title: An anti-Chitinase malaria transmission-blocking single-chain antibody as an effector molecule for creating a Plasmodium falciparum-refractory mosquito.
abstract: Indirect evidence has suggested the existence of a second chitinase gene, PgCHT2, in the avian malaria parasite Plasmodium gallinaceum. We have now identified PgCHT2 as the orthologue of the P. falciparum chitinase gene PfCHT1, a malaria transmission-blocking target. Computational phylogenetic evidence and biochemical and cell biological functional data support the hypothesis that an avian-related Plasmodium species was the ancestor of both P. falciparum and P. reichenowi, and this single lineage gave rise to another lineage of malaria parasites, including P. vivax, P. knowlesi, P. berghei, P. yoelii, and P. chabaudi. A recombinant PfCHT1/PgCHT2-neutralizing single-chain antibody significantly reduced P. falciparum and P. gallinaceum parasite transmission to mosquitoes. This single-chain antibody is the first anti-P. falciparum effector molecule to be validated for making a malaria transmission-refractory transgenic Anopheles species mosquito. P. gallinaceum is a relevant animal model that facilitates a mechanistic understanding of P. falciparum invasion of the mosquito midgut.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, University of California-San Diego School of Medicine, La Jolla, California 92093-0640, USA.
authors.forename: Fengwu
authors.initials: F
authors.lastname: Li
authors.forename: Kailash P
authors.initials: KP
authors.lastname: Patra
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Vinetz
mesh_terms: D000330:Aedes / Q000469:parasitology*; D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles / Q000469:parasitology*; D000913:Antibodies, Protozoan / Q000235:genetics / Q000276:immunology*; D001483:Base Sequence; D001681:Biological Assay; D002688:Chitinases / Q000235:genetics / Q000276:immunology*; D008289:Malaria, Avian / Q000469:parasitology / Q000517:prevention & control / Q000635:transmission*; D016778:Malaria, Falciparum / Q000469:parasitology / Q000635:transmission*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010963:Plasmodium falciparum / Q000201:enzymology* / Q000235:genetics; D010964:Plasmodium gallinaceum / Q000201:enzymology* / Q000235:genetics; D015800:Protozoan Proteins; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000913:Antibodies, Protozoan; D015800:Protozoan Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D002688:Chitinases; C402444:pfCHT1, chitinase