부산대학교 도서관

Human plasma cells (PC) are present in cell suspensions obtained from the tonsil by mechanical disaggregation (PCMECH). The present study shows that a collagenase treatment of tonsillar debris remaining after mechanical disaggregation yielded similar proportions of PC (PCCOLL). Moreover, PCMECHwere present in suspensions highly enriched in germinal center cells whereas PCCOLLcontained most of the IgA‐secreting cells, suggesting their predominant location in follicular and parafollicular areas and connective tissue‐rich zones such as tonsil subepithelium, respectively. Tonsil PCMECHand PCCOLLshared the phenotype CD38highCD19+CD20lowCD45high, expressed equivalent amounts of PRDI BF1/Blimp‐1 transcription factor, and carried similarly mutated IgVH6 genes. However, they differed in several features. 1) PCMECHstill expressed the early B cell transcription factor BSAP and were HLA‐DRhigh; in contrast, PCCOLLwere BSAP−and HLA‐DRlow. 2) PCMECHwere CD95+and Bcl‐2+/−whereas PCCOLLshowed CD95+/−and Bcl‐2+expression; in addition, PCMECHexhibited increased spontaneous apoptosis. 3) The two PC subsets exhibited distinctive adhesion molecule profiles, since PCCOLLexpressed higher levels of CD31, CD44, and CD49d, but a lower level of CD11a than PCMECH. These results suggest that PCMECHare recently generated, short‐living PC, and PCCOLLconstitutes a subset with higher maturity and survival, which resides in connective tissue‐rich areas.