PARASITOLOGY, MICROBIOLOGY, AND PUBLIC HEALTH

EFFECT OF DIET ON SUSCEPTIBILITY OF CATTLE TO RESPIRATORY DISEASE

Type of receiving ration significantly affects morbidity and mortality in feedlot cattle. This study will try and determine the underlying reasons for the positive association noted in feedlots between high energy diet and increased susceptibility of calves to bovine respiratory disease (BRD). Calves fed different diets will be infected with both bovine herpesvirus-1 and Pasteurella haemolytica to experimentally induce respiratory disease. Clinical disease, pulmonary lesions, virus and bacterial shedding, and immune responses will be monitored.

Oklahoma Agricultural Experimental Station
Jean d'Offay, Rebecca Morton, Fred Owens, and Roger Panciera

CONSTRUCTION OF A GENE-DELETION BHV-1 VACCINE VIRUS

Bovine herpesvirus type 1 (BHV-1) is one of several viruses that can cause respiratory disease in feedlot cattle. During the course of this project, the Cooper BHV-1 gIII gene was cloned, and a gIII negative (gIII-) construct was made by deleting the gIII coding sequence while retaining the initiation codon and 5' upstream regulatory sequence. This construct is now ready to accept other genes from other bovine respiratory viruses, genes that code for immunogenic proteins that can be translated by BHV-1in vitro for vaccine purposes.

Oklahoma Agricultural Experimental Station
Richard Eberle, Jean d'Offay, and Robert Fulton

DEVELOPMENT OF RAPID DIAGNOSTIC TESTS FOR MONKEY B VIRUS

Monkey B Virus is a herpesvirus of macaques which produces disease very similar to oral/genital herpes of humans. However, when transmitted to humans via bites or scratches, B virus usually produces an extremely severe and usually fatal encephalitic infection. Rapid diagnosis of human B virus cases is essential in order that effective chemotherapy can be initiated at the earliest point possible. Serological diagnosis of B virus infections has been difficult due to the time required for antibodies to appear following infection and the extensive antigenic crossreactivity that exists between the two human herpesviruses (HSV1 and HSV2) to which most humans have antibody. The goal of this research program is to develop rapid diagnostic tests capable of detecting B virus infections against a background of pre-existing HSV infection. PCR-based tests will be developed for direct detection of virus in lesions. Using recombinant DNA technology, virus- specific antigens will be identified, cloned, and expressed in in vitro systems. These will serve as a basis for development of B virus-specific serological immunoassays, useful for screening of macaques to identify infected individuals.

Division of Research Resources, National Institute of Health (NIH)
Richard W. Eberle and Darla H. Black

INTERFERON AND HOST DEFENSE MECHANISMS

Various biologics, including viral and bacterial vaccines, have not been adequately successful in lessening economic losses in cattle with shipping fever (pneumonic pasteurellosis). Several viruses cause respiratory infections, often in combination with stress, predisposing cattle to more severe disease, especially pneumonic pasteurellosis. This research will determine the effects of interferon (IFN) and other immunomodulators on the immune system and the induction of 2'-5'-oligoadenylate synthetase. It will also define IFN pharmacokinetics in cattle.

USDA Animal Health Formula 1433
Hoffman-LaRoche, Inc.
Genentech, Inc.
Robert W. Fulton, Anthony W. Confer, and Everett C. Short

GROWTH PROMOTANT ACTIVITIES OF INTERFERON IN CHICKENS

The growth promotant activities of orally administered interferon (IFN) in broiler chickens will be evaluated. Parameters to be measured will include mortality reduction, feed intake, weight gain, feed conversion, dressing percentage at processing, breast weight at processing, and carcass specific gravity to estimate carcass fat.

