Higher maturity and connective tissue association distinguish resident from ecently generated human tonsil plasma cells

Publisher Website
Google Scholar
Abstract
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, PCMECH were present in suspensions highly enriched in germinal center cells whereas PCCOLL contained 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 PCMECH and PCCOLL shared the phenotype CD38high CD19+ CD20low CD45high, expressed equivalent amounts of PRDI BF1/Blimp-1 transcription factor, and carried similarly mutated IgVH6 genes. However, they differed in several features. 1) PCMECH still expressed the early B cell transcription factor BSAP and were HLA-DRhigh; in contrast, PCCOLL were BSAP−and HLA-DRlow. 2) PCMECH were CD95+ and Bcl-2+/− whereas PCCOLL showed CD95+/− and Bcl-2+ expression; in addition, PCMECH exhibited increased spontaneous apoptosis. 3) The two PC subsets exhibited distinctive adhesion molecule profiles, since PCCOLL expressed higher levels of CD31, CD44, and CD49d, but a lower level of CD11a than PCMECH. These results suggest that PCMECH are recently generated, short-living PC, and PCCOLL constitutes a subset with higher maturity and survival, which resides in connective tissue-rich areas.
Funding Information
  • Fondo de Investigaciones Sanitarias of Spain (PI052357, PI052406)