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.
Romero-Steiner
Sandra
S
Division of Bacterial and Mycotic Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333, USA. Ssteiner@cdc.gov
Caba
Joseph
J
Rajam
Gowrisankar
G
Langley
Travis
T
Floyd
Andrea
A
Johnson
Scott E
SE
Sampson
Jacquelyne S
JS
Carlone
George M
GM
Ades
Edwin
E
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