Variation in susceptibility of Schistosoma mansoni to damage by polycations.
We have studied the characteristics of binding of the polycation poly-L-lysine to the schistosome surface. Two consequences of this binding were measured: (a) tegumental damage, as assessed by the uptake of the DNA binding stain Hoechst 33258, and (b) the effect of cation binding on the uptake of a lipid analogue, 5-(N-octadecanoyl) aminofluorescein. Schistosomes were incubated with a preparation of eosinophil cationic proteins; these naturally occurring polycations bound to and damaged the parasites in a manner similar to poly-L-lysine. The different developmental stages of the parasite vary in the degree to which the poly-L-lysine binds, in susceptibility to tegumental damage, and in the degree to which lipid uptake is affected. The lung stage is most resistant to damage, and 3-week-old worms are the most susceptible. The teguments of male and female adult worms differ in the binding of the poly-L-lysine. Individual schistosomula, and batches of schistosomula shed at different times, show non-genetic variation in binding and susceptibility to damage. These findings may relate to variation in immune killing in vivo.
Jones
J T
JT
Biochemistry Department, University of Glasgow, Scotland.
Helm
C N
CN
Kusel
J R
JR
D000818:Animals; D001667:Binding, Competitive; D001700:Biomphalaria / Q000469:parasitology; D006690:Bisbenzimidazole / Q000378:metabolism; D001798:Blood Proteins / Q000302:isolation & purification / Q000494:pharmacology; D004804:Eosinophils / Q000032:analysis; D005260:Female; D005452:Fluoresceins / Q000378:metabolism; D008168:Lung / Q000469:parasitology; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D011107:Polylysine / Q000378:metabolism / Q000494:pharmacology*; D012550:Schistosoma mansoni / Q000033:anatomy & histology / Q000187:drug effects* / Q000254:growth & development / Q000276:immunology; D012737:Sex Factors
D001798:Blood Proteins; D005452:Fluoresceins; D011107:Polylysine; C030864:5-aminofluorescein; D006690:Bisbenzimidazole