A Review of host pulmonary defenses with reference to cattle

Abstract

Bovine respiratory disease is a leading cause of morbidity and mortality for the cattle industry. Cattle can be protected from respiratory disease by both structural and dynamic defense mechanisms of the respiratory tract, which are critical for prevention of pathogen entry and colonization. Dynamic defenses include those mediated by the innate and adaptive branches of the immune response. The immune response to pathogens is complex, and requires immune cell migration, proliferation, and adaptation. Secretion of molecules, including cytokines, host defense peptides, and opsonins, by cells within the respiratory tract promotes respiratory defense, including pathogen neutralization and phagocytosis. Ongoing discoveries in the field of immunology should guide the development of novel immunotherapeutic interventions for the prevention and treatment of bovine respiratory disease.