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Robust intrapulmonary CD8 T cell responses and protection with an attenuated N1L deleted vaccinia virus.

Mathew A, O'Bryan J, Marshall W, Kotwal GJ, Terajima M, Green S, Rothman AL, Ennis FA - PLoS ONE (2008)

Bottom Line: Vaccinia viruses have been used as a model for viral disease and as a protective live vaccine.Infection by the intranasal, intraperitoneal, and tail scarification routes resulted in the robust induction of cytolytic virus-specific CD8 T cells in the spleens and the lungs.These results indicate that the attenuated vGK5 virus protects against subsequent infection and suggest that the N1L protein limits the strength of the early antiviral CD8 T cell response following respiratory infection.

View Article: PubMed Central - PubMed

Affiliation: Center for Infectious Disease and Vaccine Research, University of Massachusetts Medical School, Worcester, Massachusetts, USA. anuja.mathew@umassmed.edu

ABSTRACT

Background: Vaccinia viruses have been used as a model for viral disease and as a protective live vaccine.

Methodology and principal findings: We investigated the immunogenicity of an attenuated strain of vaccinia virus engineered to inactivate the N1L gene (vGK5). Using the intranasal route, this recombinant virus was 2 logs less virulent compared to the wildtype VACV-WR. Infection by the intranasal, intraperitoneal, and tail scarification routes resulted in the robust induction of cytolytic virus-specific CD8 T cells in the spleens and the lungs. VACV-specific antibodies were also detected in the sera of mice infected 3-5 months prior with the attenuated vGK5 virus. Finally, mice immunized with vGK5 were significantly protected when challenged with a lethal dose of VACV-WR.

Conclusions: These results indicate that the attenuated vGK5 virus protects against subsequent infection and suggest that the N1L protein limits the strength of the early antiviral CD8 T cell response following respiratory infection.

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Related in: MedlinePlus

Cytokine responses and cytolytic activity in target organs.(A) IFN-γ responses of splenocytes from intranasally infected mice were measured in response to 3 VACV-specific CD8 T cell peptides (1 µg/ml) in an Elispot assay. Assays were performed using triplicate wells for each condition and individual mice/group. * = no responses detected. Seven days post infection, (B) splenocytes and (C) lung lymphocytes were isolated and CTL assays were carried out using RMA cells infected with VACV-WR (moi = 5), vGK5 (moi = 5) at different effector to target (E/T) ratios. Data shown are 1of 2 experiments performed. (D) PRNT50 antibody titers were measured in the sera of mice immunized 5 months prior with varying doses of vGK5 or 103.5 PFU of VACV-WR (n = 5/group).
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pone-0003323-g003: Cytokine responses and cytolytic activity in target organs.(A) IFN-γ responses of splenocytes from intranasally infected mice were measured in response to 3 VACV-specific CD8 T cell peptides (1 µg/ml) in an Elispot assay. Assays were performed using triplicate wells for each condition and individual mice/group. * = no responses detected. Seven days post infection, (B) splenocytes and (C) lung lymphocytes were isolated and CTL assays were carried out using RMA cells infected with VACV-WR (moi = 5), vGK5 (moi = 5) at different effector to target (E/T) ratios. Data shown are 1of 2 experiments performed. (D) PRNT50 antibody titers were measured in the sera of mice immunized 5 months prior with varying doses of vGK5 or 103.5 PFU of VACV-WR (n = 5/group).

Mentions: We assessed the ability of splenocytes from mice infected intranasally with different doses of vGK5 to secrete IFN-γ in response to the B8R20–27 peptide as well as two additional VACV-specific peptides K3L6–15 and A47L138–146 [20]. Frequencies of IFN-γ secreting cells to all 3 peptides were significantly higher in mice infected with 106 PFU than lower doses of vGK5 (Fig. 3A). Similar responses were detected in mice infected with 103.5 or 104.5 PFU of vGK5 to all peptides. A cardinal property of activated CD8 T cells during acute viral infections is their ability to lyse and eliminate virus infected cells. Splenocytes and lung lymphocytes from mice infected by the i.n. route were therefore tested for their ability to lyse virus infected target cells in ex vivo CTL assays. Splenocytes from mice infected with 103.5, 104.5 and 106 PFU of vGK5 all effectively lysed virus infected target cells (Fig. 3B). No CTL activity was detected in the spleens of mice infected with 102.5 PFU of vGK5 (data not shown). CTL activity was only detected in lung lymphocytes of mice infected with 106 and 104.5 PFU of vGK5 by the i.n. route (Fig. 3C). Our data thus far indicated that T lymphocytes in the spleens and lungs of mice immunized with vGK5 were activated, elicited cytokine responses to VACV-specific peptides and had lytic activity against virus infected cells.


