Use of XXXX and flow cytometry to assess the effects of leukocytes on the malarial parasite @entity3964 .

@entity137 @entity5611 @entity23410 @entity5895 @entity3964 @entity15835
Flow cytometry was evaluated as a method of assessing in vitro the effects of leukocytes on blood-stage @entity3964 . @entity23410 is converted by metabolizing cells to @entity5611 , a nucleic acid fluorochrome. After incubation with @entity23410 , viable and dead leukocytes and parasitized and uninfected erthrocytes could all be identified on the basis of fluorescence intensity and size. Leukocytes can therefore be eliminated from further analysis; this allows assessment, at any parasite developmental stage, of the level of @entity5895 within erythrocytes in the presence of any of several types of leukocytes. Whether leukocytes actually kill intraerythrocytic parasites can therefore be determined and the level of @entity137 can be assessed. The ability of leukocytes to prevent merozoites from invading new erythrocytes, i.e., inhibition of parasite invasion, can also be assessed by this method. When erythrocytes containing schizont-stage parasites were cocultured with different leukocyte populations and the level of @entity5895 was determined after merozoite release and invasion, only cultures containing gamma delta T cells inhibited parasite invasion. The different blood-stage forms of the parasite vary in nucleic acid content, which allows each of the developmental stages to be distinguished by flow cytometry; this permits assessment of changes in parasite development in the presence of leukocytes. @entity15835 ( @entity15835 ) appeared to have an effect on parasite development. In this instance, when erythrocytes containing ring-form parasites were cocultured with @entity15835 and harvested 24 h later, the parasites in cultures containing @entity15835 were at the late schizont stage, whereas parasites in control cultures were early trophozoites; this finding suggests that @entity15835 accelerate parasite development. Together, these results indicate that flow cytometry is potentially useful for measuring the following effects mediated by leukocytes: (i) level of @entity137 , (ii) changes in parasite development, and (iii) inhibition of parasite invasion.
