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Inverse relationship of CA 2+ mobilization and cell proliferation in CD8 + memory and virgin T cells
Author(s) -
Schlunck Tilman,
Schraut Winfried,
Riethmüller Gert,
ZieglerHeitbrock H. W. Löms
Publication year - 1990
Publication title -
european journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 201
eISSN - 1521-4141
pISSN - 0014-2980
DOI - 10.1002/eji.1830200913
Subject(s) - biology , cytotoxic t cell , cd8 , monoclonal antibody , microbiology and biotechnology , interleukin 21 , antibody , immunology , antigen , biochemistry , in vitro
Abstract Memory T cells can now be defined with various monoclonal antibodies but little is known about the functional properties of these cells as compared to virgin T cells. We have studied Ca 2+ mobilization and proliferation of memory and virgin cells in both the CD4 and CD8 subsets in response to phytohemagglutinin. Using two‐color fluorescence (yellow, red) for cell surface staining combined with two‐color fluorescence for the Ca 2+ chelator indo‐1 (violet, blue) we can demonstrate that CD8 + UCHL1 + memory cells exhibit a 1,5‐fold higher influx than the CD8 + UCHL1 − virgin cells. The same pattern was obtained when CD8 memory and virgin cells were defined by a reciprocal marker (Leu‐18) indicating that the higher response of memory CD8 cells is independent of the monoclonal antibody used to identify the cells. For the respective CD4 subsets no such clear‐cut pattern of Ca 2+ influx was evident. Analysis of proliferation in both subsets indicates that CD8 + UCHL1 − cells strongly proliferate in response to PHA, while CD8 + UCHL1 + memory cells show only a minimal response with the average cpm values being 6‐fold lower. In some instances no proliferation at all was detectable in the CD8 + UCHL1 + cells. Identification of the subsets by reciprocal markers confirmed the lower proliferative response in the CD8 memory cells. Hence, within the CD8 compartment the memory cells, after phytohemagglutinin stimulation, exhibit a high Ca 2+ mobilization but a low to absent proliferation, while the converse is true for the naive cells. These data show that (a) Ca 2+ mobilization and proliferation are inversely correlated and (b) an initially vigorous response of memory cells may be subject to negative control mechanisms.