CYTOKINE TRANSCRIPTION IN LYMPH-NODES OF CATTLE IN DIFFERENT STAGES OF BOVINE LEUKEMIA-VIRUS INFECTION

Bovine leukemia virus (BLV) is a transforming oncovirus that contains no oncogenes or preferred site of proviral integration. The role of cy tokines in the disease process of BLV is potentially important due to the similarity of BLV with other retroviruses in which cytokines play a role, such as HTLV-I and -II. Mesenteric and supra-mammary lymph nod es were obtained from a panel of nine cattle. Three were non-infected controls, three were BLV-positive aleukemic (AL), and three were BLV-p ositive persistent lymphocytotic (PL). Mononuclear cells were perfused from the organs and total RNA extracted from either 1 X 10(8) unsepar ated cells or 1 x 10(7) purified CD4/CD8 T-cells. cDNA was generated a nd subjected to RT-PCR to analyze cytokine transcription during diseas e progression. cDNA levels were normalized using beta-actin PCR at sub -plateau cycle number, enabling a semi-quantitative assessment of cyto kine gene transcripts. Using this approach, IL-2, IL-10 and IFN-gamma message was detected in the T-cell fractions of all of the BLV-infecte d animals, but not in the non-infected controls. (C) 1997 Elsevier Sci ence B.V.