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Identification of novel avian influenza virus derived CD8+ T-cell epitopes.

Reemers SS, van Haarlem DA, Sijts AJ, Vervelde L, Jansen CA - PLoS ONE (2012)

Bottom Line: Epitope predictions based on anchor residues resulted in 33 candidate epitopes.This resulted in the identification of 12 MHC B12-restricted, 3 B4-restricted and 1 B19-restricted AIV- specific CD8+ T-cell epitopes.In conclusion, we have identified novel AIV-derived CD8+ T-cell epitopes for several inbred chicken strains.

View Article: PubMed Central - PubMed

Affiliation: Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.

ABSTRACT
Avian influenza virus (AIV) infection is a continuing threat to both humans and poultry. Influenza virus specific CD8+ T cells are associated with protection against homologous and heterologous influenza strains. In contrast to what has been described for humans and mice, knowledge on epitope-specific CD8+ T cells in chickens is limited. Therefore, we set out to identify AIV-specific CD8+ T-cell epitopes. Epitope predictions based on anchor residues resulted in 33 candidate epitopes. MHC I inbred chickens were infected with a low pathogenic AIV strain and sacrificed at 5, 7, 10 and 14 days post infection (dpi). Lymphocytes isolated from lung, spleen and blood were stimulated ex vivo with AIV-specific pooled or individual peptides and the production of IFNγ was determined by ELIspot. This resulted in the identification of 12 MHC B12-restricted, 3 B4-restricted and 1 B19-restricted AIV- specific CD8+ T-cell epitopes. In conclusion, we have identified novel AIV-derived CD8+ T-cell epitopes for several inbred chicken strains. This knowledge can be used to study the role of CD8+ T cells against AIV infection in a natural host for influenza, and may be important for vaccine development.

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Screening of MHC B12-restricted CD8+ T-cell epitopes using individual peptides.Lung cells were isolated, in vitro re-stimulated with B12-restricted peptide pools and IFNγ-producing cells were determined by IFNγ ELIspot analysis at 7 dpi (A) and 10 dpi (B). Mean plus SEM is shown, n = 4 per group. Positive responses (*) and “significant” peptides inducing a positive response in 2 out of 3 chickens (↓) are indicated.
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pone-0031953-g004: Screening of MHC B12-restricted CD8+ T-cell epitopes using individual peptides.Lung cells were isolated, in vitro re-stimulated with B12-restricted peptide pools and IFNγ-producing cells were determined by IFNγ ELIspot analysis at 7 dpi (A) and 10 dpi (B). Mean plus SEM is shown, n = 4 per group. Positive responses (*) and “significant” peptides inducing a positive response in 2 out of 3 chickens (↓) are indicated.

Mentions: The initial screening of pools of predicted B12-restricted peptides resulted in 14 candidate epitopes. These peptides were tested individually together with a peptide from a pool that was not significantly positive in the first screening as a negative control. At 7 dpi, all 14 peptides induced IFNγ-producing cells in the lung, and 8 peptides were significantly positive (Fig. 4A). Also in PBMC many peptides tested significantly positive (Fig. S1C). Six peptides were both significantly positive in lung and PBMC (A1, A5, A6, A7, A11, F7, Table 1), 1 peptide was significantly positive in lung only (B6, Table 1) and 4 peptides were significantly positive only in PBMC (A12, B5, F2, F3, Table 1). However, these peptides induced IFNγ production in lung cells as well, but this was not significant. At 10 dpi, the numbers of spots were lower compared to 7 dpi both in the lung (Fig. 4B) and PBMC (Fig. S1D). Also the number of significantly positive peptides had decreased: 1 peptide was still positive in the lung while 5 peptides tested positive in PBMC. Again, the peptide that was recognized by CD8+ T cells in the lung was recognized also by CD8+ T cells in PBMC and the peptides found positive in PBMC did induce IFNγ-producing cells in the lung also but, based on our criteria, failed to test significantly positive. Individual testing of the B4-restricted candidate epitopes on frozen lung cells resulted in 3 significantly positive peptides (Fig. 5).


