The response of ponies to Myxovirus influenzae A-equi 2. II. Immunoglobulin classes of antibody to the virus in serum and nasal secretions.

Nasal secretions and serum were collected from ponies in order to determine the types of immunoglobulins responsible for antibody activity against Myxovirus influenzae A-equi 2. Using specific antisera to remove each immunoglobulin, the antiviral activity of serum was shown to be a property of IgG globulin, whereas in nasal secretions activity was found in both IgG and IgG(T) globulins. However in secretions the predominant activity was attributed to IgG(T) globulin. Because of its sensitivity to 2 mercaptoethanol, early serum antibody was assumed to belong to the IgM class of immunoglobulins. From its behaviour in sucrose density gradients and on Sephadex G 200 columns, the antibody in nasal secretions was assumed to be of 7S mobility not 11S such as is found in man.