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Dextran sulfate induces changes in the free intracellular calcium ion concentration of a subpopulation of immature thymocytes
Author(s) -
WESTON SUSAN A.,
TELLAM ROSS L.,
PARISH CHRISTOPHER R.
Publication year - 1991
Publication title -
immunology and cell biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.999
H-Index - 104
eISSN - 1440-1711
pISSN - 0818-9641
DOI - 10.1038/icb.1991.53
Subject(s) - thymocyte , calcium , flow cytometry , biology , intracellular , dextran , microbiology and biotechnology , chemistry , immunology , biochemistry , t cell , immune system , organic chemistry
Summary Previous studies have shown that certain sulfated polysaccharides, such as dextran Sulfate (DxS), can induce a rapid and sustained increase in the free intracellular calcium ion concentration ([Ca 2+ ] i ) of thymocytes, whereas they cannot induce a change in the [Ca 2+ ] i of peripheral lymphocytes. This study examined this phenomenon in more detail and clearly demonstrated that only immature thymocytes can respond to DxS. Cortisone‐resistant thymocytes failed to exhibit an increase in [Ca 2+ ] i when exposed to DxS. Furthermore, analysis of [Ca 2+ ] i changes at the single cell level using a flow cytometer demonstrated that only a subpopulation of immature thymocytes responded to DxS. Additional flow cytometry studies revealed that DxS and Con‐A induce a [Ca 2+ ], response in different subpopulations of thymocytes, approximately 3O% of thymocytes responding to Con‐A and 15–20% to DxS. Thus, responsiveness to Con‐A and DxS. in terms of increases in [Ca 2± ] i , may represent a novel marker for two different thymocyte subpopulations. Such metabolic markers could be used to complement the conventional serological methods currently employed to define stages in thymocyte differentiation.