Reactions of normal and leukemic cell surfaces to a wheat germ agglutinin.

Abstract

A variety of differences between normal and leukemic cells have been reported, involving such diverse characteristics as alkaline phosphatase content,"' 12 glycolytic rate, and nucleic acid metabolism.6 In most cases, however, the differences observed could have been due to variations in cell maturation levels rather than to leukemia-specific changes. We still do not know whether leukemia results from a malignant change within the leucocyte population or from an increase in essentially normal cells due to interference with leucocyte control mechanisms.In our laboratory, we have been investigating an agglutinin present in certain wheat germ lipase preparations which produces more clumping in murine tumor cells than in isologous normal cells.3 Hakamori and Jeanloz have found that the cell surface material involved in the reaction is also present in a glycolipid isolated from a human adenocarcinoma.7' 8 The lipase enzyme itself is not responsible for the agglutination observed since enzyme inactivation by heat or by p-chloromercuribenzoic acid does not destroy agglutinating activity. We have shown that the increased reactivity of tumor cells does not merely reflect a cell surface property related to rapid cell growth and division since spleen cells from newborn animals do not clump more than those from adults, nor do cells from regenerating liver clump more than those from normal liver. It was considered interesting, therefore, to determine whether or not a leukemic cell would behave like a tumor cell in respect to clumping when treated with wheat germ agglutinin.Materials and Methods.-Leucocyte preparation: Leucocyte suspensions were prepared according to a modification of Amos' procedure.' Fifty milliliters of normal blood and 5-10 ml of leukemic blood were used for each experiment. Na2EDTA (5%) was added as an anticoagulant (0.5 ml/5 ml blood), and 5% P.V.P. (1.0 ml/5 ml blood) was used to sediment Ithe red blood cells. The supernatant was centrifuged at 100 X g for 10 min, and the packed cels were resuspended in 0.1 ml of supernatant plasma. The majority of the remaining red blood cells settled out within 1 hr, and the leucocyte-containing supernatant was drawn off to be counted and diluted with calcium-free phosphate-buffered saline (PBS) to a final concentration of 5 X 106 cells/ml. At least 95% of the leucocytes prepared by this method appeared structually intact when tested for trypan blue uptake. (N.B.: Skoog and Beck's fibrinogen citrate method was used for the first two experiments in this series.10) Twenty-four fresh blood samples from 17 patients with leukemia were provided-by Massachusetts General Hospital clinics or private physicians, and most experiments were run in duplicate. Each patient was compared with a normal donor of the same ABO and Rh blood types, and comparisons were made between normal and leukemic of each pair, rather than between experiments.Lymphocyte preparation: Virtually pure lymphocyte preparations were made with a nylon filter. A unit of blood was drawn into a heparin receiving p...

Genetically modified organisms and risks of their introduction

“…By binding to glycans at cell surface, lectins promote cell agglutination and disrupt the physiological functions of organisms. This property of plant lectins was the backbone of the 40-year-long history of their application as cytotoxic agents for cancer chemotherapy [58,59]. We have already mentioned Effect of some plant and bacterial toxins on target organisms and humans [19-30, 34- above that some transgenic lectins evoke immune responses [6-8, 10, 11].…”

Biochemistry of the Cell Wall in Relation to Infective Processes

“…Viral or chemical transformation of normal cells to the neoplastic state is accompanied by a (1,79). A wheat germ component which specifically agglutinates virally transformed neoplastic cells has been described (4,5,6). This ag glutinin has been isolated and found to be a glycoprotein (19,20,32).…”

Lectins: Carbohydrate-specific Reagents and Biological Recognition Molecules

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