Lander Foquet1, Cornelus C Hermsen2, Lieven Verhoye1, Geert-Jan van Gemert2, Riccardo Cortese3, Alfredo Nicosia4, Robert W Sauerwein2, Geert Leroux-Roels1, Philip Meuleman5. 1. Center for Vaccinology, Ghent University, De Pintelaan 185, 9000 Gent, Belgium. 2. Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands. 3. Keires AG, Elisabethenstrasse 15, 4051 Basel, Switzerland. 4. CEINGE, Via Comunale Margherita, 484-538, 80131 Naples, Italy Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Corso Umberto I, 80138 Naples, Italy. 5. Center for Vaccinology, Ghent University, De Pintelaan 185, 9000 Gent, Belgium philip.meuleman@ugent.be.
Abstract
OBJECTIVES: Plasmodium falciparum sporozoites, deposited in the skin by infected Anopheles mosquitoes taking a blood meal, cross the endothelium of skin capillaries and travel to the liver where they traverse Kupffer cells and hepatocytes to finally invade a small number of the latter. In hepatocytes, sporozoites replicate, differentiate and give rise to large numbers of merozoites that are released into the bloodstream where they invade red blood cells, thus initiating the symptomatic blood stage. Using in vitro systems and rodent models, it has been shown that the hepatocyte receptors CD81 and scavenger receptor type B class I (SR-BI) play a pivotal role during sporozoite invasion. We wanted to evaluate whether these two entry factors are genuine drug targets for the prevention of P. falciparum infection in humans. METHODS: Immunodeficient mice of which the liver is largely repopulated by human hepatocytes were treated with monoclonal antibodies blocking either CD81 or SR-BI 1 day prior to challenge with infected mosquitoes. P. falciparum infection of the liver was demonstrated using a qPCR assay. RESULTS: In human liver chimeric mice, an antibody directed against CD81 completely blocked P. falciparum sporozoite invasion while SR-BI-specific monoclonal antibodies did not influence in vivo infection. CONCLUSIONS: These observations confirm the role of CD81 in liver-stage malaria and question that of SR-BI. CD81 might be a valuable drug target for the prevention of malaria.
OBJECTIVES:Plasmodium falciparum sporozoites, deposited in the skin by infected Anopheles mosquitoes taking a blood meal, cross the endothelium of skin capillaries and travel to the liver where they traverse Kupffer cells and hepatocytes to finally invade a small number of the latter. In hepatocytes, sporozoites replicate, differentiate and give rise to large numbers of merozoites that are released into the bloodstream where they invade red blood cells, thus initiating the symptomatic blood stage. Using in vitro systems and rodent models, it has been shown that the hepatocyte receptors CD81 and scavenger receptor type B class I (SR-BI) play a pivotal role during sporozoite invasion. We wanted to evaluate whether these two entry factors are genuine drug targets for the prevention of P. falciparum infection in humans. METHODS: Immunodeficient mice of which the liver is largely repopulated by human hepatocytes were treated with monoclonal antibodies blocking either CD81 or SR-BI 1 day prior to challenge with infected mosquitoes. P. falciparum infection of the liver was demonstrated using a qPCR assay. RESULTS: In human liver chimeric mice, an antibody directed against CD81 completely blocked P. falciparum sporozoite invasion while SR-BI-specific monoclonal antibodies did not influence in vivo infection. CONCLUSIONS: These observations confirm the role of CD81 in liver-stage malaria and question that of SR-BI. CD81 might be a valuable drug target for the prevention of malaria.
Authors: Iset Medina Vera; Margarida T Grilo Ruivo; Leonardo F Lemos Rocha; Sofia Marques; Sangeeta N Bhatia; Maria M Mota; Liliana Mancio-Silva Journal: JCI Insight Date: 2019-12-19
Authors: Ryan W J Steel; Vladimir Vigdorovich; Nicholas Dambrauskas; Brandon K Wilder; Silvia A Arredondo; Debashree Goswami; Sudhir Kumar; Sara Carbonetti; Kristian E Swearingen; Thao Nguyen; Will Betz; Nelly Camargo; Bridget S Fisher; Jo Soden; Helen Thomas; Jim Freeth; Robert L Moritz; D Noah Sather; Stefan H I Kappe Journal: Sci Rep Date: 2021-05-31 Impact factor: 4.379