Résumé
Objective:To construct mouse ScFv against pemphigus vulgaris antigen (PVA) through phage displayed antibody technology Methods:Total RNA was isolated from the spleen cells of mice immunized with recombinant pemphigus vulgaris antigen (rPVA) after six weeks, and then reverse transcripted into cDNA Primers specific for mouse V H and V L were synthesized to amply the V H and V L by ploymerase chain reaction (PCR) V L gene was modified and amplified with linker primer (which contain 3′ region of V H, linker, and 5′ region of V L), the resultant gene called V L′ Purified V L′ and V H were subjected to SOE (splicing by overlap extension) ligation, and resultant ScFv gene was digested with SfiI and NotI, cloned to the identically digested pCantab 5E Library of TG1 transfected with recombinant phagemid were derived with diversity of 1 5?10 6 Results:The pemphigus vulgaris phage antibody library was constructed, and one positive TG1 clone was obtained, which can highly expresses phage displayed antibody Conclusion:Specific genetic antibody against PVA can be made from phage displayed antibody library
Résumé
BACKGROUND: Pemphigus are chronic autoimmune blistering disorcers characterized by acantholysis. In addition to pemphigus vulgaris(PV), the major clinical variarts are pemphigus foliaceus(PF), paraneoplastic pemphigus(PNP) and drug-induced pemphigus(DP). Detection of pemphigus antigen is important for differential diagnosis as well as research work. Most investigators have identified pemphigus antigens by means of immunoprecipitation using metabolically radiolabeled cultured keratinocytes. However, immunorepitation is generally more expensive, hazardous and time-consuming than immunoblotting. Therefore, establishment of the immunoblotting as a standard technique for the detection of the pemphig us antigens is desirable. OBJECTIVE: To characterized pemphigus antigens by an immunobloting analysis of human epidermal extract and by indirect itnmunofluroscence study using human of cultured keratinocytes as a substraie. METHOD: We performed imrnunoblotting analysis af sera from patieiits with PV, PF, PNP and DP with human epidermal extract as a source of antigen. Indirect immunof uorescence study was also performed using human keratinocytes cultured in high or low calcium media for detection of pemphigus antigens. RESULTS: In an immunoblotting analysis, all(9/9) PV sera showed secific reactivities with a 130-KD protein and all(5/5) FF sera showed reactivities with a 150-KK protein, which is most likely desmoglein 1. Furthermore, one of nine PV serum also reacted with a 150-KD protein, which seems to be the identical antigen detected in PF. All PNP(3/3) sera showed reactivities with two protein bands, 210KD and 190KD. In our indirect imrnunofluorescence study using culltured human keratinocytes as a substrate, when keratinocytes were grown in low calcium media, no pimphigus antigens could be detected. However, when grown in high calciurn media, pemphigus vulga ris and paraneoplastic pernphigus antigens were present t the cell-cell contact areas with a puncta;e pattern, whereas pemphigus foliaceus antigen was not, presint in keratinocytes even when cultured in high calcium media. CONCLUSION: Our results suggests (1) immunoblotting analysis is a reliable technique for defining pemphigus antigen and could be a valuable tool for the differentiation of PV, PF and PNP and(2) PF antigen rnay not be expresseden cultured keratinocytes.