Host responses contributing to the attenuation of severe acute respiratory syndrome coronaviruses missing E protein domains
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ABSTRACT: Severe acute respiratory syndrome coronavirus (SARS-CoV) causes a respiratory disease leading to death in 10% of the infected people. A mouse adapted SARS-CoV lacking the envelope (E) protein (rSARS-CoV-MA15-ΔE) is attenuated in vivo. To identify E protein domains and host responses that contribute to rSARS-CoV-MA15-ΔE attenuation, several mutants (rSARS-CoV-MA15-E*) containing point mutations or deletions in the amino-terminal or the carboxy-terminal regions of E protein, respectively, were generated. Amino acid substitutions in the amino terminus, or deletion of domains in the internal carboxy terminal region of E protein led to viral attenuation. Attenuated viruses induced minimal lung injury and limited neutrophil influx to the lungs but, interestingly, increased CD4+ and CD8+ T cell counts in BALB/c mice. To analyze the host responses leading to rSARS-CoV-MA15-E* attenuation, the differential gene expression elicited by the native virus and the mutant ones in infected cells was analyzed. The expression levels of a large number of proinflammatory cytokines inducing lung injury was reduced in the lungs of rSARS-CoV-MA15-E* infected mice, whereas the levels of anti-inflammatory cytokines were increased, both at the mRNA and protein levels. These results suggested that the reduction in lung inflammation together with a specific antiviral T cell response, contributed to rSARS-CoV-MA15-E* attenuation. Interestingly, the attenuated viruses completely protected mice against the challenge with the lethal parental virus, being promising vaccine candidates.
ORGANISM(S): Mus musculus
PROVIDER: GSE59185 | GEO | 2015/05/19
SECONDARY ACCESSION(S): PRJNA254698
REPOSITORIES: GEO
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