IDENTIFICATION OF ALPHA-FODRIN AS A CANDIDATE AUTOANTIGEN IN PRIMARY SJOGRENS-SYNDROME

It is unclear whether organ-specific autoantigens are critical for the development of primary Sjogren's syndrome (SS). A 120-kilodalton orga n-specific autoantigen was purified from salivary gland tissues of an NFS/sld mouse model of human SS. The amino-terminal residues were iden tical to those of the human cytoskeletal protein alpha-fodrin. The pur ified antigen induced proliferative T cell responses and production of interleukin-2 and interferon-gamma in vitro. Neonatal immunization wi th the 120-kilodalton antigen prevented the disease in mice. Sera from patients with SS reacted positively with purified antigen and recombi nant human alpha-fodrin protein, whereas those from patients with syst emic lupus erythematosus and rheumatoid arthritis did not. Thus, the i mmune response to 120-kilodalton alpha-fodrin could be important in th e initial development of primary SS.