Manno(Rhamno)Biose-Containing Capsular Polysaccharides of Klebsiella pneumoniae Enhance Opsono-Stimulation of Human Polymorphonuclear Leukocytes

作者：Sahly Hany^*; Keisari Yona; Ofek Itzhak

来源：Journal of Innate Immunity, 2009, 1(2): 136-144.

DOI：10.1159/000154812

• Capsular polysaccharides
• Complement
• Innate immunity
• Klebsiella
• Lipopolysaccharides
• Mannose-binding lectin
• Polymorphonuclear leukocytes
• Respiratory burst

We tested the relationship between the capsular and the O-antigen structures and the ability of bacteria to trigger respiratory burst in human polymorphonuclear leukocytes (PMNL). Capsulated and non-capsulated variants as well as capsule-switched derivatives of Klebsiella serotypes bearing or lacking manno(rhamno)biose repeats in their capsular polysaccharides and expressing either mannose-rich or mannose-poor 0 antigens were tested for their ability to induce respiratory burst and survive in human PMNL. Luminol-enhanced chemiluminescence (CL) was measured to quantify respiratory burst. Intracellular survival was quantified by determining the viable counts of intracellular bacteria. K serotypes and the capsule-switched derivative lacking manno(rhamno)biose induced significantly lower CL than those expressing manno(rhamno)biose. Manno(rhamno)biose-lacking serotypes survived in the cells significantly better than serotypes expressing these repeats. C1q depletion did not affect CL induced by the manno(rhamno)biose-containing serotype, whereas factor B depletion revealed a significantly reduced CL. Likewise, EGTA in the presence of Mg(2+) significantly decreased CL, but the values were higher than those induced by the bacterium opsonized with factor B-depleted serum. In the presence of EGTA, Mg(2+)-treated factor B-depleted serum revealed a significant reduction in the CL response compared with the responses induced by opsonization with factor B-depleted serum alone. These results indicate, in addition to the alternative pathway, a manno(rhamno)biose pattern recognition of Klebsiella by PMNL probably by the complement lectin pathway.

• 出版日期2009