Histopathological examination and analysis of mortality in DBA/2 mouse vasculitis induced with CAWS, a water-soluble extracellular polysaccharide fraction obtained from Candida albicans

CAWS, a water-soluble extracellular polysaccharide fraction obtained from the culture supernatant of Candida albicans, is one of the fungal pathogen-associated molecular patterns (PAMPs). It has been reported to show potent activity inducing arteritis and coronaritis in mice. Especially, CAWS-induced arteritis has a 100% incidence and severe mortality in the DBA/2 mouse strain. This artificial vasculitis was reported to provide a good murine model of Kawasaki disease and other inflammatory vascular disease. However, severe mortality was observed only in DBA/2 mice, which is a CAWS-sensitive strain. In this study, to clarify the mechanisms of CAWS-induced arteritis and mortality, we investigated microscopic histopathological changes in cardiovascular tissues in DBA/2 mice. Severe inflammatory infiltration was observed from the external elastic lamina in the aorta and proximal coronary arteries within 1 week after CAWS administration. Severe stenosis of the aorta and coronary arteries was observed more than 3 weeks after CAWS administration. Fibrinoid necrosis was observed in these vessel walls. All CAWS-treated mice died between the fifth and twelfth week after administration. Severe inflammatory change with aortic valve transformation suggested that CAWS-treated mice died of valvular endocarditis or cardiac dysfunction. Based on the simple induction method and complete incidence, these data suggest that CAWS-induced arteritis is a good model of not only Kawasaki disease but also other cardiovascular diseases such as valvular endocarditis.