Splenic retention of Plasmodium falciparum gametocytes to block the transmission of malaria.
Plasmodium falciparum is transmitted from humans to Anopheles mosquito vectors via the sexual erythrocytic forms termed gametocytes. Erythrocyte filtration through microsphere layers (microsphiltration) had shown that circulating gametocytes are deformable. Compounds reducing gametocyte deformability would induce their splenic clearance, thus removing them from the blood circulation and blocking malaria transmission. The hand-made, single-sample prototype for microsphiltration was miniaturized to a 96-well microtiter plate format, and gametocyte retention in the microsphere filters was quantified by high-content imaging. The stiffening activity of 40 pharmacological compounds was assessed in microtiter plates, using a small molecule (calyculin) as a positive control. The stiffening activity of calyculin was assessed in spleen-mimetic microfluidic chips and in macrophage-depleted mice. Marked mechanical retention (80% to 90%) of mature gametocytes was obtained in microplates following exposure to calyculin at concentrations with no effect on parasite viability. Of the 40 compounds tested, including 20 antimalarials, only 5 endoperoxides significantly increased gametocyte retention (1.5- to 2.5-fold; 24 h of exposure at 1 μM). Mature gametocytes exposed to calyculin accumulated in microfluidic chips and were cleared from the circulation of macrophage-depleted mice as rapidly as heat-stiffened erythrocytes, thus confirming results obtained using the microsphiltration assay. An automated miniaturized approach to select compounds for their gametocyte-stiffening effect has been established. Stiffening induces gametocyte clearance both in vitro and in vivo. Based on physiologically validated tools, this screening cascade can identify novel compounds and uncover new targets to block malaria transmission. Innovative applications in hematology are also envisioned.
Centre d'Immunologie et des Maladies Infectieuses de Paris (CIMI-Paris), INSERM U1135, UPMC CR7, CNRS ERL 8255, Paris, France Eskitis Institute for Drug Discovery, Griffith University, Nathan, QLD, Australia Laboratoire d'Excellence GR-Ex, Paris, France.
Julien
J
Duez
Eskitis Institute for Drug Discovery, Griffith University, Nathan, QLD, Australia.
John P
JP
Holleran
Centre d'Immunologie et des Maladies Infectieuses de Paris (CIMI-Paris), INSERM U1135, UPMC CR7, CNRS ERL 8255, Paris, France Laboratoire d'Excellence GR-Ex, Paris, France.
Papa Alioune
PA
Ndour
Eskitis Institute for Drug Discovery, Griffith University, Nathan, QLD, Australia.
Sasdekumar
S
Loganathan
INSERM U1163/CNRS ERL 8254, Institut Imagine, Paris Descartes-Université Sorbonne Paris Cité, Paris, France Laboratoire d'Excellence GR-Ex, Paris, France Institut National de la Transfusion Sanguine (INTS), Paris, France.
Pascal
P
Amireault
Ecole Normale Supérieure de Cachan, CNRS, BIOMIS-SATIE, UMR 8029, Cachan, France.
Olivier
O
Français
Institut National de la Transfusion Sanguine (INTS), Paris, France.
Wassim
W
El Nemer
Ecole Normale Supérieure de Cachan, CNRS, BIOMIS-SATIE, UMR 8029, Cachan, France.
Bruno
B
Le Pioufle
Institut Pasteur de Paris, Paris, France.
Inês F
IF
Amado
Institut Pasteur de Paris, Paris, France.
Sylvie
S
Garcia
Centre d'Immunologie et des Maladies Infectieuses de Paris (CIMI-Paris), INSERM U1135, UPMC CR7, CNRS ERL 8255, Paris, France.
Nathalie
N
Chartrel
Institut National de la Transfusion Sanguine (INTS), Paris, France.
Caroline
C
Le Van Kim
Institut Pasteur de Paris, Paris, France.
Catherine
C
Lavazec
Eskitis Institute for Drug Discovery, Griffith University, Nathan, QLD, Australia.
Vicky M
VM
Avery
Centre d'Immunologie et des Maladies Infectieuses de Paris (CIMI-Paris), INSERM U1135, UPMC CR7, CNRS ERL 8255, Paris, France Laboratoire d'Excellence GR-Ex, Paris, France pabuffet@gmail.com.
Pierre A
PA
Buffet
D000818:Animals; D000962:Antimalarials / Q000494:pharmacology; D001331:Automation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004906:Erythrocyte Count; D004912:Erythrocytes / Q000469:parasitology; D005374:Filtration; D005434:Flow Cytometry; D007091:Image Processing, Computer-Assisted; D008264:Macrophages / Q000469:parasitology; D016778:Malaria, Falciparum / Q000469:parasitology* / Q000517:prevention & control / Q000635:transmission*; D008387:Marine Toxins; D051379:Mice; D046210:Microfluidic Analytical Techniques; D008863:Microspheres; D008954:Models, Biological; D010080:Oxazoles / Q000494:pharmacology; D010270:Parasite Egg Count; D010963:Plasmodium falciparum / Q000254:growth & development*; D013154:Spleen / Q000187:drug effects / Q000469:parasitology*
D000962:Antimalarials; D004791:Enzyme Inhibitors; D008387:Marine Toxins; D010080:Oxazoles; C059041:calyculin A