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Interactions of the scid or beige mutations with the viable motheaten mutation
1Laboratoire d'immunologie, Université de Strasbourg 1, France.
Abstract:
The viable motheaten (mev) mice are characterized by a moth-eaten appearance of the coat, immunodeficiency, autoimmunity, generalized inflammatory disease, paws necroses, and early death. The target of the single point mev mutation is PTP1C, a protein tyrosine phosphatase whose deficient expression in hematopoietic cells should explain all phenotypic features of mev mice, particularly their autoimmune and inflammatory pathologies. In order to evaluate their role in the development of the mev mouse disease, we constructed mevscid congenics to probe the impact of autoimmunity and mevbeige congenics to probe the impact of elastase and cathepsine G neutrophil activities. Both mevscid and mevbeige mice were nearly equivalent to mev mice with regards to moth-eaten appearance, paw necroses and early death. Thus, autoimmunity does neither initiate nor substantially enhance the mev mouse syndrome. Moreover, the beige mutation-linked deficiency of protease activity of neutrophils is unable to significantly reduce the mev mutation-dependent inflammatory pathology.
Insights
Motheaten (mev) mice exhibit autoimmune and inflammatory diseases due to PTP1C deficiency. Congenic mice studies reveal autoimmunity and neutrophil protease deficiencies do not significantly impact the disease progression or severity.
Area of Science:
- Immunology
- Genetics
- Pathology
Background:
- The viable motheaten (mev) mouse model displays a complex phenotype including immunodeficiency, autoimmunity, inflammation, and premature death.
- The mev mutation targets PTP1C, a protein tyrosine phosphatase, suggesting its deficiency in hematopoietic cells underlies the observed pathologies.
Purpose of the Study:
- To investigate the specific roles of autoimmunity and neutrophil protease activity in the development and severity of the mev mouse syndrome.
- To determine if correcting autoimmunity or neutrophil function can ameliorate the mev mouse phenotype.
Main Methods:
- Construction of mevscid congenic mice to isolate the impact of autoimmunity.
- Construction of mevbeige congenic mice to assess the role of neutrophil elastase and cathepsin G activities.
- Comparative analysis of phenotypic features (coat, paw necrosis, survival) in mev, mevscid, and mevbeige mice.
Main Results:
- mevscid and mevbeige mice exhibited phenotypes nearly equivalent to mev mice, including moth-eaten coat, paw necrosis, and early mortality.
- Autoimmunity was found to neither initiate nor substantially exacerbate the mev mouse syndrome.
- Deficiency in neutrophil protease activity, linked to the beige mutation, did not significantly reduce the inflammatory pathology associated with the mev mutation.
Conclusions:
- Autoimmunity is not a primary driver or significant enhancer of the mev mouse disease.
- Neutrophil protease activity does not play a critical role in modulating the inflammatory pathology of mev mice.
- The PTP1C deficiency in mev mice leads to a complex syndrome where autoimmunity and neutrophil proteases are not key contributing factors to its core pathology.