Monoclonal antibodies raised against coccidia and malarial parasites recognize antigenic epitopes found in lankesterellid and adeleorin parasites.

Three murine monoclonal antibodies (MAbs) raised against poultry coccidia or murine malarial parasites were tested for cross-reactivity with 2 sporozoan parasites with different life histories and hosts: Lankesterella minima (Eimeriorina), an intraerythrocytic parasite of frogs that is transmitted by leeches; and Heptazoon catesbianae (Adeleinorina) that infects the red blood cells of frogs and is transmitted by mosquitoes. MAb 1209 recognized both refractile bodies of sporozoites of L. minima, using the indirect fluorescent antibody (IFA) technique and immunoelectron microscopy, and recognized antigens with relative rates of migration (M(r)) of 17, 23, 26, 43, and 48 kDa on a chemiluminescent western blot of L. minima sporozoite antigens. MAbs C(3)4F1 and E12 demonstrated spotty cytoplasmic staining and labeling of the anterior pellicle of L. minima sporozoites, respectively. Gamonts of H. catesbianae labeled with only MAb E12, using IFA. These gamonts exhibited staining similar to that observed with the L. minima sporozoites. The presence of the cross-reactive epitopes recognized by these MAbs in the same conserved locations suggests that these antigens are homologous.