Human adipose tissue-derived stem cells inhibit coronary artery vasculitis in a mouse model of Kawasaki disease

BACKGROUND

Adipose tissue-derived mesenchymal stem cells (ADSCs) are used for the treatment of various diseases because of their rapid proliferation and high anti-inflammatory and tissue repair properties. Kawasaki disease is a systemic vasculitis with coronary arteritis and aneurysms occurring in pediatric patients. In this study, we examined serologically and pathologically whether the administration of human ADSCs (hADSCs) to a mouse model of Kawasaki disease could suppress vasculitis.

METHODS

Candida albicans water-soluble fractions were intraperitoneally injected into DBA/2 mice for 5 consecutive days to generate a mouse model of Kawasaki disease. The model mice were intravenously administered hADSCs or phosphate-buffered saline (PBS). Serum samples collected on days 15 and 29 were used to compare cytokine levels. Mouse hearts dissected on day 29 were subjected to hematoxylin and eosin and immunohistological staining using Galectin-1 (Gal-1), a protein involved in cardiovascular homeostasis, and CD44, a cell-surface marker of hADSCs.

RESULTS

Comparison of inflammation-related cytokines showed a significant decrease in IL-1α expression at day 15 (P<0.05) and IL-6 expression at day 29 (P<0.01) in the hADSCs-treated group compared to the PBS group. Evaluation by hematoxylin and eosin staining showed decreased inflammatory cell infiltration and a tendency towards increased Gal-1 expression in the hADSCs group. CD44 expression was not observed in both the groups. The survival curve showed that the hADSCs group had a significantly longer survival time (P<0.05).

CONCLUSIONS

The present experimental results indicate that hADSCs have an early anti-inflammatory effect, and that Gal-1 may be involved in preventing inflammation and reducing tissue damage.

Statins Show Anti-Atherosclerotic Effects by Improving Endothelial Cell Function in a Kawasaki Disease-like Vasculitis Mouse Model

Kawasaki disease (KD) is an acute inflammatory syndrome of unknown etiology that is complicated by cardiovascular sequelae. Chronic inflammation (vasculitis) due to KD might cause vascular cellular senescence and vascular endothelial cell damage, and is a potential cause of atherosclerosis in young adults. This study examined the effect of KD and HMG-CoA inhibitors (statins) on vascular cellular senescence and vascular endothelial cells. Candida albicans water-soluble fraction (CAWS) was administered intraperitoneally to 5-week-old male apolipoprotein E-deficient (ApoE-) mice to induce KD-like vasculitis. The mice were then divided into three groups: control, CAWS, and CAWS+statin groups. Ten weeks after injection, the mice were sacrificed and whole aortic tissue specimens were collected. Endothelial nitric oxide synthase (eNOS) expression in the ascending aortic intima epithelium was evaluated using immunostaining. In addition, eNOS expression and levels of cellular senescence markers were measured in RNA and proteins extracted from whole aortic tissue. KD-like vasculitis impaired vascular endothelial cells that produce eNOS, which maintains vascular homeostasis, and promoted macrophage infiltration into the tissue. Statins also restored vascular endothelial cell function by promoting eNOS expression. Statins may be used to prevent secondary cardiovascular events during the chronic phase of 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.

Recombinant Human Soluble Thrombomodulin Suppresses Arteritis in a Mouse Model of Kawasaki Disease

INTRODUCTION AND OBJECTIVE

Kawasaki disease (KD) is associated with diffuse and systemic vasculitis of unknown aetiology and primarily affects infants and children. Intravenous immunoglobulin (IVIG) treatment reduces the risk of developing coronary aneurysms, but some children have IVIG-resistant KD, which increases their risk of developing coronary artery injury. Here, we investigated the effect of recombinant human soluble thrombomodulin (rTM), which has anticoagulant, anti-inflammatory, and cytoprotective properties on the development of coronary arteritis in a mouse model of vasculitis.

