The large sialoglycoprotein of human lymphocytes. I. Distribution on T and B lineage cells as revealed by a monospecific chicken antibody.

Chickens were immunized with highly purified large sialoglycoprotein of human lymphocytes (L-LSGP; gp 150) which was isolated from neuraminidase-treated normal peripheral blood lymphocytes by affinity chromatography to HP-Sepharose and further purified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Antibodies isolated from plasma and egg yolk were highly specific for desialylated L-LSGP (apparent molecular mass approximately 150 kDa). The antigenic sites recognized by the antibodies are probably located in the peptide moiety of the molecule since antibody binding to lymphocytes was not inhibited by a variety of different sugars or abrogated by absorption on various erythrocytes. In immunofluorescence experiments, greater than or equal to 75% of neuraminidase-treated thymocytes and peripheral blood lymphocytes, virtually all E+ cells and T4+ or T8+ T chronic lymphocytic leukemia (CLL) cells were stained by anti-gp 150. A small fraction (approximately 10%) of thymocytes and a larger fraction (greater than or equal to 30%) of T CLL cells in some patients were stained before neuraminidase treatment. Thymocytes appear to contain considerably lower amounts of a less sialylated form of L-LSGP than peripheral blood lymphocytes. In contrast to blast cells of 5-day concanavalin A or leucoagglutinin cultures (greater than or equal to 90% anti-gp150+) only about 50% of the blast cells generated in 5-day mixed leukocyte cultures were anti-gp150+. The large majority (greater than or equal to 75%) of both the anti-gp150+ and anti-gp150- cells were T3+ and T11+.(ABSTRACT TRUNCATED AT 250 WORDS)