Electron Microscopy of Intracellular Protozoa.

摘要

We performed immunoelectron microscopy to investigate the distribution of malarial antigens in the various stages of malaria parasites. Monoclonal antibodies, which recognize different epitopes of the Plasmodium yoelii Circumsporozoite protein, reacted with the surface of oocyst and salivary gland sporozoites. However, a small percentage of developing oocysts did not express CS antigen on the surface of sporoblasts or sporozoites. These sporozoites were still capable of completing development and invading salivary glands. Their presence may explain in part the failure of CS vaccines to completely protect immunized animals against challenge. The non-CS antigen did not become abundant until late in sporogony. The Non-CS protein was most abundant within the cytoplasm and micronemes, although non-CS protein was also seen on the sporozoite surface. Keywords: Immunoelectron microscopy; Malarial parasites; Non-CS proteins; Sporozoites; EE stages; Dense granules; Merozoite invasion; RAI. (JG)