METHODS

An animal model of KD-like vasculitis was created by injecting mice with Candida albicans water-soluble fraction (CAWS). This model was used to investigate the mRNA expression of interleukin (IL)-10, tumour necrosis factor alpha (TNF-α), and tissue factor (TF), in addition to histopathology of heart tissues.

RESULTS

rTM treatment significantly reduces cardiac vascular endothelium hypertrophy by 34 days after CAWS treatment. In addition, mRNA expression analysis revealed that rTM administration increased cardiac IL-10 expression until day 27, whereas expression of TNF-α was unaffected. Moreover, in the spleen, rTM treatment restores IL-10 and TF expression to normal levels.

CONCLUSION

These findings suggest that rTM suppresses CAWS-induced vasculitis by upregulating IL-10. Therefore, rTM may be an effective treatment for KD.

Adipose tissue-derived stem cells suppress coronary arteritis of Kawasaki disease in vivo

BACKGROUND

Kawasaki disease (KD) is a systemic inflammatory disease resulting in an acute febrile syndrome commonly affecting children younger than 5 years. Coronary arteritis in KD is occasionally non-responsive to several treatments. Recently, adipose tissue-derived stem cells (ADSCs) have been shown to have anti-inflammatory, immunosuppressive, and tissue-repair characteristics and are considered a useful treatment for inflammatory disease. The present study aimed to elucidate whether the administration of ADSCs can suppress KD-associated vasculitis in vivo.

METHODS

Candida albicans water-soluble fraction is often used to model KD via the induction of severe coronary arteritis. Kawasaki disease model mice were intravenously administered ADSCs and phosphate-buffered saline (PBS). On day 29, the mice were sacrificed and hearts from mice in each group were dissected. This was followed by serum collection. Cardiac tissue sections were subjected to histopathological examination to evaluate the inflammatory area. The levels of pro-inflammatory cytokines in the serum were analyzed at days 15 and 29. The survival rates of both groups were compared.

RESULTS

The mean inflammatory area in coronary arteritis was significantly lower in the ADSC group compared to the PBS group (P < 0.01). Furthermore, the levels of pro-inflammatory cytokines, such as IL-1β, IL-12, IL-17, RANTES, INF-γ, and TNF-α, in the ADSC group were significantly lower than those in the PBS group. Moreover, the ADSC group had a significantly higher survival rate than the PBS group.

CONCLUSIONS

These findings highlight that ADSCs have anti-inflammatory and immune regulatory functions that could provide novel cell-based therapeutic strategies for severe KD.

Crucial role of NLRP3 inflammasome in a murine model of Kawasaki disease

Kawasaki disease (KD) is a systemic febrile syndrome during childhood that is characterized by coronary arteritis. The etiopathogenesis of KD remains to be elucidated. NLRP3 inflammasome is a large multiprotein complex that plays a key role in IL-1β-driven sterile inflammatory diseases. In the present study, we investigated the role of NLRP3 inflammasome in a murine model of KD induced by Candida albicans water-soluble fraction (CAWS) and found that NLRP3 inflammasome is required for the development of CAWS-induced vasculitis. CAWS administration induced IL-1β production, caspase-1 activation, leukocyte infiltration, and fibrotic changes in the aortic root and coronary arteries, which were significantly inhibited by a deficiency of IL-1β, NLRP3, and ASC. In vitro experiments showed that among cardiac resident cells, macrophages, but not endothelial cells or fibroblasts, expressed Dectin-2, but did not produce IL-1β in response to CAWS. In contrast, CAWS induced caspase-1 activation and IL-1β production in bone marrow-derived dendritic cells (BMDCs), which were inhibited by a specific caspase-1 inhibitor and a deficiency of NLRP3, ASC, and caspase-1. CAWS induced NLRP3 and pro-IL-1β expression through a Dectin-2/Syk/JNK/NF-κB pathway, and caspase-1 activation and cleavage of pro-IL-1β through Dectin-2/Syk/JNK-mediated mitochondrial ROS generation, indicating that CAWS induces the priming and activation of NLRP3 inflammasome in BMDCs. These findings provide new insights into the pathogenesis of KD vasculitis, and suggest that NLRP3 inflammasome may be a potential therapeutic target for KD.

