Natural antibodies to interferon-alpha and interferon-beta are a common feature of inbred mouse strains.

Neutralizing antibodies to murine interferon-alpha (MuIFN-alpha) and MuIFN-beta of the immunoglobulin (Ig)G and IgM class were naturally present in sera of BALB/c and C57BL/6 mice of four different age groups, ranging from 1 to 15 mo. These antibodies not only neutralized IFN made by C-243 cells (Swiss genotype), but also isogenic IFN-alpha and IFN-beta, and can therefore be considered to be real autoantibodies. Natural anti-MuIFN antibodies were also found in the sera of mice from 12 other inbred strains, and seem to be a common feature of inbred mouse strains.