Transfer of innate resistance and susceptibility to Leishmania donovani infection in mouse radiation bone marrow chimaeras.

Reciprocal radiation bone marrow chimaeras were made between H-2-compatible strains of mice innately resistant or susceptible to visceral leishmaniasis. In initial experiments, susceptibility but not resistance to Leishmania donovani could be transferred with donor bone marrow into irradiated recipients. In subsequent experiments it was possible to transfer both resistance and susceptibility. This was achieved either by selecting more radiosensitive mouse strains as susceptible recipients, or alternatively by increasing the irradiation dose for the susceptible recipients used in the initial experiments. Using the higher irradiation dose, successful transfer of resistance and susceptibility between congenic mice carrying the Lshr and Lshs alleles on the more radioresistant B10 genetic background provided firm evidence that the results obtained in this study were specifically related to expression of the Lsh gene. We conclude that Lsh gene-controlled resistance and susceptibility to L. donovani is determined by bone marrow-derived cells. The cell type(s) involved is likely to be of the macrophage lineage.