Phenotypes Associated with This Genotype

Genotype
MGI:2654932

• Allelic Composition: Lyz2^tm1.1Graf/Lyz2^tm1.1Graf
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ * C57BL/6

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

immune system

increased inflammatory response ( J:82642 )

• 5 days after s.c. injection of live or heat-inactivated Micrococcus luteus (a normally nonpathogenic and highly lysozyme-sensitive bacterium), homozygotes display persistent swelling and redness at the injection site, with significantly larger, more purulent and inflamed lesions than in wild-type controls where lesions are resolved by day 2 after challenge

• similar large, inflamed, and purulent lesions are observed at 48 hrs after s.c. injection of purified M. luteus peptidoglycan

• at 7 hrs after M. luteus injection, mutant infected lesions contain bacteria with well-preserved cell walls and normal electron-dense cytoplasm, indicating a delay in the enzymatic degradation of peptidoglycan

• although M. luteus survival is significantly prolonged in 1- or 2-day lesions, only few if any viable bacteria are found by day 5, indicating that delayed bacterial killing is unlikely to contribute to the severe tissue pathology observed in mutant mice

homeostasis/metabolism

abnormal enzyme/coenzyme level ( J:82642 )

• at 48 hrs after M. luteus infection, homozygotes exhibit ~15-fold lower concentrations of lysozyme in their s.c. inflammatory lesions (where neutrophils predominate) than controls

• unexpectedly, M. luteus-infected homozygotes display a partial compensation by newly expressing lysozyme P (normally expressed in intestinal Paneth cells) in alveolar macrophages, but not in neutrophils