Adherence of recombinant pneumococcal surface adhesin A (rPsaA)-coated particles to human nasopharyngeal epithelial cells for the evaluation of anti-PsaA functional antibodies.
Pneumococcal surface adhesin A (PsaA) is a pneumococcal vaccine candidate. In this study, we detect functional antibodies to PsaA by using carboxylate-modified fluospheres coated with either recombinant non-lipidated PsaA (rPsaA) or synthetic peptides with relevant epitopes of PsaA. Peptides P1-P3 were derived from phage display sequences; peptides P4-P7 were homologous to rPsaA. P1- and P4-coated fluospheres had similar adherence to Detroit 562 nasopharyngeal cells when compared to rPsaA-coated fluospheres. Homologous and heterologous competitive inhibitions with peptides in solution determined the specificity of the adherence. There was no significant difference (P=0.25) between the inhibition of adherence of rPsaA- and P4-coated fluospheres. This study indicates that P1 and P4 contain a functional epitope(s) for the adherence of PsaA to nasopharyngeal cells making them suitable targets for the measurement of functional antibodies to PsaA.
Division of Bacterial and Mycotic Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333, USA. Ssteiner@cdc.gov
Sandra
S
Romero-Steiner
Joseph
J
Caba
Gowrisankar
G
Rajam
Travis
T
Langley
Andrea
A
Floyd
Scott E
SE
Johnson
Jacquelyne S
JS
Sampson
George M
GM
Carlone
Edwin
E
Ades
D018829:Adhesins, Bacterial / Q000276:immunology* / Q000378:metabolism; D000327:Adsorption; D000907:Antibodies, Bacterial / Q000032:analysis*; D001422:Bacterial Adhesion; D045744:Cell Line, Tumor; D004847:Epithelial Cells / Q000378:metabolism*; D005453:Fluorescence; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008074:Lipoproteins / Q000276:immunology* / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008863:Microspheres; D009305:Nasopharynx / Q000166:cytology; D009842:Oligopeptides / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
D018829:Adhesins, Bacterial; D000907:Antibodies, Bacterial; D008074:Lipoproteins; D009842:Oligopeptides; C085000:PsaA protein, Streptococcus; D011994:Recombinant Proteins