Conclusion
The unfolded protein response is an essential cellular mechanism that
promotes the survival of a cell during conditions of cellular stress,
including intracellular parasitic infections. Pathogens are known to
induce ER stress and UPR via interacting with the ER functions, while
some are recognized to subvert the UPR to promote their survival and
replication. Leishmania amozonensis activated the IRE1-XBP1
branch of the UPR to promote their growth in an IFN-1β depended manner,
while activation of the PERK/eIF2α/ATF4 signaling cascade protected
infected macrophages from oxidative stress. A mild ER stress response
induced in Leishmania infantum infections may act as a
possible adaptive mechanism for the cell to build up resistance to
subsequent ER stress. Leishmania donovani infection induces the
UPR in PERK dependent manner and has shown to delay apoptosis of
infected macrophages. Thus, it is important to characterize the nature
of the ER stress response to target the UPR pathway as a potential
treatment option.
This review is intended to provide a comprehensive view of the available
knowledge on the ER stress response markers and the UPR pathways
characterized in intracellular parasitic infection by Trypanasomatids
and particularly during infection Leishmania spp.infections.