Assessing the role of the acute phase protein and opsonin MBL in protective immune responses against erysipelas in chickens
Erysipelas is an infectious disease that is a major problem in layinghens, especially in organic production. The disease is caused by the bacteriumErysipelothrix rhusiopathiae (ER), which can infect a wide range of speciesincluding humans. Basic knowledge on immune responses to ER in chickens hasbeen lacking: however, we have recently monitored immune events duringexperimental infection of chickens and identified prominent responses ofheterophils and the acute phase protein mannose-binding lectin (MBL) concurrentwith bacteraemia during the early phases of infection. The ER capsule hasmannose as a major component and MBL has a function as an opsonin for phagocytosis.Thus, it is likely that the observed MBL responses in infected chickens play arole in the successful clearance of experimental ER infection observed in ourstudies. In contrast, the disease is often fatal under field conditions, makingthe identification of protective immune responses critical. At VetBioNetpartner AU there are two unique chicken lines (L10H and L10L) that have highand low MBL baseline levels and show high and low MBL responses upon microbialchallenge. We therefore propose to perform an ER infection experiment at the AUfacilities using these lines to further elucidate the role of MBL in thedefence against ER infection.