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Microstructured Blood Vessel Surrogates Reveal Structural Tropism of Motile Malaria Parasites

CiteULike malaria tags - 25 January 2017 - 6:08pm
Adv. Healthcare Mater. (1 January 2017), pp. n/a-n/a, doi:10.1002/adhm.201601178

Plasmodium sporozoites, the highly motile forms of the malaria parasite, are transmitted naturally by mosquitoes and traverse the skin to find, associate with, and enter blood capillaries. Research aimed at understanding how sporozoites select blood vessels is hampered by the lack of a suitable experimental system. Arrays of uniform cylindrical pillars can be used to study small cells moving in controlled environments. Here, an array system displaying a variety of pillars with different diameters and shapes is developed in order to investigate how Plasmodium sporozoites associate to the pillars as blood vessel surrogates. Investigating the association of sporozoites to pillars in arrays displaying pillars of different diameters reveals that the crescent-shaped parasites prefer to associate with and migrate around pillars with a similar curvature. This suggests that after transmission by a mosquito, malaria parasites may use a structural tropism to recognize blood capillaries in the dermis in order to gain access to the blood stream.
Mendi Muthinja, Johanna Ripp, Janina Hellmann, Tamas Haraszti, Noa Dahan, Leandro Lemgruber, Anna Battista, Lucas Schütz, Oliver Fackler, Ulrich Schwarz, Joachim Spatz, Friedrich Frischknecht
Categories: malaria news feeds

Motility precedes egress of malaria parasites from oocysts

CiteULike malaria tags - 25 January 2017 - 12:56pm
eLife, Vol. 6 (jan 2017), e19157, doi:10.7554/elife.19157

Malaria is transmitted when an infected Anopheles mosquito deposits Plasmodium sporozoites in the skin during a bite. Sporozoites are formed within oocysts at the mosquito midgut wall and are released into the hemolymph, from where they invade the salivary glands and are subsequently transmitted to the vertebrate host. We found that a thrombospondin-repeat containing sporozoite-specific protein named thrombospondin-releated protein 1 (TRP1) is important for oocyst egress and salivary gland invasion, and hence for the transmission of malaria. We imaged the release of sporozoites from oocysts in situ, which was preceded by active motility. Parasites lacking TRP1 failed to migrate within oocysts and did not egress, suggesting that TRP1 is a vital component of the events that precede intra-oocyst motility and subsequently sporozoite egress and salivary gland invasion.
Dennis Klug, Friedrich Frischknecht
Categories: malaria news feeds

Role of Anopheles (Cellia) rufipes (Gough, 1910) and other local anophelines in human malaria transmission in the northern savannah of Cameroon: a cross-sectional survey

CiteULike malaria tags - 19 January 2017 - 1:32pm
Parasites & Vectors, Vol. 10, No. 1. (11 January 2017), doi:10.1186/s13071-016-1933-3
Raymond Tabue, Parfait Awono-Ambene, Josiane Etang, Jean Atangana, Antonio-Nkondjio, Jean Toto, Salomon Patchoke, Rose Leke, Etienne Fondjo, Abraham Mnzava, Tessa Knox, Alexis Tougordi, Martin Donnelly, Jude Bigoga
Categories: malaria news feeds

Deconvoluting multiple infections in Plasmodium falciparum from high throughput sequencing data

CiteULike malaria tags - 13 January 2017 - 9:01am
bioRxiv (10 January 2017), 099499, doi:10.1101/099499

bioRxiv - the preprint server for biology, operated by Cold Spring Harbor Laboratory, a research and educational institution
Sha Zhu, Jacob Almagro-Garcia, Gil McVean
Categories: malaria news feeds

Capturing in vivo RNA transcriptional dynamics from the malaria parasite P. falciparum

CiteULike malaria tags - 13 January 2017 - 9:00am
bioRxiv (12 January 2017), 099549, doi:10.1101/099549

bioRxiv - the preprint server for biology, operated by Cold Spring Harbor Laboratory, a research and educational institution
Heather Painter, Manuela Carrasquilla, Manuel Llinás
Categories: malaria news feeds

Characterisation of the opposing effects of G6PD deficiency on cerebral malaria and severe malarial anaemia

CiteULike malaria tags - 12 January 2017 - 11:41am
eLife, Vol. 6 (jan 2017), e15085, doi:10.7554/elife.15085

