In Vivo Assessment of NS1-Truncated Influenza Virus with a Novel SLSYSINWRH Motif as a Self-Adjuvanting Live Attenuated Vaccine

Influenza viruses cause severe diseases and mortality in humans on an annual basis. The current influenza virus vaccines can confer protection when they are well-matched with the circulating strains. However, due to constant changes of the virus surface glycoproteins, the vaccine efficacy can drop substantially in some seasons. In addition, the current seasonal influenza virus vaccines do not protect from avian influenza viruses of human pandemic potential. Novel influenza virus vaccines that aim to elicit antibodies against conserved epitopes like the hemagglutinin stalk could not only reduce the burden of drifted seasonal viruses but potentially also protect humans from infection with zoonotic and emerging pandemic influenza viruses. In this paper, we generated influenza virus vaccine constructs that express chimeric hemagglutinins consisting of exotic, avian head domains and a consistent stalk domain of a seasonal virus. Using such viruses in a sequential immunization regimen can redirect the immune response towards conserved epitopes. In this study, male ferrets received a live-attenuated vaccine virus based on the A/Ann Arbor/6/60 strain expressing a chimeric H8/1 (cH8/1) hemagglutinin, which was followed by a heterologous booster vaccination with a cH5/1N1 formalin inactivated non-adjuvanted whole virus. This group was compared to a second group that received a cH8/1N1 inactivated vaccine followed by a cH5/1N1 inactivated vaccine. Both groups showed a reduction in viral titers in the upper respiratory tract after the A(H1N1)pdm09 virus challenge. Animals that received the live-attenuated vaccine had low or undetectable titers in the lower respiratory tract. The results support the further development of chimeric hemagglutinin-based vaccination strategies. The outcome of this study confirms and corroborates findings from female ferrets primed with a A/Leningrad/134/17/57-based live attenuated cH8/1N1 vaccine followed by vaccination with an AS03-adjuvanted cH5/1N1 split virus vaccine 10.

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A novel live attenuated RSV vaccine candidate with mutations in the L protein SAM binding site and the G protein cleavage site is protective in cotton rats and a rhesus macaque

Journal of Virology ◽

10.1128/jvi.01568-20 ◽

2020 ◽

Author(s):

Tiffany Jenkins ◽

Rongzhang Wang ◽

Olivia Harder ◽

Miaoge Xue ◽

Phylip Chen ◽

...

Keyword(s):

Binding Site ◽

Rhesus Macaque ◽

Vaccine Candidate ◽

Vero Cells ◽

Virus Yield ◽

Vaccine Production ◽

Live Attenuated Vaccine ◽

Attenuated Vaccine ◽

Cotton Rats

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infections in children < 5 years of age worldwide, infecting the majority of infants in their first year of life. Despite the widespread impact of this virus, no vaccine is currently available. For over 50 years, live attenuated vaccines (LAV) have been shown to protect against other childhood viral infections, offering the advantage of presenting all viral proteins to the immune system for stimulation of both B and T cell responses and memory. The RSV LAV candidate described here, rgRSV-L(G1857A)-G(L208A), contains two modifications: an attenuating mutation in the S-adenosylmethionine (SAM) binding site of the viral mRNA cap methyltransferase (MTase) within the large (L) polymerase protein and a mutation in the attachment (G) glycoprotein that inhibits its cleavage during production in Vero cells, resulting in virus with a “non-cleaved G” (ncG). RSV virions containing the ncG have an increased ability to infect primary well-differentiated human bronchial epithelial (HBE) cultures which model the in vivo site of immunization, the ciliated airway epithelium. This RSV LAV candidate is produced efficiently in Vero cells, is highly attenuated in HBE cultures, efficiently induces neutralizing antibodies that are long-lasting, and provides protection against an RSV challenge in the cotton rat, without causing enhanced disease. Similar results were obtained in a rhesus macaque. Importance Globally, RSV is a major cause of death in children under one year of age, yet no vaccine is available. We have generated a novel RSV live attenuated vaccine candidate containing mutations in the L and G proteins. The L polymerase mutation does not inhibit virus yield in Vero cells, the cell type required for vaccine production, but greatly reduces virus spread in HBE cultures, a logical in vitro predictor of in vivo attenuation. The G attachment protein mutation reduces its cleavage in Vero cells, thereby increasing vaccine virus yield, making vaccine production more economical. In cotton rats, this RSV vaccine candidate is highly attenuated at a dose of 105 PFU and completely protective following immunization with 500 PFU, 200-fold less than the dose usually used in such studies. It also induced long-lasting antibodies in cotton rats and protected a rhesus macaque from RSV challenge. This mutant virus is an excellent RSV live attenuated vaccine candidate.

