Stanley D. Fowler

Biodistribution and radioimmunopharmacokinetics of 131I-Ama monoclonal antibody in atherosclerotic rabbits

Monoclonal antibodies have been raised against Ama isolated from human and experimental atherosclerotic plaque. 131I-Ama-MoAb in the whole antibody form was injected into normal NZW rabbits and Watanabe hyperlipidemic rabbits. Biodistribution studies showed that atheromatous aortas had a significantly higher (5-7X) uptake of 131I-Ama-MoAb than that of normal aortas. However, 131I-Ama-MoAb was cleared very slowly from atherosclerotic rabbits. As a result, atheromas could not be identified by imaging because of the low target to non-target ratios.

Cellular Models of Atherosclerosis in the Younga

The current interest in vascular lesions formed during childhood and adolescence is both pertinent and timely, as atherosclerosis research has never been more exciting that at the present. A number of attractive hypotheses about the pathogenesis of atherosclerosis have been proposed which provide different perspectives for understanding the disease process. A host of animal and cell models of early lesions are now available for study and new technological advances, such as recombinant DNA techniques and sensitive imaging procedures, will allow these models to be studied in greater depth. Consequently, the next decade should bring new insight on the pathogenesis of atherosclerosis, especially the early lesions of youth.

Transformation of rabbit arterial smooth muscle cells with simian virus 40.

SummaryIn vitro studies were carried out to induce viral transformation of vascular smooth muscle cells. Cultured rabbit arterial smooth muscle cells were infected with simian virus 40 (SV 40), and transformed cultures were produced that exhibit altered morphology, increased growth rate and plating efficiency, growth on semi-solid substrate, and chromosomal abnormalities. Nuclear SV 40 T-antigen was detected in all cells of these cultures. Muscle-specific actin was identified by a specific monoclonal antibody suggesting retention of smooth muscle cell characteristics by the transformed cells. Significant cytoplasmic lipid accumulation occurred in transformed cells incubated with β-very low density lipoprotein, as revealed both by chemical analyses and Nile Red lipid staining of the cultures. The transformed smooth muscle cells grow permanently in cell culture. Our investigations show that arterial smooth muscle cells transformed with SV 40 virus exhibit altered phenotypic properties distinct from that of normal arterial smooth muscle cells.

Transformation of Rabbit Vascular Smooth Muscle Cells by SV40 Virus

Evidence is accumulating that viruses may participate in atherogenesis. In chickens, infection with Marek’s disease virus induces atherosclerotic lesions in the absence of hypercholesterolemia. In humans, several distinct viruses have been found in atherosclerotic lesions. To assess the possible effects of viral transformation on vascular smooth muscle cell growth and metabolism, we infected subconfluent cultured rabbit arterial smooth muscle cells with simian virus 40 (SV40), Baylor strain, wild type. Three weeks after infection, a transformed cell line was isolated. The transformed cells expressed intranuclear SV40 T antigen yet still retained smooth muscle characteristics as documented by a uniform positive reaction with antibodies against smooth muscle cell-specific actin. These transformed cells were further subcultured, and 18 clones were obtained, each exhibiting a characteristic phenotype. The morphological appearances of the cells in the different clones ranged from multinucleated giant cells of variable shape to small uniform-sized cells. The transformed cell clones contained significantly more polyploid cells than control cells, and the modal chromosome number ranged from 41 to 83, whereas the control smooth muscle cells maintained a modal diploid number of 44. The transformed cells grew both faster and to a higher saturation density than did control smooth muscle cells in culture medium containing either 1% or 5% fetal calf serum. When the cells were incubated in the presence of lipoprotein-deficient serum, the clones displayed greater diversity in their intracellular lipid content. In preliminary experiments, incubation of certain clonal cell lines with lipoproteins resulted in massive lipid overloading. These results indicate that virus-transformed smooth muscle cells exhibit phenotypic changes that should be of considerable value for studying the consequences of viral infection of vascular smooth muscle cells in atherogenesis.