Studies on a Phytohemagglutinin from the Lentil III. REACTION OF LENS CULINARIS HEMAGGLUTININ WITH POLYSACCHARIDES, GLYCOPROTEINS, AND LYMPHOCYTES

Abstract Two purified hemagglutinins from the lentil, Lens culinaris hemagglutinin A (LcH-A) and L. culinaris hemagglutinin B (LcH-B) react with a phosphomannan from Pichia pinus and with human serum glycoproteins (primarily α2-macroglobulin, β-lipoprotein, and IgM) in a precipitin type reaction. The precipitin reactions are inhibited by simple sugars, such as d-glucose, d-mannose, and their glycosides, which are known to inhibit the hemagglutination reaction. Methyl α-d-mannoside is the most potent inhibitor of precipitation tested. Although methyl α-d-glucoside is also a good inhibitor, none of the dextrans tested precipitated with the lentil hemagglutinins. LcH-A, LcH-B, concanavalin A, and a homogeneous mushroom hemagglutinin (Agaricus campestris hemagglutinin) stimulate human lymphocytes in culture to incorporate tritiated thymidine. Stimulation of lymphocytes by LcH-A, LcH-B, and concanavalin A is inhibited by methyl α-d-mannoside. Stimulation of lymphocytes by A. campestris hemagglutinin is not inhibited by this sugar (nor is hemagglutination).