Interferon-gamma expression associated with suppression of bovine leukemia virus at the early phase of infection in sheep.
Immunological control of bovine leukemia virus (BLV)-infection has been reported as dependent on the expression balance of types 1 and 2 cytokines. In this report, mRNA expression of interferon (IFN)-gamma and interleukin (IL)-2 (type 1 cytokines), and of IL-4 and IL-10 (type 2 cytokines) were evaluated in concanavalin A-stimulated peripheral blood mononuclear cells (PBMC) from BLV-infected sheep. Despite the same dose of BLV-infection, the extent of viral propagation was markedly different between eight individual sheep by 12 weeks post infection. The virus did not propagate well in three sheep, which showed augmented mRNA expression of IFN-gamma, a strong indicator of cell-mediated immunity, immediately after BLV-infection. Among the other five sheep having more than 2% of BLV-infected cells among PBMC at 12 weeks post infection, four sheep developed B-cell leukemia or lymphoma within 2 years after infection. These observations indicate IFN-gamma expression may play an important role in the protective mechanism against BLV propagation at the early phase of the infection.
Usui
Tatsufumi
T
Laboratory of Infectious Diseases, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
Konnai
Satoru
S
Ohashi
Kazuhiko
K
Onuma
Misao
M
D000818:Animals; D002417:Cattle; D016583:Enzootic Bovine Leukosis / Q000276:immunology*; D007371:Interferon-gamma / Q000235:genetics*; D016753:Interleukin-10 / Q000235:genetics; D007376:Interleukin-2 / Q000235:genetics; D015847:Interleukin-4 / Q000235:genetics; D001909:Leukemia Virus, Bovine; D012333:RNA, Messenger / Q000032:analysis; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology*
D007376:Interleukin-2; D012333:RNA, Messenger; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma