Syntheses ofSalmonellaParatyphi A Associated Oligosaccharide Antigens and Development towards Anti-Paratyphoid Fever Vaccines
CHEMISTRY-A EUROPEAN JOURNAL
Authors: Dhara, Debashis; Baliban, Scott M.; Huo, Chang-Xin; Rashidijahanabad, Zahra; Sears, Khandra T.; Nick, Setare Tahmasebi; Misra, Anup Kumar; Tennant, Sharon M.; Huang, Xuefei
Abstract
With the emergence of multidrug resistantSalmonellastrains, the development of anti-Salmonellavaccines is an important task. Currently there are no approved vaccines againstSalmonellaParatyphi A, the leading cause of paratyphoid fever. To fill this gap, oligosaccharides corresponding to theO-polysaccharide repeating units from the surface ofSalmonellaParatyphi A have been synthesized through convergent stereoselective glycosylations. The synthetic glycan antigen was conjugated with a powerful immunogenic carrier system, the bacteriophage Q beta. The resulting construct was able to elicit strong and long-lasting anti-glycan IgG antibody responses, which were highly selective towardSalmonellaParatyphi A associated glycans. The availability of well-defined glycan antigen enabled the determination that one repeating unit of the polysaccharide is sufficient to induce protective antibodies, and the paratose residue and/or theO-acetyl modifications on the backbone are important for recognition by antibodies elicited by a Q beta-tetrasaccharide conjugate. Immune sera provided excellent protection to mice from lethal challenge withSalmonellaParatyphi A, highlighting the potential of the synthetic glycan-based vaccine.
Quantitative analysis of bovine whey glycoproteins using the overall N-linked whey glycoprofile
INTERNATIONAL DAIRY JOURNAL
Authors: Valk-Weeber, Rivca L.; Eshuis-de Ruiter, Talitha; Dijkhuizen, Lubbert; van Leeuwen, Sander S.
Abstract
Bovine whey is an important ingredient in human nutrition and contains many biofunctional, glycosylated proteins. Knowledge on the glycoprotein composition of whey and whey products is valuable for the dairy industry. This paper describes a method for the characterisation of whey, or whey powders, by N-linked glycoprofile analysis. Application of the method for analysis of whey protein products showed clear differences in glycoprotein composition between concentrate, isolate and demineralised whey powders. The quantitative potential was explored by screening 100 pooled farm milk samples. IgG and lactoferrin protein concentrations determined by N-glycoprofile analysis matched well with ELISA results. The protein concentration of GIyCAM-1 was determined to be >= 1 mg mL(-1). The approaches presented in this work allow simultaneous concentration estimation of the three major whey glycoproteins, lactoferrin, IgG and GIyCAM-1 on the basis of their N-linked glycoprofiles, also in highly processed samples where conventional methods of detection (ELISA) are less suitable. (C) 2020 The Authors. Published by Elsevier Ltd.