Objective To study the effects of anti-keratin autoantibody (AK auto Ab) on apoptosis of human keratinocytes. Methods Light and electron microscopy were used to observe morphological changes, flow cytometry (FCM) to analyze cell cycle, and electrophoresis to analyze DNA profiles of cultured keratinocytes. Results Typical morphological changes with apoptotic characteristics such as karyopyknosis, chromatin agglutination and apoptosis bodies were found. The subdiploid peaks due to apoptosis were also found in cell cycle analyses. DNA electrophoresis of keratinocytes showed characteristic ladder. Conclusions AK auto Ab could induce apoptosis in cultured human keratinocytes.

Objective To prepare natural anti-keratin IgM monoclonal antibody. Methods Spleen cells of BALB/c mice raised in specific pathogen free conditions were directly fused with Sp2/0 myeloma cells. The hybridoma supernatants were tested by ELISA using pre-extracted keratin. The natural IgM obtained was further identified by immunochemistry and immunoblot methods. Results The cell fusion rate was about 60% without pre-immunization. About 14% supernatants reacted with the keratin antigen. Three hybridoma strains secreting natural IgM monoclonal antibody against keratin were obtained. The immunochemistry results showed that the natural anti-keratin IgM was able to bind to epidermis, sebaceous gland, hair follicule, and muscle tissues. Conclusion B lymphocytes in normal BALB/c mice spleen can produce natural antibody against kerain.