The IL-1β - BHLHE40 Axis in the Pathogenesis of Kawasaki Disease: Insights from Cell-Type-Specific Expression Analysis

Kawasaki disease (KD) is a mysterious acute systemic vasculitis that predominantly affects young children, potentially leading to coronary artery dilation or aneurysm formation. Early treatment has enhanced outcomes, yet the immune mechanisms driving vascular inflammation in KD are not fully understood. Researchers have linked innate immune activation, specifically IL-1 signaling, to KD pathogenesis.

Additionally, a microbial component-induced mouse model has successfully replicated key aspects of KD-like coronary arteritis. BHLHE40 is an inflammation-associated transcription factor that modulates cytokines like GM-CSF, IFN-gamma, and IL-10, hinting at a potential relationship between IL-1 signaling and downstream effector programs in KD.

In this study, scientists analyzed single-cell and bulk transcriptomic datasets from human KD and LCWE-induced murine vasculitis. The human analysis compared data from KD patients and febrile controls to healthy individuals, while the mouse analysis examined cellular expression within vasculitis and the effects of IL-1 receptor blockade.

Both IL1B and BHLHE40 exhibited augmented expression levels in independent whole-blood KD cohorts, showing modest yet statistically significant positive correlations between their expression levels. Single-cell analysis revealed that IL1B was predominantly found in myeloid populations, while BHLHE40 was distributed across various immune cell types, including NK and T cells.

In mice treated with LCWE, vascular Bhlhe40 expression was decreased by Anakinra, and there was a strong correlation between Il1b and Bhlhe40 within the LCWE group.