Cryptosporidium: cellular localization, structural analysis of absorptive cell-parasite membrane-membrane interactions in guinea pigs, and suggestion of protozoan transport by M cells.

摘要: In ilea of spontaneously infested guinea pigs, we examined the interface between plasma membranes cryptosporidia and absorptive cells using thin section freeze fracture techniques. Initially, invaginate microvilli, resulting redundant folds membrane envelop protozoan, thereby internalizing it in a sac host cell origin. Subsequently, pentalaminar fusion site develops at base protozoan parasite's outer internalized membrane. The domains isolated by this are then modified: disintegrates, parasite membrane, which now directly contacts cytoplasm, becomes amplified. While restricted to apex cells, they may be found deep within cytoplasm M overlying Peyer's patches. Moreover, both intact partially digested cryptosporidial organisms associate with macrophages subjacent such cells. These findings define intracellular localization suggest that antigens sampled intestinal lymphoid sites underlying