PRODUCTION AND CHARACTERIZATION OF MONOCLONAL-ANTIBODIES DIRECTED AGAINST EIMERIA-FALCIFORMIS AND CROSS-REACTIVE WITH SPOROZOITES FROM 2 SPECIES OF AVIAN COCCIDIA

Monoclonal antibodies (mAbs) were obtained against the surface antigen s of the Eimerin falciformis sporozoite by immunizing mice with whole homogenized sporozoite. The hybridomas were selected by their reactivi ties against oocyst extracts, then against glutaraldehyde-treated spor ozoites. Three mAbs recognized both the surface of E. falciformis, E. tenella, and E. acervulina and their refractile bodies, whereas a four th mAb recognized only one epitope on the refractile bodies. All mAbs bound to the same immunoaffinity-purified antigens in Western-blot ana lysis (P27 for E. falciformis and P25 for E, tenella and E. acervulina ). Thus, the mAbs define at least two shared epitopes between sporozoi te antigens from different eimerian species. Two of these mAbs are inv olved in the in vitro phagocytosis of E. falciformis sporozoites by ma crophages and also in their lysis by neutrophils. Altogether, these pr operties showed that the four mAbs came from different activated B-cel ls. The P27 antigen recognized by our mAbs represents a major target o f the in vitro destructive immune response.