IMMUNOGLOBULIN CLASSES OF ALEUTIAN DISEASE VIRUS-ANTIBODY

Aleutian disease virus (ADV) persistently infects mink and causes marked hypergammaglobulinemia. Ig class-specific antisera were used to define the total Ig of each class by radial immunodiffusion and the Ig class of ADV-specific antibody by immunofluorescence in experimentally and naturally infected mink. Electrophoretic .gamma.-globulin closely reflects the IgG level in mink, and the majority of the increased Ig and ADV antibody in infected mink is IgG. IgM becomes elevated within 6 days after infection, reaches peak levels by 15-18 days, and returns to normal by 60 days after infection. The 1st ADV antibody demonstrable is IgM, and most mink have virus-specific IgM antibody for at least 85 days postinfection. Serum IgA levels in normal mink are not normally distributed, and ADV infection causes a marked elevation of IgA. Low levels of ADV-specific IgA antibody can be shown throughout the course of infection. Failure of large amounts of virus-specific IgG antibody to inhibit the reaction of virus-specific IgM and IgA antibodies suggests that the various classes of antibodies are directed against spatially different antigenic determinants. The IgM and IgA were shown not to be rheumatoid factors.