Changes of T cell subsets in major immune organs during sepsis / 中国小儿急救医学

ABSTRACT

Objective:To explore the changes in the proportion and number of T cell subsets in different immune organs during sepsis.Methods:Eight-week-old female C57BL/6 mice were randomly divided into sepsis group and sham group.The experimental sepsis model was constructed through cecal ligation and puncture, and the sham group just underwent sham operation.Then we detected the changes in the total number of lymphocytes and in the ratio and absolute number of CD4 + T cells, CD8 + T cells, CD4 + CD25 high Foxp3 + regulatory T cells(Treg) and CD4 + CD25 low Foxp3 - effector T cells(Teff) in the mouse spleen, axillary and inguinal lymph nodes and bone marrow by cell counting and flow cytometry 24 h and 16 d after modeling. Results:In the spleens of septic mice, the ratio and absolute numbers of CD4 + T cells and Teff, as well as the absolute number of CD8 + T cells were significantly reduced 24 h and 16 d after modeling.There was no significant change in the number of Treg 24 h after modeling, but a significant increase occurred 16 d after modeling.During sepsis, the changes of CD4 + T cells, CD8 + T cells and Teff in mouse lymph nodes were basically the same as those in the spleen; but the changes in Treg were different, with no significant change in the early stage and a significant decrease in the late stage.In addition, the absolute numbers of CD4 + T cells, CD8 + T cells, and Teff in the bone marrow did not change significantly in the 24 h model, but decreased significantly in the 16 d model.The proportion and absolute number of Treg during sepsis were significantly reduced. Conclusion:During different periods of sepsis, there is a large consumption of lymphocytes in the spleen, lymph nodes and bone marrow.In most cases, the trend of Treg changes is inconsistent or even opposite to that of other T cell subsets.There are differences in the changes of T cells among major immune organs, suggesting that the responses of different immune organs to sepsis are heterogeneous.