© 2015 Longley et al. The development of an efficacious vaccine against the Plasmodium parasite remains a top priority. Previous research has demonstrated the ability of a prime-boost virally vectored sub-unit vaccination regimen, delivering the liver-stage expressed malaria antigen TRAP, to produce high levels of antigen-specific T cells. The liver-stage of malaria is the main target of T cell-mediated immunity, yet a major challenge in assessing new T cell inducing vaccines has been the lack of a suitable pre-clinical assay. We have developed a flow-cytometry based in vitro T cell killing assay using a mouse hepatoma cell line, Hepa1-6, and Plasmodium berghei GFP expressing sporozoites. Using this assay, P. berghei TRAP-specific CD8 + T cell enriched splenocytes were shown to inhibit liver-stage parasites in an ef-fector- to-target ratio dependent manner. Further development of this assay using human hepatocytes and P. falciparum would provide a new method to pre-clinically screen vaccine candidates and to elucidate mechanisms of protection in vitro.
Longley, R. J., Bauza, K., Ewer, K. J., Hill, A. V. S., & Spencer, A. J. (2015). Development of an in vitro assay and demonstration of Plasmodium berghei liver- Stage inhibition by TRAP-specific CD8+ T Cells. PLoS ONE, 10(3). https://doi.org/10.1371/journal.pone.0119880