EFFECT OF ATP ON THE ADHESION OF RED BLOOD CELLS TO ENDOTHELIAL CELLS ELICITED BY PLASMODIUM FALCIPARUM

BLANCO, RENATA; SOUSA, EMILIA; SAFFIOTI, NICOLÁS; SCHWARZBAUM, PABLO; ALVAREZ, CORA LILIA

Mar del Plata, provincia de Buenos Aires

Congreso; Reunión anual de Sociedades de Biociencias; 2022

SAIC-SAI-SAFIS

Plasmodium falciparum, the most dangerous parasitic agent causing malaria, invades human red blood cells (RBCs) causing hemolysis, adhesion of infected RBCs (iRBCs) to endothelium and microvascular obstruction. ATP and its byproducts are important extracellular ligands modulating purinergic signaling within the intravascular space. In RBCs extracellular ATP regulation depends on the balance between ATP release by specific transporters and extracellular ATP hydrolysis by ectonucleotidases. Previously, we demonstrated that, in a suspension of iRBCs at low parasitemia, not only iRBCs but also non-infected RBCs (cultured in the presence of iRBCs (niRBCs)) presented activation of ATP release via Pannexin 1, and of extracellular ATP degradation by ectoATPase activity. This activation might be involved in microvascular obstruction caused by malaria, thus we studied whether extracellular ATP affects the adhesive properties of iRBCs and niRBCS. P. falciparum was cultured in RBCs. iRBCs and niRBCs were purified by magnetic columns. Adhesion to a surface covered with poly-Lysine was measured by a colorimetric method (crystal violet). Adhesion to a monolayer of confluent endothelial cells (EA.hy 926) growing on coverslips was measured by cell counting. Suspensions of iRBCs and niRBCs were incubated with endothelial cells for 30 minutes at 37 °C, washed to remove non-adhered RBCs, and fixed with 3% glutaraldehyde. Then, RBCs were counted by bright field optical microscopy.Results show that the adhesion of iRBCs is greater than that of the niRBCs. There were non-statistical differences between niRBCs and control RBCs i.e. RBCs cultured in the absence of P.falciparum. Preliminary results suggest that exposure to µM concentrations of ATP, ADP, AMP and ADO did not affect adhesion of either iRBCs or niRBCs. Future studies will also assess the effect of purinergic signaling in RBCs aggregation and deformability to understand it’s role in microvascular obstruction in malaria.