P. Tato et al., SUPPRESSION OF MURINE LYMPHOCYTE-PROLIFERATION INDUCED BY A SMALL RNAPURIFIED FROM THE TAENIA-SOLIUM METACESTODE, Parasitology research, 81(3), 1995, pp. 181-187
A substance from Taenia solium metacestodes that decreases lymphocyte
proliferation induced by concanavalin A was isolated. The molecular we
ight of this substance was estimated to be slightly more than 1,450 Da
. Crude metacestode factor was fractionated through a Bio-gel P-6 colu
mn. Peak 1 showed suppressive activity. After incubation with RNase th
e substance lost its activity. Incubation of this material with trypsi
n or papain increased its suppressive activity. It was stable at boili
ng temperature for 10 min. The incubation of this substance with murin
e macrophages had no effect on [H-3]-thymidine uptake by cocultured fr
esh splenic lymphocytes stimulated with concanavalin A. Conversely, co
cultures of lymphocytes pretreated with the substance and fresh spleni
c lymphocytes showed a decreased incorporation of [H-3]-thymidine. The
se results suggest that this substance is a RNA-peptide molecule whose
RNA moiety accounts for its suppressive activity. The findings also s
uggest that in vivo the factor may be a modulator of the immune respon
se.