Robust Intrapulmonary CD8 T Cell Responses and Protection with an Attenuated N1L Deleted Vaccinia Virus

Center for Infectious Disease and Vaccine Research, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
PLoS ONE (Impact Factor: 3.23). 02/2008; 3(10):e3323. DOI: 10.1371/journal.pone.0003323
Source: PubMed


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

Download full-text


Available from: Anuja Mathew, Feb 04, 2015
  • Source
    • "As such, N1L has been hypothesized and shown to impair NF-kB signalling mediated by the engagement of TNFa receptors, TLRs, and lymphotoxin receptors (DiPerna et al., 2004), as well as to impair the production of anti-inflammatory cytokines that are NF-kB-dependent (Zhang et al., 2005). To this end, N1L has also been shown to strongly modulate the host immune response (Jacobs et al., 2008; Mathew et al., 2008). A direct interaction between N1L and IKKa, IKKb, IKKg and TANK-binding kinase 1 (TBK1) has been observed and suggested to account for N1L inhibitory effects on NF-kB activation (DiPerna et al., 2004). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Viruses are the most abundant and diverse pathogens challenging the host immune system, and as such are a severe threat to human health. To this end, viruses have evolved multiple strategies to evade and subvert the host immune response. Host-pathogen interactions are usually initiated via recognition of pathogen-associated molecular patterns (PAMPs) by host sensors known as pattern recognition receptors (PRRs), which include, Toll-like receptors (TLRs), RIG-I-like receptors (RLRs), NOD-like receptors (NLRs) and DNA receptors. Effective sensing of PAMPs rapidly triggers host immune responses, via activation of complex signalling pathways that culminates in the induction of inflammatory responses and the eradication of pathogens. Activation of the nuclear factor-κB (NF-κB) transcription pathway is crucial for the immediate early step of immune activation. This review discusses the recent evidence describing a variety of viral effectors that have been shown to prevent NF-κB signalling. Most of these viral effectors can be broadly classified into three categories based on the site of inhibition within the NF-κB pathway, that is, at the (i) TLRs, (ii) IKK complex or (iii) the transcriptional level.
    Preview · Article · Nov 2011 · Cellular Microbiology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Vaccinia virus (VACV) elicits a robust CD8 T cell response that plays an important role in host resistance. To date, there is little information on the molecules that are essential to generate large pools of VACV-specific effector CD8 T cells. In this study, we show that the adaptor molecule MyD88 is critical for the magnitude of primary CD8 T cell responses to both dominant and subdominant VACV epitopes. MyD88(-/-) mice exhibit profound reduction in CD8 T cell expansion and antiviral cytokine production. Surprisingly, the defect was not due to impaired APC function, as MyD88(-/-) dendritic cells matured normally and were able to promote strong CD8 T cell priming following VACV infection. Rather, adoptive transfer experiments demonstrated that intrinsic MyD88-dependent pathways in CD8 T cells were critical. MyD88-deficient CD8 T cells failed to accumulate in wild-type hosts and poor expansion of MyD88-deficient VACV-specific CD8 T cells resulted after virus infection. In contrast, no defect was evident in the absence of TRIF, TLR2, TLR4, TLR9, and IL-1R. Together, our results highlight an important role for MyD88 in initial antiviral CD8 T cell responses and suggest that targeting this pathway may be useful in promoting and sustaining anti-VACV immunity.
    Full-text · Article · Jun 2009 · The Journal of Immunology
  • [Show abstract] [Hide abstract]
    ABSTRACT: Neurovirulence is one of the pathological complications associated with vaccinia virus (VV) infection/vaccination. Although the viral N1L protein has been identified as the neurovirulence factor, none of the host N1L-interacting factors have been identified so far. In the present study, we identified N1L-interacting proteins by screening a human brain cDNA expression library with N1L as a bait protein in a yeast two-hybrid analysis. The analysis revealed that N1L interacts with human brain-originated cellular basement membrane-associated chondroitin sulfate proteoglycan (bamacan). The N1L-binding domain of bamacan was mapped to its C-terminal 227 amino acids. The N1L-bamacan interaction was further confirmed in both VV-infected and N1L-transfected mammalian cells. Following the confirmation of the protein interactions by coimmunoprecipitation experiments, confocal microscopic analysis revealed that N1L colocalizes with bamacan both in VV-infected B-SC-1 cells as well as in mice neuronal tissue. Furthermore, a human neural cell line, which expresses bamacan to moderately elevated levels relative to a non-neural cell line, supported enhanced viral growth. Overall, these studies clearly suggest that bamacan interacts with the VV-N1L and such interactions seem to play a positive role in promoting the viral growth and perhaps contribute to the virulence of VV in neural cells.
    No preview · Article · Jun 2009 · Journal of NeuroVirology
Show more