A monoclonal antibody recognizing Golgi apparatus produced using affinity purified material from a patient with...

Serum antibodies recognizing the Golgi apparatus have been reported in patients with connective tissue diseases, but little is known of their significance. Serum from a systemic lupus erythematosus patient with polymyositis was found to have high titers of anti-Golgi apparatus antibody. This serum recognized a 64 kD polypeptide in immunoblotting with HEp-2 cells. To verify that the 64 kD polypeptide was associated with the Golgi apparatus and to characterize which Golgi component was recognized, a monoclonal antibody was produced. IgG, isolated from this serum, was used in affinity chromatography to produce purified material which was used to generate a mouse monoclonal antibody. The monoclonal antibody had an indirect immunofluorescent pattern identical to that produced by the patient's serum, and similarly recognized a 64kD polypeptide in immunoblotting. A 59 kD polypeptide was also recognized by the monoclonal antibody, suggesting that the antigens recognized by the monoclonal and serum antibodies may be only partially identical. The antigen appears to be a glycoprotein and an integral component of the Golgi cisternae membranes.