Explain/Teach Concepts to a Friend

1. Explain the signaling cascade that is involved in T. cruzi invasion.  Include all known proteins, signaling molecules, and enzymes involved.
2. Explain how Nramp1 and Nramp2 are a host defense mechanism and how Leishmania circumvents them.
3. Explain what happens in LIT1 -/- mutants of Leishmania in cell invasion and replication.