comparison to a L. plantarum wild-type derivative, TLR2 activation remained unaffected by the Δcps1A-I and Δcps3A-J mutants but appeared slightly increased after stimulation with the Δcps2A-J and Δcps4A-J mutants, while the Δcps1A-3J and Δcps1A-3J, Δcps4A-J mutants elicited the strongest responses and clearly displayed enhanced TLR2 signaling.ConclusionsOur study reveals that modulation of surface glycan characteristics in L. plantarum highlights the role of these molecules in shielding of cell envelope embedded host receptor ligands. Although the apparently complete cps clusters (cps2A-J and cps4A-J) contributed individually to this shielding, the removal of all cps clusters led to the strongest signaling enhancement. Our findings provide new insights into cell surface glycan biosynthesis in L. plantarum, which bears relevance in the context of host-cell signaling by probiotic bacteria.

【 授权许可】

Unknown   
© Remus et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.