Role of Yops and Adhesins in Resistance of Yersinia enterocolitica to Phagocytosis

ABSTRACT Yersinia enterocolitica is a pathogen endowed with two adhesins, Inv and YadA, and with the Ysc type III secretion system, which allows extracellular adherent bacteria to inject Yop effectors into the cytosol of animal target cells. We tested the influence of all of these virulence determinants on opsonic and nonopsonic phagocytosis by PU5-1.8 and J774 mouse macrophages, as well as by human polymorphonuclear leukocytes (PMNs). The adhesins contributed to phagocytosis in the absence of opsonins but not in the presence of opsonins. In agreement with previous results, YadA counteracted opsonization. In every instance, the Ysc-Yop system conferred a significant level of resistance to phagocytosis. Nonopsonized single-mutant bacteria lacking either YopE, -H, -T, or -O were phagocytosed significantly more by J774 cells and by PMNs. Opsonized bacteria were phagocytosed more than nonopsonized bacteria, and mutant bacteria lacking either YopH, -T, or -O were phagocytosed significantly more by J774 cells and by PMNs than were wild-type (WT) bacteria. Opsonized mutants lacking only YopE were phagocytosed significantly more than were WT bacteria by PMNs but not by J774 cells. Thus, YopH, -T, and -O were involved in all of the phagocytic processes studied here but YopE did not play a clear role in guarding against opsonic phagocytosis by J774. Mutants lacking YopP and YopM were, in every instance, as resistant as WT bacteria. Overexpression of YopE, -H, -T, or -O alone did not confer resistance to phagocytosis, although it affected the cytoskeleton. These results show that YopH, YopT, YopO, and, in some instances, YopE act synergistically to increase the resistance of Y. enterocolitica to phagocytosis by macrophages and PMNs.

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Resistance of Capnocytophaga canimorsus to Killing by Human Complement and Polymorphonuclear Leukocytes

Infection and Immunity ◽

10.1128/iai.01324-08 ◽

2009 ◽

Vol 77 (6) ◽

pp. 2262-2271 ◽

Cited By ~ 32

Author(s):

Hwain Shin ◽

Manuela Mally ◽

Salome Meyer ◽

Chantal Fiechter ◽

Cécile Paroz ◽

...

Keyword(s):

Type Iii Secretion ◽

Polymorphonuclear Leukocytes ◽

Capsular Polysaccharide ◽

Membrane Attack Complex ◽

Innate Immune ◽

Classical Pathway ◽

Wild Type ◽

Capnocytophaga Canimorsus ◽

Oral Flora ◽

Human Polymorphonuclear Leukocytes

ABSTRACT Capnocytophaga canimorsus is a bacterium of the canine oral flora known since 1976 to cause rare but severe septicemia and peripheral gangrene in patients that have been in contact with a dog. It was recently shown that these bacteria do not elicit an inflammatory response (H. Shin, M. Mally, M. Kuhn, C. Paroz, and G. R. Cornelis, J. Infect. Dis. 195:375-386, 2007). Here, we analyze their sensitivity to the innate immune system. Bacteria from the archetype strain Cc5 were highly resistant to killing by complement. There was little membrane attack complex (MAC) deposition in spite of C3b deposition. Cc5 bacteria were as resistant to phagocytosis by human polymorphonuclear leukocytes (PMNs) as Yersinia enterocolitica MRS40, endowed with an antiphagocytic type III secretion system. We isolated Y1C12, a transposon mutant that is hypersensitive to killing by complement via the antibody-dependent classical pathway. The mutation inactivated a putative glycosyltransferase gene, suggesting that the Y1C12 mutant was affected at the level of a capsular polysaccharide or lipopolysaccharide (LPS) structure. Cc5 appeared to have several polysaccharidic structures, one being altered in Y1C12. The structure missing in Y1C12 could be purified by classical LPS purification procedures and labeled by tritiated palmitate, indicating that it is more likely to be an LPS structure than a capsule. Y1C12 bacteria were also more sensitive to phagocytosis by PMNs than wild-type bacteria. In conclusion, a polysaccharide structure, likely an LPS, protects C. canimorsus from deposition of the complement MAC and from efficient phagocytosis by PMNs.

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Regulation of the Ysa Type III Secretion System of Yersinia enterocolitica by YsaE/SycB and YsrS/YsrR

Journal of Bacteriology ◽

10.1128/jb.186.13.4056-4066.2004 ◽

2004 ◽

Vol 186 (13) ◽

pp. 4056-4066 ◽

Cited By ~ 56

Author(s):

Kimberly A. Walker ◽

Virginia L. Miller

Keyword(s):

