Fasciola Hepatica Isolates Induce Different Immune Responses in Unmaturated Bovine Macrophages

Fasciola hepatica (liver fluke) is a parasite of great socioeconomic importance. A number of fluke isolates have been identified; however, to date the differences between the immunomodulatory properties of different parasite isolates have not been sufficiently investigated. The aim of this study was to explore differences between the immunomodulatory properties of two F. hepatica isolates using unmaturated bovine macrophages.

A cell line of bovine macrophages was stimulated with excretory/secretory products released by adult flukes from either a laboratory (Fh-WeyES) or wild (Fh-WildES) strain and subsequently subjected to microarray and ELISA analyses. Results: Both Fh-WeyES and Fh-WildES dampened the release of interleukin-10 by bovine macrophages, but only Fh-WildES dampened the release of proinflammatory tumour necrosis factor-α. Microarray analysis revealed that Fh-WildES down- and upregulated 90 and 18 genes, respectively, when compared to Fh-WeyES.

The results indicated different impacts of the isolates on macrophages. A number of researchers use flukes obtained from local slaughterhouses for experiments. Our findings may explain some discrepancies between published results arising from parasite strain choice. The findings indicate that consideration should be given to the use of different strains, and open new and currently unexplored avenues in parasitology for controlling the parasite.