Pathogenesis of aleutian disease of mink: identification of nonpersistent infections

Aleutian disease virus usually produces a persistent infection and progressive immune comples disease in mink of the Aleutian genotype. Study of Aleutian disease virus infection in non-Aleutian mink showed that about one-quarter developed nonpersistent infections by the virus, and that the nonpersistence was not genetically determined by the host. The nonpersistently infected mink developed only a transient elevation of serum gamma globulin, and much lower specific Aleutian disease virus antibody titers than persistently infected mink. No lesions were found in the nonpersistently infected mink.

Some properties of precipitating antigens associated with infectious bursal disease virus

Infection of the bursa of Fabricius and chicken embryo fibroblast cell cultures with avian infectious bursal disease virus resulted in production of a number of virus-induced antigens. The antigens were specific, forming three precipitin lines by immunodiffusion with antiserum (designated PA-1, -2, and -3). To separate immunoprecipitin from the remaining viral particles, two (PA-1 and PA-3) were partially purified by subjection to two cycles of diethylaminoethyl-cellulose chromatography and filtration through a column of Sephadex G-150 gel. The precipitating antigen, PA-1, was found to migrate most slowly through the agar gel, remaining serologically active after treatment with heating (56 C for 1 h), trypsin, lipolytic solvents, deoxyribonuclease, and ribonuclease. Its density was 1.27 g/ml. Morphologically the antigen displayed a doughnut-shaped structure 8 to 12 nm in size. PA-3 migrated most rapidly through the agar gel. It was destroyed by treatment with heating and trypsin but not with lipolytic solvents, deoxyribonuclease, and ribonuclease. Density was about 1.25 g/ml. This suggests that the antigen is a part of viral structural components. PA-2 migrated through agar gel at a rate between that of PA-1 and PA-3. Because of its low concentration, PA-2 was not further characterized.

Antigen and antibody in Aleutian disease in mink. II. The reaction of antibody with the Aleutian disease agent using immunodiffusion and immunoelectroosmophoresis

Aleutian disease viral (ADV) antigen was prepared by fluorocarbon extraction of spleen, liver, and lymph nodes from mink experimentally infected ten days previously. Using a potent ADV antigen, antibody was detected by immunodiffusion (ID) and immunoelectroosmophoresis (IEOP). Utilizing these precipitin tests, antibody was detected in all the mink sera tested as early as seven days after experimental infection. Titer of antibody increased throughout the infection period. Titers of more than 100 were reached by 15 days post infection, titers of 1,000 at one month, and titers of more than 5,000 to 10,000 were achieved at two months post infection and thereafter. The immunodiffusion test gave similar or slightly lower titers than those detected by the IEOP. The IEOP test promises to be a most useful technique for the diagnosis of aleutian disease because it is simple, rapid and specific and is capable of detecting infection early in the course of the disease. It is suggested that this test should be utilized especially for the screening of animals purchased or imported as breeding stock onto ranches.

Isolation of Aleutian mink disease virus by affinity chromatography

Affinity chromatography was used to isolate the Aleutian disease virus of mink. Dissociation of the immunoadsorbent-virus complex with 0.75 molar sodium chloride and then with a glycine-hydrochloride gradient released infective particles resembling picornaviruses. The elution profile suggests that two different types of virus-antibody complexes are formed, one dissociated by sodium chloride and another that requires glycine-hydrochloride in addition to sodium chloride for release of virus.

Antibody response in vitro to an animal virus: production of rabies virus neutralizing antibodies by mouse cells in culture

Rabies virus neutralizing antibodies were produced in vitro by the exposure of mouse spleen cells to live and inactivated rabies virus suspensions and to sheep erythrocytes coated with rabies virus. These antibodies did not neutralize two other rhabdoviruses: Kern Canyon and vesicular stomatitis viruses, and were precipitable by treatment with an antiserum to mouse IgG. Removal of "glass-adhering" cells from mouse spleen cell suspensions abolished the antibody response, which could be restored by the addition of mouse peritoneal exudate cells, rich in macrophages.