Identification of novel avian influenza virus derived CD8+ T-cell epitopes.

Reemers SS, van Haarlem DA, Sijts AJ, Vervelde L, Jansen CA - PLoS ONE (2012)

Screening of MHC B12-restricted CD8+ T-cell epitopes using individual peptides.Lung cells were isolated, in vitro re-stimulated with B12-restricted peptide pools and IFNγ-producing cells were determined by IFNγ ELIspot analysis at 7 dpi (A) and 10 dpi (B). Mean plus SEM is shown, n = 4 per group. Positive responses (*) and “significant” peptides inducing a positive response in 2 out of 3 chickens (↓) are indicated.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3285639&req=5

pone-0031953-g004: Screening of MHC B12-restricted CD8+ T-cell epitopes using individual peptides.Lung cells were isolated, in vitro re-stimulated with B12-restricted peptide pools and IFNγ-producing cells were determined by IFNγ ELIspot analysis at 7 dpi (A) and 10 dpi (B). Mean plus SEM is shown, n = 4 per group. Positive responses (*) and “significant” peptides inducing a positive response in 2 out of 3 chickens (↓) are indicated.
Mentions: The initial screening of pools of predicted B12-restricted peptides resulted in 14 candidate epitopes. These peptides were tested individually together with a peptide from a pool that was not significantly positive in the first screening as a negative control. At 7 dpi, all 14 peptides induced IFNγ-producing cells in the lung, and 8 peptides were significantly positive (Fig. 4A). Also in PBMC many peptides tested significantly positive (Fig. S1C). Six peptides were both significantly positive in lung and PBMC (A1, A5, A6, A7, A11, F7, Table 1), 1 peptide was significantly positive in lung only (B6, Table 1) and 4 peptides were significantly positive only in PBMC (A12, B5, F2, F3, Table 1). However, these peptides induced IFNγ production in lung cells as well, but this was not significant. At 10 dpi, the numbers of spots were lower compared to 7 dpi both in the lung (Fig. 4B) and PBMC (Fig. S1D). Also the number of significantly positive peptides had decreased: 1 peptide was still positive in the lung while 5 peptides tested positive in PBMC. Again, the peptide that was recognized by CD8+ T cells in the lung was recognized also by CD8+ T cells in PBMC and the peptides found positive in PBMC did induce IFNγ-producing cells in the lung also but, based on our criteria, failed to test significantly positive. Individual testing of the B4-restricted candidate epitopes on frozen lung cells resulted in 3 significantly positive peptides (Fig. 5).

Bottom Line: Epitope predictions based on anchor residues resulted in 33 candidate epitopes.This resulted in the identification of 12 MHC B12-restricted, 3 B4-restricted and 1 B19-restricted AIV- specific CD8+ T-cell epitopes.In conclusion, we have identified novel AIV-derived CD8+ T-cell epitopes for several inbred chicken strains.

View Article: PubMed Central - PubMed

Affiliation: Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.

ABSTRACT
Avian influenza virus (AIV) infection is a continuing threat to both humans and poultry. Influenza virus specific CD8+ T cells are associated with protection against homologous and heterologous influenza strains. In contrast to what has been described for humans and mice, knowledge on epitope-specific CD8+ T cells in chickens is limited. Therefore, we set out to identify AIV-specific CD8+ T-cell epitopes. Epitope predictions based on anchor residues resulted in 33 candidate epitopes. MHC I inbred chickens were infected with a low pathogenic AIV strain and sacrificed at 5, 7, 10 and 14 days post infection (dpi). Lymphocytes isolated from lung, spleen and blood were stimulated ex vivo with AIV-specific pooled or individual peptides and the production of IFNγ was determined by ELIspot. This resulted in the identification of 12 MHC B12-restricted, 3 B4-restricted and 1 B19-restricted AIV- specific CD8+ T-cell epitopes. In conclusion, we have identified novel AIV-derived CD8+ T-cell epitopes for several inbred chicken strains. This knowledge can be used to study the role of CD8+ T cells against AIV infection in a natural host for influenza, and may be important for vaccine development.

Show MeSH
Related in: MedlinePlus