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Nilo A, Morelli L, Passalacqua I, Brogioni B, Allan M, Carboni F, Pezzicoli A, Zerbini F, Maione D, Fabbrini M, Romano MR, Hu QY, Margarit I, Berti F, Adamo R. Anti-Group B Streptococcus Glycan-Conjugate Vaccines Using Pilus Protein GBS80 As Carrier and Antigen: Comparing Lysine and Tyrosine-directed Conjugation. ACS Chem Biol 2015; 10:1737-46. [PMID: 25906283 DOI: 10.1021/acschembio.5b00247] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gram-positive Streptococcus agalactiae or group B Streptococcus (GBS) is a leading cause of invasive infections in pregnant women, newborns, and elderly people. Vaccination of pregnant women represents the best strategy for prevention of neonatal disease, and GBS polysaccharide-based conjugate vaccines are currently under clinical testing. The potential of GBS pilus proteins selected by genome-based reverse vaccinology as protective antigens for anti-streptococcal vaccines has also been demonstrated. Dressing pilus proteins with surface glycan antigens could be an attractive approach to extend vaccine coverage. We have recently developed an efficient method for tyrosine-directed ligation of large glycans to proteins via copper-free azide-alkyne [3 + 2] cycloaddition. This method enables targeting of predetermined sites of the protein, ensuring that protein epitopes are preserved prior to glycan coupling and a higher consistency in glycoconjugate batches. Herein, we compared conjugates of the GBS type II polysaccharide (PSII) and the GBS80 pilus protein obtained by classic lysine random conjugation and by the recently developed tyrosine-directed ligation. PSII conjugated to CRM197, a carrier protein used for vaccines in the market, was used as a control. We found that the constructs made from PSII and GBS80 were able to elicit murine antibodies recognizing individually the glycan and protein epitopes on the bacterial surface. The generated antibodies were efficacious in mediating opsonophagocytic killing of strains expressing exclusively PSII or GBS80 proteins. The two glycoconjugates were also effective in protecting newborn mice against GBS infection following vaccination of the dams. Altogether, these results demonstrated that polysaccharide-conjugated GBS80 pilus protein functions as a carrier comparably to CRM197, while maintaining its properties of protective protein antigen. Glycoconjugation and reverse vaccinology can, therefore, be combined to design vaccines with broad coverage. This approach opens a path to a new generation of vaccines. Tyrosine-ligation allows creation of more homogeneous vaccines, correlation of the immune response to defined connectivity points, and fine-tuning of the conjugation site in glycan-protein conjugates.
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Affiliation(s)
- Alberto Nilo
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Laura Morelli
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Irene Passalacqua
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Barbara Brogioni
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Martin Allan
- Novartis Institutes for BioMedical Research, 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | - Filippo Carboni
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Alfredo Pezzicoli
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Francesca Zerbini
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Domenico Maione
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Monica Fabbrini
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | | | - Qi-Ying Hu
- Novartis Institutes for BioMedical Research, 100 Technology Square, Cambridge, Massachusetts 02139, United States
| | | | - Francesco Berti
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
| | - Roberto Adamo
- Novartis Vaccines & Diagnostics, Via Fiorentina 1, 53100 Siena, Italy
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Dangor Z, Kwatra G, Izu A, Lala SG, Madhi SA. Review on the association of Group BStreptococcuscapsular antibody and protection against invasive disease in infants. Expert Rev Vaccines 2014; 14:135-49. [DOI: 10.1586/14760584.2014.953939] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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A new flow-cytometry-based opsonophagocytosis assay for the rapid measurement of functional antibody levels against Group B Streptococcus. J Immunol Methods 2012; 378:11-9. [DOI: 10.1016/j.jim.2012.01.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 01/20/2012] [Accepted: 01/23/2012] [Indexed: 11/19/2022]
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Bröker M, Costantino P, DeTora L, McIntosh ED, Rappuoli R. Biochemical and biological characteristics of cross-reacting material 197 (CRM197), a non-toxic mutant of diphtheria toxin: Use as a conjugation protein in vaccines and other potential clinical applications. Biologicals 2011; 39:195-204. [DOI: 10.1016/j.biologicals.2011.05.004] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 05/16/2011] [Accepted: 05/24/2011] [Indexed: 12/30/2022] Open
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