Background
Fasciola hepatica causes economically important disease in livestock worldwide. The relevance of this parasitic infection extends beyond its direct consequences due to its immunoregulatory properties. Objectives: Given the importance of the T helper 1 (Th1) immune response in controlling infections with Mycobacterium avium subspecies paratuberculosis (MAP) in cattle, we aimed to establish the immunological consequences that co-infection with F. hepatica might have on the course of Johne's disease (JD).
Conclusions
Overall, F. hepatica infection had little impact on the in vitro response of immune cells to MAP, whereas in vitro co-stimulation with F. hepatica molecules had a measurable effect. Whether this is likely to affect JD progression during in vivo chronic conditions remains unclear.
Methods
This study compared the in vitro response of bovine immune cells to infection with MAP or exposure to MAP antigens following F. hepatica infection or stimulation with F. hepatica products.
Results
We found a decreased proliferation of peripheral blood mononuclear cells (PBMCs) after infection with F. hepatica. This reduction was inversely correlated with fluke burden. Pre-stimulation with F. hepatica molecules produced a significant reduction of ileocaecal lymph node leucocyte proliferation in response to MAP antigens. Additionally,F. hepatica products reduced expression of the CD14 receptor by macrophages and increased levels of apoptosis and bacterial (MAP) uptake. Conclusions: Overall, F. hepatica infection had little impact on the in vitro response of immune cells to MAP, whereas in vitro co-stimulation with F. hepatica molecules had a measurable effect. Whether this is likely to affect JD progression during in vivo chronic conditions remains unclear.