Interleukin-1beta Inhibition Attenuates Vasculitis in a Mouse Model of Kawasaki Disease

BACKGROUND

Kawasaki disease (KD), a systemic vasculitis, is suspected to be related to abnormalities in innate immunity. Based on the important role of IL-1 signaling in innate immunity, we investigated the effects of an anti-IL-1β antibody using a Candida albicans water-soluble fraction (CAWS)-induced mouse model of KD.

METHODS

CAWS (0.5 mg/mouse) was injected intraperitoneally into 5-week-old DBA/2 mice on five consecutive days. An anti-Murine IL-1β antibody (01BSUR) was administered at various doses (2.5, 5.0, and 10.0 mg/kg) and time points (2 days before, same day, and 2, 5, 7, and 14 days after CAWS administration). After 4 weeks, vasculitis in the aortic root was investigated histologically. Cytokines including IL-1β, -6, -10, and TNF-α were also measured.

RESULTS

Groups administered 01BSUR at all doses showed a significant reduction in the area of vasculitis. In addition, 01BSUR inhibited vasculitis until 7 days after CAWS administration. In the analysis of various time points, the level of IL-6 was lower in all groups compared to the CAWS only group, but the levels of IL-1β, TNFα, and IL-10 were lower when 01BSUR was administered before CAWS. On the other hand, TNFα and IL-10 levels were restored when 01BSUR was administered after CAWS, suggesting that 01BSUR may have additional effects beyond blocking IL-1β signaling.

CONCLUSIONS

The anti-IL-1β antibody significantly attenuated CAWS-induced vasculitis. The mechanism of inhibiting vasculitis is thought to include inhibition of the IL-1β pathway and additional effects beyond blocking IL-1β signaling.

Ficolin-1 is a promising therapeutic target for autoimmune diseases

Previously, we reported that mRNA expression of ficolin-1 (FCN1), a component of the complement lectin pathway, is elevated in peripheral blood mononuclear cells of patients with vasculitis syndrome, and that FCN1-positive cells infiltrate into inflamed regions in patient specimens. In addition, we reported that the serum FCN1 concentration is elevated in patients with Kawasaki disease (KD), a pediatric vasculitis, but dramatically decreases after intravenous immunoglobulin (IVIG) treatment. Furthermore, we showed that FCN1 binds to IgG1 in a pull-down assay. These results suggested that removal of FCN1 may be a therapeutic mechanism of IVIG. In this study, we prepared anti-FCN1 monoclonal antibody (mAb) and examined its therapeutic potential in mice treated with Candida albicans water-soluble fraction (CAWS), which induces KD-like vasculitis in the coronary artery. Indeed, treatment with anti-FCN1 mAb decreased the histological score of vasculitis (P = 0.03). To investigate the role of FCN1, we assessed blood samples of patients with various autoimmune diseases and demonstrated that serum levels of FCN1 were elevated not only in patients with vasculitis, but also in those with rheumatoid arthritis. Additionally, FCN1-targeted treatment of a mouse model of arthritis [collagen antibody-induced arthritis (CAIA)] revealed that administration of anti-FCN1 mAb ameliorated symptoms of arthritis (P < 0.01). These results suggest that FCN1 is involved in the pathogenesis of autoimmune diseases, and that targeting FCN1 represents a promising strategy for treating these diseases.

Characterization of a murine model with arteritis induced by Nod1 ligand, FK565: A comparative study with a CAWS-induced model

OBJECTIVE

Kawasaki disease (KD) occurs via activation of the innate immune system. Nucleotide oligomerization domain-1 (NOD1) is a pattern recognition receptor regulating the innate immunity. We characterized histopathology of arteritis induced by FK565, a ligand for NOD1, in mice, compared with Candida albicans water-soluble fraction (CAWS)-induced model.

METHODS

Vasculitis was induced by injection of FK565 or CAWS into C57BL6/J mice (n = 9 and n = 11, respectively). At 4 weeks, they were sacrificed, and plasma cytokines and chemokines were measured.

