Dynamics Of γδT Lymphocytes And Their Associated Cytokines In C57BL/6J Mouse Model Of Mastitis Challenged With Staphylococcus Aureus

γ δ T cells play an important role in connecting innate and adapt immune response.These cells are vital for preventing pathogens invasion and mucosal immune response.According to secretions γ δ T cells can divide into tow types. IL-17is one of secretion whichis secreted by IL-17γ δ T cells. The other is IFN-gamma γ δ T cells. These two types of cellsare distinct in differentiation periods and play different roles against inflammation. γδTlymphocytes change in mouse model of S. aureus mastitis is poorly understood. This is ourresearch basis on. This study give us a novel idea in immune system against mastitis and alsoexpand our horizon for mastitis study.C57BL/6J mice were intramamamary inoculation (IMI) with S. aureus for buildingmastitis mouse model. Firstly, we identified the mice model by clinical observation,pathological anatomy and histological observation. Secondly, γδT cells in spleen andmammary gland were detected by flow cytometry. Thirdly, Real-time fluorescentPCR(RT-PCR) was using for testing differentiation and secretion of γδT cell cytokines andthe transcript factors in mammary gland during the different stages of infection. The elisa kitswere using for testing TGF-β, IL-6, IL-17in mammary gland. All the methods were used forfinding out the change of γδT cells and their functions during mouse model of mastitis whichinfected by S. aureus. We can conclude that：1. From clinical l and histological observation, we can see mammary gland tissues wereswollen and hyperemic. Lots of inflammatory cells were infiltrated in interstitial. Comparedwith the control group, the infection group's acinar lumina and the acinar structure weredisintergration during injection.2. From flow cytometric analysis, we can see in spleen and mammary gland IFN-γ+γ δT cell percentage in the early stage of infection higher than control group. IL-17+γ δ T cellpercentage increased in the later period.3. From RT-PCR testing, IFN-γ+γ δ T cell secreted cytokine: IFN-γ mRNA peaked after8h IMI; IL-12p35was γ δ T cell differentiation cytokine, it peaked at4h injection; The transcript factor T-bet mRNA was maximum at8h. IL-17+γ δ T cell related mRNAexpressing were increased in the later period. IL-1β, IL-6and TGF-β1cytokines were forIL-17+γ δ T cell differentiation. These cytokines mRNA were maximum at8h; IL-17+γ δ Tcell secreted cytokine: IL-17mRNA peaked at12h and48h IMI; The transcript factor RORγtand surface marker CCR6were maximum at12h and48h injection.Result：This study found new way to recognize mammary gland immune defensemechanism which would help us to prevent and cure mastitis.