Bovine collectins: Role in health and disease

Mammalian collectins play key roles in innate immunity, health and disease. These have been well studied in humans and other mammalian species, but much has still to be learned about the bovine collectins and the role they may play in the health and disease in cattle which have significant economic implications to the agricultural and food industries. This chapter focuses on the bovine collectins, which are important innate immune molecules and play a key role in immunoregulation and protection against pathogens. Like other mammalian collectins, they all have a related structure comprised of an N-terminal triple-helical collagen-like region and a ligand binding C-terminal C-type lectin domain. The bovine collectins are able to recognise and bind to complex glycoconjugates, particularly on the surface of microbes, neutralising infection, enhancing clearance by phagocytes and modulating immune response. Here, we will review the bovine collectins, surfactant proteins A (SP-A) and D (SP-D), mannose binding lectins (MBL-A and MBL-C), conglutinin (CGN), collectin 43 (CL-43) and collectin 46 (CL-46), and their role in bovine immunity and disease. We will particularly focus on the structural, functional and anti-microbial roles of these collectins with an additional focus on genetic polymorphisms in their genes and predisposition to infectious diseases in the bovine host. In the absence of specific data on the bovine host, findings from studies with other mammalian collectins will be discussed with respect to bovine health and disease.