|Keen James E|
Submitted to: Veterinary Immunology and Immunopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/1994
Publication Date: N/A
Citation: N/A Interpretive Summary: Ovine pulmonary carcinoma (OPC, sheep pulmonary adenomatosis, jaagsiekte) is a naturally occurring lung cancer of sheep. The disease is economically important in Europe, Africa, Asia, and South America, but it has been recognized infrequently in North America. This low reported frequency of OPC in North American sheep may reflect a truly low incidence of the disease or failure to diagnosis it in adult sheep at slaughter. The long incubation period, short life span of most sheep in modern management systems, and an absence of a means to culture this virus makes diagnosis of the disease solely dependent on the end-stage characteristic lesions in the infected lung tissue. Consequently, the OPC virus may enter and spread widely in a flock before the disease is recognized. A simple, rapid, and sensitive immunoassay has been developed for OPC by using genetic engineering techniques to produce a protein unique to the OPC virus. This OPC protein has been incorporated into an assay for detection of OPC in the early phase of the infection. This will make it possible to determine the prevalence of OPC in flocks of sheep and to determine the effect of OPC on sheep production
Technical Abstract: Ovine pulmonary carcinoma (OPC) is caused by a type-D retrovirus inducing pulmonary neoplasia. The major core protein (P27) of the OPC virus cross-reacts with antibodies to P27 of the Mason-Pfizer monkey virus (MPMV), a type-D retrovirus. So far, this serological reactivity serves as the only biological marker for OPC. In order to make a useful reagent for the detection of OPC for serodiagnosis and epidemiological studies, the MPMV-P27 coding region was cloned and expressed in Escherichia coli. Gel purified recombinant MPMV-P27 protein was used to develop an immunoassay. The recombinant enzyme-linked immunosorbent assay (ELISA) was then used to screen 223 sera from U.S. sheep and 176 sera from Italian sheep. In this study, we found: 1) a high prevalence of infection with potential type-D retrovirus in sheep with chronic pneumonia; 2) a subclinical infection with OPC virus may be more common in U.S. sheep than indicated by the rare recorded occurrence of pulmonary carcinoma; and 3) an apparent association between ovine lentivirus (OLV) and OPC infection.