Toxoplasma gondii is an intracellular parasite that lives inside phagocytic and nonphagocytic cells by generating its own intracellular vesicle. This may allow it to avoid recognition and killing by CDS+ lymphocytes, which require the presentation of foreign peptides transported into the endoplasmic reticulum and loaded onto MHC molecules that have

  •  a beta2 domain instead of a beta 2 microglobulin
  •  two similar chains
  •  invariant chains
  •  a peptide-binding groove
  •  a single transmembrane domain