RESULTS

FK565 injection induced vasculitis mainly involving bilateral coronary arteries whereas the aortic root was diffusely affected in CAWS mice. In FK565 animals, the abdominal aorta and its branching arteries also exhibited inflammation with atherosclerosis. IL-1α, IL-1β, IL-5 and RANTES were increased in FK565 group whereas IL-6, IL-13, G-CSF, IFN-γ, and TNF-α were higher in CAWS animals (p < .05 for all variables). The total area of inflammation in FK565 mice appeared to correlate with IL-1β levels (r = 0.71, p = .05).

CONCLUSIONS

Histopathology of FK565-induced model demonstrated 'site-specific' coronary arteritis mimicking KD. This histopathological difference from CAWS model may be due to different cytokine expression profiles.

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.

Vasculitis and anaphylactoid shock induced in mice by cell wall extract of the fungus Candida metapsilosis

To investigate whether cell wall mannan from Candida metapsilosis induces vasculitis similar to that in Kawasaki syndrome and anaphylactoid shock in mice, we examined the pathogenic effects of C. metapsilosis cell wall extracts. Our results show that intraperitoneal injection of cell wall extracts induced severe coronary arteritis, and intravenous injection induced acute anaphylactoid shock similar to extracts from Candida albicans (C. albicans). Structural analysis of cell wall mannan from C. metapsilosis using NMR spectroscopy showed it to contain only a-mannan, indicating that a-mannan might be contributing to Candida pathogenicity by inducing coronary arteritis and acute shock.

Trafficking of QD-Conjugated MPO-ANCA in Murine Systemic Vasculitis and Glomerulonephritis Model Mice

In systemic vasculitis, the serum level of myeloperoxidase (MPO)-specific anti-neutrophil cytoplasmic autoantibodies (MPO-ANCA) is significantly elevated with the progression of disease. We have established a model of murine systemic vasculitis by administration of MPO-ANCA and fungal mannoprotein to C57BL/6 mice. We examined the role of MPO and MPO-ANCA in the pathogenesis of glomerulonephritis and systemic vasculitis in this model using quantum dots (QDs). We demonstrated that QD-conjugated MPO-ANCA (ANCA-QD) visualized the translocation of MPO on the neutrophil membrane surface after stimulation with proinflammatory cytokines. We also observed that MPO translocation on neutrophils in both patients with rapid progressive glomerulonephritis and these model mice without any stimulation, suggesting that MPO translocation is certain to contribute to the development of glomerular lesion. In addition, blood flow on the kidney surface vessel was significantly decelerated in both SCG/Kj mice and this model, suggesting that ANCA induces the damage of blood vessel. These results indicate that MPO-ANCA and surface-translocated MPO on the activated neutrophils coordinately plays essential roles in the initial steps of the glomerulonephritis.

β-Glucan Derived from Zymosan Acts as an Adjuvant for Collagen-Induced Arthritis

Collagen-induced arthritis (CIA) is an experimental model of rheumatoid arthritis (RA) and has helped researchers to analyze the pathogenesis of inflammatory joint disease. In classical CIA, Freund's complete adjuvant (FCA), which contains heat-killed Mycobacterium tuberculosis, is used as an adjuvant. In our previous study, we reported that particles of beta-glucan, OX-CA, derived from Candida albicans, acted as a proper adjuvant in the CIA model. In this study, to establish pure beta-glucan as an adjuvant for CIA, we tested a commercially available preparation of Zymosan A (ZYM) and modified its products. beta-Glucan fractions of ZYM were prepared by oxidation with various concentrations of NaClO. The oxidized ZYM (OX-ZYM) was mainly composed of beta-glucan. In this study, we examined its effect as an adjuvant for CIA. DBA/1 mice injected with CII and OX-CA developed arthritis 7-10 days after receiving booster injections; the OX-ZYM fractions induced arthritis with the same time course. 0.01% OX-ZYM (oxidized with a 0.01% NaClO solution) caused arthritis faster than 0.1% OX-ZYM or 0.5% OX-ZYM. In conclusion, beta-glucan derived from ZYM by brief oxidation with NaClO is a suitable adjuvant for a CIA model with anti-CII antibody production.

