Quantification of mRNA encoding cytokines and chemokines and assessment of ciliary function in canine tracheal epithelium during infection with canine respiratory coronavirus (CRCoV).
One of the first lines of defence against viral infection is the innate immune response and the induction of antiviral type I interferons (IFNs). However some viruses, including the group 2 coronaviruses, have evolved mechanisms to overcome or circumvent the host antiviral response. Canine respiratory coronavirus (CRCoV) has previously been shown to have a widespread international presence and has been implicated in outbreaks of canine infectious respiratory disease (CIRD). This study aimed to quantify pro-inflammatory cytokine mRNAs following infection of canine air-interface tracheal cultures with CRCoV. Within this system, immunohistochemistry identified ciliated epithelial and goblet cells as positive for CRCoV, identical to naturally infected cases, thus the data obtained would be fully transferable to the situation in vivo. An assay of ciliary function was used to assess potential effects of CRCoV on the mucociliary system. CRCoV was shown to reduce the mRNA levels of the pro-inflammatory cytokines TNF-alpha and IL-6 and the chemokine IL-8 during the 72 h post-inoculation. The mechanism for this is unknown, however the suppression of a key antiviral strategy during a period of physiologic and immunological stress, such as on entry to a kennel, could potentially predispose a dog to further pathogenic challenge and the development of respiratory disease.
Priestnall
Simon L
SL
Department of Pathology and Infectious Diseases, The Royal Veterinary College, Hatfield, Hertfordshire, UK. spriestnall@rvc.ac.uk
Mitchell
Judy A
JA
Brooks
Harriet W
HW
Brownlie
Joe
J
Erles
Kerstin
K
D000818:Animals; D001483:Base Sequence; D018925:Chemokines / Q000235:genetics*; D002923:Cilia / Q000502:physiology; D018352:Coronavirus Infections / Q000276:immunology / Q000503:physiopathology / Q000662:veterinary*; D000086462:Coronavirus Nucleocapsid Proteins; D017939:Coronavirus, Canine / Q000235:genetics / Q000302:isolation & purification; D016207:Cytokines / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D004283:Dog Diseases / Q000276:immunology* / Q000503:physiopathology*; D004285:Dogs; D004848:Epithelium / Q000276:immunology / Q000503:physiopathology / Q000821:virology; D005814:Genes, Viral; D015850:Interleukin-6 / Q000235:genetics; D016209:Interleukin-8 / Q000235:genetics; D019590:Nucleocapsid Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D046509:Tissue Culture Techniques; D014132:Trachea / Q000276:immunology* / Q000503:physiopathology* / Q000821:virology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
D018925:Chemokines; D000086462:Coronavirus Nucleocapsid Proteins; D016207:Cytokines; D017931:DNA Primers; D015850:Interleukin-6; D016209:Interleukin-8; D019590:Nucleocapsid Proteins; D012333:RNA, Messenger; D012367:RNA, Viral; D014409:Tumor Necrosis Factor-alpha