Inhibition of Pneumococcal Adherence to Human Nasopharyngeal Epithelial Cells by Anti-PsaA Antibodies

• DOI: 10.1128/cdli.10.2.246-251.2003
• Publication Date: 2003-03-07T20:51:51Z
• Authors: Sandra Romero-Ste...; Tamar Pilishvili; Jacquelyn S. Sampson; Scott E. Johnson; Annie Stinson; George M. Carlone; Edwin W. Ades
• Keywords: Polyclonal antibodies

ABSTRACT The role of pneumococcal (Pnc) surface adhesin A (PsaA) in the adherence Streptococcus pneumoniae (pneumococcus) to host cells is not well defined. We examined effect anti-PsaA antibodies an inhibition assay using Detroit 562 nasopharyngeal human epithelial cells. Rabbit polyclonal (Pab) anti-recombinant PsaA (rPsaA) sera, a purified mouse monoclonal antibody (MAb) (MAb 6F62G8E12), and 22 healthy adult sera with known IgG levels (obtained by enzyme-linked immunosorbent assay) were evaluated for their abilities inhibit Pnc confluent monolayers (measured as percent reduction CFU counts compared those uninhibited controls). was dependent on capsular phenotype (no or low opaque strains). With inoculum 10 4 5 bacteria/well, mean ± standard deviation count controls 163 32 CFU/well transparent strains. Low observed PsaA-minus mutant even at higher doses. Mean inhibitions Pab MAb 54 50%, respectively. Adult showed dose-response fashion range 98 8%, depending serum concentration. Absorption rPsaA restored control levels. did result significant decrease ( P >0.05) activity. Additionally, nearly 100% inhibited lipidated 2.5 μg/ml. Our data support argument that mediates This functional may be useful evaluating elicited response vaccination.