Leishmania mexicana can utilize amino acids as major carbon sources in macrophages but not in animal models

Abstract

Leishmania parasites target macrophages in their mammalian hosts and proliferate within the mature phagolysosome compartment of these cells. Intracellular amastigote stages are dependent on sugars as a major carbon source in vivo, but retain the capacity to utilize other carbon sources. To investigate whether amastigotes can switch to using other carbon sources, we have screened for suppressor strains of the L. mexicana Δlmxgt1-3 mutant which lacks the major glucose transporters LmxGT1-3. We identified a novel suppressor line (Δlmxgt1-3s2) that has restored growth in rich culture medium and virulence in ex vivo infected macrophages, but failed to induce lesions in mice. Δlmxgt1-3s2 amastigot..