Cell Type-Specific Relationships Among Immune Cells in Human Aortic Dissection Tissue.

Background: Although recent studies have revealed the importance of inflammation in the pathogenesis of aortic dissection (AD), little is known about the relationships among inflammatory cells in human AD tissue.

Methods and results: We assessed the relationships among various immune cell types, including neutrophils, macrophages (M1 and M2), B cells, and helper T cells (Th1, Th2, Th17, Treg and Tfh ) in human AD tissue. AD tissues displayed abundant infiltration of immune cells. Correlation analysis revealed two groups of highly correlated cell types: a group of neutrophils and M1 and M2 macrophages, and another group consisting of B cells and helper T cells. In one particular case of AD, we were able to analyze the correlations between neutrophils and M1 and M2 macrophages in the entry, border, and intact zones of the AD lesions. Neutrophils showed significant correlations with M1 and M2 macrophages in the border zones. The entry and border zones showed M1-dominant polarization, whereas the intact zone showed M2-dominant polarization.

Conclusions: These findings indicate the existence of cell type-specific and site-specific interactions among immune cell types in human AD tissues.