Amarillo Cell Culture Company, Inc.
Robert W. Fulton and Robert Teeter

ONSET AND DURATION OF SERUM ANTIBODIES IN CATTLE ADMINISTERED VACCINE CONTAINING MODIFIED LIVE VIRAL AND PASTEURELLA HAEMOLYTICA IMMUNOGENS

The study will determine (1) the onset and magnitude of serum antibodies, and (2) the duration of antibodies in calves administered vaccine containing modified live bovine herpesvirus-1 (BHV-1), bovine viral diarrhea virus (BVDV), parainfluenza-3 virus (PI-3V), bovine respiratory syncytial virus (BRSV), and Pasteurella haemolytica bacterin toxoid. The calves' serologic response to revaccination will be determined.

SmithKline Beecham Animal Health
Robert W. Fulton and Anthony W. Confer

STABILITY OF NATURAL HUMAN INTERFERON ALPHA

The stability of a natural human interferon alpha will be determined by measuring antiviral activity retained in (1) tablets maintained under storage conditions, and (2) dilutions maintained at 37ĄC, 22ĄC, 4ĄC, and -20ĄC. The purpose will be to assess retention of IFN activity for preparations designed to deliver IFN to animals.

Amarillo Cell Culture Company, Inc.
Robert W. Fulton

ONSET AND DURATION OF SERUM ANTIBODIES IN CATTLE ADMINISTERED INACTIVATED BOVINE RESPIRATORY VACCINE

Cattle will be vaccinated with inactivated vaccines containing bovine herpesvirus-1 (BHV-1), bovine viral diarrhea virus (BVDV), parainfluenza-3 virus (PI-3V), bovine respiratory syncytial virus (BRSV), and Pasteurella haemolytica immunogens. The onset, magnitude, and duration of serum antibodies to each immunogen will be determined after both primary (initial) vaccination and revaccination five months later. The serologic responses will be compared to other animals receiving modified live and other inactivated vaccines.

Fort Dodge Laboratories
Franklin Laboratories
Robert W. Fulton and Anthony W. Confer

ORAL ADMINISTRATION OF INTERFERON IN CATTLE

The purpose of the study will be to determine the absorption, distribution, and elimination of interferon (IFN) in cattle administered human IFN orally. Parameters to be measured will include serum IFN levels, 2',5'-oligoadenylate synthetase (IFN induced enzyme) in blood leukocytes, febrile response, IFN antibody levels, and peripheral leukocyte counts.

Amarillo Cell Culture Company, Inc.
Robert W. Fulton, Everett C. Short, Rick Cowell, and Anthony W. Confer

ANTIVIRAL AND INDUCIBLE ENZYME PROPERTIES OF A NATURAL HUMAN INTERFERON ALPHA

The antiviral properties of a natural human interferon alpha (nHuIFN-_) and the ability of nHuIFN-_ to induce 2',5'-oligoadenylate synthetase (2',5'-OAS) in bovine and feline cells will be determined. Bovine monolayers, Madin Darby bovine kidney (MDBK), and feline lung monolayers will be exposed to nHuIFN-_ and challenged with viruses to determine antiviral properties. The 2',5'-OAS, an IFN induced enzyme will be measured in the IFN treated cultures.

Amarillo Cell Culture Company, Inc.
Robert W. Fulton and Everett C. Short

DOSE CONFIRMATIONŃEPSIPRANTEL/PYRANTEL IN NATURALLY OCCURRING PARASITIC INFECTIONS IN DOGS

This study will demonstrate the activity of epsiprantel or pyrantel at recommended oral doses. These drugs will be compared to a group of non-medicated dogs in replicates of at least four dogs.

Beecham Laboratories
Alan Kocan

OPTIMIZATION OF HATCHING AND REARING OF RANCHED OSTRICH

Project objectives include determinations of factors influencing mortalities in artificially hatched ostriches up to three months of age. Diagnostics and necropsies are used to determine causes of mortalities. Additional feeding trials are in progress to determine formulations that maximize growth and minimize mortalities. Extension short courses are presented yearly for both producers and veterinarians.

