CHANGE IN IL-12 EXPRESSION AND ITS ROLE IN IMMUNODISSONANCE IN MODS MICE / 解放军医学杂志

ABSTRACT

Objective To determine the dynamic change in IL-12 in MODS mice at different post-trauma time points and its relationship with immunodissonance. Methods 96 male C57BL/6 mice, 6-8 weeks old, were randomly divided into normal control, 3h, 24h, 3d, 7d and 12d post-trauma groups. MODS model were replicated by injection of zymosan into the peritoneal cavity of the mice. Spleen and blood were sampled at different time points. Pathological changes of spleen were observed by light microscope. Immunohistochemistry marker of IL-12p40 in spleen was produced by Powervision method. The levels of IL-12p40 and IL-12p70 in serum and homogenate of spleen were determined by enzyme-link immuno-sorbent assay,and T lymphocyte subsets were analyzed by flow cytometry, respectively. Results Atrophy of the white pulps, proliferation of monocytes and dendritic cells, infiltration of neutrophilic granulocytes in the red pulps could be seen in 12d post trauma group. During the "two hits" in early period (3-24h) and late period (12d) in MODS, the amount of IL-12p40 positive cells increased significantly in the spleen; the level of IL-12p40 increased, whereas the level of IL-12p70 decreased evidently, in serum and the homogenate of the spleen. In the early period, the amount of CD8 + T cells in peripheral blood increased, while the amount of CD4 + T cells reduced obviously in the late stage, thus CD4/CD8 ratio declined in both periods. Conclusions The results indicated that over expression of IL-12p40 by antigen presenting cells in immune organs was correlated with immunosuppression of MODS mice.