Paschall et al. (2021). ACS Infectious Diseases. doi: 10.1021/acsinfecdis.1c00415
…Bio-Rad). The samples were subsequently transferred to nitrocellulose membranes with a 0.2 μm pore size (Bio-Rad… Baby rabbit complement (Pel-Freez) was added to HL-60 cells at a 1…
Pel-Freez products cited: Baby Rabbit Complement (31061)
Abstract
Group B <i>Streptococcus</i> (GBS) is a leading cause of neonatal infections and invasive diseases in nonpregnant adults worldwide. Developing a protective conjugate vaccine targeting the capsule of GBS has been pursued for more than 30 years; however, it has yet to yield a licensed product. In this study, we present a novel bioconjugation platform for producing a prototype multivalent GBS conjugate vaccine and its subsequent analytical and immunological characterizations. Using a glycoengineering strategy, we generated strains of <i>Escherichia coli</i> that recombinantly express the type Ia, type Ib, and type III GBS capsular polysaccharides. We then combined the type Ia-, Ib-, and III-capsule-expressing <i>E. coli</i> strains with an engineered <i>Pseudomonas aeruginosa</i> exotoxin A (EPA) carrier protein and the PglS oligosaccharyltransferase. Coexpression of a GBS capsule, the engineered EPA protein, and PglS enabled the covalent attachment of the target GBS capsule to an engineered serine residue on EPA, all within the periplasm of <i>E. coli</i>. GBS bioconjugates were purified, analytically characterized, and evaluated for immunogenicity and functional antibody responses. This proof-of-concept study signifies the first step in the development of a next-generation multivalent GBS bioconjugate vaccine, which was validated by the production of conjugates that are able to elicit functional antibodies directed against the GBS capsule.