TRANSMISSION AND SCANNING ELECTRON-MICROSCOPY OF HOST-CELL ENTRY BY TOXOPLASMA-GONDII

  • 1 January 1977
    • journal article
    • research article
    • Vol. 87  (2) , 285-296
Abstract
Entry by tachyzoites of T. gondii, the causative agent of toxoplasmosis, into mouse peritoneal cells was investigated with transmission and scanning electron microscopy. The process of entry is initiated by the parasite contacting the host cell with its anterior end, creating a small depression in the plasmalemma of the host cell. Occasionally, a small portion of the host cell cytoplasm protrudes and contacts the anterior end of the parasite. A cyclindrical structure (35 nm in diameter) extends from the pellicle of the parasite to the host cell. Such structures appear to assist host cell entry by T. gondii. As the entry process progresses, pseudopods of the host cell surround the parasite and finally T. gondii becomes intracellular, being located in a vacuole separated from the host cell cytoplasm by a unit membrane.