Yersinia Enterocolitica ◽

Type Iii Secretion ◽

Shigella Flexneri ◽

Wild Type ◽

Secretion Systems ◽

Type Iii ◽

Regulatory Cascade ◽

Two Component

ABSTRACT Yersinia enterocolitica biovar 1B contains two type III secretion systems (TTSSs), the plasmid-encoded Ysc-Yop system and the chromosomally encoded Ysa-Ysp system. Proteins secreted from the Ysa TTSS (Ysps) have only been detected in vitro when cells are cultured at 26°C in a high-NaCl medium. However, the exact role of the Ysa TTSS is unclear. Thus, investigations into the regulation of this system may help elucidate the role of the Ysps during the life cycle of Y. enterocolitica. Here we present evidence that the AraC-like regulator YsaE acts together with the chaperone SycB to regulate transcription of the sycByspBCDA operon, a phenomenon similar to that seen in the closely related Salmonella SPI-1 and Shigella flexneri Mxi-Spa-Ipa TTSSs. Deletion of either sycB or ysaE results in a twofold reduction in the activity of a sycB-lacZ fusion compared to the wild type. In a reconstituted Escherichia coli system, transcription of sycB was activated sixfold only when both YsaE and SycB were present, demonstrating that they are necessary for activation. ysrR and ysrS are located near the ysa genes and encode a putative two-component regulatory system. Mutations in either gene indicated that both YsrR and YsrS were required for secretion of Ysps. In addition, transcription from sycB-lacZ and ysaE-lacZ fusions was decreased 6.5- and 25-fold, respectively, in the ysrS mutant compared to the wild type. Furthermore, in the absence of NaCl, the activity of ysaE-lacZ was reduced 25-fold in the wild-type and ΔysrS strains, indicating that YsrS is probably required for the salt-dependent expression of the ysa locus. These results suggest that the putative two-component system YsrRS may be a key element in the regulatory cascade for the Ysa TTSS.

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Quantitation of Conjugate Formation Between Human Polymorphonuclear Leukocytes and Antibody-Coated Target Cells by Flow Cytometry: The Role of Fc Receptor and LFA-1 Antigen

Journal of Leukocyte Biology ◽

10.1002/jlb.46.5.467 ◽

1989 ◽

Vol 46 (5) ◽

pp. 467-475 ◽

Cited By ~ 1

Author(s):

Kok P.M. van Kessel ◽

Jos A.G. van Strijp ◽

Marijke E. van der Tol ◽

Henny J. van Kats-Renaud ◽

Rik M.W.M. Thijssen ◽

...

Keyword(s):

Flow Cytometry ◽

Polymorphonuclear Leukocytes ◽

Fc Receptor ◽

Target Cells ◽

Human Polymorphonuclear Leukocytes

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Role of YadA in resistance of Yersinia enterocolitica to phagocytosis by human polymorphonuclear leukocytes.

Infection and Immunity ◽

10.1128/iai.62.4.1275-1281.1994 ◽

1994 ◽

Vol 62 (4) ◽

pp. 1275-1281 ◽

Cited By ~ 45

Author(s):

B China ◽

B T N'Guyen ◽

M de Bruyere ◽

G R Cornelis

Keyword(s):

Yersinia Enterocolitica ◽

Polymorphonuclear Leukocytes ◽

Human Polymorphonuclear Leukocytes

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Role of Serotype-Specific Polysaccharide in the Resistance of Streptococcus mutans to Phagocytosis by Human Polymorphonuclear Leukocytes

Infection and Immunity ◽

10.1128/iai.68.2.644-650.2000 ◽

2000 ◽

Vol 68 (2) ◽

pp. 644-650 ◽

Cited By ~ 30

Author(s):

Hiromasa Tsuda ◽

Yoshihisa Yamashita ◽

Kuniaki Toyoshima ◽

Noboru Yamaguchi ◽

Takahiko Oho ◽

...

Keyword(s):

Cell Surface ◽

Streptococcus Mutans ◽

Polymorphonuclear Leukocytes ◽

The Other ◽

Wild Type ◽

Transmission Electron ◽

Specific Polysaccharide ◽

Human Pmns ◽

Human Polymorphonuclear Leukocytes

ABSTRACT To clarify the role of cell surface components ofStreptococcus mutans in resistance to phagocytosis by human polymorphonuclear leukocytes (PMNs), several isogenic mutants ofS. mutans defective in cell surface components were studied with a luminol-enhanced chemiluminescence (CL) assay, a killing assay, and a transmission electron microscope. The CL responses of human PMNs to mutant Xc11 defective in a major cell surface antigen, PAc, and mutant Xc16 defective in two surface glucosyltransferases (GTF-I and GTF-SI) were the same as the response to the wild-type strain, Xc. In contrast, mutant Xc24R, which was defective in serotype c-specific polysaccharide, induced a markedly higher CL response than the other strains. The killing assay showed that human PMNs killed more Xc24R than the parent strain and the other mutants. The transmission electron microscopic observation indicated that Xc24R cells were more internalized by human PMNs than the parental strain Xc. These results may be reflected by the fact that strain Xc24R was more phagocytosed than strain Xc. The CL response of human PMNs to a mutant defective in polysaccharide serotype e or f was similar to the response to Xc24R. Furthermore, mutants defective in serotype-specific polysaccharide were markedly more hydrophobic than the wild-type strains and the other mutants, suggesting that the hydrophilic nature of polysaccharides may protect the bacterium from phagocytosis. We conclude that the serotype-specific polysaccharide, but not the cell surface proteins on the cell surface of S. mutans, may play an important role in the resistance to phagocytosis.

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