Novartis Institute for Tropical Diseases, Emeryville, United States; Novartis Institute for Tropical Diseases, Singapore, Singapore
Laurent Dembele
Novartis Institute for Tropical Diseases, Singapore, Singapore; Faculty of Pharmacy, Université des Sciences, des Techniques et des Technologies de Bamako (USTTB), MRTC – DEAP, Bamako, Mali
Faculty of Tropical Medicine, Mahidol Vivax Research Center, Bangkok, Thailand
Sebastian Mikolajczak
Novartis Institute for Tropical Diseases, Emeryville, United States; Center for Infectious Disease Research, Seattle, United States
Pablo Bifani
Novartis Institute for Tropical Diseases, Singapore, Singapore; Singapore Immunology Network (SIgN), Singapore, Singapore; Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
Clemens HM Kocken
Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, Netherlands
Plasmodium vivax hypnozoites persist in the liver, cause malaria relapse and represent a major challenge to malaria elimination. Our previous transcriptomic study provided a novel molecular framework to enhance our understanding of the hypnozoite biology (Voorberg-van der Wel A, et al., 2017). In this dataset, we identified and characterized the Liver-Specific Protein 2 (LISP2) protein as an early molecular marker of liver stage development. Immunofluorescence analysis of hepatocytes infected with relapsing malaria parasites, in vitro (P. cynomolgi) and in vivo (P. vivax), reveals that LISP2 expression discriminates between dormant hypnozoites and early developing parasites. We further demonstrate that prophylactic drugs selectively kill all LISP2-positive parasites, while LISP2-negative hypnozoites are only sensitive to anti-relapse drug tafenoquine. Our results provide novel biological insights in the initiation of liver stage schizogony and an early marker suitable for the development of drug discovery assays predictive of anti-relapse activity.