Robust intrapulmonary CD8 T cell responses and protection with an attenuated N1L deleted vaccinia virus.

Mathew A, O'Bryan J, Marshall W, Kotwal GJ, Terajima M, Green S, Rothman AL, Ennis FA - PLoS ONE (2008)

Cytokine responses and cytolytic activity in target organs.(A) IFN-γ responses of splenocytes from intranasally infected mice were measured in response to 3 VACV-specific CD8 T cell peptides (1 µg/ml) in an Elispot assay. Assays were performed using triplicate wells for each condition and individual mice/group. * = no responses detected. Seven days post infection, (B) splenocytes and (C) lung lymphocytes were isolated and CTL assays were carried out using RMA cells infected with VACV-WR (moi = 5), vGK5 (moi = 5) at different effector to target (E/T) ratios. Data shown are 1of 2 experiments performed. (D) PRNT50 antibody titers were measured in the sera of mice immunized 5 months prior with varying doses of vGK5 or 103.5 PFU of VACV-WR (n = 5/group).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2553181&req=5

pone-0003323-g003: Cytokine responses and cytolytic activity in target organs.(A) IFN-γ responses of splenocytes from intranasally infected mice were measured in response to 3 VACV-specific CD8 T cell peptides (1 µg/ml) in an Elispot assay. Assays were performed using triplicate wells for each condition and individual mice/group. * = no responses detected. Seven days post infection, (B) splenocytes and (C) lung lymphocytes were isolated and CTL assays were carried out using RMA cells infected with VACV-WR (moi = 5), vGK5 (moi = 5) at different effector to target (E/T) ratios. Data shown are 1of 2 experiments performed. (D) PRNT50 antibody titers were measured in the sera of mice immunized 5 months prior with varying doses of vGK5 or 103.5 PFU of VACV-WR (n = 5/group).
Mentions: We assessed the ability of splenocytes from mice infected intranasally with different doses of vGK5 to secrete IFN-γ in response to the B8R20–27 peptide as well as two additional VACV-specific peptides K3L6–15 and A47L138–146 [20]. Frequencies of IFN-γ secreting cells to all 3 peptides were significantly higher in mice infected with 106 PFU than lower doses of vGK5 (Fig. 3A). Similar responses were detected in mice infected with 103.5 or 104.5 PFU of vGK5 to all peptides. A cardinal property of activated CD8 T cells during acute viral infections is their ability to lyse and eliminate virus infected cells. Splenocytes and lung lymphocytes from mice infected by the i.n. route were therefore tested for their ability to lyse virus infected target cells in ex vivo CTL assays. Splenocytes from mice infected with 103.5, 104.5 and 106 PFU of vGK5 all effectively lysed virus infected target cells (Fig. 3B). No CTL activity was detected in the spleens of mice infected with 102.5 PFU of vGK5 (data not shown). CTL activity was only detected in lung lymphocytes of mice infected with 106 and 104.5 PFU of vGK5 by the i.n. route (Fig. 3C). Our data thus far indicated that T lymphocytes in the spleens and lungs of mice immunized with vGK5 were activated, elicited cytokine responses to VACV-specific peptides and had lytic activity against virus infected cells.

Bottom Line: Vaccinia viruses have been used as a model for viral disease and as a protective live vaccine.Infection by the intranasal, intraperitoneal, and tail scarification routes resulted in the robust induction of cytolytic virus-specific CD8 T cells in the spleens and the lungs.These results indicate that the attenuated vGK5 virus protects against subsequent infection and suggest that the N1L protein limits the strength of the early antiviral CD8 T cell response following respiratory infection.

View Article: PubMed Central - PubMed

Affiliation: Center for Infectious Disease and Vaccine Research, University of Massachusetts Medical School, Worcester, Massachusetts, USA. anuja.mathew@umassmed.edu

ABSTRACT

Background: Vaccinia viruses have been used as a model for viral disease and as a protective live vaccine.

Methodology and principal findings: We investigated the immunogenicity of an attenuated strain of vaccinia virus engineered to inactivate the N1L gene (vGK5). Using the intranasal route, this recombinant virus was 2 logs less virulent compared to the wildtype VACV-WR. Infection by the intranasal, intraperitoneal, and tail scarification routes resulted in the robust induction of cytolytic virus-specific CD8 T cells in the spleens and the lungs. VACV-specific antibodies were also detected in the sera of mice infected 3-5 months prior with the attenuated vGK5 virus. Finally, mice immunized with vGK5 were significantly protected when challenged with a lethal dose of VACV-WR.

Conclusions: These results indicate that the attenuated vGK5 virus protects against subsequent infection and suggest that the N1L protein limits the strength of the early antiviral CD8 T cell response following respiratory infection.

Show MeSH
Related in: MedlinePlus