Anti-TBX21 monoclonal antibody, clone fCjp5C20

The differentiation of naive T helper (Th) cells is induced by TCR activation and IL-12/STAT4 or IL-4/STAT6 signaling pathways, forming Th1 and Th2 cells, respectively. In this study, oligonucleotide arrays were used to identify genes regulated during the initiation of human Th1 and Th2 cell differentiation at 2 and 6 h in presence or absence of immunosuppressive TGF-beta. As a result the immediate targets of IL-12, IL-4 and TGF-beta were identified. The effects of IL-12 at this early stage were minimal and consistent with the known kinetics of IL-12R beta 2 expression. IL-4, however, was observed to rapidly regulate 63 genes, 26 of which were differentially expressed at both the 2- and 6-h time points. Of these IL-4 regulated genes, one-third have previously been observed to display expression changes in the later phases of the polarization process. Similarly to the key regulators, TBX21 and GATA3, the transcription factors SATB1, TCF7 and BCL6 were differentially regulated at the protein level during early Th1 and Th2 cell polarization. Moreover, the developing Th1 and Th2 cells were demonstrated to be responsive to the immunosuppressive TGF-beta and IL-10. In this study, a panel of novel factors that may be important regulators of the differentiation process was identified.

Owing to the limitations of traditional Bacillus Calmette-Guerin vaccines and the low efficacy of DNA vaccines expressing single antigens of Mycobacterium tuberculosis, there is a pressing requirement for adjuvants capable of strengthing the immunogenicity and effectiveness of these vaccines against tuberculosis (TB). T-bet (TBX21) is a transcription factor, which controls the optimal development of type-1 immune responses responsible for the potent protection of vaccines against TB. However, little is known about the efficiency of the TB vaccine combined with T-bet. In this study, we report an approach to intensify the immunogenicity of Ag85B DNA-based vaccines using T-bet as an adjuvant. Balb/c mice were immunized by 3 intramuscular inoculations with pcDNA3.1-FLAG-T-bet in combination with pcDNA3.1-FLAG-Ag85B, and the immune responses were compared with those induced by vaccination with Ag85B DNA alone. We found that pcDNA3.1-T-bet-Ag85B not only induced evidently higher IgG2a antibody responses, but also increased the production of interferon-gamma (IFN-gamma) and interleukin (IL)-2 with the concomitant repression of IL-4 and IL-10 compared with pcDNA3.1-Ag85B alone or the empty vector. Thus, plasmid DNA coding for T-bet enhanced Ag85B-specific immune responses and shifted them to a predominant Thl-type immune response. In conclusion, T-bet is an efficacious Thl-inducing adjuvant in the context of the Ag85B DNA-based vaccination, and could also prove to be a promising candidate for DNA vaccine development against TB.