Open AccessA preliminary study on the application of PspA as a carrier for group A meningococcal polysaccharide
Author(s) -
Lichan Wang,
Yajun Tan,
Wei Chen,
Huajie Zhang,
Peng Luo,
Shumin Zhang,
Xiao Ma
Publication year - 2019
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.0218427
Subject(s) - polysaccharide , microbiology and biotechnology , flow cytometry , titer , immune system , biology , conjugate , meningitis , antibody , virology , medicine , immunology , biochemistry , mathematical analysis , mathematics , psychiatry
This study aimed to explore the feasibility of pneumococcal surface protein A (PspA) as a carrier protein. Three recombinant pneumococcal surface proteins from three different clades were expressed by the prokaryotic expression system and conjugated to group A meningococcal polysaccharide (GAMP) to generate three polysaccharide-protein conjugates. The conjugates, unconjugated proteins, GAMP, and GAMP-TT vaccine bulk (used as positive control) were immunized into mice, and their immune effects were assessed by the methods of enzyme-linked immunosorbent assay (ELISA), flow cytometry (FCM), and serum bactericidal assay (SBA). The results showed that the polysaccharide-protein conjugates could 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 unconjugated GAMP. The conjugation of PspAs to GAMP also enhanced the anti-PspA responses compared with unconjugated PspAs except for PspA3. In conclusion, the results indicated that the three PspAs were appropriate carrier proteins, as demonstrated by the characteristics of T-cell dependent responses to the GAMP, and might protect against group A of epidemic cerebrospinal meningitis.