Eimeria tenella: localisation of rhoptry antigens during parasite-host cell interactions by a rhoptry-specific monoclonal antibody in PCKC culture.

A rhoptry-specific monoclonal antibody (mab) A4C6 was obtained by fusion of X63-Ag 8.653 plasmacytoma cells with splenocytes of BALB/c mice. Mab A4C6 reacted with three protein bands at about 94, 66 and 45 kDa under non-reducing conditions. Gel electrophoresis under reducing conditions separated these protein complexes into several protein fragments ranging between 20 and 200 kDa. Antigens recognised by mab A4C6 were concentrated in the rhoptry sacs located in the apical region of sporozoites as shown by immunoelectron microscopy. During parasite-host cell interaction and development in PCKC culture, mab A4C6 located rhoptry antigens in the parasitophorous vacuole space between intracellular sporozoites and the vacuole membrane.