Phagocyte-Bacteria Interactions

Keisari, Yona; Kabha, K.; Nissimov, L.; Schlepper-Schäfer, Jutta; Ofek, Itzhak

doi:10.1177/08959374970110011601

Cited by 21 publications

(14 citation statements)

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“…20 Previous studies showed that the strains of K. pneumoniae expressing Man-a2/3-Man or Rha-a2/3-Rha sequences in their CPS structure could be recognized by macrophage mannose receptors and readily ingested by macrophages. 26,27 Interestingly, serotypes K1 and K2 of K. pneumoniae strains lack the Man-a2/3-Man or Rha-a2/3-Rha sequences in their CPS structure, are not recognized by the macrophage lectin, they would be able to escape from lectinophagocytosis and proliferate, and will then express other virulent factors. Our previous study also demonstrated that after 30 min of incubation with neutrophils, the cell wall structure of K1 in the phagocytosed cells still remain intact without any morphological alterations indicating resistant to lysis.…”

Section: Determination Of Neutrophil Influx Into the Liver Bymentioning

confidence: 99%

Immune response and pathophysiological features of Klebsiella pneumoniae liver abscesses in an animal model

Fung

Chang

Lin

et al. 2011

Laboratory Investigation

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Capsular serotypes K1 and K2, the rmpA gene (a regulator of the mucoid phenotype) and aerobactin from Klebsiella pneumoniae have been identified as the major virulence factors for pyogenic liver abscesses with high morbidity, mortality and severe complications. The pathological mechanisms remain unclear. In this study, we compared liver immune responses and pathological changes in response to different serotypes of K. pneumoniae infections. A mouse model was used to investigate cytokine and chemokine production, histopathology findings, phagocytic uptake and mortality induced by serotypespneumoniae serotypes K1 and K2 showed lower 50% lethal dose values and more phagocytic resistance to neutrophils than K62 and the DK1 mutant. In sequential liver samples, viable bacteria counts increased 3 h to 3 days after low-dose inoculation (o10 1 colony-forming unit (cfu)) with K1 and K2, while K62 and DK1 cleared rapidly and became undetectable even with high-dose inoculation (B2.9 Â 10 5 cfu). Time-dependent increases in cytokines and chemokines, including tumor necrosis factor-a, interleukin (IL)-1b, IL-6, IL-10, keratinocyte-derived chemokines and macrophage inflammatory protein-2, were observed in the serum and liver tissue of K1-and K2-infected mice, and severe disease progression manifesting as microabscesses was also identified. K62 and DK1 inoculation did not result in similar immune responses and histological changes. These findings illustrate the critical role of phagocytic resistance against innate immunological defense mechanisms as well as its contribution to the development of liver abscesses.

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Section: Determination Of Neutrophil Influx Into the Liver Bymentioning

confidence: 99%

Immune response and pathophysiological features of Klebsiella pneumoniae liver abscesses in an animal model

Fung

Chang

Lin

et al. 2011

Laboratory Investigation

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“…A number of different serotypes isolated at high and low frequencies were tested for their ability to bind to rat alveolar macrophages (AMs) in a serum-free system (2). Serotypes that express a CPS containing Man-␣2-3-Man or L-Rha-␣2-3-L-Rha (di-Man/Rha) sequences bound with high affinity to AMs (Table 3) (2,31,35,70). The binding resulted in the ingestion and killing of the organisms.…”

Section: Interaction Of Klebsiella Cps With the Mrmentioning

confidence: 99%

Recognition of Bacterial Surface Polysaccharides by Lectins of the Innate Immune System and Its Contribution to Defense against Infection: the Case of Pulmonary Pathogens

