A study of the effect of surface damage on the uptake of Texas Red–BSA by schistosomula of Schistosoma mansoni

Abstract

In this paper we describe the effect of poly-L-lysines of different molecular weight on the schistosomula. In the control sample, the schistosomula of Schistosoma mansoni take up fluorescent Texas Red conjugated to bovine serum albumin (TxR-BSA) into the gut. Following slight damage by 24.0 kDa poly-L-lysine, a high proportion of schistosomula take up fluorescent TxR-BSA into the excretory system. Subsequently, the dye diffused into the bodies of the schistosomula. We suspected that this diffusion involved the process of endocytosis so we investigated this with the use of endocytosis inhibitor, Latrunculin A. Addition of the endocytosis inhibitor Latrunculin A following poly-L-lysine treatment inhibited gut uptake of TxR-BSA as well as the diffusion of excretory-ingested TxR-BSA molecules.

Responses of the surface membrane and excretory system ofSchistosoma mansonito damage and to treatment with praziquantel and other biomolecules

“…The effect of pH, various cytokines and LPS have been investigated due to their known effects on P-glycoproteins (Stavrovskaya, 2000). Finally, membrane perturbing agents were used, (poly-L-lysine, beta-methyl cyclodextrin), since it has been found (Tan et al 2003) that membrane damage can affect the excretory system.…”

“…The function of the excretory system is largely unknown but some aspects of its function are linked to the surface membrane in that in vitro damage to the membrane can result in retrograde uptake of macromolecules (Tan et al 2003 ;Wippersteg et al 2003). …”

The cytoskeleton and motor proteins of human schistosomes and their roles in surface maintenance and host–parasite interactions

“…Interestingly, many epithelial structures in neodermatans are syncytial, including the protonephridial ducts (¼excretory system), (3) which also have been implicated in macromolecular endocytosis in schistosomes. (4) The closest relatives of the neodermatans are the predominately free-living flatworms, the Turbellaria, which have a ciliated, cellular epithelium as the body wall. Schistosomes belong to the Order Trematoda, a monophyletic group of neodermatans characterized, among other features, by parasitism of a gastropod or mollusc first intermediate host and, most often, vertebrates as definitive hosts.…”

Uptake of macromolecules by cercariae during skin penetration and transformation to schistosomula (Schistosoma mansoni)

“…During the tail loss, the nephridiopore (the aperture representing the external exit of the excretory system) is fully exposed to the external environment. Recently, a pathway was described that involves the entry of large molecules into the body through the nephridiopore after surface membrane damage (Tan et al 2003). In the present paper we describe the process of uptake of membrane-impermeable fluorescent dyes by the cercariae as they penetrate the skin and we propose that these molecules may enter through both the nephridiopore and the surface membrane.…”