An association between activity of the Na/K‐pump and resistance of Schistosoma mansoni towards complement‐mediated killing

Abstract

The Na/K-pump or Na+/K(+)-ATPase (EC 3.6.1.37), couples the hydrolysis of ATP to the active transport of Na+ and K+ ions across the plasma membrane of virtually all animal cells. The relationship between activity of the Na+/K(+)-ATPase and the sensitivity of Schistosoma mansoni to immunological attack has been investigated. It has been observed that ouabain, the specific inhibitor of the pump, via a synergistic effect with specific antibody and complement, affects the average membrane potential causing depolarization and death of complement resistant parasites. Thus, apparently, there is association between the inhibition of the Na/K-pump and the lysis and death of the complement-resistant parasite.

A preliminary proteomic characterisation of extracellular vesicles released by the ovine parasitic nematode, Teladorsagia circumcincta

“…C. elegans Ce-eat-6 mutations have been associated with paralysis of the pharyngeal muscles in C. elegans ( Davis et al, 1995 ). Moreover, studies in the trematode, Schistosoma mansoni , have shown that Na/K-ATPase has been associated with the acquisition of resistance to complement after the parasite has penetrated the skin ( Tarrab-Hazdai et al, 1997 ) but there are no published studies to show whether or not this ATPase is found in the EVs of this species.…”

DNA Immunization with Na + -K + ATPase ( Sseat-6 ) Induces Protective Immunity to Larval Strongyloides stercoralis in Mice

“…A second possible mechanism is based on the finding that the Na ϩ -K ϩ ATPase has been implicated in resistance of Schistosoma mansoni cercaria to complement-mediated killing (50). Because complement is required for immune-mediated killing of larval S. stercoralis (5,31,34), it is possible that disruption of the S. stercoralis Na ϩ -K ϩ ATPase in any location in the worm leads to a decreased ability to defend against complementmediated larval killing.…”

The schistosome in the mammalian host: understanding the mechanisms of adaptation

“…Thus, changes in lipid composition alone may be sufficient to alter antigenicity. Tarrab-Hazdai et al (1997) adopted a novel approach by showing that a decrease in tegumental membrane potential increased the ability of antibody and complement to damage the schistosome surface. Thus, the maintenance of the tegumental membrane potential by a Na+/K+ ATPase pump is important for the concealment of parasite antigen and, incidentally, also for maintaining the membrane potential of muscle systems (Bricker et al 1982).…”

“…Factors relevant to surface membrane potential include the surface pH, which will have an influence on the uptake of essential amino acids, and the inner membrane pH, which will regulate fatty acid transport (Angelucci et al 2004). Disruption of membrane potential has been shown to result in the exposure of surface proteins and thus allow immune damage (Pearce et al 1986; Tarrab-Hazdai et al 1997). Breternitz et al (1992) showed that the re-acquisition of membrane potential reflected repair of membrane that had been damaged by bacterial cytotoxin.…”