Campylobacter jejuni infection is now the main cause of diarrhea-related illnesses in humans. An efficacious vaccine for the traveler and developing world market would be welcomed. We are engaged in the discovery and characterization of serotype-specific C. jejuni capsule polysaccharides (CPSs) to study their role in virulence and as protective vaccine antigens. Our prototype conjugate vaccine with serotype HS23 CPS (strain 81-176) has been shown to fully protect non-human primates against diarrhea inflicted by C. jejuni HS23, but ultimately, a useful CPS-based vaccine will have to be multivalent. To this end, we describe here the creation of a CPS-conjugate vaccine against C. jejuni serotype HS15. Structural analysis revealed that a repeating block consisting of l-α-arabinofuranose (Ara) and 6-deoxy-l-α-gulo-heptopyranose (6d-gulo-Hep) comprised the CPS of serotype HS15 type strain ATCC 43442 [→3)-α-L-Araf-(1→3)-6d-l-α-gulo-Hepp(1→](n). Strategically, the non-reducing end of the CPS was activated and used in the attachment of CPS to CRM(197) to yield a conjugate vaccine. A serological assessment of the CPS(HS15)-CRM(197) conjugate with an anti-HS15 polyclonal antibody confirmed the conservation of antigenic epitopes, and subsequent inoculation of mice with CPS(HS15)-CRM(197) revealed that this conjugate was indeed capable of raising anti-CPS(HS15) antibodies.

Campylobacter jejuni, capsule polysaccharide, conjugate vaccine, Diarrheal vaccine, 6-deoxy-gulo-heptose

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6	C7
3	aL6dgulHepp	95.67	64.31	76.99	69.67	64.16	31.63	58.14
	aLAraf	109.49	80.54	79.336	80.79	61.13


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6	H7
3	aL6dgulHepp	?	4.06	3.95	3.94	4.21	1.77-1.89	3.76
	aLAraf	?	4.31	4.09	4.16	3.76-3.89


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6	C7/H7
3	aL6dgulHepp	95.67/?	64.31/4.06	76.99/3.95	69.67/3.94	64.16/4.21	31.63/1.77-1.89	58.14/3.76
	aLAraf	109.49/?	80.54/4.31	79.336/4.09	80.79/4.16	61.13/3.76-3.89

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

*O[C@H]1[C@H](O)[C@H](CCO)O[C@@H](O[C@H]2[C@H](CO)O[C@@H](*)[C@@H]2O)[C@H]1O

308.283 g/mol (C₁₂H₂₀R₂O₉, R = next and previous repeats, not counted in mol weight)