Objective: To evaluate the mechanism of T follicular helper cells ( Tfh ) in experimental autoimmune encephalomyelitis (EAE) via in vivo experiments. Methods:C57BL/6 mice were randomly divided into four groups,CFA group,EAE group,anti-ICOSL group and control group. Lymphocytes of different time points isolated from draining lymph nodes and spleen were stained for T follicular helper cells surface marker and T cells activation surface marker and analyzed by FACS. Observed parameters include inflammatory infiltration,demyelination in spinal cord and germinal center in spleen. ELISA was used to measure the level of antigen specific antibodies. Results: Mice in anti-ICOSL treated group developed mild disease was with lower clinical scores when compared with the EAE group. HE staining results turned out with alleviated inflammation and Luxol Fast Blue staining( LFB) showed no demyelization in anti-ICOSL treated mice compared with non-treated EAE models. Flow cytometry results revealed that percentages of T follicular helper cells decreased though the whole activated degree T cells was not influenced in anti-ICOSL treated group. Fewer ger minal center was found in both anti-ICOSL group and CFA group with reduced secretion of MOG-specific Ab. Conclusion:T follicular helper cells supported the development of cognate B cells,promoted the formation of germinal center,facilitate pathogenic MOG-specific Ab secretion,thus enhance EAE.

To investigate the effects of leptin on expression of acyl-coenzymeA: cholesterol acyl-transferases-1 (ACAT-1) in monocyte-macrophage differentiation, human monocytic cells (THP-1) were cultured in RPMI 1640 and made to differentiate into macrophages under the incubation with phorbol myristate acetate (PMA) for 48 h. The cells were divided into 4 groups according to different intervention factors as follows: MCs cultured in RPM11640 medium with 10% FBS for 48 h served as MC group (control group), MCs cultured in medium with serum-free RPM11640 containing 5% BSA, 100 nmol/L PMA for 48 h as MP group, MCs cultured in RPMI1640 medium with 10% FBS, 10 micromol/ml leptin for 48 h as leptin-MC group, and MCs cultured in medium with serum-free RPMI1640 containing 5% BSA. 100 nmol/L PMA, and 10 micromol/ml leptin for 48 h as leptin-MP group. Immunocytochemistry, reverse transcription polymerase chain reaction (RT-PCR) and Western blot were performed, respectively, to observe the effects of leptin on expression of ACAT-1 in the monocyte-macrophage differentiation. Our results showed that expression of ACAT-1 protein and mRNA in MP-group is two times that in MC-group (P<0.05), and the expression of ACAT-1 protein and mRNA increased by up to 4 folds in leptin-MP group-as compared with that of MC group (P<0.01). Thus, our results support the idea that expression of ACAT-1 increases more in cultured human macrophages than in monocytes, and leptin can significantly promote ACAT-1 expression. It was concluded that high expression of ACAT-1 may accelerate the development of human atherogenesis, and leptin might participate in atherogenesis by increasing expression of ACAT-1.
Atherosclerosis ; enzymology ; Cell Differentiation ; Cells, Cultured ; Humans ; Leptin ; pharmacology ; Macrophages ; cytology ; enzymology ; Monocytes ; cytology ; enzymology ; Sterol O-Acyltransferase ; biosynthesis ; genetics ; Tetradecanoylphorbol Acetate