Project: Understanding mucosal immunology and co-infections in the chicken to drive vaccine strategies

Despite the fact that vaccine use in poultry is greater than in any other farmed species, the mechanisms by which they induce protection, particularly at mucosal surfaces, are poorly understood. Many diseases constraining avian productivity and welfare affect the respiratory tract and are multi-factorial. A better understanding of responses in the respiratory tract to bacterial and viral infections, co-infections and vaccines is needed to control endemic production diseases. Avian pathogenic Escherichia coli (APEC) cause severe respiratory and systemic disease, threatening food security and avian welfare at a time of increasing global demand. Infections frequently involve sepsis, inflammation of visceral organs and reduced egg yield/quality, with losses through early mortality, reduced productivity and product condemnation. The expansion of free-range production systems will increase the incidence of colibacillosis through greater exposure of birds to environmental pathogens, stress and injury associated with forming a social hierarchy. Importantly, APEC infections are frequently associated with respiratory viral infections. The nature and consequences of host-pathogen interactions during APEC (co-)infections are poorly understood. Virulence factors of APEC, antagonistic or synergistic effects of co-infection and the basis of immunity and resistance are ill-defined. The EC-wide ban on prophylactic antibiotic use and transmissible resistance render poultry susceptible to APEC infection. Existing vaccines confer limited serogroup-specific protection. This project will advance understanding of mucosal immune responses in the avian respiratory tract. It will provide a comprehensive description of the respiratory tract immune system, leading to new tools to study immune responses and improved understanding of the mechanism and site of antigen presentation in the lung. We will thereby identify correlates of resistance and susceptibility to, and the impact of viral infections on the outcome of, APEC infection. Using transgenic chickens we will further characterise the role of antigen-presenting cells and humoral immunity during APEC infection and vaccination, for example by using our unique MacRed chickens (in which all cells of the mononuclear phagocyte lineage (macrophages, monocytes and dendritic cells) express a fluorescent protein driven by the chicken CSF-1 receptor), and immunoglobulin knock-out chickens (which lack the B cell receptor and thus antibody).

Acronym MICHIC
Website visit project website
Network ANIHWA
Call 2nd ANIHWA Joint Call

Project partner

Number Name Role Country
French National Institute for Agricultural Research - Infectiology and Public Health France
Ludwig Maximilian University of Munich Germany
University of Edinburgh Coordinator United Kingdom