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Recombinant Vesicular Stomatitis Virus Expressing Influenza Nucleoprotein Induces CD8 T-Cell Responses That Enhance Antibody-Mediated Protection after Lethal Challenge with Influenza Virus

Clinical and Vaccine Immunology ◽

10.1128/cvi.00451-08 ◽

2009 ◽

Vol 16 (4) ◽

pp. 488-498 ◽

Cited By ~ 15

Author(s):

Brice E. Barefoot ◽

Christopher J. Sample ◽

Elizabeth A. Ramsburg

Keyword(s):

T Cells ◽

Influenza Virus ◽

Cd8 T Cells ◽

Influenza Infection ◽

Clinical Signs ◽

Lethal Challenge ◽

Live Attenuated Vaccine ◽

Virus Challenge ◽

Vesicular Stomatitis

ABSTRACT Live attenuated vaccine vectors based on recombinant vesicular stomatitis viruses (rVSVs) expressing foreign antigens are highly effective vaccines in animal models. In this study, we report that an rVSV expressing influenza nucleoprotein (VSV NP) from the first position of the VSV genome induces robust anti-NP CD8 T cells in immunized mice. These CD8 T cells are phenotypically similar to those induced by natural influenza infection and are cytotoxic in vivo. Animals immunized with an rVSV expressing the influenza hemagglutinin (rVSV HA) were protected but still exhibited considerable morbidity after challenge. Animals receiving a cocktail vaccine of rVSV NP and rVSV HA had reduced pulmonary viral loads, less weight loss, and reduced clinical signs of illness after influenza virus challenge, relative to those vaccinated with rVSV HA alone. Influenza NP is a highly conserved antigen, and induction of protective anti-NP responses may be a productive strategy for generating heterologous protection against divergent influenza strains.

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Influenza A Virus Lacking M2 Protein as a Live Attenuated Vaccine

Journal of Virology ◽

10.1128/jvi.00450-09 ◽

2009 ◽

Vol 83 (11) ◽

pp. 5947-5950 ◽

Cited By ~ 38

Author(s):

Shinji Watanabe ◽

Tokiko Watanabe ◽

Yoshihiro Kawaoka

Keyword(s):

Influenza Virus ◽

Immune Responses ◽

Influenza A ◽

Wild Type Virus ◽

Type Virus ◽

Wild Type ◽

Lethal Challenge ◽

Live Attenuated Vaccine ◽

Attenuated Vaccine ◽

Live Attenuated Influenza Vaccine

ABSTRACT Mutant influenza virus that lacks the transmembrane and cytoplasmic tail domains of M2 (M2 knockout [M2KO]) is attenuated in both cell culture and mice. Here, we examined the potency of M2KO influenza virus as a live attenuated influenza vaccine. M2KO virus grew as efficiently as the wild-type virus in cells stably expressing the wild-type M2, indicating the feasibility of efficient vaccine production. Mice intranasally vaccinated with M2KO virus developed protective immune responses and survived a lethal challenge with the wild-type virus, suggesting that the M2KO virus has potential as a live attenuated vaccine.

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Enhanced pathogenicity of low-pathogenic H9N2 avian influenza virus after vaccination with infectious bronchitis live attenuated vaccine

Veterinary World ◽

10.14202/vetworld.2018.977-985 ◽

2018 ◽

Vol 11 (7) ◽

pp. 977-985 ◽

Cited By ~ 4

Author(s):

Zainab Mohamed Ismail ◽

Ayman Hanea EL-Deeb ◽

Mounir Mohamed EL-Safty ◽

Hussein Aly Hussein

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Avian Influenza Virus ◽

Live Attenuated Vaccine ◽

H9n2 Avian Influenza Virus ◽

Infectious Bronchitis ◽

Attenuated Vaccine

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Live attenuated SARS-CoV-2 vaccine candidate: Protective immunity without serious lung lesions in Syrian hamsters

10.1101/2021.02.15.430863 ◽

2021 ◽

Author(s):

Shinya Okamura ◽

Akiho Kashiwabara ◽

Hidehiko Suzuki ◽

Shiori Ueno ◽

Paola Miyazato ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Vaccine Candidate ◽

