Canine morbillivirus infection of primary alveolar macrophages provides insights into mechanisms of viral interference with innate immune defense responses

Morbillivirus canis (formerly: canine distemper virus, CDV) is a highly contagious pathogen with a broad host range among carnivore species. During respiratory infection, alveolar macrophages (AMs) are among the first cell types facing the virus, which has previously been shown for measles virus infection. While AMs contribute to pulmonary homeostasis, they likewise bear great potential in establishing a pro-inflammatory environment once confronted with viruses. This study aimed to investigate cellular defense responses by AMs, allowing assumptions on early pathogenesis of CDV. Overall design: Primary canine AMs were obtained by post mortem bronchoalveolar lavage. Cells were subsequently infected with CDV Onderstepoort (Ond), a broadly used vaccine strain, and the virulent strain CDV R252. Samples from 1 day post infection were used for bulk RNA sequencing.