PT - JOURNAL ARTICLE AU - Lichan-Wang AU - Yajun-Tan AU - Chen-Wei AU - Huajie-Zhang AU - Peng-Luo AU - Shumin-Zhang AU - Xiao-Ma TI - Preliminary study on the application of PspA as carrier AID - 10.1101/305102 DP - 2018 Jan 01 TA - bioRxiv PG - 305102 4099 - http://biorxiv.org/content/early/2018/04/20/305102.short 4100 - http://biorxiv.org/content/early/2018/04/20/305102.full AB - The aim of the study is to research the feasibility of pneumococcal surface protein A (PspA) using as carrier protein. Three recombinant pneumococcal surface proteins A (come from family1 and family 2) were expressed by prokaryotic expression system and were conjugated to group A meningococcal polysaccharide (GAMP) to make three polysaccharide-protein conjugates. The conjugates, un-conjugated proteins, GAMP and GAMP-TT vaccine bulk (used as positive control) were immunized to mice and their immune effects were evaluated by the method of ELISA, FCM and SBA. The results showed that the polysaccharide-protein conjugates can produce higher levels of anti-GAMP IgG titers (P < 0.05), higher ratios of Th1/Th2 (P < 0.05) and higher levels of serum bactericidal activity (P < 0.05) compared with the un-conjugated GAMP. The conjugation of PspAs to GAMP also enhanced the anti-PspA responses compared with un-conjugated PspAs except PspA3. In conclusion, all the results indicated that three PspAs were suitable carrier protein as demonstrated by the characteristics of a T-cell dependent response to the GAMP, and would protect against group A of epidemic cerebrospinal meningitis and also have the potential to provide broad protection from Streptococcus pneumonia.AbbreviationsPspApneumococcal surface protein AGAMPgroup A meningococcal polysaccharideELISAenzyme linked immune sorbent assayFCMflow cytometrySFCspot forming cellsSBAserum bactericidal assayThhelper T cellTIthymus independentTDthymus dependentNIFDCnational institutes for food and drug controlGMTgeometric mean antibody titersIFN-γfibronectin γIL-4interleukin −4ANOVAone-way analysis of variance