Nonstructural Protein ◽

Wild Type Virus ◽

Temperature Sensitive ◽

Live Attenuated Vaccine ◽

Syrian Hamsters ◽

Attenuated Vaccine

AbstractVarious COVID-19 vaccine candidates are currently under clinical trial. However, no live attenuated vaccine has been developed yet, despite their generally high efficacy. Here, we established temperature-sensitive mutant strains of SARS-CoV-2, whose growth was significantly slower than that of the parent strain at 37°C. One of the strains, A50-18, which presented mutations in nonstructural protein 14, did not replicate at all at 37°C in vitro. In vivo experiments demonstrated that this strain replicated inefficiently in the lungs of Syrian hamsters, and intra-nasal inoculation induced sufficient anti-SARS-CoV-2-neutralizing antibodies to protect against wild type virus infection. These results suggest that the A50-18 strain could be a promising live attenuated vaccine candidate against SARS-CoV-2.One Sentence SummaryA live attenuated virus provided immunity against SARS-CoV-2 in an animal model, making it a promising vaccine candidate.

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Development of a novel equine influenza virus live-attenuated vaccine

Virology ◽

10.1016/j.virol.2018.01.005 ◽

2018 ◽

Vol 516 ◽

pp. 76-85 ◽

Cited By ~ 8

Author(s):

Laura Rodriguez ◽

Stephanie Reedy ◽

Aitor Nogales ◽

Pablo R. Murcia ◽

Thomas M. Chambers ◽

...

Keyword(s):

Influenza Virus ◽

Equine Influenza Virus ◽

Live Attenuated Vaccine ◽

Equine Influenza ◽

Attenuated Vaccine

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Corrigendum to “Phenotypic properties resulting from directed gene segment reassortment between wild-type A/Sydney/5/97 influenza virus and the live attenuated vaccine strain” [Virology 367 (2007) 275–287]

Virology ◽

10.1016/j.virol.2008.01.021 ◽

2008 ◽

Vol 374 (2) ◽

pp. 535-539

Author(s):

Christopher L. Parks ◽

Theresa Latham ◽

Adriana Cahill ◽

Robert E. O'Neill ◽

Christopher J. Passarotti ◽

...

Keyword(s):

Influenza Virus ◽

Vaccine Strain ◽

Gene Segment ◽

Type A ◽

Wild Type ◽

Phenotypic Properties ◽

Live Attenuated Vaccine ◽

Attenuated Vaccine

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In Vitro and In Vivo Analyses of Constitutive and In Vivo-Induced Promoters in Attenuated Vaccine and Vector Strains ofVibrio cholerae

Infection and Immunity ◽

10.1128/iai.68.3.1171-1175.2000 ◽

2000 ◽

Vol 68 (3) ◽

pp. 1171-1175 ◽

Cited By ~ 17

Author(s):

Manohar John ◽

Thomas I. Crean ◽

Stephen B. Calderwood ◽

Edward T. Ryan

Keyword(s):

Immune Responses ◽

Vaccine Strain ◽

Antigen Expression ◽

Live Attenuated Vaccine ◽

Attenuated Vaccine ◽

In Vivo Expression ◽

Antibody Titers ◽

Heterologous Antigens

ABSTRACT The optimal promoter for in vivo expression of heterologous antigens by live, attenuated vaccine vector strains of Vibrio cholerae is unclear; in vitro analyses of promoter activity may not accurately predict expression of antigens in vivo. We therefore introduced plasmids expressing the B subunit of cholera toxin (CtxB) under the control of a number of promoters into V. choleraevaccine strain Peru2. We evaluated the tac promoter, which is constitutively expressed in V. cholerae, as well as the in vivo-induced V. cholerae heat shock htpGpromoter and the in vivo-induced V. cholerae iron-regulatedirgA promoter. The functionality of all promoters was confirmed in vitro. In vitro antigenic expression was highest in vaccine strains expressing CtxB under the control of thetac promoter (2 to 5 μg/ml/unit of optical density at 600 nm [OD600]) and, under low-iron conditions, in strains containing the irgA promoter (5 μg/ml/OD600). We orally inoculated mice with the various vaccine strains and used anti-CtxB immune responses as a marker for in vivo expression of CtxB. The vaccine strain expressing CtxB under the control of thetac promoter elicited the most prominent specific anti-CtxB responses in vivo (serum immunoglobulin G [IgG], P≤ 0.05; serum IgA, P ≤ 0.05; stool IgA,P ≤ 0.05; bile IgA, P ≤ 0.05), despite the finding that the tac and irgApromoters expressed equivalent amounts of CtxB in vitro. Vibriocidal antibody titers were equivalent in all groups of animals. Our results indicate that in vitro assessment of antigen expression by vaccine and vector strains of V. cholerae may correlate poorly with immune responses in vivo and that of the promoters examined, thetac promoter may be best suited for expression from plasmids of at least certain heterologous antigens in such strains.

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