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Updated: Aug 11, 2026
Generation of Human CD40-activated B cells
Published on: October 17, 2009
Human interdigitating dendritic cells directly stimulate CD40-activated naive B cells
P Björck1, L Flores-Romo, Y J Liu
1Schering-Plough, Laboratory for Immunological Research, Dardilly, France. pia-bjorck@omrf.uokhsc.edu
Insights
Human interdigitating dendritic cells (IDC) promote naive B cell proliferation and differentiation into IgM-producing plasma cells. These findings suggest a role for IDC in initiating extrafollicular immune responses.
Area of Science:
- Immunology
- Cell Biology
Background:
- Interdigitating dendritic cells (IDC) are crucial immune cells found in lymphoid tissues.
- Understanding IDC function is key to deciphering adaptive immune responses.
Purpose of the Study:
- To characterize human tonsillar IDC phenotype and function.
- To investigate the role of IDC in B cell activation and differentiation.
Main Methods:
- Isolation of human tonsillar IDC based on CD40+ lineage-negative expression.
- Phenotypic analysis using flow cytometry and functional assays (mixed lymphocyte reaction).
- In vitro co-culture experiments with B cells and surrogate activated T cells.
Main Results:
- Isolated IDC exhibited a mature dendritic cell phenotype (MHC class II, CD80, CD86, CD83).
- IDC induced allogeneic mixed lymphocyte reactions.
- In the presence of T cell help, IDC enhanced naive B cell proliferation and IgM production.
Conclusions:
- Human tonsillar IDC possess a distinct phenotype and functional capacity.
- IDC contribute to B cell activation and differentiation, suggesting a role in extrafollicular immune responses.
Abstract:
Human interdigitating dendritic cells (IDC) were isolated from tonsils based on their CD40+ lineage-negative expression in situ. Isolated IDC displayed a phenotypic profile similar to that of IDC in tonsils and spleen in situ, characterized by high-level expression of major histocompatibility complex class II, the co-stimulatory molecules B7.1 (CD80) and B7.2 (CD86), expression of the late DC maturation marker CD83, and no expression of CD1a, CD13, or CD33. IDC also showed weak nonspecific esterase staining and had the ability to induce an allogeneic mixed lymphocyte reaction. In this study, we further show that in the presence of surrogate activated T cells in the form of CD40 ligation and IL-2, IDC enhance the proliferation of naive B cells and induce their differentiation into plasma cells producing IgM. Evidence for the anatomical co-localization of naive B cells and IDC in the T cell area together with the data obtained in vitro implies a role for IDC in the initiation of the extrafollicular reaction.
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