Isolation and structural characterization of an R‐form lipopolysaccharide from <i>Yersinia enterocolitica</i> serotype O:8

Oertelt, Clemens; Lindner, Buko; Skurnik, Mikael; Holst, Otto

doi:10.1046/j.1432-1327.2001.01891.x

Cited by 47 publications

(43 citation statements)

References 36 publications

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“…For Yersinia, Aussel et al (2) recently studied the lipid A structures of various species including Y. pestis. They presented the fully acylated structure of lipid A as a major molecule, but in other studies Yersinia was reported to have less-acylated lipid A (19,26). In our preliminary experiments we found that Y. pestis strain Yreka (a virulent strain) produced a lipid A containing 3-OH-C 14:0 as the only fatty acid component when grown at 37°C.…”

Section: Discussionmentioning

confidence: 50%

Modification of the Structure and Activity of Lipid A inYersinia pestisLipopolysaccharide by Growth Temperature

et al. 2002

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Yersinia pestis strain Yreka was grown at 27 or 37°C, and the lipid A structures (lipid A-27°C and lipid A-37°C) of the respective lipopolysaccharides (LPS) were investigated by matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry. Lipid A-27°C consisted of a mixture of tri-acyl, tetra-acyl, penta-acyl, and hexa-acyl lipid A's, of which tetra-acyl lipid A was most abundant. Lipid A-37°C consisted predominantly of tri-and tetra-acylated molecules, with only small amounts of penta-acyl lipid A; no hexa-acyl lipid A was detected. Furthermore, the amount of 4-amino-arabinose was substantially higher in lipid A-27°C than in lipid A-37°C. By use of mouse and human macrophage cell lines, the biological activities of the LPS and lipid A preparations were measured via their abilities to induce production of tumor necrosis factor alpha (TNF-␣). In both cell lines the LPS and the lipid A from bacteria grown at 27°C were stronger inducers of TNF-␣ than those from bacteria grown at 37°C. However, the difference in activity was more prominent in human macrophage cells. These results suggest that in order to reduce the activation of human macrophages, it may be more advantageous for Y. pestis to produce less-acylated lipid A at 37°C.Yersinia pestis was isolated as a causative agent of plague in Hong-Kong in 1894 independently by A. Yersin and S. Kitasato (3). Since then, this highly pathogenic bacterium has been investigated, and many virulence factors have been identified, including fraction 1 antigen, murine toxin, Yop proteins, pH 6 antigen, and iron acquisition systems (5, 28). Lipopolysaccharide (LPS) has also been studied for many decades as one of the virulence factors of Y. pestis, and its composition and endotoxic activity have been examined in earlier studies (1,40,41). By use of modern analytical methods, the LPS of Y. pestis was proven to be a rough type LPS without O-antigenic polysaccharide (7,8,25,29,30,35) that contains 3-hydroxy-myristic acid (3-OH-C 14:0 ) as a main fatty acid in the lipid A portion. However, there was a discrepancy in the amounts of the nonhydroxy-fatty acids found. Hartley et al. reported that nearly 90% of fatty acids in the lipid A of Y. pestis strain 195/R (a virulent strain) consisted of 3-OH-C 14:0 (14). On the other hand, considerable amounts of lauric acid (C 12:0 ), palmitic acid (C 16:0 ), and palmitoleic acid (C 16:1 ) were detected in the lipid A of Y. pestis strain EV40 (an avirulent strain) (4, 39). Using the same strain, Aussel et al. (2) proposed a hexa-acylated lipid A structure (four molecules of 3-OH-C 14:0 , one of C 12:0 , and one of C 16:1 ). In our preliminary experiment we isolated the lipid A from Y. pestis strain Yreka (virulent strain) grown at 37°C and found that it contained 3-OH-C 14:0 and only trace amounts of other fatty acids. A possible explanation of the controversy on fatty acids may be differences in strains or culture conditions. Darveau et al. (8) reported that the molecular size of the LPS from Y. pestis strain EV76 ...

