Figure 3
From: Evaluation of immunity against malaria using luciferase-expressing Plasmodium berghei parasites
Transgenic Pb GFP-Luc con sporozoite hepatocyte invasion inhibition assay. (A) Huh-7 cells were seeded in 24 well plates and were grown to confluency as described in Materials and Methods. Graded numbers of Pb GFP-Luc con sporozoites were added to the culture wells in duplicate and incubated for 40 h at 37 C in 5% CO2. Infectivity was quantified by analyzing the luminescent flux (p/sec/cm2) in each well. (B) Invasion inhibition of sporozoites by plasma from CPS (n = 6) and RAS (n = 7) immunized mice. 30.000 Pb GFP-Luc con sporozoites were incubated in plasma of naive or immune mice for 30 min on ice and subsequently added to Huh-7 cells. Infectivity was quantified by analyzing the luminescent flux (p/sec/cm2) in each well. The baseline represents the inhibition level of plasma from naive mice (approximately 4 × 10^7 p/sec/cm2). Percent inhibition was calculated by the following formula; 1 - (average bioluminescence in immune plasma sample/average bioluminescence in naive plasma sample) × 100%. The level of invasion inhibition in the immunized mice was significantly higher compared to the inhibition from the plasma of naive mice (95% CI CPS 36-79%; 95% CI RAS 58-81%).