Vaccine candidates PhtD and PhtE of Streptococcus pneumoniae are adhesins that elicit functional antibodies in humans.

ABSTRACT: We evaluated the role of vaccine candidate surface proteins, PhtD and PhtE as antigens with functional importance for Streptococcus pneumoniae (pneumococci) in adherence to nasopharyngeal (D562) and lung (A549) epithelial cell lines. Comparing TIGR4 to PhtD and PhtE- isogenic mutants, a 40% (p=0.001) and 42% (p=0.002) drop in the number of epithelial cells with adherent pneumococci was observed to both cells lines with the mutants, as quantitated using flow cytometry. We expressed PhtD and PhtE on the surface of Escherichia coli and demonstrated that when PhtD and PhtE were surface expressed on E. coli, adherence increased to D562 and A549 cells, compared with the E. coli parent strain (p=0.005, 0.013 for D562 and p=0.034, p=0.035 for A549). Using flow cytometry and confocal microscopy we

SUBMITTER: Khan MN 

PROVIDER: S-EPMC3490617 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature