Expression of glycoconjugates on normally developing and immunologically impaired Hymenolepis diminuta

The carbohydrates on the surface of Hymenolepis diminuta were analyzed with gold-labelled lectins, and it was found that the surface coat of the anterior body differs from that of the strobila in its lectin-binding properties. Binding sites for lectins from Abrus precatorius (APA), Arachis hypogaea (PNA), Glycine max (SBA) and for wheat germ agglutinin (WGA) and succinylated WGA were located on the scolex and strobilation zone. Lectin-gold particles attached mainly to the electron-dense spines. The surface coat may therefore expose sugar residues of the N-acetylglucosamine and galactose types. In contrast, the strobila had few binding sites for the above-mentioned lectins but bound concanavalin A (ConA). Lectins from Dolichos biflorus (DBA) and Ulex europaeus (UEA-I) were not bound to H. diminuta. In juvenile worms from rats, the extension of the WGA- and SBA-positive region of the strobilation zone increased in length with the development of the worms. Lectin binding in juveniles from mice was similar when the mice had been immunosuppressed with cortisone. After the onset of the immune defense against H. diminuta in nontreated mice, a moderate expression of lectin-binding substance also occurred on the strobila. Destrobilated worms were entirely covered with the N-acetylglucosamine- and galactose-containing glycoconjugates, and it is suggested that these worm remnants correspond to the lectin-binding part of normal, growing juveniles. The presence of the carbohydrates is discussed with respect to the relative resistance of the scolex-strobilation zone of H. diminuta to immune rejection.