CAWS administration increases the expression of interferon γ and complement factors that lead to severe vasculitis in DBA/2 mice

Background

Candida albicans water-soluble fraction (CAWS), a mannoprotein-β-glucan complex obtained from the culture supernatant of C. albicans NBRC1385, causes CAWS-mediated vasculitis (CAWS-vasculitis) in B6 and DBA/2 mice with mild and lethal symptoms, respectively. Why CAWS is lethal only in DBA/2 mice remains unknown.

Results

We performed DNA microarray analyses using mRNA obtained from peripheral blood mononuclear cells (PBMCs) of B6 and DBA/2 mice and compared their respective transcriptomes. We found that the mRNA levels of interferon-γ (Ifng) and several genes that regulate the complement system, such as C3, C4, Cfb, Cfh, and Fcna, were increased dramatically only in DBA/2 mice at 4 and 8 weeks after CAWS administration. The dramatic increase was confirmed by quantitative real-time polymerase chain reactions (qRT-PCR). Moreover, mRNA levels of immune-related genes, such as Irf1, Irf7, Irf9, Cebpb, Ccl4, Itgam, Icam1, and IL-12rb1, whose expression levels are known to be increased by Ifng, were also increased, but only in DBA/2 mice. By contrast, the mRNA level of Dectin-2, the critical receptor for the α-mannans of CAWS, was increased slightly and similarly in both B6 and DBA/2 mice after CAWS administration.

Conclusions

Taken together, our results suggest that CAWS administration induces Dectin-2 mediated CAWS-vasculitis in both B6 and DBA/2 mice and the expression of Ifng, but only in DBA/2 mice, which led to increased expression of C3, C4, Cfb, Cfh, and Fcna and an associated increase in lethality in these mice. This model may contribute to our understanding of the pathogenesis of severe human vasculitis.

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.

[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.

Mizoribine provides effective treatment of sequential histological change of arteritis and reduction of inflammatory cytokines and chemokines in an animal model of Kawasaki disease

The incidence of panvasculitis in the coronary arteries and aortic root was 100% in the control group. The incidence of panvasculitis in the MZR group decreased to 50%. Moreover, the scope and severity of the inflammation of those sites were significantly reduced in the MZR group as well as the IgG group. On the other hand, increased cytokines and chemokines, such as IL-1α, TNF-α, KC, MIP-1α, GM-CSF, and IL-13, in the nontreatment group were significantly suppressed by treatment with MZR, but the MCP-1 level increased. In addition, IL-1α, TNF-α, IL-10, IL-13, and MIP-1α were suppressed by treatment in the IgG group.

BACKGROUND

Intravenous immunoglobulin (IVIg) treatment results in an effective response from patients with acute-phase Kawasaki disease (KD), but 16.5% of them remain nonresponsive to IVIg. To address this therapeutic challenge, we tried a new therapeutic drug, mizoribine (MZR), in a mouse model of KD, which we have established using injections of Candida albicans water-soluble fractions (CAWS).

METHODS

CAWS (4 mg/mouse) were injected intraperitoneally into C57BL/6N mice for 5 consecutive days. MZR or IgG was administered for 5 days. After 4 weeks, the mice were sacrificed and autopsied, the hearts were fixed in 10% neutral formalin, and plasma was taken to measure cytokines and chemokines using the Bio-Plex system.

RESULTS

The incidence of panvasculitis in the coronary arteries and aortic root was 100% in the control group. The incidence of panvasculitis in the MZR group decreased to 50%. Moreover, the scope and severity of the inflammation of those sites were significantly reduced in the MZR group as well as the IgG group. On the other hand, increased cytokines and chemokines, such as IL-1α TNF-α, KC, MIP-1α, GM-CSF, and IL-13, in the nontreatment group were significantly suppressed by treatment with MZR, but the MCP-1 level increased. In addition, IL-1α, TNF-α, IL-10, IL-13, and MIP-1α were suppressed by treatment in the IgG group.

