A potential new role for bFGF in host-parasite interactions.

Basic fibroblast growth factor (bFGF) is a mitogenic polypeptide highly conserved between species, implicated in regenerative processes and present in all tissues examined. In the heart, bFGF is localized in association with nuclei, extracellular matrix and intercalated discs of cardiomyocytes. In this article is reported bFGF association with the intramuscular parasitic protozoan Sarcocystis in situ, in bovine hearts, detected by indirect immunofluorescence. Parasitic cysts appear connected directly to specialized host cell junctions: bFGF provides structural continuity between parasitic cyst wall and myocyte intercalated discs. Other proteins associated with intercalated discs such as desmin or desmoplakin are not detected in the cysts. Association with Sarcocystis suggests a new role for bFGF in the context of parasitic invasion and establishment.