title: Transmission-blocking activity of antibodies to Plasmodium falciparum GLURP.10C chimeric protein formulated in different adjuvants.
abstract: BACKGROUND
  Plasmodium falciparum is transmitted from person to person by Anopheles mosquitoes after completing its sexual reproductive cycle within the infected mosquito. An efficacious vaccine holds the potential to interrupt development of the parasite in the mosquito leading to control and possibly eradication of malaria. A multi-component, R0.10C, was developed comprising P. falciparum glutamate-rich protein (R0) fused in frame to a correctly folded fragment of Pfs48/45 (10C). Here, a series of novel adjuvants were screened for their ability to elicit transmission-blocking (TB) antibodies.
  
  
  METHODS
  The recombinant fusion protein R0.10C was produced in Lactococcus lactis and purified by affinity-chromatography on a monoclonal antibody (mAb 85RF45.1) against a major epitope for TB antibodies (epitope 1) harboured on R0.10C. Immune-purified R0.10C was mixed with a series of adjuvants and tested in mice and rats.
  
  
  RESULTS
  In general, all R0.10C formulations elicited high levels of antibodies recognizing native Pfs48/45 in macrogametes/zygotes. TB activity of anti-R0.10C antisera was assessed in the standard membrane-feeding assay (SMFA). Potency of different adjuvant/R0.10C combinations was tested in mice and rats using aluminium hydroxide (Alum), Alum with micellar and emulsion formulations of a synthetic TLR4 agonist, Glucopyranosyl Lipid Adjuvant (GLA), stable emulsion (SE)/GLA, AbISCO-100 and Freund's adjuvant (as reference). All formulations produced high antibody titres recognizing the native Pfs48/45 protein in macrogametes/zygotes. Interestingly, the GLA-Alum combination adjuvant was the most potent inducer of TB antibodies based on serum collected after two immunizations. In agreement with previous observations, biological activity in the SMFA correlated well with the level of anti-Pfs48/45 antibodies.
  
  
  CONCLUSIONS
  The combined data provide a strong basis for entering the next phase of clinical grade R0.10C production and testing.
authors.affiliation: Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands. will.roeffen@radboudumc.nl.
authors.forename: Will
authors.initials: W
authors.lastname: Roeffen
authors.affiliation: Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark. MTH@ssi.dk.|Department of International Health, Immunology, and Microbiology, Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark. MTH@ssi.dk.|Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark. MTH@ssi.dk.
authors.forename: Michael
authors.initials: M
authors.lastname: Theisen
authors.affiliation: Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands. Marga.vandeVegte-Bolmer@radboudumc.nl.
authors.forename: Marga
authors.initials: M
authors.lastname: van de Vegte-Bolmer
authors.affiliation: Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands. Geert-Jan.vanGemert@radboudumc.nl.
authors.forename: GeertJan
authors.initials: G
authors.lastname: van Gemert
authors.affiliation: Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands. Theo.Arens@radboudumc.nl.
authors.forename: Theo
authors.initials: T
authors.lastname: Arens
authors.affiliation: Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark. gormicon@gmail.com.
authors.forename: Gorm
authors.initials: G
authors.lastname: Andersen
authors.affiliation: Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark. MIC@ssi.dk.
authors.forename: Michael
authors.initials: M
authors.lastname: Christiansen
authors.affiliation: Gennova Biopharmaceuticals Limited, Pune, India. Laxman.Sevargave@gennova.co.in.
authors.forename: Laxman
authors.initials: L
authors.lastname: Sevargave
authors.affiliation: Gennova Biopharmaceuticals Limited, Pune, India. Singh.Shrawankumar@gennova.co.in.
authors.forename: Shrawan Kumar
authors.initials: SK
authors.lastname: Singh
authors.affiliation: Gennova Biopharmaceuticals Limited, Pune, India. Swarnendu.Kaviraj@gennova.co.in.
authors.forename: Swarnendu
authors.initials: S
authors.lastname: Kaviraj
authors.affiliation: Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands. Robert.Sauerwein@radboudumc.nl.
authors.forename: Robert
authors.initials: R
authors.lastname: Sauerwein
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000536:Aluminum Hydroxide / Q000494:pharmacology; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D004655:Emulsions / Q000494:pharmacology; D005260:Female; D005960:Glucosides / Q000494:pharmacology; D007074:Immunoglobulin G / Q000235:genetics / Q000378:metabolism; D008050:Lipid A / Q000494:pharmacology; D016778:Malaria, Falciparum / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010963:Plasmodium falciparum / Q000276:immunology*; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D016052:Protozoan Vaccines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012503:Saponins / Q000494:pharmacology
chemical_list: D000276:Adjuvants, Immunologic; D000913:Antibodies, Protozoan; D004655:Emulsions; D005960:Glucosides; D007074:Immunoglobulin G; D008050:Lipid A; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D011993:Recombinant Fusion Proteins; D012503:Saponins; C000608161:glucopyranosyl lipid-A; C072492:glutamate-rich protein, Plasmodium; D000536:Aluminum Hydroxide