ABSTRACT
Patients affected by pulmonary tuberculosis (PTB) manifest deficiencies in innate cellular immunity. The Tim3/Galectin-9 axis is an important regulator of Th1 cell immunity, leading to Th1 cell apoptosis. Herein, thisstudy aims to clarify the underlying roles of the Tim-3/Galectin-9 axis in T-cell immunity in PTB. Peripheralblood mononuclear cells (PBMCs) were extracted from subjects with and without PTB to examine theexpression of CD4, CD8, CD25, and Tim-3 under the stimulation of Mycobacterium tuberculosis (MTB) andpurified protein derivative (PPD). In addition, the expression of Tim-3 and Galectin-9 in PBMCs was determined. The Tim-3/Galectin-9 axis in the PBMCs was activated or blocked to detect the secreted levels of IFNc, TNF-a, IL-2, and IL-22. MTB stimulation increased the expression of CD4, CD8, CD25, Tim-3, andGalectin-9 in PBMCs. The blockade of Tim-3/Galectin-9 axis resulted in reduced secretion of IFN-c, TNF-a,IL-2, and IL-22 from T-cells. Moreover, Tim-3?CD4?T, Tim-3?CD8?, and Tim-3?CD25?T cells exhibited agreater ability to inhibit the replication of MTB in macrophages. Taken conjointly, the blockade of Tim-3/Galectin-9 axis inhibits the secretion of inflammatory cytokines in T-cells to regulate the T-cell immunity inPTB.
ABSTRACT
The effects of combined RNA interference(RNAi)of human telomerase RNA(hTR)and human telomerase reverse transcriptase(hTERT)genes on telomerase activity in a bladder cancer cell line(BIU-87 cells)were investigated by using gene chip technology in vitro with an attempt to evaluate the role of RNAi in the gene therapy of bladder transitional cell cancer(BTCC).Three TR-specific double-stranded small interfering RNAs(siRNAs)and three TERT-specific double-stranded siRNAs were designed to target different regions of TR and TERT mRNA.The phTR-siRNA,pbTERT-siRNA,and the combination of both plasmids phTR+phTERT-siRNA were transfected into BIU-87 cells.The expression of hTR and hTERT mRNA was detected by quantitative fluorescent reverse transcription-polymerase chain reaction,and a telomeric repeat amplification protocol was applied to detect telomerase activity.Growth inhibition of BIU-87 cells was measured by MTT assay.Gene chip analysis was performed to evaluate the effects of the combined RNAi of hTR+hTERT genes on telomerase activity and growth of BIU-87 cells in vitro.The results showed that the expression of hTERT and hTR mRNA was inhibited by pRNAT-hTERT-Ⅲ,pRNAT-hTR-Ⅲ,and pRNAT-hTR-Ⅲ+hTERT-Ⅲ in BIU-87 cells.The inhibition efficiency of pRNAT-hTERT-Ⅲ,pRNAT-hTR-Ⅲ,pRNAT-hTERT-Ⅲ+pRNAT-hTR-Ⅲ was 67% for TERT mRNA,41% for TR mRNA,57% for TR mRNA and 70% for TERT mRNA in BIU-87 cells respectively.The growth of BIU-87 cells was inhibited and telomerase activity was considerably decreased,especially in the cells treated with combined RNAi-hTR and-hTERT.Gene chip analysis revealed that 21 genes were down-regulated(ATM,BAX,BCL2,BCL2L1,B1RC5,CD44,CTNNB1,E2F1,JUN,MCAM,MTA1,MYC,NFKB1,NFKBIA.NME4,PNN,PNN,SERPINE1,THBS1,TNFRSF1A,and UCC1).The results indicated that hTR-siRNA and hTERT-siRNA,especially their combination,siRNA hTR+hTERT,specifically and effectively suppressed the expression of both hTR and hTERT mRNA and telomerase activity.Molecular biological mechanism by which combined siRNA-TR and-TERT inhibited telomerase activity and growth of BIU-87 cells in vitro may involve the down-regulation ofthe 21 genes.