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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

Tetramer frequencies following i.n. infection with vGK5.Mice were infected with varying doses of vGK5 by the i.n. route. (A) We used a gating strategy to identify live CD3+CD8+ T lymphocytes (live dead aqua negative and forward scatter positive; CD3+CD8+). Frequencies of B8R20–27 tetramer+ T cells were assessed in the (B) splenocytes and (C) lung lymphocytes 7 days after i.n. infection. (D) The absolute numbers of B8R20–27 tetramer+ T cells in the lung following i.n. infection. Each symbol represents the frequency of tetramer+ T cells obtained in target organs of individual mice; median values are denoted by horizontal lines.
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pone-0003323-g002: Tetramer frequencies following i.n. infection with vGK5.Mice were infected with varying doses of vGK5 by the i.n. route. (A) We used a gating strategy to identify live CD3+CD8+ T lymphocytes (live dead aqua negative and forward scatter positive; CD3+CD8+). Frequencies of B8R20–27 tetramer+ T cells were assessed in the (B) splenocytes and (C) lung lymphocytes 7 days after i.n. infection. (D) The absolute numbers of B8R20–27 tetramer+ T cells in the lung following i.n. infection. Each symbol represents the frequency of tetramer+ T cells obtained in target organs of individual mice; median values are denoted by horizontal lines.

Mentions: In order to more carefully dissect out the immunogenicity of the attenuated N1L deleted VACV, we infected mice with varying sublethal doses of vGK5 (106, 104.5, 103.5 and 102.5) by the i.n. route. To measure frequencies of antigen-specific T cells in target organs, we obtained a tetramer directed against the immunodominant epitope B8R20–27 described in H-2b mice [20]. Using the gating strategy shown in Fig. 2A, the highest frequencies of tetramer+ T cells were detected in spleens of mice that were infected with 106 and 104.5 PFU of vGK5 (Fig. 2B). Frequencies of B8R20–27 -specific tetramer+T cells were lower in mice infected with 103.5 PFU of vGK5 and near background levels with 102.5 of vGK5. Lungs of mice infected with 106 PFU of vGK5 also had the highest frequencies (Fig. 2C) as well as total number of tetramer+ T cells (Fig. 2D) compared to lungs of mice infected with lower doses of virus. All of the tetramer positive cells expressed high levels of the activation marker CD44 (data not shown). The data suggest that administration of the attenuated vGK5 by the i.n. route induced robust activation of CD8 T cells in mucosal and systemic sites.


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)

Tetramer frequencies following i.n. infection with vGK5.Mice were infected with varying doses of vGK5 by the i.n. route. (A) We used a gating strategy to identify live CD3+CD8+ T lymphocytes (live dead aqua negative and forward scatter positive; CD3+CD8+). Frequencies of B8R20–27 tetramer+ T cells were assessed in the (B) splenocytes and (C) lung lymphocytes 7 days after i.n. infection. (D) The absolute numbers of B8R20–27 tetramer+ T cells in the lung following i.n. infection. Each symbol represents the frequency of tetramer+ T cells obtained in target organs of individual mice; median values are denoted by horizontal lines.
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Related In: Results  -  Collection

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

pone-0003323-g002: Tetramer frequencies following i.n. infection with vGK5.Mice were infected with varying doses of vGK5 by the i.n. route. (A) We used a gating strategy to identify live CD3+CD8+ T lymphocytes (live dead aqua negative and forward scatter positive; CD3+CD8+). Frequencies of B8R20–27 tetramer+ T cells were assessed in the (B) splenocytes and (C) lung lymphocytes 7 days after i.n. infection. (D) The absolute numbers of B8R20–27 tetramer+ T cells in the lung following i.n. infection. Each symbol represents the frequency of tetramer+ T cells obtained in target organs of individual mice; median values are denoted by horizontal lines.
Mentions: In order to more carefully dissect out the immunogenicity of the attenuated N1L deleted VACV, we infected mice with varying sublethal doses of vGK5 (106, 104.5, 103.5 and 102.5) by the i.n. route. To measure frequencies of antigen-specific T cells in target organs, we obtained a tetramer directed against the immunodominant epitope B8R20–27 described in H-2b mice [20]. Using the gating strategy shown in Fig. 2A, the highest frequencies of tetramer+ T cells were detected in spleens of mice that were infected with 106 and 104.5 PFU of vGK5 (Fig. 2B). Frequencies of B8R20–27 -specific tetramer+T cells were lower in mice infected with 103.5 PFU of vGK5 and near background levels with 102.5 of vGK5. Lungs of mice infected with 106 PFU of vGK5 also had the highest frequencies (Fig. 2C) as well as total number of tetramer+ T cells (Fig. 2D) compared to lungs of mice infected with lower doses of virus. All of the tetramer positive cells expressed high levels of the activation marker CD44 (data not shown). The data suggest that administration of the attenuated vGK5 by the i.n. route induced robust activation of CD8 T cells in mucosal and systemic sites.

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