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Impact of insecticide resistance in Anopheles arabiensis on malaria incidence and prevalence in Sudan and the costs of mitigation

CiteULike malaria tags - 14 December 2017 - 1:52pm
Proceedings of the National Academy of Sciences (11 December 2017), 201713814, doi:10.1073/pnas.1713814114
Hmooda Kafy, Bashir Ismail, Abraham Mnzava, Jonathan Lines, Mogahid Shiekh Eldin Abdin, Jihad Eltaher, Anuar Banaga, Philippa West, John Bradley, Jackie Cook, Brent Thomas, Krishanthi Subramaniam, Janet Hemingway, Tessa Knox, Elfatih Malik, Joshua Yukich, Martin Donnelly, Immo Kleinschmidt
Categories: malaria news feeds

Immune evasion of Plasmodium falciparum by RIFIN via inhibitory receptors.

CiteULike malaria tags - 4 December 2017 - 9:00am
Nature (29 November 2017)

Malaria is among the most serious infectious diseases affecting humans, accounting for approximately half a million deaths each year. Plasmodium falciparum causes most life-threatening cases of malaria. Acquired immunity to malaria is inefficient, even after repeated exposure to P. falciparum, but the immune regulatory mechanisms used by P. falciparum remain largely unknown. Here we show that P. falciparum uses immune inhibitory receptors to achieve immune evasion. RIFIN proteins are products of a polymorphic multigene family comprising approximately 150-200 genes per parasite genome that are expressed on the surface of infected erythrocytes. We found that a subset of RIFINs binds to either leucocyte immunoglobulin-like receptor B1 (LILRB1) or leucocyte-associated immunoglobulin-like receptor 1 (LAIR1). LILRB1-binding RIFINs inhibit activation of LILRB1-expressing B cells and natural killer (NK) cells. Furthermore, P. falciparum-infected erythrocytes isolated from patients with severe malaria were more likely to interact with LILRB1 than erythrocytes from patients with non-severe malaria, although an extended study with larger sample sizes is required to confirm this finding. Our results suggest that P. falciparum has acquired multiple RIFINs to evade the host immune system by targeting immune inhibitory receptors.
Fumiji Saito, Kouyuki Hirayasu, Takeshi Satoh, Christian Wang, John Lusingu, Takao Arimori, Kyoko Shida, Nirianne Marie Palacpac, Sawako Itagaki, Shiroh Iwanaga, Eizo Takashima, Takafumi Tsuboi, Masako Kohyama, Tadahiro Suenaga, Marco Colonna, Junichi Takagi, Thomas Lavstsen, Toshihiro Horii, Hisashi Arase
Categories: malaria news feeds