UNASSIGNED: In this study, we investigated the impact of the cell membrane composition of @entity797 on its recognition by the host immune system. To this end, we employed an @entity797 deletion mutant (  bgsA) that does not synthesize the major cell membrane glycolipid @entity70184 ( @entity43898 ). Proteomic analysis revealed that 13 of a total of 21 upregulated surface-associated proteins of @entity797   bgsA were lipoproteins. This led to a total lipoprotein content in the cell membrane of 35.8% in   bgsA compared to only 9.4% in wild-type bacteria. Increased lipoprotein content strongly affected the recognition of   bgsA by @entity19 macrophages in vitro with an increased stimulation of @entity637 production by heat-fixed bacteria and secreted antigens. Inactivation of the prolipoprotein @entity2366 transferase ( @entity5053 ) in   bgsA abrogated @entity637 induction by a   bgsA_lgt double mutant indicating that lipoproteins mediate increased activation of @entity19 macrophages by   bgsA. Heat-fixed   bgsA bacteria, culture supernatant, or cell membrane lipid extract activated transfected HEK cells in a TLR2-dependent fashion; the same was not true of wild-type bacteria. In @entity19 infected intraperitoneally with a sublethal dose of @entity797 we observed a 70% greater mortality in @entity19 infected with   bgsA compared with wild-type-infected @entity19 . Increased mortality due to   bgsA infection was associated with elevated plasma levels of the inflammatory cytokines @entity637 , IL-6 and MIP-2. In summary, our results provide evidence that an @entity797 mutant lacking its major bilayer forming glycolipid @entity43898 upregulates lipoprotein expression leading to increased activation of the host innate immune system and virulence in vivo.

XXXX Glycolipids Modulate Lipoprotein-Content of the Bacterial Cell Membrane and Host Immune Response.

@entity2366 :: ('CHEBI:41847', 'Chemical') :: ['diacylglycerol'] @entity19 :: ('10090', 'Species') :: ['mice', 'mouse'] @entity70184 :: ('MESH:C114516', 'Chemical') :: ['diglycosyl-diacylglycerol'] @entity43898 :: ('MESH:C025142', 'Chemical') :: ['DGlcDAG'] @entity797 :: ('1351', 'Species') :: ['E. faecalis'] @entity5053 :: ('11085', 'Species') :: ['lgt'] @entity637 :: ('21926(Tax:10090)', 'Gene') :: ['TNF-a']
@entity797 :: (1351,Species) :: ['Enterococcus faecalis']