The Ratite Research Foundation
A. Alan Kocan, Stanley Vanhooser, and Joe Berry

IDENTIFICATION OF T CELL VACCINE CANDIDATES FOR BRUCELLA ABORTUS IN CATTLE

Brucella abortus Strain 19 vaccine is a live attenuated vaccine currently used in the United States in cattle to induce immunity against brucellosis. This vaccine has several shortcomings, the most major of which is the occasional incidence of persistent infection with the live vaccine strain in some vaccinates. This usually causes positive serological test results and impedes surveillance/eradication programs. In order to develop a subunit vaccine for bovine brucellosis, definition of the antigenic molecules which stimulate the helper T lymphocytes of immune cattle is required. Systematic fractionation of Brucella abortus protein antigens derived from the cytosol and membranes of the bacteria has been undertaken in order to evaluate the recognition of the most stimulatory proteins through the use of bovine T lymphocyte cell lines and clones derived from S19-immunized cattle. This evaluation of antigens will allow selection of appropriate subunit vaccine candidates.

USDA/Cooperative State Research Service/Special Research Grants Program
John H. Wyckoff III and Anthony W. Confer

A SUBUNIT VACCINE FOR BOVINE BRUCELLOSIS

Currently, Brucella abortus Strain 19 (S19) is the vaccine used for induction of immunity against brucellosis in cattle. S19 is a live attenuated strain of B. abortus that is known to occasionally cause persistent infections in vaccinates. This results in a vaccine-induced positive serological test and impedes the efforts of the national eradication program. Since vaccination is expected to continue to be important for control, serological distinction between vaccinates and field-strain infected cattle will become more important as the numbers of field-strain infected cattle declines. S19 does not allow this discrimination and a effective subunit vaccine could provide this feature. Therefore, through the use of immune bovine T lymphocyte cell lines and clones, a systematic investigation of the pertinent antigens and the particular T lymphocyte subsets responding to these antigens in vitro is being conducted, and appropriate subunit vaccine candidates will be identified. Subsets of T lymphocytes known to mediate protective immunity against similar facultative intracellular pathogens, such as helper and cytotoxic T lymphocytes, are the major cell types being used to identify prospective antigens that may induce immunity.

OCAST Applied Research Program
John H. Wyckoff III and Anthony W. Confer

IDENTIFICATION OF IMMUNODOMINANT BRUCELLA ABORTUS ANTIGENS WITH BOVINE T CELLS

Despite the use of B. abortus Strain 19 (S19) vaccine as a successful avenue of inducing resistance against brucellosis in cattle, the eradication of brucellosis from certain regions of the country is progressing at a slow rate. As fewer and fewer cattle acquire the infection, it will become increasingly more important to distinguish vaccinated from infected cattle through the serological tests used for surveillance of this disease. S19 induces persistent infections and positive serological test responses in a minority of cattle immunized with the vaccine. Thus, a new vaccine that allows for distinction of these two classes of cattle would be of great advantage. Since bovine immunity to B. abortus is apparently controlled by T lymphocytes, identification of the antigenic molecules stimulating these particular cells is of primary importance in designing a subunit vaccine. Various antigen preparations derived from Brucella abortus Strain 19 (S19) have been evaluated for immune stimulation in vitro of long-term bovine T lymphocyte cell lines derived from S19-immunized cattle. Results indicated that gamma-irradiated bacteria provide much better stimulation than do heat-killed whole bacteria or an extract of autoclaved bacteria. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the soluble portions of these antigen preparations indicated the increase in stimulatory capacity coincided with the observation of either new proteins or greater concentrations of proteins in the relative molecular mass range of 20-60 kD. Further studies using preparative isoelectric focusing and SDS- PAGE are being pursued to define individual molecules that preferentially stimulate particular T lymphocyte subsets and ultimately control the bovine immune response to B. abortus.

USDA (Cooperative State Research ServiceŃCompetitive Grants Program)
John H. Wyckoff III and Anthony W. Confer