CONCLUSION

MZR treatment suppressed not only the incidence, range, and degree of vasculitis, but also inflammatory cytokines and chemokines in the plasma of the KD vasculitis model mice, suggesting that MZR may be useful for treatment of KD.

Vasculitis and anaphylactoid shock in mice induced by the polysaccharide fraction secreted into culture supernatants by the fungus Candida metapsilosis

The biological effects of Candida metapsilosis water-soluble fraction (CMWS), prepared using a completely synthesized medium, were examined to determine whether CMWS induces vasculitis similar to that seen in Kawasaki disease, and anaphylactoid shock, in mice. It was found that intraperitoneal injection of CMWS induces coronary arteritis and i.v. injection induces acute anaphylactoid shock in mice, similar to Candida albicans water-soluble fraction (CAWS)-induced arteritis and anaphylactoid shock. The mannan structure of the polysaccharide fraction was then analyzed by performing antiserum reactivity tests and nuclear magnetic resonance spectroscopy. The mannan structure was investigated because the present authors have recently found that the mannan moiety within the polysaccharide fraction might be responsible for these pathogenic activities. The structural analysis showed that the mannan structure within CMWS expresses α-mannan residues, but not β-mannan. In addition, the mannan structure of CMWS is quite similar to that of CAWS. The present findings indicate that the polysaccharide fraction from C. metapsilosis, which is mainly composed of mannan, contributes to coronary arteritis and acute shock, and that the mannan structure could be responsible for this pathogenicity.

[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.

NMR characterization of the structure of a beta-(1-->3)-D-glucan isolate from cultured fruit bodies of Sparassis crispa

SCG, a purified beta-d-glucan, obtained from Sparassis crispa, exhibits various biological activities including an antitumor effect, enhancement of the hematopoietic response in cyclophosphamide-induced leukopenic mice, and induction of the production of cytokines. The mechanisms of these effects have been extensively investigated; however, an unambiguous structural characterization of SCG is yet to be achieved. It is well accepted that the biological effects of beta-glucan depend on its primary structures, conformation, and molecular weight. In the present study, we examine the difference of biological effects among beta-glucans, elucidate the primary structure of SCG, and compare with SPG from Schizophyllum commune using NMR spectroscopy. Our data reveal that SCG but not SPG induce cytokine production from bone marrow-derived dendritic cells (BMDCs) and their major structural units are a beta-(1-->3)-d-glucan backbone with single beta-(1-->6)-d-glucosyl side branching units every three residues.

Neutrophil activation and arteritis induced by C. albicans water-soluble mannoprotein-beta-glucan complex (CAWS)

We have established a mouse model which shows the symptoms of coronary arteritis after consecutive injections of CAWS, which is released from Candida albicans. In this study, we examined neutrophil activation in the initial period after CAWS injection intraperitoneally. During 10 min to 16 h after the injection, blood profiles and neutrophil functions were determined. At the same time, levels of inflammatory cytokines and chemokines in plasma were measured. Furthermore, level of ICAM-1 as a marker of lesion in arterial endothelial cells was measured. Counts of the peripheral leukocytes increased immediately after CAWS injection, especially involving neutrophil. In vitro sensitivity of neutrophils to stimuli was enhanced. Moreover, proinflammatory cytokines (IL-1beta, IL-12 and IL-6) increased in plasma initially followed by an increase in IL-10, G-CSF, MIP-2 and soluble ICAM-1. Locally, ICAM-1 message in arterial walls was significantly increased 16 h after CAWS injection. A decrease in C3 levels was observed in plasma, suggesting complement activation and consumption. In summary, neutrophil activation occurred after CAWS injection, followed by complement activation, and production of proinflammatory cytokines chemokines and G-CSF which may be involved in development of coronary arteritis.

