Cell surface expression of the bovine leukemia virus-binding receptor on B and T lymphocytes is induced by receptor engagement.

Abstract

Bovine leukemia virus (BLV), one of the most common infectious viruses of cattle, is endemic in many herds. Approximately 30-40% of adult cows in the United States are infected by this oncogenic C-type retrovirus and 1-5% of animals will eventually develop a malignant lymphoma. BLV, like the human and simian T cell leukemia viruses, is a deltaretrovirus but, in contrast with the latter, the BLV receptor remains unidentified. In this study, we demonstrate that the amino-terminal 182 residues of the BLV envelope glycoprotein surface unit encompasses the receptor-binding domain. A bona fide interaction of this receptor-binding domain with the BLV receptor was demonstrated by specific interference with BLV, but not human T cell leukemia virus, envelope glycoprotein-mediated binding. We generated a rabbit Ig Fc-tagged BLV receptor-binding domain construct and ascertained that the ligand binds the BLV receptor on target cells from multiple species. Using this tool, we determined that the BLV-binding receptor is expressed on differentiating pro/pre-B cells in mouse bone marrow. However, the receptor was not detected on mature/quiescent B cells but was induced upon B cell activation. Activation of human B and T lymphocytes also induced surface BLV-binding receptor expression and required de novo protein synthesis. Receptor levels were down-regulated as activated lymphocytes returned to quiescence. In the human thymus, BLV-binding receptor expression was specifically detected on thymocytes responding to the IL-7 cytokine. Thus, expression of the BLV-binding receptor is a marker of enhanced metabolic activity in B cells, T cells, and thymocytes.

• Authors: Madakasira Lavanya, Sandrina Kinet, Amélie Montel-Hagen, Cédric Mongellaz, Jean-Luc Battini, Marc Sitbon, Naomi Taylor
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 181 Issue 2 Pg. 891-8 (Jul 15 2008) ISSN: 1550-6606 [Electronic] United States
• PMID: 18606640 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antigens, CD
• BLVR protein, Bos taurus
• Interleukin-7
• Receptors, Virus
• Recombinant Fusion Proteins
• Viral Envelope Proteins

Topics

• Animals
• Antigens, CD (immunology, metabolism)
• B-Lymphocytes (immunology, metabolism)
• Cattle
• Cell Line, Tumor
• Cells, Cultured
• Deltaretrovirus (immunology, metabolism)
• Humans
• Interleukin-7 (immunology, metabolism)
• Leukemia Virus, Bovine (chemistry, immunology, metabolism)
• Lymphocyte Activation
• Mice
• Protein Structure, Tertiary
• Rabbits
• Receptors, Virus (metabolism)
• Recombinant Fusion Proteins (metabolism)
• T-Lymphocytes (immunology, metabolism)
• Thymus Gland
• Up-Regulation
• Viral Envelope Proteins (chemistry, metabolism)