et al. 2008

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5Many pathogenic bacterial species are classified into serological types, distinguished by their carbohydrate-rich surface antigens. These antigens are referred to as serotypic epitopes or glycoepitopes. Glycoepitopes are most commonly associated with capsular polysaccharides (CPS) or the O-antigen domains of bacterial lipopolysaccharides (LPS).The association of specific bacterial serotypes of a given genus with defined clinical infections is a common phenomenon that applies to a variety of gram-negative bacteria and gram-positive bacteria. As discussed below, of the 77 distinct capsular serotypes in the species Klebsiella pneumoniae, only 25 account for most pulmonary and blood infections (12). Likewise, of the more than 90 capsular serotypes of Streptococcus pneumoniae, only 23 account for most infections, and these are included in the current capsular vaccine (25).The surfaces of the pulmonary pathogens Klebsiella pneumoniae and Streptococcus pneumoniae are coated with a variety of glycoconjugates that confer specific properties. For example, the polysaccharide capsules enable these pathogens to resist phagocytosis. In a few cases, it has been argued that serotype-associated differences in capsular size contribute to virulence and the high frequency of isolation. However, there is no satisfactory explanation why only a limited number of capsular serotypes are responsible for most infections (12,25).Because lectins are important components of the lung's innate immune system, it is reasonable to hypothesize that differences in the frequencies of isolation of specific serotypes in the setting of pneumonia are in part determined by the recognition, or the lack of recognition, of their corresponding glycoepitopes by lectins. We propose that the lack of recognition of glycoconjugates by one or more lectins of the lung contributes to the high frequency of isolation from pneumonia patients of the pulmonary pathogens bearing reactive glycoepitopes. Conversely, lectins that recognize serotype-specific glycoepitopes contribute to the eradication of these serotypes, resulting in a lower frequency of their isolation from clinical samples.In this review, we first correlate the sugar specificities of several types of lung lectins with the glycoconjugates on the surfaces of selected pulmonary pathogens. We then briefly describe in vitro data that suggest mechanisms through which the lung C-type lectins contribute to the elimination of specific glycoepitope-bearing serotypes. Finally, we review available evidence supporting our hypothesis that the high frequency of isolation of serotypes bearing a specific glycoepitope results from the ability of these serotypes to evade recognition by lectins of the innate immune system. PULMONARY LECTINS OF THE INNATE IMMUNE SYSTEMDuring the last 3 decades, there has been intensive research on animal lectins (59, 90). Although lung lectins play a variety of homeostatic roles (38, 89), considerable research has focused on the contributions of several lectins to the innate, natural defense s...

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“…Gels were viewed and photographed under UV irradiation as described previously (20), and cytokine mRNA expression was measured by the TINA 2.1g program. The results were expressed as ratios of the optical density of the cytokine to the optical density of ␤-actin (averages Ϯ standard errors) calculated from three separate experiments.…”

Section: Animalsmentioning

confidence: 99%

“…Binding of SP-A and MR to K. pneumoniae is serotype dependent. Previous studies have shown that capsulated K. pneumoniae strains that containing Man␣2/3Man or Rha␣2/ 3Rha sequences in their CPS are directly recognized by the macrophage MR or following opsonization with SP-A, which results in attachment, ingestion, and killing of the bacteria by the phagocytic cells (2,18,20). Capsulated Klebsiella strains that lack such sequences in their CPS are not recognized by either MR or SP-A.…”

mentioning

confidence: 99%

NoncapsulatedKlebsiella pneumoniaeBearing Mannose-Containing O Antigens Is Rapidly Eradicated from Mouse Lung and Triggers Cytokine Production by Macrophages following Opsonization with Surfactant Protein D

et al. 2005

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To better understand the relationship between the surface polysaccharides of pulmonary pathogens and components of the lung innate immune system, we employed selected serotypes of Klebsiella pneumoniae expressing distinct capsular polysaccharides and/or O antigen in a murine model of K. pneumoniae infection. In addition, we examined the effect of surfactant protein D (SP-D) on the cytokine response of human monocyte-derived macrophages to these serotypes in vitro. Noncapsulated mannose-containing O3 serotypes (K50/n and K55/n), which react efficiently with SP-D in vitro, triggered high levels of interleukin-1␤ (IL-1␤) and IL-6 production. In vivo, they were more efficiently cleared from the lungs of mice but not from macrophage-depleted mice. They also were more efficiently internalized by alveolar macrophages in vivo. In contrast, galactose-containing O1 serotypes (K2/n and K21a/n), which interact poorly with SP-D, exhibited significantly lower cytokine production and less efficient pulmonary clearance and were ineffectively internalized by alveolar macrophages. These findings are consistent with in vitro results showing that production of IL-1␤ and IL-6 mRNA and IL-6 protein by human macrophages exposed to mannose-bearing Klebsiella O serotypes is significantly increased by SP-D. Thus, survival of inhaled bacteria in the lung depends partially on the lipopolysaccharide structure of the bacteria and their interactions with innate immunity components. We speculate that an imbalance of host SP-D and therefore cytokine levels may result in high susceptibility of the host to the pathogen.

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Phagocyte-Bacteria Interactions

Cited by 21 publications

References 50 publications

Immune response and pathophysiological features of Klebsiella pneumoniae liver abscesses in an animal model

Immune response and pathophysiological features of Klebsiella pneumoniae liver abscesses in an animal model

Recognition of Bacterial Surface Polysaccharides by Lectins of the Innate Immune System and Its Contribution to Defense against Infection: the Case of Pulmonary Pathogens

NoncapsulatedKlebsiella pneumoniaeBearing Mannose-Containing O Antigens Is Rapidly Eradicated from Mouse Lung and Triggers Cytokine Production by Macrophages following Opsonization with Surfactant Protein D

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