Cell surface characteristics of an allotransplantable TA3 ascites subline resulting from a process of immunoselection.

Comparison of the cell surface characteristics of the parental strain-specific TA3-St ascites cell (I) of the strain A mouse and the more allotransplantable TA3-St/ticol ascites cell (II), immunoselected for reduced absorption of anti-H-2a antibody from Cell I, revealed the following. Cell II, like Cell I, possessed no detectable epiglycanin at its surface, as neither cell absorbed more than 0.5% as much of the antiepiglycanin antibody as was absorbed by the epiglycanin-containing allotransplantable TA3-Ha ascites cell. Tritium-labeled glycoproteins, with polyacrylamide slab gel electrophoresis with sodium dodecyl sulfate and with isoelectric focusing of detergent-treated cells, exhibited marked quantitative differences, but qualitative differences were not established. Glycopeptides cleaved from each cell by proteolysis and fractionated by gel filtration gave similar elution profiles, and the column fractions possessed similar carbohydrate and amino acid compositions. Less sialic acid (170 micrograms/10(9) cells) was removed by neuraminidase from Cell II than from Cell I (270 micrograms/10(9) cells), and the compositions (9% N-glycolylneuraminic acid for Cell II and 20% for Cell I) were different. Transmission and scanning electron microscopy showed rough irregular folds and ridges on the surfaces of each cell, but Cell II appeared more pleomorphic and less rounded than did Cell I. High-resolution transmission electron microscopy showed filamentous material at the surface of Cell II, but not at the surface of Cell I.