Resilience to infection by Mycobacterium avium subspecies paratuberculosis following direct intestinal inoculation in calves.

Mycobacterium avium subspecies paratuberculosis (Map) is the cause of Johne's disease, a chronic enteritis of cattle. A significant knowledge gap is how persistence of Map within the intestinal tract after infection contributes to progression of disease. To address this, we exposed calves to Map by direct ileocecal Peyer's patch injection.

Bovine WC1 and WC1 γδ T Lymphocytes Influence Monocyte Differentiation and Monocyte-Derived Dendritic Cell Maturation during Subspecies Infection.

During early subspecies () infection, complex interactions occur between the bacteria, cells from the mononuclear phagocyte system (MPS) including both resident (macrophages and dendritic cells) and recruited (monocytes) cells, and other mucosal sentinel cells such as γδ T lymphocytes. Though the details of early host-pathogen interactions in cattle remain largely underexplored, our hypothesis is that these significantly influence development of host immunity and ultimate success or failure of the host to respond to infection. The aims of the present study were to first characterize monocyte-derived MPS cells from young calves with respect to their immunophenotype and function.

Bovine peripheral blood WC1 and WC1 γδ T lymphocytes modulate monocyte-derived macrophage effector functions during in vitro Mycobacterium avium subspecies paratuberculosis infection.

The importance of bovine γδ T lymphocytes during anti-mycobacterial immunity is recognized; however, the role of major subsets of γδ T lymphocytes (WC1 and WC1) in this process remains unclear. We investigated how WC1 and WC1 γδ T lymphocyte subsets of calves modulate monocyte-derived macrophage (MDM) functions during Map infection in vitro. To achieve this, Map-infected or uninfected MDMs from young calves were co-cultured with autologous WC1 or WC1 γδ T lymphocytes.

Bovine WC1(+) γδ T lymphocytes modify monocyte-derived macrophage responses during early Mycobacterium avium subspecies paratuberculosis infection.

Following Mycobacterium avium subspecies paratuberculosis (Map) infection, some calves are apparently able to successfully clear the pathogen whereas others become persistently infected; however the reasons for this remain unknown. The importance of innate immunity, and in particular the role of γδ T lymphocytes, during early anti-mycobacterial immune response is recognized but specific mechanisms remain incompletely characterized. The objective of this study was to investigate how bovine WC1(+) γδ T lymphocytes mediate macrophage function during early Map infection.