Kawasaki Disease-Specific Molecules in the Sera Are Linked to Microbe-Associated Molecular Patterns in the Biofilms

Abstract

BackgroundKawasaki disease (KD) is a systemic vasculitis of unknown etiology. The innate immune system is involved in its pathophysiology at the acute phase. We have recently established a novel murine model of KD coronary arteritis by oral administration of a synthetic microbe-associated molecular pattern (MAMP). On the hypothesis that specific MAMPs exist in KD sera, we have searched them to identify KD-specific molecules and to assess the pathogenesis.MethodsWe performed liquid chromatography-mass spectrometry (LC-MS) analysis of fractionated serum samples from 117 patients with KD and 106 controls. Microbiological and LC-MS evaluation of biofilm samples were also performed.ResultsKD samples elicited proinflammatory cytokine responses from human coronary artery endothelial cells (HCAECs). By LC-MS analysis of KD serum samples collected at 3 different periods, we detected a variety of KD-specific molecules in the lipophilic fractions that showed distinct m/z and MS/MS fragmentation patterns in each cluster. Serum KD-specific molecules showed m/z and MS/MS fragmentation patterns almost identical to those of MAMPs obtained from the biofilms formed in vitro (common MAMPs from Bacillus cereus, Yersinia pseudotuberculosis and Staphylococcus aureus) at the 1st study period, and from the biofilms formed in vivo (common MAMPs from Bacillus cereus, Bacillus subtilis/Bacillus cereus/Yersinia pseudotuberculosis and Staphylococcus aureus) at the 2nd and 3rd periods. The biofilm extracts from Bacillus cereus, Bacillus subtilis, Yersinia pseudotuberculosis and Staphylococcus aureus also induced proinflammatory cytokines by HCAECs. By the experiments with IgG affinity chromatography, some of these serum KD-specific molecules bound to IgG.ConclusionsWe herein conclude that serum KD-specific molecules were mostly derived from biofilms and possessed molecular structures common to MAMPs from Bacillus cereus, Bacillus subtilis, Yersinia pseudotuberculosis and Staphylococcus aureus. Discovery of these KD-specific molecules might offer novel insight into the diagnosis and management of KD as well as its pathogenesis.

Kawasaki disease: a matter of innate immunity

“…To confirm these findings, we searched for unknown ligands that may activate NOD1 or other vasculitis‐inducing pathways. We first prepared whole extracts and fractionated samples from the sera of KD patients and found that KD sera contain bioactive substances that induce production of IL‐6 and IL‐8 in HCAECs . However, no NOD1‐activating ligands were detected in these KD samples by cell‐based reporter systems or liquid chromatography‐mass spectrometry (LC‐MS) analysis .…”

“…We first prepared whole extracts and fractionated samples from the sera of KD patients and found that KD sera contain bioactive substances that induce production of IL‐6 and IL‐8 in HCAECs . However, no NOD1‐activating ligands were detected in these KD samples by cell‐based reporter systems or liquid chromatography‐mass spectrometry (LC‐MS) analysis . Thus, these results suggest that other innate immune receptor(s) may be associated with the development of KD vasculitis.…”

Distinct Distribution of Immunocytes in a Retropharyngeal Lymphadenopathy Associated with Kawasaki Disease: A Case Study Compared with Tonsillitis

“…Cervical lymphadenopathies in KD patients may implicate the entry of causative agents or their derived substances (pathogen-associated molecular patterns) leading to the systemic vasculitis [11]. CD4 + T-cell proliferation in the interstitium of KD tonsils in the index case may account for active antigen presentations and reactive lymphoproliferation in these areas [6].…”

“…This heterophilic adhesion mediates bacterial phagocytosis by neutrophils, and is involved in the initial tethering of granulocytes to E-selectin on the endothelium prior to their transendothelial migration during inflammatory responses [14]. From this view point, certain pathogen-associated molecular patterns might shape the tonsillar pathology during the acute phase of KD [11,15,16]. The tonsilla palatina is a primitive lymphoid organ, where the innate and acquired immunocytes interacts in the milieu on the direct contact to environment.…”

“…In our KD patient, streptococci were isolated from both throat and aspiration cultures (Table 1). Kusuda et al [11] have recently reported that KD-specific molecules, but not bacteria itself, may be involved in the pathophysiology during the acute phase of KD. In this context, pharyngeal pathogen-associated molecular patterns may trigger the endothelial activation leading to the systemic vasculitis, which might be the reason why there was no pus in the tonsilla and peritonsillar space [11,15,16].…”