title: Expression of tumor necrosis factor-alpha in IgM+ B-cells from bovine leukemia virus-infected lymphocytotic sheep.
abstract: Tumor necrosis factor (TNF)-alpha is thought to be one of the cytokines that account for bovine leukemia virus (BLV)-induced B-cell lymphoproliferative disorder, however, information on TNF-alpha expression in B-cells is limited. In this study, the expression of TNF-alpha in IgM(+) B-cells from BLV-infected sheep with or without lymphocytosis was determined. Freshly isolated IgM(+) B-cells from three sheep with lymphocytosis constitutively transcribed TNF-alpha mRNA. Although TNF-alpha mRNA expression in IgM(+) B-cells was transiently up-regulated after cell culture, TNF-alpha mRNA expression was markedly higher in lymphocytotic sheep when compared to that of non-lymphocytotic sheep or uninfected sheep. Expression of membrane-bound TNF-alpha on IgM(+) B-cells was also augmented in lymphocytotic sheep. TNF-alpha expression in lymphocytotic sheep may support the proliferation of B-cells.
authors.affiliation: Laboratory of Infectious Diseases, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors.forename: Tatsufumi
authors.initials: T
authors.lastname: Usui
authors.forename: Satoru
authors.initials: S
authors.lastname: Konnai
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ohashi
authors.forename: Misao
authors.initials: M
authors.lastname: Onuma
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000821:virology; D017977:Deltaretrovirus / Q000276:immunology*; D006800:Deltaretrovirus Infections / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D005434:Flow Cytometry / Q000662:veterinary; D007075:Immunoglobulin M / Q000096:biosynthesis* / Q000276:immunology; D008213:Lymphocyte Activation; D008218:Lymphocytosis / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology* / Q000821:virology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D014412:Tumor Virus Infections / Q000276:immunology / Q000662:veterinary / Q000821:virology
chemical_list: D007075:Immunoglobulin M; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha