Construction and preliminary identification of a prokaryotic expression single-chain antibody fragments library against Streptococcus pneumoniae from antibody-producing cells in human tonsil.

Tonsillitis is the inflammation of the tonsils due to infection, many patients ultimately have to undergo tonsillectomy. In order to improve the accuracy of diagnosis and even create a new treatment for tonsillitis, we constructed a prokaryotic expression single-chain antibody fragment library against Streptococcus pneumoniae with immunoglobulin heavy chain variable region (VH), kappa light chain (V kappa), and lambda light chain (V lambda) genes by using human tonsil tissue. Plasmid DNA sequencing showed that single-chain antibodies were complete and constructed correctly. The binding activity of recombinant clones was detected by enzyme-linked immunosorbent assay (ELISA), results showed that the binding activity and specificity of anti-S. pneumoniae single-chain fragment variable (scfv) is proved to be successful. The single-chain antibody may be an attractive strategy for tonsillitis etiologic diagnosis and therapy.