Inhibition of T cells by direct contact with macrophages after murine-amputation injury.
OBJECTIVE: To determine whether macrophages post trauma have inhibitory effect on normal T cells via direct cell to cell contact. METHODS: A murine amputation injury model was used, macrophages were harvested from abdominal cavity and treated with mitomycin-C to abrogate the secretion of cytokines. Separation of T cells from splenocytes in normal mice was performed using nylon column method. Mitomycin-C treated macrophages from control and traumatized mice were added into the normal T cell culture systems, then various parameters of T cell functions were determined. RESULTS: The production and secretion of interleukin 1 (IL-1), interleukin 6 (IL-6), tumor necrosis factor (TNF) and prostaglandin E-2 (PGE-2) could be abrogated after macrophages were treated with 25 &mgr;g/mL mitomycin-C for 30 minutes. Mitomycin-C treated macrophages from traumatized mice could obviously suppress T lymphocyte transformation, IL-2 mRNA and IL-2Ralpha mRNA levels, IL-2 production, IL-2Ralpha expression, IL-2 mediated lymphocyte proliferation response of normal T cells, could not affect IL-2-IL-2R interaction but elevated suppressive action of Ts cells. Removal of Ts cells from T cells could almost abolish the inhibition of macrophages. CONCLUSIONS: Macrophages post trauma can suppress T cell functions by depressing IL-2 and IL-2Ralpha gene expression via direct cell to cell contact, and this effect may be mediated mainly by increasing the action of Ts cells.
Liang
Huaping
H
Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042, China.
Wang
Zhengguo
Z
Zhu
Peifang
P
Geng
Bo
B
Xu
Xiang
X
Luo
Yan
Y