LANGHANS CELLS OF HUMAN ARTERIAL INTIMA - UNIFORM BY STELLATE APPEARANCE BUT DIFFERENT BY NATURE

The stellate cells in human arterial intima known as Langhans cells we re investigated. Arterial specimens were obtained during carotid endar terectomy and aortic reconstruction and included atherosclerotic lesio ns as well as areas of the adjacent normal appearing arterial wall, Fo llowing immunohistochemical and electron microscopic analysis, most of the stellate cells were found to inhabit the elastic-hyperplastic lay er of the intima in the normal arterial wall but in atherosclerotic le sions, stellate cells were distributed throughout all intimal layers. Immunohistochemical examination revealed that different types of intim al cells, including smooth muscle cells (HHF-35: smooth muscle alpha-a ctin(+)) and vascular dendritic cells (CD1a(+), S-100(+)), exhibited a typical stellate appearance but the cell processes of macrophages (HA M56(+), CD68(+)) were too short for macrophages to be considered as st ellate. No other intimal cells formed processes which could be detecte d under immunohistochemical examination, In atherosclerotic lesions, s ome smooth muscle cells transforming to foam cells retained their stel late shape. Smooth muscle cells interacted with each other through gap junctions while other intimal cells including vascular dendritic cell s contacted each other without forming any specialized structures, We conclude that Langhans cells comprise two histological types of intima l cells, namely, smooth muscle cells and vascular dendritic cells.