Binding to and Opsonophagocytic Activity of O-Antigen-Specific Monoclonal Antibodies against Encapsulated and Nonencapsulated<i>Klebsiella pneumoniae</i>Serotype O1 Strains

Held, T.; Jendrike, Nina; Rukavina, Tomislav; Podschun, Rainer; Trautmann, Matthias

doi:10.1128/iai.68.5.2402-2409.2000

Cited by 24 publications

(26 citation statements)

References 59 publications

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“…These data are confirming data by Cortes et al [23], who showed that phagocytosis of unencapsulated mutant strains was more efficient than that of wild‐type strains or LPS O‐side‐chain‐deficient strains. Although it was shown that O‐specific antibodies may penetrate the capsule of Klebsiella K2 strains [13,16], we have shown previously that supplementation of human sera with O‐antigen‐specific monoclonal antibodies did not increase phagocytic uptake of O1:K2 strains, and to a rather limited extent the uptake of strains of other K‐antigen serotype [9].…”

Section: Discussionmentioning

confidence: 65%

K-antigen-specific, but not O-antigen-specific natural human serum antibodies promote phagocytosis ofKlebsiella pneumoniae

Lepper

Möricke

Held

et al. 2003

FEMS Immunology &Amp; Medical Microbiology

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Infections due to Klebsiella pneumoniae and other Klebsiella spp. are a leading cause of hospital-associated morbidity, especially in the intensive care setting. In this study, the hypothesis that normal human sera contain sufficient concentrations of K-antigen-specific antibodies to promote phagocytic killing of encapsulated, highly virulent Klebsiella organisms was tested. K2-antigen-specific IgG and IgM antibodies were detected in each of 10 normal sera, and such antibodies were functionally active in a phagocytic killing assay. Phagocytosis depended critically on sufficient numbers of neutrophils and was impaired by the presence of soluble Klebsiella capsular polysaccharide (CPS). Thus, insufficient numbers of neutrophils and circulation of soluble CPS but not lack of K-specific antibodies may be detrimental in Klebsiella sepsis. The efficacy of hyperimmune sera might be based not on enhancement of phagocytosis but on the neutralization of these detrimental effects of circulating CPS and LPS.

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Section: Discussionmentioning

confidence: 65%

K-antigen-specific, but not O-antigen-specific natural human serum antibodies promote phagocytosis ofKlebsiella pneumoniae

Lepper

Möricke

Held

et al. 2003

FEMS Immunology &Amp; Medical Microbiology

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“…Effect of kvgA, kvhA, and kvhR gene deletion on expressions of P kvgAS , P kvhAS , and P kvhR . Synthesis of Capsular Polysaccharide in K. pneumoniae CG43 reduction of the bacterial CPS, an important virulence factor that affects bacterial resistance to phagocytosis by polymorphonuclear cells (44)(45)(46), leads to decrease of the virulence. The kvhA deletion mutant, AhZ01, of group II exhibited unchanged LD 50 and a slight increase of glucuronic acid content in comparing with that of wild type bacteria Z01.…”

Section: Resultsmentioning

confidence: 99%

Homologous Response Regulators KvgA, KvhA and KvhR Regulate the Synthesis of Capsular Polysaccharide in Klebsiella pneumoniae CG43 in a Coordinated Manner

Lin

Huang

Liang

et al. 2006

The Journal of Biochemistry

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On the basis of phenotypic analysis, the Klebsiella pneumoniae CG43 derived mutants with deletions of the gene encoding respectively the response regulators KvgA, KvhA, and KvhR were classified into two groups. Group I bacteria carrying either kvgA- or kvhR- exhibited less mucoidy, lower level of capsular polysaccharide (CPS) synthesis and higher LD50 than the parental strain. No apparent change of the group II, including kvhA- and kvhA- kvhR- mutants, was observed. However, the mucoidy of kvhA- kvhR- mutant was found to be diminished after introducing into a kvhA- expressing plasmid. Via promoter-lacZ fusion analysis, kvhA deletion was found to reduce kvhR expression. A regulatory role of KvhA for the expression of kvhR was supported further by EMSA showing a specific binding of KvhA to the putative promoter of kvhR. The promoter activity measurement and EMSA also revealed that KvgA acted as an autoregulator and an activator for the expression of kvhAS and kvhR. In addition, deletion of kvgA suppressed slightly the promoter activity of the cps-orf16-17, and the expression of all three cps transcripts orf1-2, orf3-15, and orf16-17 were reduced in the kvhR- mutant. These suggest that the three homologous response regulators interact to control, in coordination, the bacterial cps expression.

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“…We may attribute the differential effect of changes in CSH induced by mAb 13F1 and 18B7 to the pattern of mAb binding, since mAb18B7 binds near the surface in an annular pattern (15, 26, 51), while mAb 13F1 binds throughout the capsule in a punctate pattern (52, 53). There is precedence for our observation in the encapsulated bacteria, Klebsiella aerogenes , where the pattern of diffusion of some mAbs through the polysaccharide capsule has been shown to influence the cell surface hydrophobicity (54, 55).…”

Section: Discussionmentioning

confidence: 91%

Variation in cell surface hydrophobicity amongCryptococcus neoformansstrains influences interactions with amoeba

Vij

Crawford

Casadevall

2019

Preprint

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ABSTRACTCryptococcus neoformans and Cryptococcus gattii are pathogenic fungi that cause significant morbidity and mortality. Cell surface hydrophobicity (CSH) is a biophysical parameter that influences the adhesion of fungal cells or spores to biotic and abiotic surfaces. C. neoformans is encased by polysaccharide capsule that is highly hydrophilic and is a critical determinant of virulence. In this study, we report large differences in the CSH of some C. neoformans and C. gattii strains. The capsular polysaccharides of C. neoformans strains differ in repeating motifs, and therefore vary in the number of hydroxyl groups, which along with higher-order structure of the capsule, may contribute to the variation in hydrophobicity that we observed. For C. neoformans, CSH correlated with phagocytosis by natural soil predator Acanthamoeba castellani. Furthermore, capsular binding of the protective antibody (18B7), but not the non-protective (13F1) antibody altered the CSH of C. neoformans strains. Variability in CSH could be an important characteristic when comparing the biological properties of cryptococcal strains.IMPORTANCEThe interaction of a microbial cell with its environment is influenced by the biophysical properties of a cell. The affinity of the cell surface for water, defined by the Cell Surface Hydrophobicity (CSH), is a biophysical parameter that varied amongst different strains of Cryptococcus neoformans. The CSH influenced the phagocytosis of the yeast by its natural predator in the soil, Amoeba. Studying variation in biophysical properties like CSH gives us insight into the dynamic host-predator interaction, and host-pathogen interaction in a damage-response framework.

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Binding to and Opsonophagocytic Activity of O-Antigen-Specific Monoclonal Antibodies against Encapsulated and NonencapsulatedKlebsiella pneumoniaeSerotype O1 Strains

Cited by 24 publications

References 59 publications

K-antigen-specific, but not O-antigen-specific natural human serum antibodies promote phagocytosis ofKlebsiella pneumoniae

K-antigen-specific, but not O-antigen-specific natural human serum antibodies promote phagocytosis ofKlebsiella pneumoniae

Homologous Response Regulators KvgA, KvhA and KvhR Regulate the Synthesis of Capsular Polysaccharide in Klebsiella pneumoniae CG43 in a Coordinated Manner

Variation in cell surface hydrophobicity amongCryptococcus neoformansstrains influences interactions with amoeba

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