Fig. 6
Treatment of human RBCs with CDP3 and Cyclosporin A (CsA) suggests Cyclophilin B plays a crucial role in P. falciparum invasion of host RBCs. Invasion Assay using CDP3: a Invasion inhibition of P. falciparum strains 3D7 and Dd2 by CDP3 into culture. Purified recombinant CDP3 protein (1–25 µM) was added to mature schizont stage parasite culture and the parasitaemia estimated after 40 h using flow cytometry. The data represent an average of three independent experiments each performed in duplicate. Invasion observed in control culture was taken as 100%. The CDP3 buffer components did not affect parasite invasion. b Similarly, Uninfected RBCs were treated with CDP3 (10, 25, 50 µM) for 4 h at RT followed by 3D7 merozoites infection. Parasitemia was analyzed using FACS. c−e Dose dependent inhibition of invasion by CsA treatment of RBC: Uninfected BCs treated with CsA (2.5–100 µM) followed by 3D7 merozoites infection. Invasion was reduced by ~80%. Similar results were obtained by using different strains of P. falciparum including Dd2, HB3 and 7G8. CsA (12.5–50 µM) added in culture at late schizont stage; parasitemia was estimated after 40 h. 80–90% inhibition of invasion was observed. Statistical significance was determined using the unpaired t-test with Welch’s correction. **P < 0.01 was considered significant. Each bar represents the mean ± S.D. for three independent biological replicates
