Open AccessAdhesion of Thymocytes to Bone Marrow Stromal Cells: Regulation by bFGF and IFN‐γ
Author(s) -
BardaSaad Mira,
Zhang AnSheng,
Zipori Dov,
Rozenszajn Leon A.
Publication year - 1997
Publication title -
stem cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.159
H-Index - 229
eISSN - 1549-4918
pISSN - 1066-5099
DOI - 10.1002/stem.150229
Subject(s) - calcein , stromal cell , biology , thymocyte , bone marrow , cell adhesion , basic fibroblast growth factor , stroma , microbiology and biotechnology , t cell , immunology , cell , cancer research , growth factor , biochemistry , immune system , receptor , immunohistochemistry , membrane
We recently reported on selective interactions between immature T cell subpopulations and bone marrow (BM) stromal cells. To further study this process, we first examined the efficacy of methods estimating cell‐cell adhesion and then investigated the effects of cytokines on thymocyte‐stroma associations. Techniques based on the use of the fluorochromes calcein‐acetomethylester (calcein‐AM) and fluorescein diacetate (FDA) were studied and compared to regular cell counting methods. With calcein‐AM labeling, the retention time was relatively long, while with FDA labeling, there was a rapid cellular efflux. Using calcein‐AM, we developed an accurate quantitative fluorometric assay for determining the adherence of thymocytes to a BM stromal cell line (MBA‐13). A maximal fraction of about 29% thymocytes was found to adhere to confluent MBA‐13 cell layers after four to six h of coculture. Whereas interleukin 1 did not change the rate of adhesion of thymocytes to the stroma, interferon‐γ (IFN‐γ) significantly increased adhesion. Basic fibroblast growth factor (bFGF) had a dose‐dependent biphasic effect on thymocyte adhesion, and a greater fraction of double negative thymocytes adhered to stroma pretreated with bFGF. Taken together, these results suggest that IFN‐γ and bFGF modulate T cells‐BM stromal cell adhesion.