Objective To study the effect and molecular mechanism of vitamin D(VitD)on Tfh cells of MRL/lpr lupus mice.Methods C57/B6 mice and MRL/lpr lupus mice were transfected with siRNA to construct VDR knockout mouse models.Splenic Tfh cells of C57/B6 mice and MRL/lpr lupus mice were divided into control group,lupus group and VDRsiRNA lupus group(treated with vitamin D 0,1 and 10 nmol·L-1,respectively)by siRNA transfection.The percentage of Tfh cells was detected by flow cytometry.MRL/lpr lupus mice Peyer node Tfh cells were randomly divided into 7 groups,blank control group,vitamin D dose groups of 1 and 10 nmol·L-1,paricalcitol group(VitD 10 nmol·L-1+PA),VDRsiRNA control group,VDRsiRNA group(VitD 10 nmol·L-1),CaN inhibitor group(VitD 10 nmol·L-1+CsA),and incubated for 72 h.The concentration of calcium ions in Tfh of each group was detected.The expressions of AT1R,NFAT,CaN and P-CaN in Tfh cells were determined by Western blotting.Results The percentage of Tfh cells decreased significantly with the increase of vitamin D dose.Vitamin D CaN reduce the intracellular calcium concentration of Tfh,up-regulate the expression of AT1 protein in Tfh cells,and down-regulate the expression of CAN,P-CaN and NFAT protein in a dose-dependent manner,and the effect is more obvious when combined with PA.Conclusion Vitamin D may regulate the activation of follicular T helper cells in MRL/lpr mice via the Ca-CaN-NFAT pathway.

Objective To study the effect and molecular mechanism of vitamin D(VitD)on Tfh cells of MRL/lpr lupus mice.Methods C57/B6 mice and MRL/lpr lupus mice were transfected with siRNA to construct VDR knockout mouse models.Splenic Tfh cells of C57/B6 mice and MRL/lpr lupus mice were divided into control group,lupus group and VDRsiRNA lupus group(treated with vitamin D 0,1 and 10 nmol·L-1,respectively)by siRNA transfection.The percentage of Tfh cells was detected by flow cytometry.MRL/lpr lupus mice Peyer node Tfh cells were randomly divided into 7 groups,blank control group,vitamin D dose groups of 1 and 10 nmol·L-1,paricalcitol group(VitD 10 nmol·L-1+PA),VDRsiRNA control group,VDRsiRNA group(VitD 10 nmol·L-1),CaN inhibitor group(VitD 10 nmol·L-1+CsA),and incubated for 72 h.The concentration of calcium ions in Tfh of each group was detected.The expressions of AT1R,NFAT,CaN and P-CaN in Tfh cells were determined by Western blotting.Results The percentage of Tfh cells decreased significantly with the increase of vitamin D dose.Vitamin D CaN reduce the intracellular calcium concentration of Tfh,up-regulate the expression of AT1 protein in Tfh cells,and down-regulate the expression of CAN,P-CaN and NFAT protein in a dose-dependent manner,and the effect is more obvious when combined with PA.Conclusion Vitamin D may regulate the activation of follicular T helper cells in MRL/lpr mice via the Ca-CaN-NFAT pathway.

Cerebral hemorrhage is one of the refractory diseases which seriously endangers the safety of human life. Immune and inflammatory reaction participate in the whole process of cerebral hemorrhage, which can destroy the blood-brain barrier, accelerate brain edema, at the same time start and amplify the oxidative stress reaction, and aggravate the nerve function damage. After cerebral hemorrhage, many kinds of signal molecules are produced, which can activate the microglia and astrocytes around the hematoma, produce inflammatory factors and oxidizing mediators, and regulate the inflammatory response of the brain. Exploring the relationship between glial cell and immune, inflammatory responses is helpful to understand the mechanism of intracerebral hemorrhage intervention, find out a new target for the intervention of glial cells and develop new drugs and schemes for the treatment of intracerebral hemorrhage.

T-cell exhaustion is characterized by the stepwise and progressive loss of T cell functions under conditions of antigen-persistence, which occurs following chronic infections and tumor outgrowth. Exhausted T cells present functional defects, express multiple inhibitory receptors and show reprogrammed transcriptional regulation. As T cell exhaustion is correlated to its dysfunction to control infections and tumors, exploring new strategies to target exhausted T cell may reverse this dysfunctional state and reinvigorate immune response. This study takes CD8+ T cell as an example, which acts as an important subset involved in exhaustion state, discuss current understanding of the properties of exhausted T cell and the mechanisms that promote and maintain this state, and reveal new therapeutic targets for chronic infection and cancer.