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Published on: March 23, 2014
Inbred mouse strain resistance to Mycobacterium lepraemurium follows the Ity/Lsh pattern
Abstract:
Inbred mouse strains and their F1 hybrids infected intravenously with Mycobacterium lepraemurium showed different mean survival times (MST). BALB/c and C57BL mice were particularly susceptible, whereas C3H, CBA and DBA/2 mice were relatively resistant. Resistance as judged by MST was dominant in the F1 hybrids. A similar ranking order was obtained by comparing the doubling time of the bacillus in the bone marrow, the increase in spleen weight between 4 and 12 weeks after infection, and the pathology of the liver during infection. The general pattern suggests that mouse resistance to M. lepraemurium is, at least in part, controlled by a gene with the same strain distribution as the genes for resistance to Salmonella typhimurium (Ity') and Leishmania donovani (Lsh') and the gene controlling resistance to Mycobacterium bovis BCG (Bcg). Ity, Lsh and Bcg are all known to be on chromosome 1, suggesting a centre controlling reactions to intracellular infections.
Insights
Mouse strain differences influence resistance to Mycobacterium lepraemurium infection. Genetic resistance to this leprosy bacterium appears linked to genes controlling other intracellular infections on chromosome 1.
Area of Science:
- Immunology
- Genetics
- Microbiology
Background:
- Inbred mouse strains exhibit varying susceptibility to infectious diseases.
- Understanding genetic control of host-pathogen interactions is crucial for disease management.
Purpose of the Study:
- To investigate genetic differences in mouse susceptibility to Mycobacterium lepraemurium.
- To identify potential genetic loci controlling resistance to M. lepraemurium.
Main Methods:
- Intravenous infection of inbred mouse strains and F1 hybrids with M. lepraemurium.
- Assessment of mean survival times (MST) as a primary measure of resistance.
- Evaluation of bacillus doubling time, spleen weight, and liver pathology.
Main Results:
- Significant variation in MST observed among different mouse strains.
- BALB/c and C57BL mice were highly susceptible; C3H, CBA, and DBA/2 mice were resistant.
- Resistance was found to be dominant in F1 hybrids, indicating genetic control.
Conclusions:
- Mouse resistance to M. lepraemurium is genetically controlled, with resistance being dominant.
- The genetic basis for M. lepraemurium resistance shares similarities with genes for resistance to Salmonella typhimurium (Ity), Leishmania donovani (Lsh), and Mycobacterium bovis BCG (Bcg).
- These resistance genes (Ity, Lsh, Bcg) are located on chromosome 1, suggesting a shared genetic locus for controlling intracellular infections.