An Unambiguous Assignment and Structural Analysis Using Solution NMR Experiments of O-Antigen from Escherichia coli ATCC23505 (Serotype O9)

Bacterial lipopolysaccharide from Escherichia coli O9 (O9 LPS) has various characteristic biological activities other than endotoxic activities. The biological activities exhibited depend on the structure of the O-antigen. The O-antigen region of O9 LPS is composed of the mannose homopolysaccharide (MHP). This structure was reported previously, but not all its proton and carbon signals were assigned. In the present study, we completely assign all proton and carbon signals of the O-antigen of O9 LPS using (1)H- and (13)C-NMR spectroscopy, including the DQF-COSY, TOCSY, NOESY, HSQC, H2BC, HSQC-TOCSY and HMBC methods.

Involvement of Platelet Activating Factor, Histamine and Serotonin in Acute Lethal Shock Induced by Candida albicans Water-Soluble Extracellular Polysaccharide Fraction (CAWS) in Mice

CAWS (Candida albicans water-soluble extracellular polysaccharide fraction) is a water-soluble extracellular mannoprotein-beta-glucan complex obtained from the culture supernatant following the culture of pathogenic Candida albicans in a completely synthetic medium. CAWS administered intraperitoneally induces vasculitis in mice, however, administered intravenously, it causes lethal shock. The acute lethal reaction to CAWS occurs within 1 h of intravenous administration, with the mice demonstrating anaphylactic shock-like symptoms including convulsion, diarrhea, and collapse. In this study, we analyzed the factors involved in this lethal effect. We examined physiologically active substances believed to be involved in anaphylactic shock, and found that the lethal effect of CAWS could be inhibited by blocking histamine, serotonin, and platelet activating factor (PAF) simultaneously, but by blocking only one. This finding strongly suggests that the acute lethal reaction to CAWS is a result of the simultaneous production of several physiologically active substances.

Beta-mannosyl linkages negatively regulate anaphylaxis and vasculitis in mice, induced by CAWS, fungal PAMPS composed of mannoprotein-beta-glucan complex secreted by Candida albicans

Candida albicans water soluble fraction (CAWS) is a water-soluble extracellular mannoprotein-beta-glucan complex obtained from the culture supernatant of Candida albicans, which grows in a chemically defined medium. CAWS induced toxic reactions, such as acute anaphylactoid reaction, by intravenous administration and coronary arteritis by intraperitoneal administration. To clarify the structure responsible for these toxic reactions, C. albicans was cultured in pH- and temperature-controlled conditions and prepared with CAWS with or without the beta-1,2-linked mannosyl segment (BM). The structure of CAWS was assessed by immunochemical and spectroscopic methodologies, and we found that CAWS prepared under the natural culture conditions contained only small amounts of BM and CAWS prepared at neutral conditions at 27 degrees C contained a significantly higher percentage of BM. Both the acute lethal toxicity and coronary arteritis induction was significantly more severe in the absence of BM. Activation of a complement pathway, the lectin pathway, by CAWS was significantly stronger in the absence of BM. These facts strongly suggest that BM linkages in CAWS negatively modulate acute and chronic toxicity of CAWS, and may be strongly related to the lectin pathway of the complement activation.

F1 hybrid mice (BALB/c x DBA/1) are resistant to collagen-induced arthritis with beta-glucan as an adjuvant

Collagen-induced arthritis (CIA) is an experimental model of rheumatoid arthritis (RA) used for studying the clinical, immunological and genetic factors of the disease. Many studies of genetic susceptibility to CIA have been performed, usually with two strains of mice, DBA/1 and B10.RIII, since they are highly susceptible to CIA. Furthermore, F1 hybrid mice of susceptible and resistant strains reportedly develop arthritis. Recently, we reported that particles of beta-glucan, OX-CA, prepared from Candida albicans by NaClO-oxidation, acted as an adjuvant for CIA. Although, there have been many studies about the relationship between antigen and the major histocompatibility complex (MHC) in F1 hybrid mice, little is known argument about susceptibility to adjuvants. Therefore, we checked the susceptibility of F1 hybrids to CIA using OX-CA as an adjuvant. BALB/c and DBA/1 were mated to generate F1 hybrids which were then immunized with type II collagen (CII) plus Freund's complete adjuvant (FCA) or OX-CA. The results showed that F1 hybrids injected with CII plus FCA developed severe arthritis at an incidence ratio 80%, versus only 20% in mice injected with CII plus OX-CA. Furthermore, levels of anti-CII antibody, especially of the IgG2a subclass, in sera from mice treated with CII plus OX-CA were significantly low. Susceptibility to CIA might depend on not only MHC but also the adjuvant used for immunoactivation.

