Modifications of Bordetella bronchiseptica core lipopolysaccharide influence immune response without affecting protective activity

SISTI F; FERNÁNDEZ, J; CORDERO, A; CASABUONO, A; COUTO A; HOZBOR D

BIOORGANIC & MEDICINAL CHEMISTRY LETTERS

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2017 vol. 27 p. 432 - 436

0960-894X

Bordetella bronchiseptica produces respiratory disease primarily in mammals including humans. Althougha considerably amount of research has been generated regarding lipopolysaccharide (LPS) role duringinfection and stimulating innate and adaptive immune response, mechanisms involved in LPS synthesisare still unknown. In this context we searched in B. bronchiseptica genome for putative glycosyltransferases.We found possible genes codifying for enzymes involved in sugar substitution of the LPS structure.We decided to analyse BB3394 to BB3400 genes, closed to a previously described LPS biosyntheticlocus in B. pertussis. Particularly, conservation of BB3394 in sequenced B. bronchiseptica genomes suggeststhe importance of this gene for bacteria normal physiology. Deletion of BB3394 abolished resistance tonaive serum as described for other LPS mutants. When purified LPS was analyzed, differences in theLPS core structure were found. Particularly, a GalNA branched sugar substitution in the core was absentin the LPS obtained from BB3394 deletion mutant. Absence of GalNA in core LPS alters immune responsein vivo but is able to induce protective response against B. bronchiseptica infection.