Thymic Dendritic Cells and B Cells: Isolation and Function
作者:
InabaKayo,
HosonoMasamichi,
InabaMuneo,
期刊:
International Reviews of Immunology
(Taylor Available online 1990)
卷期:
Volume 6,
issue 2-3
页码: 117-126
ISSN:0883-0185
年代: 1990
DOI:10.3109/08830189009056623
出版商: Taylor&Francis
关键词: anergy;CD5+B cells;clonal deletion;Mls;tolerance;thymus
数据来源: Taylor
摘要:
The thymus is the primary organ in which T cells undergo rearrangement of T cell receptorαandβgenes, positive selection for affinity to self MHC products, and elimination (negative selection) of reactivity to self antigens. These events require an interaction of the developing T cell with other cell types in the thymus. The latter include epithelial cells, macrophages, dendritic cells, and the recently described thymic B cells the majority of which are CD5+. Here we review the identification and isolation of thymic dendritic cells and CD5+B cells. We consider phenotype, ontogeny, and function, including possible contributions to the induction of self tolerance. Thymic dendritic cells are similar to spleen dendritic cells, but are larger and exhibit a few differences in phenotype. Dendritic cells from both organs are equally potent accessory cells for the MLR and lectin-induced, T cell proliferation. Thymic dendritic cells have higher levels of Fc receptors and support anti-CD3 dependent mitogenesis. Thymic CD5+B cells share phenotypic features with peritoneal CD5+B cells. However thymic B cells neither proliferate nor form antibody producing cells in response to the stimulation with LPS or anti-IgM plus IL-4, but do respond to stimulation with MHC class II-restricted helper T cells. Thymic dendritic cells and CD5+B cells both appear at a similar time in ontogeny, about 14 d of gestation, which is the time T cell differentiation begins to take place. Dendritic cells from spleen, which are potent activators for peripheral T cells, are also potent inactivators for thymic-derived cytotoxic T cells. A correlation between reactivity to MIs products and the expression of TCR-Vβgenes is well documented, and B cells are the primary APC for this antigen. Therefore, thymic CD5+B cells may be a good tool for the investigation of tolerance to Mls products.
点击下载:
PDF (639KB)
返 回