AN IMPROVED MICROASSAY FOR PLASMODIUM-FALCIPARUM CYTOADHERENCE USING STABLE TRANSFORMANTS OF CHINESE-HAMSTER OVARY CELLS EXPRESSING CD36 ORINTERCELLULAR-ADHESION MOLECULE-1

Stable transformants of Chinese hamster ovary (CHO) cell lines express ing high levels of human CD36 or intercellular adhesion molecule-1 (IC AM-1) have been produced as target cells for cytoadherence of Plasmodi um falciparum-infected erythrocytes. An improved adherence microassay has been designed using small sample volumes and allowing convenient a nd reliable measurements on a large number of samples. The assay can b e used both with purified proteins spotted on plastic and with the sta bly transformed CHO cell lines. The same assay plate can be evaluated either microscopically or by scintillation counting after use of H-3-h ypoxanthine-labeled parasites. Using the microassay, functional expres sion of the transfected receptor molecules on CHO-CD36 and CHO-ICAM wa s confirmed using parasites with different cytoadherence phenotypes an d cytoadherence inhibition experiments with a panel of anti-CD36 antib odies. The use of isolates from The Gambia confirmed the applicability of these assays for laboratory studies of these isolates.