Leishmania
are obligate intracellular parasites that invade
and survive within host macrophages and can result
in visceral leishmaniasis, a major public health problem
worldwide. The entry of intracellular parasites, in general,
involves interaction with the plasma membrane of host cells. The
molecular mechanisms involved in host-parasite interaction leading to attachment
on the cell surface and subsequent internalization of the
parasite are poorly characterized (Pucadyil and Chattopadhyay (2007)
Trends Parasitol.). We have shown, for the first time, that cholesterol
in host cell membranes is necessary for binding and internalization of
Leishmania into host macrophages (Pucadyil
et al. (2004) Mol. Biochem. Parasitol.). Importantly,
we showed that entry of Escherichia coli remains
unaffected by cholesterol depletion. We proposed
the specific requirement of plasma membrane cholesterol
in efficient attachment and internalization of
the parasite into macrophage cells
leading to a productive infection. These results are significant
in developing novel therapeutic strategies
to tackle leishmaniasis. A part of this work has been
patented (U.S. patent # 7186702).