Histopathological Examination and Analysis of Mortality in DBA/2 Mouse Vasculitis Induced with CAWS, a Water-soluble Extracellular Polysaccharide Fraction Obtained from Candida albicans

The impact of glucocorticoids therapy on cutaneous wounds in Kawasaki disease: A meta-analysis of randomized controlled trials

Kawasaki disease (KD) is one of the most challenging diseases that is defined as an acute vasculitis that affects the coronary arteries primarily in children. It causes complications if left untreated at early stages, ultimately leading to death. Corticosteroids have been recognized to treat and cause great impact on the patients with KD. Glucocorticoid is one of the main corticosteroids that are being used to treat KD and cutaneous wounds. However, ineffectiveness of a few glucocorticoids can limit the efficacy of this treatment. This study particularly aimed to elucidate the impact of glucocorticoids on cutaneous wounds in KD. To perform the meta-analysis, a comprehensive literature survey was conducted to unveil the studies and research conducted on Kawasaki patients that revealed different glucocorticoids in the form of specific interventions influencing KD. The literature was searched using numerous keywords, screened and data was extracted to perform the meta-analysis and then it was conducted using the metabin function of R package meta. A total of 2000 patients from both intervention and control groups were employed to carry out the meta-analysis to analyse and evaluate the impact of glucocorticoids on curing KD and cutaneous wounds in patients. The results disclosed that glucocorticoids along with other steroids, mainly IVIG (intravenous immunoglobulin), was an effective intervention to patients suffering from Kawasaki. The results depicted significant outcomes with the values (risk ratio [RR]: 1.08, 95% confidence interval [CI]: 0.58-2.00, p < 0.01) and enlightened the fact that adopting different glucocorticoids may significantly improve the efficacy of skin lesions along with KD. Hence, interventions of glucocorticoids must be utilized in the clinical practice to reduce the incidence of skin wounds and adverse effects caused due to KD.

Emerging evidence of microbial infection in causing systematic immune vasculitis in Kawasaki disease

Kawasaki disease (KD) is a systematic vasculitis that is often complicated by coronary artery lesions and is a leading cause of acquired heart disease in developed countries. Previous studies have suggested that genetic susceptibility, together with an inducing infectious agent, could be involved in KD pathogenesis; however, the precise causative agent of this disease remains unknown. Moreover, there are still debates concerning whether KD is an infectious disease or an autoimmune disease, although many studies have begun to show that various pathogens functioning as critical inducers could activate different kinds of immune cells, consequently leading to the dysfunction of endothelial cells and systematic vasculitis. Here in this review, we attempt to summarize all the available evidence concerning pathogen infections associated with KD pathogenesis. We also discuss the related mechanisms, present a future perspective, and identify the open questions that remain to be investigated, thereby providing a comprehensive description of pathogen infections and their correlations with the host immune system in leading to KD.

Sivelestat's effect on Candida albicans water-soluble fraction-induced vasculitis

BACKGROUND

We investigated the efficacy of sivelestat sodium hydrate (SSH) as a treatment for Kawasaki disease, and its pharmacological action sites, in mice with Candida albicans water-soluble fraction-induced vasculitis.

METHODS

Sivelestat sodium hydrate was administered intraperitoneally to Candida albicans water-soluble fraction-induced vasculitis model mice to assess its efficacy in preventing the development of coronary artery lesions based on the degree of inflammatory cell infiltration in the aortic root and coronary arteries (vasculitis score). The pharmacological sites of action were investigated based on changes in neutrophil elastase (NE) and intercellular adhesion molecule 1 (ICAM-1) positive areas, ICAM-1 and tumor necrosis factor-α mRNA expression levels in the upper heart, and the proportion of monocytes in the peripheral blood.

RESULTS

The vasculitis score decreased below the lower limit of the 95% confidence interval of untreated mice in 69% of the SSH-treated mice. The NE- and ICAM-1-positive regions, and the mRNA expression of ICAM-1 and tumor necrosis factor-α were lower in the SSH-treated mice than in the untreated mice. The proportion of monocytes in the peripheral blood was higher in the SSH-treated mice than in the untreated mice, whereas monocyte migration to inflammation areas was suppressed in the SSH-treated mice.

CONCLUSIONS

Our results showed that SSH might prevent the development of coronary artery lesions and ameliorate disease activity. In addition to its NE-inhibitory effect, SSH sites of action may also include monocytes.

