Up-regulation of tumor necrosis factor alpha mRNA is associated with bovine-leukemia virus (BLV) elimination in the early phase of infection.
Protective immune responses were analyzed in eight sheep vaccinated with BLV envelope peptides and experimentally infected with bovine-leukemia virus (BLV). Five of eight peptide-immunized sheep showed a high T-cell proliferative response to the BLV peptides and all of these were protected from the infection. The other three peptide-immunized sheep showed no T-cell proliferative responses to any BLV antigens similar to control sheep, though they also exhibited resistance to BLV challenge. To investigate other mechanisms which suppress BLV expansion in these non-responding sheep, we measured the levels of the cytokine expressions before, and after, BLV challenge using competitive reverse-transcriptase polymerase chain-reaction systems. It was revealed that the expression of tumor necrosis factor alpha (TNFalpha) was higher in BLV-resistant sheep than in BLV-susceptible sheep. Thus, TNFalpha expression rather than specific T-cell activity may play an important role in the protective mechanism against BLV infection, at least during the primary viremia phase.
Kabeya
H
H
Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Ohashi
K
K
Oyunbileg
N
N
Nagaoka
Y
Y
Aida
Y
Y
Sugimoto
C
C
Yokomizo
Y
Y
Onuma
M
M
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D016583:Enzootic Bovine Leukosis / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D007114:Immunization / Q000662:veterinary; D001909:Leukemia Virus, Bovine / Q000302:isolation & purification / Q000502:physiology*; D008213:Lymphocyte Activation; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology; D012333:RNA, Messenger / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D013601:T-Lymphocytes / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation; D014759:Viral Envelope Proteins / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage*
D010446:Peptide Fragments; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D014759:Viral Envelope Proteins; D014765:Viral Vaccines