Inhibition Mechanisms Of Kaempferol And PD-L1to Lymphocyte Studied By Atomic Force Microscope

The immune system is one of the most important systems which are to fight against diseaseand to protect the normal physiology, and the happening and development of the disease isclosely related to the immune system response. By researching the effect of Programmed DeathLigands1(PD-L1) and kaempferol to Jurkat T cells, we explained the mechanism of cellularligands and drugs in the role of the immune response, and got the following conclusion:1, The second chapter of this thesis is aimed to study the immune inhibition of PD-L1tolymphocyte. Through the CCK-8experiment, the data pointed that PD-L1could inhibit cellproliferation, and the inhibition rate enhanced with the increasing of concentration. Through theAnnexin V/PI cell apoptosis double dye kit, cell apoptosis rate increased from4%to73%withthe ligand concentrations from0to5μg/mL. In order to investigate the expression of activatedJurkat T cell surface molecule CD69+and co-stimulate molecular PD-1, flow cytometricanalysis technology was applied. The control group cell surface of CD69+expression decreasedfrom24%to1%, which reflected the obvious inhibition of cell activation, and PD-1expressionincreased from1.2%to7.1%,which suggesting the induced receptor expression increasing. Byusing the atomic force microscope to scan the cells, compared with control group, after treatedby PD-L1, the cell height decreased, cells ultra-structure was ruined. All of these data explainedthe induced apoptosis effect to Jurkat T cells.2, The third chapter of this thesis, we studied the induced apoptosis role of kaempferol toJurkat T cell. Through the proliferation inhibit experiments, it is found that kaempferol inhibitingcell proliferation effect is concentration dependant and time dependant. Through the cell cycletest we found the kaempferol treated cells were arrested in G2/M phase, and the proportionincreased gradually with the concentration of drugs. Expression of Ca2+were detected, and morecalcium ions were released as drug concentration increasing from223(MFI) to593(MFI). Afterthe molecular docking experiment, Caspase3and F-actin were simulated to take reaction withkaempferol and the sites were presumed. Finally, through the atomic force microscope analysison the cell, we pointed out that kaempferol destroyed the cell body, ultra-structural structure wasmore coarse and Young modulus and adhesive force significantly decreased. All of above embraced the induced dysfunction of kaempferol to Jurkat T cells.