Variations in<i>Helicobacter pylori</i>Lipopolysaccharide To Evade the Innate Immune Component Surfactant Protein D

Khamri, Wafa; Moran, Anthony P.; Worku, Mulugeta; Karim, Q. N.; Walker, Marjorie M.; Annuk, Heidi; Ferris, John A.; Appelmelk, Ben J.; Eggleton, Paul; Reid, Kenneth B.M.; Thursz, Mark

doi:10.1128/iai.73.11.7677-7686.2005

Cited by 54 publications

(53 citation statements)

References 61 publications

(58 reference statements)

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“…3C, increasing concentrations of LPS significantly decreased Sp-D binding to SIRP␣. We observed 50% inhibition of Sp-D binding to SIRP␣ at a concentration of ϳ40 g/ml LPS, which is consistent with previous reports (39).…”

Section: Sp-d Binding To Sirp␣ Is Calcium-dependent Carbohydratespecsupporting

confidence: 82%

Surfactant Protein D (Sp-D) Binds to Membrane-proximal Domain (D3) of Signal Regulatory Protein α (SIRPα), a Site Distant from Binding Domain of CD47, while Also Binding to Analogous Region on Signal Regulatory Protein β (SIRPβ)

Fournier

Andargachew

Robin

et al. 2012

Journal of Biological Chemistry

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Section: Sp-d Binding To Sirp␣ Is Calcium-dependent Carbohydratespecsupporting

confidence: 82%

Surfactant Protein D (Sp-D) Binds to Membrane-proximal Domain (D3) of Signal Regulatory Protein α (SIRPα), a Site Distant from Binding Domain of CD47, while Also Binding to Analogous Region on Signal Regulatory Protein β (SIRPβ)

Fournier

Andargachew

Robin

et al. 2012

Journal of Biological Chemistry

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“…Varying the overall frequency of Lewis antigen expressors within a H. pylori population would be one mechanism whereby H. pylori modulates the inf lammatory response within the stomach (25,26). We envision that, in a persistent infection of a human stomach, a number of variants of a strain exist, and each isolate is more or less unique with respect to surface molecules, such as LPS.…”

Section: Discussionmentioning

confidence: 99%

An enzymatic ruler modulates Lewis antigen glycosylation of Helicobacter pylori LPS during persistent infection

Nilsson

Skoglund

Moran

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

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“…Thus, the capacity to produce multiple phase-variable capsular polysaccharides creates diverse populations with regard to surface architecture, including some that would be less susceptible to attack by deleterious products. Indeed, many pathogenic bacteria and parasites have evolved mechanisms by which they alter their surface antigenicity to persist in the host (26)(27)(28).…”

Section: Discussionmentioning

confidence: 99%

Role of glycan synthesis in colonization of the mammalian gut by the bacterial symbiont Bacteroides fragilis

Coyne

Chatzidaki‐Livanis

Paoletti

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

102

104

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Bacteroides species are the most abundant Gram-negative bacteria of the human colonic microbiota. These endogenous organisms are unique in that they synthesize an extensive number of phase-variable surface polysaccharides. Pathogenic bacteria phase vary expression of surface molecules for immune evasion, but the importance of the synthesis of multiple phase-variable polysaccharides to these commensal bacteria is unknown. We previously showed that a Bacteroides fragilis mutant unable to synthesize 4 of the 8 capsular polysaccharides and unable to glycosylate proteins properly is rapidly outcompeted by the wild-type strain for colonization of the gnotobiotic mouse intestine. In the present study, we constructed mutants defective only in capsule polysaccharide synthesis to define better the importance of these surface molecules to intestinal colonization. We discovered a key enzymatic activity required for synthesis of 7 of the 8 capsular polysaccharides. Deletion of its gene resulted in the first B. fragilis mutant able to synthesize only one phase-variable polysaccharide, and further mutation resulted in a stable acapsular mutant. We show that the acapsular mutant is rapidly outcompeted, but synthesis of a single polysaccharide is sufficient for the organism to colonize the gnotobiotic intestine competitively. These data demonstrate that initial colonization of the gnotobiotic mouse intestine by B. fragilis requires that the organism synthesize only a single polysaccharide and suggest that the synthesis of multiple phase-variable polysaccharides is important for the bacteria's long-term maintenance in the normally complex and competitive ecosystem. acapsular ͉ microbiota ͉ phase variation ͉ polysaccharide ͉ glycoprotein T he human intestinal tract is home to a vast and diverse alliance of microbes comprising one of the densest microbial ecosystems in the world and one that provides functions essential to human health. Many species of the order Bacteroidales are abundant members of the human intestinal microbiota and have served as models for studying mutualistic bacterial-host relationships in this ecosystem (1, 2). Despite their importance, relatively little is known about the biology of the predominant members of this ecosystem. Deciphering how these mutualistic microorganisms successfully and stably colonize the human intestine may help us understand how they are tolerated, how different members interact with one another, what additional benefits the microbiota provide us, and how microbiotaassociated diseases are triggered in the susceptible host.The intestinal Bacteroidales synthesize a vast repertoire of surface glycans. A single strain of B. fragilis synthesizes 8 distinct capsular polysaccharides (3), an extracellular polysaccharide (4), and numerous glycoproteins (5). The synthesis of extensive numbers of glycosylated molecules is a general property of the intestinal Bacteroidales (6-8). We estimate that the genome of B. fragilis 9343 encodes Ϸ80 glycosyltransferases and dedicates at least 215,000 bp of ...

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Variations inHelicobacter pyloriLipopolysaccharide To Evade the Innate Immune Component Surfactant Protein D

Cited by 54 publications

References 61 publications

Surfactant Protein D (Sp-D) Binds to Membrane-proximal Domain (D3) of Signal Regulatory Protein α (SIRPα), a Site Distant from Binding Domain of CD47, while Also Binding to Analogous Region on Signal Regulatory Protein β (SIRPβ)

Surfactant Protein D (Sp-D) Binds to Membrane-proximal Domain (D3) of Signal Regulatory Protein α (SIRPα), a Site Distant from Binding Domain of CD47, while Also Binding to Analogous Region on Signal Regulatory Protein β (SIRPβ)

An enzymatic ruler modulates Lewis antigen glycosylation of Helicobacter pylori LPS during persistent infection

Role of glycan synthesis in colonization of the mammalian gut by the bacterial symbiont Bacteroides fragilis

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