ABSTRACT
The envelope protein (Env) of the Jaagsiekte sheep retrovirus (JSRV) is known to be a unique oncoprotein responsible for inducing ovine pulmonary adenocarcinoma (OPA). The objective of this study was to prepare a specific monoclonal antibody (mAb) against the JSRV Env protein using bioinformatic analysis. According to the structure and epitope prediction results of JSRV Env, the JSRV-Env572-615 antigen was prepared via peptide synthesis (amino acid sequence 572-615, denoted as JSRV-Env572-615). BALB/c mice were immunized to prepare the anti-JSRV-Env572-615 mAb. Spleen cells were fused with SP2/0 myeloma cells after being screened by indirect ELISA and cloned by limiting dilution. The specificity of mAb was evaluated by western blot analysis and immunohistochemistry assays. Western blot results showed that the JSRV Env protein was able to bind to mAb with high specificity. Immunohistochemistry assays demonstrated that the mAb was able to recognize JSRV Env in adenomatous hyperplasia of the lung. Furthermore, JSRV was detected in peripheral blood leukocytes during the pre-clinical period of OPA in 2 of the 25 sheep using this newly synthesized mAb. Therefore, this mAb may be a useful tool for the detection of JSRV in sheep.
Subject(s)
Adenocarcinoma/diagnosis , Adenocarcinoma/veterinary , Antibodies, Monoclonal/biosynthesis , Antibodies, Viral/biosynthesis , Jaagsiekte sheep retrovirus/immunology , Lung Neoplasms/diagnosis , Lung Neoplasms/veterinary , Pulmonary Adenomatosis, Ovine/diagnosis , Adenocarcinoma/immunology , Adenocarcinoma/virology , Adenocarcinoma of Lung , Amino Acid Sequence , Animals , Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/isolation & purification , Antibodies, Viral/chemistry , Antibodies, Viral/isolation & purification , Antibody Specificity , Computational Biology , Early Diagnosis , Epitopes/chemistry , Epitopes/immunology , Gene Products, env/chemistry , Gene Products, env/immunology , Jaagsiekte sheep retrovirus/isolation & purification , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/virology , Lung/immunology , Lung/virology , Lung Neoplasms/immunology , Lung Neoplasms/virology , Mice , Mice, Inbred BALB C , Peptides/administration & dosage , Peptides/chemical synthesis , Peptides/immunology , Pulmonary Adenomatosis, Ovine/immunology , Pulmonary Adenomatosis, Ovine/virology , Sheep , Sheep, Domestic , Spleen/cytology , Spleen/immunologyABSTRACT
An outbreak of pulmonary adenomatosis (OPA) occurred in sheep in Patagonia, Argentina's southernmost region. On the affected farm, nine animals died over a 6-month period with pulmonary lesions of OPA. In all cases, the histology of the lungs was characterized by proliferation of cuboideal and prismatic cells lining the alveoli. Inflammatory exudates and accumulation of alveolar macrophages were marked in most cases, but in six of the cases there was no excess fluid in the airways. The presence of the Jaagsiekte retrovirus was demonstrated in the lungs by immunocytochemistry and PCR. To the best of our knowledge, this is the first report of OPA in Patagonia.