Submitted to: Annals of the New York Academy of Sciences
Publication Type: Proceedings
Publication Acceptance Date: 7/23/1996
Publication Date: N/A
Citation: N/A Interpretive Summary: Malignant catarrhal fever (MCF) is a serious, globally-distributed viral disease of cattle, deer certain other ruminant animals. The understanding of the disease, particularly of sheep-associated form, is very limited, primarily because of a lack of adequate detection methods for the virus. In this communication, we describe the growth characteristics of a MCF virus and review the diagnostic assays for MCF recently-developed in our laboratory. We produced a panel of monoclonal antibodies to the virus and use these monoclonal antibodies to study how the virus grew in culture and identify which viral proteins could induce protective immune function. A monoclonal antibody to a common component of MCF virus was identified and a diagnostic assay called competitive-inhibition ELISA (CI-ELISA) was developed for detection of anti-MCF antibody in sheep, cattle and other animals. A PCR assay for DNA of the sheep-associated virus was also developed, based on previously-reported primers. Comparative studies demonstrated that the CI-ELISA was useful for detection of MCF viral antibody and that the PCR was more reliable for diagnosis of animals with clinical sheep-associated MCF.
Technical Abstract: Malignant catarrhal fever (MCF) is a severe lymphoproliferative disease of certain domestic and wild ruminants. Two distinct but closely-related viruses cause clinically indistinguishable syndromes in susceptible ruminant species: wildebeest-associated MCF virus and sheep-associated MCF virus. Neither the pathogenesis nor the epidemiology of SA-MCF is understood, primarily because of a lack of adequate detection methods for the etiologic agent or antibody against that agent. Work designed to develop these tests has been underway in our laboratory. To obtain basic information about the virus, the in vitro growth properties of a U.S. isolate of MCF virus were studied and its major viral proteins identified and characterized by a panel of monoclonal antibodies (MAbs) generated against the isolate. A MAb to a broadly conserved epitope of MCF virus was identified and a competitive-inhibition ELISA (CI-ELISA) was developed for detection of anti-MCF antibody in sheep and other ruminants. The MAb 15-A reacted with an epitope located on a glycoprotein complex, which was present in all isolates of MCF virus examined. Antibody from a wide variety of ruminants infected with MCF virus of both sheep and wildebeest origin competed with the MAb 15-A for the epitope. The assay detected antibody in inapparently-infected sheep, and in cattle, deer and bison with clinical MCF. A PCR assay for DNA of the sheep-associated virus was developed, based on previously-reported primers. Comparative studies demonstrated that the CI-ELISA was specific for MCFV antibody and that the PCR was more reliable for diagnosis of clinical MCF.