Coronary Vasculitis Induced in Mice by Cell Wall Mannoprotein Fractions of Clinically Isolated Candida Species

Kawasaki disease (KD) is an inflammatory disease that was identified by Professor Tomisaku Kawasaki in 1961. Candida albicans-derived substances (CADS) such as the hot water extract of C. albicans and Candida water-soluble fractions (CAWS) induce coronary vasculitis similar to KD in mice. An increasing proportion of deep-seated candidiasis cases are caused by non-albicans Candida and are often resistant to antifungal drugs. We herein investigated whether the mannoprotein fractions (MN fractions) of clinically isolated Candida species induce vasculitis in mice. We prepared MN fractions from 26 strains of Candida species by conventional hot water extraction and compared vasculitis in DBA/2 mice. The results obtained revealed that the induction of vasculitis and resulting heart failure were significantly dependent on the species; namely, death rates on day 200 were as follows: Candida krusei (100%), Candida albicans (84%), Candida dubliniensis (47%), Candida parapsilosis (44%), Candida glabrata (32%), Candida guilliermondii (20%), and Candida tropicalis (20%). Even for C. albicans, some strains did not induce vasculitis. The present results suggest that MN-induced vasculitis is strongly dependent on the species and strains of Candida, and also that the MN fractions of some non-albicans Candida induce similar toxicity to those of C. albicans.

Coronary Vasculitis Induced in Mice by the Cell Wall Mannoprotein of Candida krusei

Kawasaki disease (KD) is an inflammatory disease that was identified by Professor Tomisaku Kawasaki in 1961. Candida albicans-derived substances, such as the hot water extract of C. albicans (CADS) and Candida water-soluble fraction (CAWS), induced coronary vasculitis similar to KD in mice. An increasing proportion of deep-seated candidiasis cases are caused by non-albicans Candida and are often resistant to antifungal drugs. We herein investigated whether the hot water extract of C. krusei, inherently resistant to fluconazole, induces vasculitis in mice. Three strains of C. krusei, NBRC1395, NBRC1162, and NBRC10737, were cultured in natural (Y) and chemically defined (C) media and cell wall mannoprotein (MN) fractions were prepared by autoclaving cells (CKY1395MN, CKC1395MN, CKY1162MN, CKC1162MN, CKY10737MN, and CKC10737MN). All MN fractions reacted strongly with Concanavalin A (Con A) and dectin-2 and induced anaphylactoid shock in ICR mice. MNs induced severe coronary vasculitis in DBA/2 mice, resulting in cardiac hypertrophy. MNs also induced coronary vasculitis in C57Bl/6 mice. These results suggest that the MNs of non-albicans Candida, such as C. krusei, induce similar toxicity to those of C. albicans.

The involvement of the vasa vasorum in the development of vasculitis in animal model of Kawasaki disease

BACKGROUND

Kawasaki Disease (KD) involves a diffuse and systemic vasculitis of unknown etiology that mainly affects infants and children. Although a considerable number of analyses of the clinical, histopathological and molecular biological details underlying the mechanism responsible for the development of coronary arterial lesions, it is still poorly understood.The purpose of this study was to analyze the state of angiogenesis, vasculogenesis and the distribution of blood vessels using an animal model of KD like vasculitis. We investigated the involvement of the vasa vasorum from the adventitia in the vascular involvement and the development of the disease state by performing sequential histopathology, scanning electron microscopy (SEM) and micro computed tomography (CT) studies using a murine model of vasculitis induced by the Candida albicans water-soluble fraction (CAWS).

METHODS

To prepare the animal model of KD like vasculitis, CAWS was intraperitoneally injected into C57BL/6N mice for five consecutive days as reported by Ohno et al. We observed the changes of the vasa vasorum at the aorta and the orifices of the coronary arteries by SEM and micro CT, and also compared the neovascularization at the media and adventitia of the aorta by an immunohistochemical analysis.

RESULTS

As previously reported, obvious inflammation was detected two weeks after the injection of CAWS, and also intimal thickening was observed three weeks after the injection. We found that the vasa vasorum in the adventitia of the aorta was increased in the model mice. The vasa vasorum started increasing one week after the injection of CAWS, before any obvious vasculitis was microscopically detected.

CONCLUSION

The present results indicate that the vasculitis in Kawasaki disease starts as a disorder of the vasa vasorum.

