| Autor: |
R J, Ray, A, Stoddart, J L, Pennycook, H O, Huner, C, Furlonger, G E, Wu, C J, Paige |
| Rok vydání: |
1998 |
| Předmět: |
|
| Zdroj: |
Journal of immunology (Baltimore, Md. : 1950). 160(12) |
| ISSN: |
0022-1767 |
| Popis: |
The proliferation, survival, and differentiation of B cell progenitors in primary hematopoietic tissues depends on extracellular signals produced by stromal cells within the microenvironment. IL-7 is a stromal-derived growth factor that plays a crucial role in B lineage development. We have shown that in the presence of IL-7, pro-B cells proliferate and differentiate to a stage in which they are responsive to stromal cells and LPS, leading to terminally differentiated IgM-secreting plasma cells. In this report, we examine in detail the role of stromal cells in the transition from the IL-7-responsive pro-B cell stage to the mature LPS-responsive B cell stage. We demonstrate that this transition fails to occur, even in the presence of stromal cells and LPS, if constant exposure to IL-7 is maintained. The transition from the large pro-B cell stage to the small cmu+ pre-B cell stage occurs independent of stromal cells. Moreover, the "stromal cell-dependent" maturation that occurs subsequent to the expression of surface IgM leading to responsiveness to B cell mitogens can also be accomplished in the absence of stromal cells if pre-B cells are cultured in proximity to each other or at high cell concentrations. Together these results suggest that stromal cells mediate B cell differentiation by providing the necessary growth requirements (i.e., IL-7) to sustain the development of pre-B cells. The progeny of these pre-B cells can then differentiate through as yet unidentified homotypic interactions, leading to the production of LPS-responsive B cells. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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