Monoclonal antibody reveals heterogeneity in human aortic intima: detection of a ganglioside antigen associated with a subpopulation of intimal cells.

The cells of the arterial wall are heterogeneous. To study the functions and peculiarities of various subpopulations of arterial cells the authors have generated an IgM mouse monoclonal antibody, designated 3-Lena, which interacts with human aortic cells (demonstrated by RIA and flow cytofluorometry). The cellular antigens interacting with monoclonal antibody 3-Lena are gangliosides GM3, GD3, GD1a, and GT1b. Presumably, the epitope is represented by the structure -NeuAc alpha 2----3Gal beta 1, a component of the oligosaccharide moiety of the ganglioside molecule. In addition to aortic cells, those dissociated from other large human vessels as well as cells of the myometrium and lung parenchyma interact with 3-Lena. Cells dissociated from the spleen and renal cortex exhibit a substantially weaker interaction, while liver and myocardial cells do not react. Compared with human aortic cells, aortic cells of other mammalian species stain less effectively (dog, swine) or do not stain at all (bovine, ram). Flow cytofluorometric analysis demonstrates that practically all human aorta medial cells interact with antibody 3-Lena, whereas a certain portion of cells in the intimal population do not. In the outer intimal sublayer adjoining the media, the cells reacting with monoclonal antibody 3-Lena make up the bulk of the cell population, and the inner sublayers are characterized by a prevalence of nonreactive cells. After separation of reactive and nonreactive human aortic intimal cells by a cytofluorometer-cell sorter, 3-Lena+ cells were found to have an elongated bipolar shape, whereas most 3-Lena- cells have multiple processes and variable elongated, stellate, or irregular shapes.(ABSTRACT TRUNCATED AT 250 WORDS)