Open AccessApplication of phage display technology for the production of antibodies against Streptococcus suis serotype 2
Author(s) -
Pattarawadee Sulong,
Natsinee Anudit,
Suphachai Nuanualsuwan,
Mariela Segura,
Kannika Khantasup
Publication year - 2021
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0258931
Subject(s) - serotype , streptococcus suis , biopanning , phage display , microbiology and biotechnology , biology , virology , antibody , clone (java method) , antigen , epitope , peptide library , virulence , peptide sequence , gene , immunology , genetics
Streptococcus suis ( S . suis ) serotype 2 infection is a problem in the swine industry and responsible for most cases of human infection worldwide. Since current multiplex PCR cannot differentiate between serotypes 2 and 1/2, then serotype-specific antibodies (Abs) are required for serotype identification to confirm infection by serotype 2. This study aimed to generate Abs specific to S . suis serotype 2 by phage display from a human heavy chain variable domain (VH) antibody library. For biopanning, whole cells of S . suis serotype 2 were used as the target antigen. With increasing selection stringency, we could select the VH Abs that specifically bound to a S . suis serotype 2 surface antigen, which was identified as the capsular polysaccharide (CPS). From ELISA analysis, the specific phage clone 47B3 VH with the highest binding activity to S . suis serotype 2 was selected and shown to have no cross-reactivity with S . suis serotypes 1/2, 1, and 14 that shared a common epitope with serotype 2 and occasionally cause infections in human. Moreover, no cross-reactivity with other bacteria that can be found in septic blood specimens was also observed. Then, 47B3 VH was successfully expressed as soluble 47B3 VH in E . coli TG1. The soluble 47B3 VH crude extract was further tested for its binding ability in a dose-dependent ELISA assay. The results indicated that the activity of phage clone 47B3 was still retained even when the Ab occurred in the soluble form. A quellung reaction demonstrated that the soluble 47B3 VH Ab could show bioactivity by differentiation between S . suis serotypes 2 and 1/2. Thus, it will be beneficial to use this VH Ab in the diagnosis of disease or discrimination of S . suis serotypes Furthermore, the results described here could motivate the use of phage display VH platform to produce serotyping antibodies.