Release of merozoite dense granules during erythrocyte invasion by Plasmodium knowlesi

Torii, Motomi; Adams, J.H.; Miller, L H; Aikawa, Masamichi

doi:10.1128/iai.57.10.3230-3233.1989

Cited by 73 publications

(24 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This apparatus, also known as the glideosome, is connected to proteins embedded in the IMC and in the plasma membrane (Bergman et al, 2003;Khater et al, 2004;Baum et al, 2006;Kono et al, 2012), so gaps in the IMC would suggest that continuity of adhesion and de-adhesion cycles may be disrupted during traction progression towards the merozoite's basal end. In addition, the openings in the IMC may provide points at which invasion organelles like dense granules might fuse with the plasma membrane post invasion (Torii et al, 1989;Riglar et al, 2013). The possibility of continuity of the IMC to internal endomembrane compartments also raises the prospect of a continuum of protein exchange with the ER-Golgi.…”

Section: Resultsmentioning

confidence: 99%

Electron tomography ofPlasmodium falciparummerozoites reveals core cellular events that underpin erythrocyte invasion

et al. 2013

View full text Add to dashboard Cite

SummaryErythrocyte invasion by merozoites forms of the malaria parasite is a key step in the establishment of human malaria disease. To date, efforts to understand cellular events underpinning entry have been limited to insights from non-human parasites, with no studies at sub-micrometer resolution undertaken using the most virulent human malaria parasite, Plasmodium falciparum. This leaves our understanding of the dynamics of merozoite sub-cellular compartments during infection incomplete, in particular that of the secretory organelles. Using advances in P. falciparum merozoite isolation and new imaging techniques we present a three-dimensional study of invasion using electron microscopy, cryo-electron tomography and cryo-X-ray tomography. We describe the core architectural features of invasion and identify fusion between rhoptries at the commencement of invasion as a hitherto overlooked event that likely provides a critical step that initiates entry. Given the centrality of merozoite organelle proteins to vaccine development, these insights provide a mechanistic framework to understand therapeutic strategies targeted towards the cellular events of invasion.

show abstract

Section: Resultsmentioning

confidence: 99%

Electron tomography ofPlasmodium falciparummerozoites reveals core cellular events that underpin erythrocyte invasion

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Some time during or shortly after merozoite invasion, the antigen is translocated by an unknown mechanism to the cytoplasmatic face of the erythrocyte membrane, where it associates with the cytoskeleton by a binding involving spectrin (13,23). In ultrastructural studies of Plasmodium knowlesi, the contents of the dense granules appear to be released into the parasitophorous vacuolar space after merozoite entry into the erythrocyte (30). Thus, antigens present in the dense granules appear not to be directly involved in the invasion process, which is inconsistent with Pf155/RESA being a target antigen for merozoite invasion inhibitory antibodies.…”

Section: Resultsmentioning

confidence: 99%

Involvement of Pf155/RESA and cross-reactive antigens in Plasmodium falciparum merozoite invasion in vitro

et al. 1992

View full text Add to dashboard Cite

Lines of Plasmodium falciparum FCR3 either expressing or not expressing the blood-stage antigen Pf155/RESA were used to analyze the possible involvement of this antigen in the merozoite invasion process in vitro. Antibodies from human sera, affinity purified on synthetic peptides corresponding to C-terminal repeated sequences in Pf155/RESA, were shown to inhibit merozoite invasion of both types of parasites with similar efficiency. Reversal of the invasion inhibition by fusion proteins containing repeated sequences of PfI55/RESA but not of the cross-reactive antigens Ag332 and Pfll.1 indicated that the inhibitory antibodies had similar target antigens in both Pf155/RESA+ and Pfl55/RESAparasites that involved cross-reacting epitopes present in Pfl55/RESA. Rabbit antibodies specific for Pf155/RESA repeats inhibited merozoite invasion of Pf155/RESA expressing parasites efficiently but had no or very small effect on the invasion of Pfl55/RESA-deficient parasites. In contrast, rabbit antibodies specific for Ag332 repeats as well as human antibodies affinity purified on synthetic Ag332 peptides inhibited merozoite invasion of both types of parasites with high efficiency. A similar inhibition pattern was seen with the human monoclonal antibody 33G2, which has specificity for Ag332 but also cross-reacts with Pfl55/RESA and Pfll.l. Taken together, our data suggest that Pf155/RESA and related cross-reactive antigens as well as Ag332 are involved in the merozoite invasion process and may constitute targets for invasion inhibitory antibodies.

show abstract

“…Early work by Bannister and colleagues (3) showed that in invading merozoites of Plasmodium knowlesi, the dense granules moved to the periphery of the merozoite and discharged their contents into the newly formed parasitophorous vacuole. This has been confirmed by immunoelectron microscopy (14). Exocytosis of the dense granules into the secondary parasitophorous vacuole has also been demonstrated for Toxoplasma gondii (1) and for Sarcocystis muris (6).…”

Section: Discussionmentioning

confidence: 60%

“…Contents of the rhoptry appear to be secreted from the organelle into the host membrane and parasitophorous-vacuole membrane during invasion (12). In contrast, dense granules are released from the invading merozoite after it invades the new host cell by a process that resembles exocytosis (5,14).…”

mentioning

confidence: 99%

Transfer of a dense granule protein of Plasmodium falciparum to the membrane of ring stages and isolation of dense granules

et al. 1992

View full text Add to dashboard Cite

A 14-kDa protein was localized to the dense granules of Plasmodium falkiparum by immunoelectron microscopy with monoclonal antibody lH1. The protein was present in dense granules in late-stage schizonts and free merozoites. After invasion, the protein was localized exclusively on the membrane of the newly invaded ring. The protein is referred to as RIMA, for ring membrane antigen. The 14-kDa protein was synthesized late in schizogony as determined by immunofluorescence microscopy and immunoblotting. At the

show abstract

Release of merozoite dense granules during erythrocyte invasion by Plasmodium knowlesi

Cited by 73 publications

References 11 publications

Electron tomography ofPlasmodium falciparummerozoites reveals core cellular events that underpin erythrocyte invasion

Electron tomography ofPlasmodium falciparummerozoites reveals core cellular events that underpin erythrocyte invasion

Involvement of Pf155/RESA and cross-reactive antigens in Plasmodium falciparum merozoite invasion in vitro

Transfer of a dense granule protein of Plasmodium falciparum to the membrane of ring stages and isolation of dense granules

Contact Info

Product

Resources

About