Anti-TBX21 (C-terminal) polyclonal antibody

To prospectively study systemic in vivo immunological effects of sex hormones, using different phases of oral combined hormonal contraceptives (CHC), and the natural menstrual cycles in both healthy women and in women with multiple sclerosis (MS), blood samples from sixty female MS patients and healthy controls with and without CHC were drawn in high and low estrogenic/progestogenic phases. Expression of Th-associated genes in blood cells was determined by qPCR and a panel of cytokines and chemokines was measured in plasma. High hormone level phases were associated with increases in Th1 (TBX21) and Th2 (GATA3) associated markers, as well as the B cell-associated chemokine CXCL13, while the inhibitory regulator CTLA-4 was decreased. These changes were not observed in MS patients, of whom most were treated with immunomodulatory drugs. Our data indicate immune activating properties in vivo of high steroid sex hormone levels during both CHC and normal menstrual cyclicity.

T-bet is a key regulator for the lineage commitment in CD4(+) T helper (Th) 1 cells by activating the hallmark production of interferon-gamma. Previously, two single nucleotide polymorphisms (SNPs) in the TBX21 promoter, T-1993C and T-1514C, have been shown by statistic studies to associate with systemic lupus erythematosus (SLE). The effect of -1993 SNP on the Yin Yang 1 transcription factor-mediated promoter activity has been already indicated. This study aimed to investigate roles of the T-1514C SNP on TBX21 transcription and its functional effect by luciferase reporter, electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP) assay, and flow cytometric analysis of intracellular T-bet, IFN-gamma, and IL-4 expression in activated CD4(+) T cells. The TBX21 promoter carrying -1514C possessed significantly lower transcriptional activity than that of -1514T and was markedly downregulated by the overexpression of upstream stimulatory factor 1 (USF-1) when compared with the promoter carrying -1514T. EMSA indicated that the transcription factor USF-1 was bound to the -1514C allele probe with the affinity higher than that to the -1514T allele probe. ChIP assay suggested that USF-1 bound around -1514 of TBX21 genomic DNA in vivo in the human T cell line Jurkat with -1514C/T. The individuals carrying -1514C allele were determined to have significantly diminished expression of T-bet and IFN-gamma and increased IL-4 production in CD4(+) T cells compared with those of -1514T allele. The findings demonstrate that the T-1514C polymorphism affects TBX21 gene expression and Th1 cytokine production by binding USF-1 to the SNP site.