Isolation of antigen from the circulating immune complex in mice infected with Plasmodium berghei

Circulating immune complex (CIC) is known to play a role in pathological gl omerular alterations in malaria. However, the nature of the antigens compri sing the CIC is still not fully understood. We report here the isolation of the antigen in CIC and its localisation in mice infected with Plasmodium b erghei NK65. The antigen was successfully isolated from CIC extracted from the blood of mice infected with P. berghei, by using Clq-coated microplates . The molecular mass of the antigen separated from CIC bound to Clq was fou nd to be 78 kDa. Furthermore, localisation of the antigen was examined by t he fluorescent antibody technique and immunoelectron microscopy. The antige n was detected in the parasitised erythrocyte and the mesangial matrix by b oth methods. These results suggest that the 78 kDa protein might be associa ted with the glomerular alterations in malaria infection. (C) 2000 Australi an Society for Parasitology Inc. Published by Elsevier Science Ltd. All rig hts reserved.