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is believed to confer protection against Plasmodium falciparum malaria, but the precise nature of the protective effect has proved difficult to define as G6PD deficiency has multiple allelic variants with different effects in males and females, and it has heterogeneous effects on the clinical outcome of P. falciparum infection. Here we report an analysis of multiple allelic forms of G6PD deficiency in a large multi-centre case-control study of severe malaria, using the WHO classification of G6PD mutations to estimate each individual’s level of enzyme activity from their genotype. Aggregated across all genotypes, we find that increasing levels of G6PD deficiency are associated with decreasing risk of cerebral malaria, but with increased risk of severe malarial anaemia. Models of balancing selection based on these findings indicate that an evolutionary trade-off between different clinical outcomes of P. falciparum infection could have been a major cause of the high levels of G6PD polymorphism seen in human populations.
Geraldine Clarke, Kirk Rockett, Katja Kivinen, Christina Hubbart, Anna Jeffreys, Kate Rowlands, Muminatou Jallow, David Conway, Kalifa Bojang, Margaret Pinder, Stanley Usen, Fatoumatta Joof, Giorgio Sirugo, Ousmane Toure, Mahamadou Thera, Salimata Konate, Sibiry Sissoko, Amadou Niangaly, Belco Poudiougou, Valentina Mangano, Edith Bougouma, Sodiomon Sirima, David Modiano, Lucas Amenga Etego, Anita Ghansah, Kwadwo Koram, Michael Wilson, Anthony Enimil, Jennifer Evans, Olukemi Amodu, Subulade Olaniyan, Tobias Apinjoh, Regina Mugri, Andre Ndi, Carolyne Ndila, Sophie Uyoga, Alexander Macharia, Norbert Peshu, Thomas Williams, Alphaxard Manjurano, Nuno Sepúlveda, Taane Clark, Eleanor Riley, Chris Drakeley, Hugh Reyburn, Vysaul Nyirongo, David Kachala, Malcolm Molyneux, Sarah Dunstan, Nguyen Phu, Nguyen Quyen, Cao Thai, Tran Hien, Laurens Manning, Moses Laman, Peter Siba, Harin Karunajeewa, Steve Allen, Angela Allen, Timothy Davis, Pascal Michon, Ivo Mueller, Síle Molloy, Susana Campino, Angeliki Kerasidou, Victoria Cornelius, Lee Hart, Shivang Shah, Gavin Band, Chris Spencer, Tsiri Agbenyega, Eric Achidi, Ogobara Doumbo, Jeremy Farrar, Kevin Marsh, Terrie Taylor, Dominic and Kwiatkowski
Categories: malaria news feeds

Natural diversity of the malaria vector Anopheles gambiae

CiteULike malaria tags - 5 January 2017 - 1:56pm
bioRxiv (22 December 2016), 096289, doi:10.1101/096289

bioRxiv - the preprint server for biology, operated by Cold Spring Harbor Laboratory, a research and educational institution
Alistair Miles, Nicholas Harding, Giordano Botta, Chris Clarkson, Tiago Antao, Krzysztof Kozak, Daniel Schrider, Andrew Kern, Seth Redmond, Igor Sharakhov, Richard Pearson, Christina Bergey, Michael Fontaine, Arlete Troco, Abdoulaye Diabate, Carlo Costantini, Kyanne Rohatgi, Nohal Elissa, Boubacar Coulibaly, Joao Dinis, Janet Midega, Charles Mbogo, Henry Mawejje, Jim Stalker, Kirk Rockett, Eleanor Drury, Dan Mead, Anna Jeffreys, Christina Hubbart, Kate Rowlands, Alison Isaacs, Dushyanth Jyothi, Cinzia Malangone, Paul Vauterin, Ben Jeffrey, Ian Wright, Lee Hart, Krzysztof Kluczynski, Victoria Cornelius, Bronwyn MacInnis, Christa Henrichs, Rachel Giacomantonio, Diego Ayala, Philip Bejon, Nora Besansky, Austin Burt, Beniamino Caputo, Alessandra Torre, Charles Godfray, Matthew Hahn, Daniel Neafsey, Samantha O'Loughlin, Joao Pinto, Michelle Riehle, Kenneth Vernick, David Weetman, Craig Wilding, Bradley White, Mara Lawniczak, Martin Donnelly, Dominic Kwiatkowski
Categories: malaria news feeds