THE INTERFERON-INDUCIBLE AUTOANTIGEN, IFI-16 - LOCALIZATION TO THE NUCLEOLUS AND IDENTIFICATION OF A DNA-BINDING DOMAIN

Abstract

The human IFI 16 gene encodes a nuclear protein whose expression is associated with activation and differentiation of cells of the myeloid lineage, and which has recently been postulated to be a frequent target of human autoantibodies. We have used a unique monoclonal antibody in immunofluorescence studies to define the intranuclear distribution of IFI 16 antigen in primary human leukocyte sub-populations. We demonstrate that IFI 16 is expressed both within the nucleoli and nucleoplasm of mononuclear cells, but is not present in granulocytes. IFI 16 expression correlated with that of the known nucleolar antigen B23, suggesting that the function of IFI 16 is restricted to cells that have nucl..