title: Attenuated Human Parainfluenza Virus Type 1 Expressing Ebola Virus Glycoprotein GP Administered Intranasally Is Immunogenic in African Green Monkeys.
abstract: The recent 2014-2016 Ebola virus (EBOV) outbreak prompted increased efforts to develop vaccines against EBOV disease. We describe the development and preclinical evaluation of an attenuated recombinant human parainfluenza virus type 1 (rHPIV1) expressing the membrane-anchored form of EBOV glycoprotein GP, as an intranasal (i.n.) EBOV vaccine. GP was codon optimized and expressed either as a full-length protein or as an engineered chimeric form in which its transmembrane and cytoplasmic tail (TMCT) domains were replaced with those of the HPIV1 F protein in an effort to enhance packaging into the vector particle and immunogenicity. GP was inserted either preceding the N gene (pre-N) or between the N and P genes (N-P) of rHPIV1 bearing a stabilized attenuating mutation in the P/C gene (CΔ170). The constructs grew to high titers and efficiently and stably expressed GP. Viruses were attenuated, replicating at low titers over several days, in the respiratory tract of African green monkeys (AGMs). Two doses of candidates expressing GP from the pre-N position elicited higher GP neutralizing serum antibody titers than the N-P viruses, and unmodified GP induced higher levels than its TMCT counterpart. Unmodified EBOV GP was packaged into the HPIV1 particle, and the TMCT modification did not increase packaging or immunogenicity but rather reduced the stability of GP expression duringin vivoreplication. In conclusion, we identified an attenuated and immunogenic i.n. vaccine candidate expressing GP from the pre-N position. It is expected to be well tolerated in humans and is available for clinical evaluation.IMPORTANCEEBOV hemorrhagic fever is one of the most lethal viral infections and lacks a licensed vaccine. Contact of fluids from infected individuals, including droplets or aerosols, with mucosal surfaces is an important route of EBOV spread during a natural outbreak, and aerosols also might be exploited for intentional virus spread. Therefore, vaccines that protect against mucosal as well as systemic inoculation are needed. We evaluated a version of human parainfluenza virus type 1 (HPIV1) bearing a stabilized attenuating mutation in the P/C gene (CΔ170) as an intranasal vaccine vector to express the EBOV glycoprotein GP. We evaluated expression from two different genome positions (pre-N and N-P) and investigated the use of vector packaging signals. African green monkeys immunized with two doses of the vector expressing GP from the pre-N position developed high titers of GP neutralizing serum antibodies. The attenuated vaccine candidate is expected to be safe and immunogenic and is available for clinical development.
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.|Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Lingemann
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Xueqiao
authors.initials: X
authors.lastname: Liu
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Sonja
authors.initials: S
authors.lastname: Surman
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Bo
authors.initials: B
authors.lastname: Liang
authors.affiliation: Experimental Primate Virology Section, Comparative Medicine Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Poolesville, Maryland, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Herbert
authors.affiliation: Experimental Primate Virology Section, Comparative Medicine Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Poolesville, Maryland, USA.
authors.forename: Ashley D
authors.initials: AD
authors.lastname: Hackenberg
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Ursula J
authors.initials: UJ
authors.lastname: Buchholz
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Collins
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA munirs@niaid.nih.gov.
authors.forename: Shirin
authors.initials: S
authors.lastname: Munir
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D002522:Chlorocebus aethiops; D046129:Ebola Vaccines / Q000008:administration & dosage / Q000235:genetics* / Q000276:immunology*; D029043:Ebolavirus / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D005822:Genetic Vectors; D006023:Glycoproteins / Q000235:genetics / Q000276:immunology; D019142:Hemorrhagic Fever, Ebola / Q000276:immunology / Q000517:prevention & control*; D006801:Humans; D010222:Parainfluenza Virus 1, Human / Q000235:genetics*; D012137:Respiratory System / Q000821:virology; D014611:Vaccination; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D014759:Viral Envelope Proteins / Q000235:genetics*; D014779:Virus Replication
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D046129:Ebola Vaccines; D006023:Glycoproteins; D014613:Vaccines, Attenuated; D014759:Viral Envelope Proteins
keywords: Ebola GP; Ebola glycoprotein GP; Ebola virus; human parainfluenza virus; human parainfluenza virus type 1; intranasal vaccine; live attenuated vaccine; mucosal vaccine; vaccine; vectored vaccine