Lethal and severe coronary arteritis in DBA/2 mice induced by fungal pathogen, CAWS, Candida albicans water-soluble fraction

CAWS is a microbial pathogen-associated molecular patterns (PAMPs) produced by Candida albicans. CAWS is a mannoprotein-beta-glucan complex and secreted into the culture supernatant. CAWS has various biological effects, causing acute shock and disrupting vascular permeability. Intraperitoneal administration of CAWS induces coronary arteritis in various strains of inbred mice. The CAWS-induced coronary arteritis is strain-dependent and most severe in DBA/2 mice with a significant number of these animals expiring with cardiomegaly during the observation period. In vivo and in vitro, splenocytes of DBA/2 mice produced various cytokines, such as IL-6, TNF-alpha, and IFN-gamma in response to CAWS. GM-CSF was also produced in response to CAWS. The production of cytokines was significantly enhanced in the presence of recombinant GM-CSF. In contrast, anti-GM-CSF significantly reduced the production of TNF-alpha and IFN-gamma. Augmented production of cytokines in response to CAWS would be a key to the severity of coronary arteritis.

Candida albicans derived fungal PAMPS, CAWS, water soluble mannoprotein-beta-glucan complex shows similar immunotoxicological activity with bacterial endotoxin from Escherichia coli O9

Candida albicans water soluble fraction (CAWS), water soluble fraction of Candida albicans mainly composed of mannoprotein-beta-glucan complex, has various biological effects, such as anaphylactoid shock and coronary arteritis. These toxicological effects fit CAWS as one of PAMPs, pathogen-associated molecular patterns. Acute anaphylactoid reaction is known to be induced by lipopolysaccharide from Escherichia coli O9 (O9 LPS), which possesses the mannose homopolysaccharide as the O-antigen region. In the present study, we compared immunotoxicological and immunochemical similarity between CAWS and O9 LPS. CAWS strongly reacted with Candida serum factors, and the reactivity was found to be partially competed with O9 LPS. CAWS induced lethal toxicity was inhibited by pretreatment of mice with i.v. injection of CAWS. The lethality was found to be inhibited by i.v. injection of O9 LPS. Vice versa, O9 LPS induced acute lethal toxicity was also inhibited by pretreatment of mice with CAWS. These results suggested that CAWS, fungal PAMPs, and O9 LPS from Gram-negative bacteria share, at least in part, immunochemical and immunotoxicological activities.

Induction of coronary arteritis with administration of CAWS (Candida albicans water-soluble fraction) depending on mouse strains

The intraperitoneal administration of CAWS (water-soluble extracellular polysaccharide fraction obtained from the culture supernatant of Candida albicans) to mice induces coronaritis similar to Kawasaki disease. We analyzed differences in the production of cytokines involved in the occurrence of coronary arteritis among mouse strains, C3H/HeN, C57BL/6, DBA/2 and CBA/J that were injected with CAWS at 4 mg/mouse for 5 consecutive days in the first week and the fifth week of administration. The incidence of arteritis was 100% in C57BL/6, C3H/HeN and DBA/2 mice, but only 10% in CBA/J mice. The coronary arteritis observed in DBA/2 mice was the most serious, with several mice expiring during the observation period. The CAWS-sensitive strains revealed increased levels of IL-6 and IFN-gamma during the course of a specific response to CAWS by spleen cells. In contrast, IL-10 levels were observed to increase markedly in CAWS-resistant CBA/J mice, but not the CAWS-sensitive strains. However, TNF-alpha levels were more elevated only in DBA/2 mice. The difference in disease development and cytokine production strongly suggests that the genetic background of the immune response to CAWS contributes to the occurrence of coronary arteritis.