Genetic susceptibility to intracellular infections: Nramp1, macrophage function and divalent cations transport

Nramp1 is one of the few host resistance genes that have been characterized at the molecular level. Nramp1 is an integral membrane protein expressed i n the lysosomal compartment of macrophages and is recruited to the membrane of bacterial phagosomes where it affects intracellular microbial replicati on. Nramp1 is pari of a very large gene family conserved from bacteria and man that codes for transporters of divalent cations transporters. We propos e that Nramp1 affects the intraphagosomal microbial replication by modulati ng divalent cations content in this organelle. Both mammalian and bacterial transporters may compete for the same substrate in the phagosomal space.