Study of the Protective Effect of CD4 +CD25 + T Cells in Lipopolysaccharide-Induced Multiple Organ Dysfunction Syndromes in Mice

WANG Yan-jun; GAO Rui; JIA Wen-yuan; LI Wei-min; YIN Wen

doi:10.3969/j.issn.1002-3429.2014.10.037

Abstract：Objective To investigate the contribution of the CD4 +CD25 + T cells to the development of multiple or-gan dysfunction syndrome ( MODS) in mice. Methods The male BALB/c mice were used for the experiment. The lipopo-lysaccharide (LPS) was intraperitoneally injected at a dose of 9. 0 mg/kg to induce the MODS model as the experiment group (n=60). For the mice in control group, the same volume of normal saline (0. 9%) was administered intraperitoneally (n=10). The level of CD4 +CD25 + T cells was evaluated in mice at the 2nd day and the 5th day by flow cytometry. And 180 mice were intraperitoneally injected with 200 μg of anti-CD25 mAb, IgG1 or phosphate buffer solution (PBS) at day-2, respective-ly. Two days later (day 0), the mice were intraperitoneally injected with LPS and grouped as LPS, IgG1+LPS and anti-CD25 mAb+LPS respectively (n=60). The percentage of CD4 +CD25 + T cells was calculated eventually and the lung tissue was separated for the histological examination by HE staining. The survival rate was observed following MODS and sample sizes were 54 for LPS, 34 for IgG1+LPS and 32 for anti-CD25 mAb+LPS. Results The number of CD4 +CD25 + T cells in ex-periment group markedly decreased on day 2(t= 2. 873,Ρ= 0. 006), and significantly increased on day 5(t= 2. 963,Ρ=0. 004)when compared with control group. And the CD4 +CD25 + T cells percentage was decreased by injection of LPS in group anti-CD25 mAb+LPS on both day 2 and day 5, there were statistical differences when compared with the other two groups (Ρ<0. 01). Moreover, the HE staining result indicated that neutralization of CD4 +CD25 + T cells profoundly in-creased the degree of lung tissue injury, and it also increased mice mortality. Conclusion CD4+CD25+ T cells are major protective modulators in MODS in mice.