| Multiple organ dysfunction syndrome (MODS) is the main reason for deathin patients with Intensive. With high mortality, long treatment cycle and theheavy burden on the family and society, it is one of the important issues to besolved in critical care medicine.In the recent three decades，although domesticand foreign scholars have done a lot of exploration, the morbidity and mortalityof MODS remains high.Systemic inflammatory response (SIRS) is considered tobe the common pathway for MODS.Currently considered,“the loss of balancebetween anti-inflammatory and pro-inflammatory factors leading to inflammatoryresponse out of control "is the main mechanism of SIRS, but the specificmechanism of regulation is not clear.CD4+Th cells play an important role in immune response and inflammatorydiseases. Which specificly expressing the transcription factor RORγt and secreting IL-17,prompted a large number of downstream inflammatory factors torelease, Th17cells play a key pro-inflammatory role in a variety of immuneinflammatory diseases；Treg cells specificlt expressing the transcription factorFoxp3directly or indirectly antagonized Th17cells, they suppress inflammationand inhibit the immune response.A lot of research has proved that the imbalance of Th17/Treg cells play animportant role in the induction of a variety of autoimmune diseases. Such asrheumatoid arthritis (RA), experimental autoimmune encephalomyelitis (EAE),asthma and systemic lupus erythematosus (SLE). During the development ofSIRS and MODS,the lung is the primary target organ to suffer injury, theperformance of SIRS in the lungs is acute lung injury (ALI). The participation ofIL-17were detected in the SIRS animal models and patients with acute lunginjury. Therefore, this study asked the following speculations:Th17cells and Treg cells may be involved in the occurrence of SIRS，andchanges between the both and the related inflammatory factors change processesmay be correlated. Through intervention, the antagonistic Th17cells, observedthe change of SIRS severity and differentiation and function of Treg cells. Furtherelucidate the role of two cells in the pathogenesis of SIRS.This study is the first part of the above conjecture.At the same time，it isalso the National Natural Science Foundation funded project in2010（No.30972854)Aim：In this study, we make a model of SIRS by intraperitoneal injectingzymosan to the mouse, And make lung as a window to observe the occurrenceand development of Th17cells and Treg cells in the SIRS model.In terms ofgenes, proteins and related inflammatory factors, multiple points in time,multi-level, to observ both the process of change systematicly. Method：120mice were randomly divided into model group（n=90）, controlgroup（n=20）and Mortality observed group（n=10）.The model group was dividedinto6h,1d,2d,3d,5d and7d six subgroups（n=15/subgroups）. Make model ofSIRS by intraperitoneal injecting zymosan to the mouse；Assess the severity ofmice through observing the mortality and poisoning symptoms (conjunctivitis,mao faling disorder, diarrhea, lethargy)；To observe the infiltration of Th17cellsand Treg cells in the lung tissue by immunofluorescence staining；And analysethe expression changes of specific transcription factor RORγt and Foxp3in bothgene and protein levels and related inflammatory factors by Elisa, real-time PCRand Western blotting.Results：After the occurrence of systemic inflammatory response, theinflammatory cells infiltrated in the lungs on1d, and then gradually increased andmassive lymphocytes infiltrated in the lung， alveolar edema, hemorrhage,alveolar wall thickened and gradually fractured.The mortality of mice reached apeak on2d； Results of Elisa showed that the IL-17in lung tissue on6h(393.30±38.78),1d (364.72±64.57) and7d (306.86±2.65) were significantlyhigher than the control group (219.67±8.50), In the lung the changes of IL-17is:it has the highest concentration at6h and1d, it started to decline on2d (86.75±7.12), on5d (129.39±5.97) the concentration increases again and on7d itbecome close to the initial state. The IL-17in the serum begin to increse on6h(113.39±5.76) and to a peak on1d(272.71±58.61). Real-time PCR resultsshowed that the expression level of transcription factor RORγt of Th17cells,began to increase on1d (0.47±0.02), to the peaked on2d (0.63±0.06) and3d(0.63±0.07) and begin to decline on5d (0.23±0.02). compared with the controlgroup (0.25±0.02). The expression levels of transcription factor Foxp3of Tregcell declined on1d(0.49±0.07)and rised on2d(0.58±0.03),then to the peak at 5d (1.41±0.07) and at last it have begun to drop at7d (0.64±0.08) comparedwith the control group (0.99±0.04). RORγt and Foxp3protein expression isconsistent with the gene expression, the two had a negative correlation no matteron gene or protein level(R=-0.4540，R=-0.2272); Expression of proinflammatorycytokines IL-6, TNF-alpha was negatively correlated with anti-inflammatorycytokines IL-10(R=-0.7455，R=-0.6323); In addition, we observed that a smallamount of Th17cells infiltrated in lung tissue by immunofluorescence doublestaining.Conclusion：After SIRS，transcription factors and protein of Th17cells andTreg cells were changed, and showed a negative relationship, RelatedInflammatory factors also showed one after another the mutual antagonizedphenomenon.But we also found that IL-17expression is not consistent with theTh17cells, nor a negative correlation with Treg cells. We can conclude thatpreliminarily: Th17cells and Treg cells involved in the occurrence anddevelopment of SIRS, In the Early stage, function of Treg cells was not onlyinhibited by Th17cells, there may be other lymphocytes which secrete IL-17.The function of Treg cells gradually recovered later, and the mortality andpoisoning symptoms improved in mice. The process of change between the two isclosely related to the severity of symptoms of mice. Correct and maintain thebalance between pro-inflammatory and anti-inflammatory factors is expected tobecome a new target for the treatment of SIRS. |
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