β-mannosyl linkages inhibit CAWS arteritis by negatively regulating dectin-2-dependent signaling in spleen and dendritic cells

AIMS

CAWS, Candida albicans water-soluble fraction, is an extracellular mannoprotein produced by C. albicans NBRC1385. It is a ligand of dectin-2, the C-type lectin receptor for innate immunity, and has strong potency for induction of vasculitis in DBA/2 mice. The structure of this mannoprotein is known to be modulated by the culture conditions. To clarify the structure required for vasculitis, CAWSs were prepared in the two culture conditions with or without pH control, and biological properties were compared.

METHODS

CAWSs prepared by the standard protocol and pH controlled at 7.0 were designated as CAWS and CAWS727, respectively. The antigenicity was detected by the anti-Candida mannan IgG. These chemical structures were assessed by nuclear magnetic resonance analysis and the lectin array system. The in vitro activity of CAWSs was tested by tumor necrosis factor-α (TNF-α) induction using bone marrow-derived dendritic cells and spleen cell cultures.

RESULTS

The antigenicity of CAWS727 was similar to CAWS but the nuclear magnetic resonance analysis showed a higher ratio of β-mannosyl linkages were detected in CAWS727. The lectin array showed relative affinities of CAWS727 to α-mannosyl specific lectins were weaker than those of CAWS. CAWS induced severe vasculitis in DBA/2 mice while CAWS727 did not. CAWS significantly induced TNF-α but CAWS727 did slightly. In addition, CAWS-induced TNF-α production was inhibited by mixing with CAWS727 in a concentration dependent manner.

CONCLUSION

The α-mannosyl linkages of Candida mannan is a key molecule for the immunotoxicity. CAWS727, which conatins β-mannosyl linkages, competitively bound to lectin receptors, and resulted in reductions in the inflammatory response.

Etanercept suppresses arteritis in a murine model of kawasaki disease: a comparative study involving different biological agents

Coronary arteritis, a complication of Kawasaki disease (KD), can be refractory to immunoglobulin (IVIG) treatment. To determine the most effective alternative therapy, we compared the efficacy of different agents in a mouse model of KD. Vasculitis was induced by injection of Candida albicans water-soluble fractions (CAWS) into a DBA/2 mouse, followed by administration of IVIG, etanercept, methylprednisolone (MP), and cyclosporine-A (CsA). At 2 and 4 weeks, the mice were sacrificed, and plasma cytokines and chemokines were measured. CAWS injection induced active inflammation in the aortic root and coronary arteries. At 2 weeks, the vasculitis was reduced only by etanercept, and this effect persisted for the subsequent 2 weeks. At 4 weeks, IVIG and CsA also attenuated the inflammation, but the effect of etanercept was more significant. MP exerted no apparent effect at 2 or 4 weeks. The suppressive effect exerted by etanercept on cytokines, such as interleukin- (IL-)6, IL-12, IL-13, and tumor necrosis factor-α (TNF-α), was more evident than that of others. The extent of arteritis correlated with the plasma TNF-α levels, suggesting a pivotal role of TNF-α in KD. In conclusion, etanercept was most effective in suppressing CAWS-induced vasculitis and can be a new therapeutic intervention for KD.

[Negative regulatory factor of CAWS (Candida albicans water-soluble fraction) -vasculitis in CBA/J mice as assessed by comparison with Bruton's tyrosine kinase-deficient CBA/N mice]

Candida albicans water-soluble fraction (CAWS) has microbial pathogen-associated molecular patterns (PAMPs). It is a mannoprotein-β glucan complex obtained from the culture supernatant of Candida albicans NBRC1385 and exhibits vasculitis-inducing activity (CAWS vasculitis) in mice. The sensitivity to CAWS vasculitis varies greatly among mouse strains. This study examined the factors contributing to or inhibiting CAWS vasculitis using CAWS-vasculitis-resistant CBA/J mice and Bruton's tyrosine kinase (Btk)-deficient CBA/N mice, which is a CAWS-vasculitis-sensitive strain having the same origin as CBA/J mice. After stimulation with various kinds of pathogen-associated molecular patterns (PAMPs), the production of inflammatory cytokines IL-6 and IFN-γwas induced in CBA/N mice, whereas that of immunosuppressive IL-10 was induced in CAWS-vasculitis-resistant CBA/J mice. The production of TIMP1, an endogenous matrix metalloproteinase (MMP) inhibitor, was observed in CBA/J mice. Furthermore, the induction of CAWS-vasculitis was inhibited by gene therapy using plasmid (pCAGGS-mIL-10). The results strongly suggest that the difference in the production of these cytokines is closely linked to the development of CAWS vasculitis.

