The capsule sensitizes Streptococcus pneumoniae to alpha-defensins human neutrophil proteins 1 to 3.

ABSTRACT: Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide. Its polysaccharide capsule causes resistance to phagocytosis and interferes with the innate immune system's ability to clear infections at an early stage. Nevertheless, we found that encapsulated pneumococci are sensitive to killing by a human neutrophil granule extract. We fractionated the extract by high-performance liquid chromatography and identified alpha-defensins by mass spectrometry as the proteins responsible for killing pneumococci. Analysis of sensitivity to the commercial alpha-defensins human neutrophil proteins 1 to 3 (HNP1-3) confirmed these findings. We analyzed the sensitivities of different pneumococcal strains to HNP1-3 and found that encapsulated strains are efficiently killed at physiologic

SUBMITTER: Beiter K 

PROVIDER: S-EPMC2493227 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature