Effects of a single intranasal dose of modified-live bovine respiratory syncytial virus vaccine on cytokine messenger RNA expression following viral challenge in calves.
OBJECTIVE
To characterize cytokine messenger RNA (mRNA) expression in intranasally vaccinated calves after bovine respiratory syncytial virus (BRSV) challenge.


METHODS
Twelve 8- to 12-week-old calves.


METHODS
Calves received modified-live BRSV vaccine (vaccinated) or spent tissue culture medium (mock-vaccinated) intranasally, followed by challenge 30 days later with BRSV, or mock challenge with spent tissue culture medium (mock-challenge controls). Interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) mRNA was measured in lungs, bronchoalveolar lavage (BAL) fluid cells, pharyngeal tonsils, and tracheobronchial lymph nodes, and tumor necrosis factor-alpha (TNF-alpha) mRNA was measured in lungs and BAL fluid cells by reverse transcriptase-competitive polymerase chain reaction assay.


RESULTS
Resistance to clinical signs of disease was conferred in vaccinated calves. Expression of TNF-alpha mRNA in lungs and BAL fluid cells was higher in mock-vaccinated calves than control or vaccinated calves. In the lung, IL-4 mRNA expression was higher in vaccinated calves than control or mock-vaccinated calves. In pharyngeal tonsils, expression of mRNA for IL-4 and IFN-gamma was higher in mock-vaccinated calves than control calves. In tracheobronchial lymph nodes, IFN-gamma mRNA expression was higher in mock-vaccinated calves than vaccinated calves.


CONCLUSIONS
Although vaccinated calves had decreased clinical signs of disease after BRSV challenge, compared with mock-vaccinated calves, this difference was not related to a T helper type 1 bias, as determined by increased expression of interferon-gamma mRNA relative to interleukin-4 mRNA in lungs, BAL fluid cells, or tracheobronchial lymph nodes of vaccinated calves. Pulmonary inflammation was decreased in vaccinated calves as determined by decreased expression of TNF-alpha mRNA.
Miao
Congrong
C
Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
Woolums
Amelia R
AR
Zarlenga
Dante S
DS
Brown
Corrie C
CC
Brown
James C
JC
Williams
Shamita M
SM
Scott
Melissa A
MA
D000281:Administration, Intranasal; D000818:Animals; D018893:Bronchoalveolar Lavage; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology* / Q000517:prevention & control; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers; D004587:Electrophoresis, Agar Gel; D007371:Interferon-gamma; D015847:Interleukin-4; D008168:Lung / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D018357:Respiratory Syncytial Virus Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D022261:Respiratory Syncytial Virus Vaccines / Q000008:administration & dosage*; D018112:Respiratory Syncytial Virus, Bovine / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha
D016207:Cytokines; D017931:DNA Primers; D012333:RNA, Messenger; D022261:Respiratory Syncytial Virus Vaccines; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D007371:Interferon-gamma