An in vitro microassay to assess the ability of Plasmodium falciparum-infected erythrocytes to bind to the human syncytiotrophoblast

PROBLEM: Erythrocytes parasitized by matures stages of Plasmodium falciparu m are frequently sequestered in human placenta. The consequences of this se questration have been well described, but little is known about the mechani sms used by the parasite to concentrate in the placenta. METHOD OF STUDY: We developed an in vitro assay to study their binding capa city to the human syncytiotrophoblast. Our cytoadherence test was scaled do wn, and each step of the assay was optimized to enhance the sensitivity of our model. RESULTS: Cytoadherence assays between P. falciparum-infected erythrocytes a nd human trophoblasts are easily performed using low numbers of trophoblast cells. The process can also be used to carry out immunofluorescence and im munostaining techniques. CONCLUSIONS: The test may be adapted to any kind of cell, is inexpensive, a nd allows the culture of virtually any kind of cell for several weeks.