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Section: Discussionmentioning

confidence: 50%

Modification of the Structure and Activity of Lipid A inYersinia pestisLipopolysaccharide by Growth Temperature

et al. 2002

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“…The supernatant was MG1655 grown in LB medium at 37°C. Interpretation of the negative-ion spectra is based on earlier studies showing that ions with masses higher than 1,000 gave signals proportional to the corresponding lipid A species present in the preparation (3,41,52,58). Important theoretical masses for the interpretation of peaks found in the present study were as follows: C 14:OH , 226; C 12 , 182, C 14 , 210; aminoarabinose (Ara4N), 131; and C 16 , 239.…”

Section: Methodsmentioning

confidence: 72%

Analysis of the Networks Controlling the Antimicrobial-Peptide-Dependent Induction of Klebsiella pneumoniae Virulence Factors

Campos²,

et al. 2011

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Antimicrobial peptides (APs) impose a threat to the survival of pathogens, and it is reasonable to postulate that bacteria have developed strategies to counteract them. Polymyxins are becoming the last resort to treat infections caused by multidrug-resistant Gram-negative bacteria and, similar to APs, they interact with the anionic lipopolysaccharide. Given that polymyxins and APs share the initial target, it is possible that bacterial defense mechanisms against polymyxins will be also effective against host APs. We sought to determine whether exposure to polymyxin will increase Klebsiella pneumoniae resistance to host APs. Indeed, exposure of K. pneumoniae to polymyxin induces cross-resistance not only to polymyxin itself but also to APs present in the airways. Polymyxin treatment upregulates the expression of the capsule polysaccharide operon and the loci required to modify the lipid A with aminoarabinose and palmitate with a concomitant increase in capsule and lipid A species containing such modifications. Moreover, these surface changes contribute to APs resistance and also to polymyxin-induced cross-resistance to APs. Bacterial loads of lipid A mutants in trachea and lungs of intranasally infected mice were lower than those of wild-type strain. PhoPQ, PmrAB, and the Rcs system govern polymyxin-induced transcriptional changes, and there is a cross talk between PhoPQ and the Rcs system. Our findings support the notion that Klebsiella activates a defense program against APs that is controlled by three signaling systems. Therapeutic strategies directed to prevent the activation of this program could be a new approach worth exploring to facilitate the clearance of the pathogen from the airways.

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“…We and others have observed that Y. enterocolitica modifies lipid A in response to temperature, producing less acylated lipid A at 37°C than at 21°C (9,52,58). These data led us to hypothesize that Y. enterocolitica late acyltransferases could be temperature controlled.…”

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Role of Lipid A Acylation in Yersinia enterocolitica Virulence

et al. 2010

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Yersinia enterocolitica is an important human pathogen. Y. enterocolitica must adapt to the host environment, and temperature is an important cue regulating the expression of most Yersinia virulence factors. Here, we report that Y. enterocolitica 8081 serotype O:8 synthesized tetra-acylated lipid A at 37°C but that hexa-acylated lipid A predominated at 21°C. By mass spectrometry and genetic methods, we have shown that the Y. enterocolitica msbB, htrB, and lpxP homologues encode the acyltransferases responsible for the addition of C 12 , C 14 and C 16:1 , respectively, to lipid A. The expression levels of the acyltransferases were temperature regulated. Levels of expression of msbB and lpxP were higher at 21°C than at 37°C, whereas the level of expression of htrB was higher at 37°C. At 21°C, an lpxP mutant was the strain most susceptible to polymyxin B, whereas at 37°C, an htrB mutant was the most susceptible. We present evidence that the lipid A acylation status affects the expression of Yersinia virulence factors. Thus, expression of flhDC, the flagellar master regulatory operon, was downregulated in msbB and lpxP mutants, with a concomitant decrease in motility. Expression of the phospholipase yplA was also downregulated in both mutants. inv expression was downregulated in msbB and htrB mutants, and consistent with this finding, invasion of HeLa cells was diminished. However, the expression of rovA, the positive regulator of inv, was not affected in the mutants. The levels of pYV-encoded virulence factors Yops and YadA in the acyltransferase mutants were not affected. Finally, we show that only the htrB mutant was attenuated in vivo.

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Isolation and structural characterization of an R‐form lipopolysaccharide from Yersinia enterocolitica serotype O:8

Cited by 47 publications

References 36 publications

Modification of the Structure and Activity of Lipid A inYersinia pestisLipopolysaccharide by Growth Temperature

Modification of the Structure and Activity of Lipid A inYersinia pestisLipopolysaccharide by Growth Temperature

Analysis of the Networks Controlling the Antimicrobial-Peptide-Dependent Induction of Klebsiella pneumoniae Virulence Factors

Role of Lipid A Acylation in Yersinia enterocolitica Virulence

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