Abstract: Objective To investigate the effects of UVB irradiation and calcium at different concentrations on the expression of pemphigus antigens by culture d human keratinocytes. Methods Human keratinocyte cultures were treated witheit her 2 mmol/L calcium added to the serum free media, or exposure to UVB irradiation. Immunofluorescence staining was performed with sera from patients with pemp higus vulgaris (PV) or pemphigus foliaceus (PF) as the first antigen. Extracts from both epidermis and keratinocytes were run on SDS-PAGE according to Laemmli's method and transferred to nitrocellulose membrane for immunoblot with PV and PF sera. Results Specific staining with PV sera was always detectable on kerati nocyte culture by immunofluorescence assay with or without high concentrations o f calcium while PF antigen was detected on stratified cells only. However, exposure to UVB irradiation could not evoke keratinocyte culture express PF antigen. The reactivities were found at 160 kd band with PF sera while at both 160 kd and 130 kd bands with PV sera. Conclusions Monolayer or stratified keratinocytes can produce PV antigen, by increasing the concentration of calcium in the culture media, the human cultured kera tinocytes can be induced to stratify and express PFA. Human keratinocytes can not express PF antigen after exposure to UVB in intro.

Key words: Keratinocytes, Pemphigus, Calcium, Ultraviolet rays