Dataset Information

Partial protection against H5N1 influenza in mice with a single dose of a chimpanzee adenovirus vector expressing nucleoprotein.

ABSTRACT: The development of adenoviral vectors based on non-human serotypes such as the chimpanzee adenovirus simian adenovirus 24 (AdC7) may allow for their utilization in populations harboring neutralizing antibodies to common human serotypes. Because adenoviral vectors can be used to generate potent T cell responses, they may be useful as vaccines against pandemic influenza such as may be caused by the H5N1 strains that are currently endemic in avian populations. The influenza nucleoprotein (NP) is known to provide MHC Class I restricted epitopes that are effective in evoking a cytolytic response. Because there is only low sequence variation in NP sequences between different influenza strains, a T cell vaccine may provide heterosubtypic protection against a spectrum of influenza A strains. An AdC7 vector expressing the influenza A/Puerto Rico/8/34 NP was tested for its efficacy in protecting BALB/c mice against two H5N1 strains and compared to a conventional human adenovirus serotype 5 vaccine. The AdC7 NP vaccine elicited a strong anti-NP T cell response. When tested in a mouse challenge model, there was improved survival following challenge with two strains of H5N1 that have caused human outbreaks, Vietnam/1203/04 and Hong Kong/483/97, although the improved survival reached statistical significance only with the strain from Vietnam.

SUBMITTER: Roy S

PROVIDER: S-EPMC2748222 | biostudies-literature | 2007 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Partial protection against H5N1 influenza in mice with a single dose of a chimpanzee adenovirus vector expressing nucleoprotein.

Roy Soumitra S Kobinger Gary P GP Lin Jianping J Figueredo Joanita J Calcedo Roberto R Kobasa Darwyn D Wilson James M JM

Vaccine 20070806 39-40

The development of adenoviral vectors based on non-human serotypes such as the chimpanzee adenovirus simian adenovirus 24 (AdC7) may allow for their utilization in populations harboring neutralizing antibodies to common human serotypes. Because adenoviral vectors can be used to generate potent T cell responses, they may be useful as vaccines against pandemic influenza such as may be caused by the H5N1 strains that are currently endemic in avian populations. The influenza nucleoprotein (NP) is kn ...[more]

PMID: 17728024

Similar Datasets

Project description:BackgroundProtection against the influenza virus by a specific antibody is relatively strain specific; meanwhile broader immunity may be conferred by cell-mediated immune response to the conserved epitopes across influenza virus subtypes. A universal broad-spectrum influenza vaccine which confronts not only seasonal influenza virus, but also avian influenza H5N1 virus is promising.MethodsThis study determined the specific and cross-reactive T cell responses against the highly pathogenic avian influenza A (H5N1) virus in four survivors and 33 non-H5N1 subjects including 10 H3N2 patients and 23 healthy individuals. Ex vivo IFN-γ ELISpot assay using overlapping peptides spanning the entire nucleoprotein (NP), matrix (M) and hemagglutinin (HA) derived from A/Thailand/1(KAN-1)/2004 (H5N1) virus was employed in adjunct with flow cytometry for determining T cell functions. Microneutralization (microNT) assay was performed to determine the status of previous H5N1 virus infection.ResultsIFN-γ ELISpot assay demonstrated that survivors nos. 1 and 2 had markedly higher T cell responses against H5N1 NP, M and HA epitopes than survivors nos. 3 and 4; and the magnitude of T cell responses against NP were higher than that of M and HA. Durability of the immunoreactivity persisted for as long as four years after disease onset. Upon stimulation by NP in IFN-γ ELISpot assay, 60% of H3N2 patients and 39% of healthy subjects exhibited a cross-reactive T cell response. The higher frequency and magnitude of responses in H3N2 patients may be due to blood collection at the convalescent phase of the patients. In H5N1 survivors, the effector peptide-specific T cells generated from bulk culture PBMCs by in vitro stimulation displayed a polyfunction by simultaneously producing IFN-γ and TNF-α, together with upregulation of CD107a in recognition of the target cells pulsed with peptide or infected with rVac-NP virus as investigated by flow cytometry.ConclusionsThis study provides an insight into the better understanding on the homosubtypic and heterosubtypic T cell-mediated immune responses in H5N1 survivors and non-H5N1 subjects. NP is an immunodominant target of cross-recognition owing to its high conservancy. Therefore, the development of vaccine targeting the conserved NP may be a novel strategy for influenza vaccine design.

Project description:Replication-deficient chimpanzee adenovirus (ChAd) vectors represent an attractive vaccine platform and are thus employed as vaccine candidates against several infectious diseases. Since inducing effective immunity depends on the interplay between innate and adaptive immunity, a deeper understanding of innate immune responses elicited by intramuscularly injected ChAd vectors in tissues can advance the platform's development. Using different candidate vaccines based on the Group C ChAd type 155 (ChAd155) vector, we characterized early immune responses in injected muscles and draining lymph nodes (dLNs) from mice, and complemented these analyses by evaluating cytokine responses and gene expression patterns in peripheral blood from ChAd155-injected macaques. In mice, vector DNA levels gradually decreased post-immunization, but local transgene mRNA expression exhibited two transient peaks [at 6 h and Day (D)5], which were most obvious in dLNs. This dynamic pattern was mirrored by the innate responses in tissues, which developed as early as 1-3 h (cytokines/chemokines) or D1 (immune cells) post-vaccination. They were characterized by a CCL2- and CXCL9/10-dominated chemokine profile, peaking at 6 h (with CXCL10/CCL2 signals also detectable in serum) and D7, and clear immune-cell infiltration peaks at D1/D2 and D6/D7. Experiments with a green fluorescent protein-expressing ChAd155 vector revealed infiltrating hematopoietic cell subsets at the injection site. Cell infiltrates comprised mostly monocytes in muscles, and NK cells, T cells, dendritic cells, monocytes, and B cells in dLNs. Similar bimodal dynamics were observed in whole-blood gene signatures in macaques: most of the 17 enriched immune/innate signaling pathways were significantly upregulated at D1 and D7 and downregulated at D3, and clustering analysis revealed stronger similarities between D1 and D7 signatures versus the D3 signature. Serum cytokine responses (CXCL10, IL1Ra, and low-level IFN-α) in macaques were predominantly observed at D1. Altogether, the early immune responses exhibited bimodal kinetics with transient peaks at D1/D2 and D6/D7, mostly with an IFN-associated signature, and these features were remarkably consistent across most analyzed parameters in murine tissues and macaque blood. These compelling observations reveal a novel aspect of the dynamics of innate immunity induced by ChAd155-vectored vaccines, and contribute to ongoing research to better understand how adenovectors can promote vaccine-induced immunity.

Dataset Information

Partial protection against H5N1 influenza in mice with a single dose of a chimpanzee adenovirus vector expressing nucleoprotein.

Publications

Partial protection against H5N1 influenza in mice with a single dose of a chimpanzee adenovirus vector expressing nucleoprotein.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets