Conjugate Vaccines Related to Capsular Polysaccharides of Campylobacter jejuni

Campylobacter jejuni is a gram-negative bacteriium that causes gastroenteritis in human. The curved, helical bacterium is commonly found in the intestines of many animals including poultry, cattle, swine, rodents, wild birds and household pets as a commensal organism. Human could be infected by C. jejeuni through the consumption or in contact with contaminated meat or drinking contaminated water. It is estimated that more than 400 million cases of C. jejuni infections occur annually worldwide, making it the most common cause of bacterial gastroenteritis. Typical symptoms can range from watery stool to bloody stool accompanied with different degree of inflammation, pyrexia, and abdominal cramping. Although the infection usually is self-limiting, there is a significant economical costs adding to the society. During recent years, antibiotic resistant stains of C. jejuni have been reported in numerous cases.

C. jejuni infection could lead to autoimmune disorders such as Guillain-Barré syndrome and Reiter’s syndrome. These autoimmune conditions are associated to the expression of lipooligosaccharides (LOSs) by the bacteria, which contain carbohydrate epitopes similar to human ganglioside structures[1]. Human hosts develop carbohydrate-specific antibodies against the bacterial LOSs, which subsequently bind to human gangliosides, leading to the development of severe autoimmune conditions. We are currently developing synthetic vaccines against the capsular polysaccharides (CPs) of C. jejuni serotype HS:4[2]. Such approach is attractive because there exists no structural similarity between C. jejuni CPs and human glycans. C. jejuni serotype HS:4 expressed unique heptoses, which consists of an unique ido-heptopyranoside with a challenging b-anomeric configuration. To date, we have developed a highly efficient methodology to prepare b-linked idopyranosides.[3-4]

References

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