A Model of Left Ventricular Dysfunction Complicated by CAWS Arteritis in DBA/2 Mice

It was reported previously that a Candida albicans water-soluble fraction (CAWS), including a mannoprotein and β-glucan complex, has strong potency in inducing fatal necrotizing arteritis in DBA/2 mice. In this study, histopathological changes and cardiac function were investigated in this system. One mg/day of CAWS was given to DBA/2 mice via peritoneal injection for five days. The CAWS-treated DBA/2 mice were induced aortitis and died at an incidence of 100% within several weeks. Histological findings included stenosis in the left ventricular outflow tract (LVOT) and severe inflammatory changes of the aortic valve with fibrinoid necrosis. Cardiomegaly was observed and heart weight increased 1.62 fold (P < 0.01). Echocardiography revealed a severe reduction in contractility and dilatation of the cavity in the left ventricle (LV): LV fractional shortening (LVFS) decreased from 71% to 38% (P < 0.01), and the LV end-diastolic diameter (LVDd) increased from 2.21 mm to 3.26 mm (P < 0.01). The titer of BNP mRNA increased in the CAWS-treated group. Severe inflammatory changes resulting from CAWS brought about lethal LV dysfunction by aortic valve deformation with LVOT stenosis. This system is proposed as an easy and useful experimental model of heart failure because CAWS arteritis can be induced by CAWS injection alone.

Candida albicans-associated necrotizing vasculitis producing life-threatening gastrointestinal hemorrhage

Patients undergoing treatment of acute lymphoblastic leukemia are at risk for fungal infections including disseminated candidiasis. We describe a case of systemic Candida albicans infection associated with life-threatening gastrointestinal hemorrhage due to unusual necrotizing vasculitis involving the gastrointestinal tract. We explore the association between Candida and such vasculopathy.

Candida albicans, Cryptococcus neoformans or Aspergillus fumigatus induces an antifungal activity in mouse serum, which is different from transferrin

It has been reported that administration of Candida albicans into mouse induces an antifungal activity in serum, which has been identified as transferrin. In the present study, we show that not only C. albicans, but also other fungus such as Cryptococcus neoformans or Aspergillus fumigatus similarly can induce an antifungal activity in mouse serum. This antifungal activity was inhibited by the addition of ferrous ion, indicating that the growth inhibition of C. albicans was due to deficiency of ferrous ion, which may be caused by transferrin. Indeed, addition of transferrin in an in vitro assay system using RPMI1640 culture medium inhibited the growth of C. albicans, C. neoformans or A. fumigatus. However, when C. albicans was grown in RPMI1640 medium with 10% fetal bovine serum (FBS), transferrin was unable to inhibit the growth of C. albicans, in sharp contrast, when C. albicans treated mouse serum was added instead of FBS, the growth of the organism was inhibited. Similar results were obtained when C. neoformans or A. fumigatus was used. Taken together, the results suggest that antifungal activity induced by C. albicans, C. neoformans or A. fumigatus was not due to transferrin but likely due to other unknown serum proteins, which may cut off the source of iron for the growth of these fungi.

[Coronary arteritis induced by CAWS (Candida albicans water-soluble fraction) in various strains of mice]

The intraperitoneal administration of CAWS (water-soluble extracellular polysaccharide fraction obtained from the culture supernatant of Candida albicans NBRC 1385) to mice induces coronaritis similar to Kawasaki disease. We analyzed differences in the occurrence of coronary arteritis among mouse strains, inbred strains, a closed colony, hybrids and mutants. CAWS vasculitis was induced in almost all of the inbred and closed colony strains tested, except for CBA / J mice; it was induced also in hybrids, CDF1 and BDF1. In mutant strains of various immunological defects, such as C57BL / 6J Ham Slc-bg , Balb / c nu / nu , C.B.17 / Icr-scid / scid , WBB6F1-W / W (v) mice, all induced CAWS vasculitis but a relatively weak phenotype. It has already been postulated that CAWS vasculitis is regulated by various genes, those related to acute as well as chronic inflammation. This might well reflect the clinical situation in human disease.