Autologous regulation of naive T cell homeostasis within the T cell compartment

W Dummer, B Ernst, E LeRoy, DS Lee… - The Journal of …, 2001 - journals.aai.org
W Dummer, B Ernst, E LeRoy, DS Lee, CD Surh
The Journal of Immunology, 2001journals.aai.org
Naive T cells undergo spontaneous slow proliferation on adoptive transfer into syngeneic T
cell (T)-deficient hosts. Recent work has shown that such “homeostatic” T cell proliferation is
driven by MHC molecules loaded with self-peptides rather than foreign peptides. Because
naive T cells in normal T-sufficient hosts remain in interphase despite continuous contact
with self-MHC/peptide ligands, T cells apparently inhibit homeostatic proliferation of
neighboring T cells. To address this, we have investigated the requirements necessary for …
Abstract
Naive T cells undergo spontaneous slow proliferation on adoptive transfer into syngeneic T cell (T)-deficient hosts. Recent work has shown that such “homeostatic” T cell proliferation is driven by MHC molecules loaded with self-peptides rather than foreign peptides. Because naive T cells in normal T-sufficient hosts remain in interphase despite continuous contact with self-MHC/peptide ligands, T cells apparently inhibit homeostatic proliferation of neighboring T cells. To address this, we have investigated the requirements necessary for “bystander” T cells to inhibit homeostatic proliferation of other T cells. Three key findings are reported. First, homeostatic proliferation of T cells only occurs in specific microenvironments, namely the T cell compartment of the secondary lymphoid tissues. Second, direct entry into T cell compartments is also required for bystander inhibition of homeostatic proliferation. Third, bystander inhibition is mediated largely by naive rather than activated/memory T cells and does not require proliferation or TCR ligation. These findings suggest that homeostasis of naive T cells is unlikely to be regulated through competition for systemic soluble factors or for specific stimulatory self-MHC/peptide ligands. Rather, the data favor mechanisms that involve competition for local non-MHC stimulatory factors or direct cell-to-cell interactions between the T cells themselves within the T cell compartment.
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