Cytoadherence of the malaria-infected erythrocyte membrane to C32 melanoma cells after merozoites are released from parasitized infected cells

Abstract

Infections with the human malaria parasite Plasmodium falciparum are characterized by cytoadherence of infected erythrocytes to the venular endothelium of several organs. Video microscopy studies have shown that at the end of the asexual life of P. falciparum, the residual body containing haemozoin is released to the extracellular environment along with merozoites, leaving behind an infected erythrocyte "ghost". It is possible that these infected erythrocyte "ghosts" could remain sequestered within the blood vessels of patients infected with P. falciparum even after merozoites have been released from infected erythrocytes. In this study an in vitro cytoadherence assay was developed to show that infected erythrocyte "ghosts" can interact with C32 melanoma cells. Adherent infected erythrocyte "ghosts" contain some of the subcellular compartments of the malaria-infected red blood cell such as the tubo-vesicular membrane network and remnants of the parasitophorous vacuolar membrane, but lack haemozoin.

Merozoite release from Plasmodium falciparum-infected erythrocytes involves the transfer of DiIC16 from infected cell membrane to Maurer’s clefts

“…Following merozoite exit, this opening could reseal, leaving behind the erythrocyte ghost containing clusters of merozoites, as observed in this study (Fig. 1e–g) and as previously described by Winograd et al (1999, 2001). Interestingly, in the light of the role calcium plays in signalling pathways, Ca 2+ -ATPase activity has been described as being associated with MC and it has been suggested that MC may contain calcium (Caldas and Wasserman 2001).…”

“…There is controversy regarding the role of the PVM and whether the PVM lyses concurrently with iE (Glushakova et al 2005), beforehand (Wickham et al 2003) or afterwards (Salmon et al 2001; Soni et al 2005). The second mechanism proposed for parasite exit involves PVM fusion with the iE membrane (Clavijo et al 1998; Winograd et al 1999, 2001). The present work was designed to show that iE cytoplasmatic content does not diffuse out as parasites are released; video microscopy was used to show that merozoites escaped from iE together with the hemozoin-containing residual body, leaving a membranous structure behind (Winograd et al 1999).…”