Anti-TBX21 Monoclonal antibody, clone 5C20 [PE]

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.

Recurrent rejection shortens graft survival after intestinal transplantation (ITx) in children, most of whom also experience early acute cellular rejection (rejectors). To elucidate mechanisms common to early and recurrent rejection, we used a test cohort of 20 recipients to test the hypothesis that candidate peripheral blood leukocyte genes that trigger rejection episodes would be evident late after ITx during quiescent periods in genome-wide gene expression analysis and would achieve quantitative real-time PCR replication pre-ITx (another quiescent period) and in the early post-ITx period during first rejection episodes. Eight genes were significantly up-regulated among rejectors in the late post-ITx and pre-ITx periods, compared with nonrejectors: TBX21, CCL5, GNLY, SLAMF7, TGFBR3, NKG7, SYNE1, and GK5. Only CCL5 was also up-regulated in the early post-ITx period. Among resting peripheral blood leukocyte subsets in randomly sampled nonrejectors, CD14(+) monocytes expressed the CCL5 protein maximally. Compared with nonrejectors, rejectors demonstrated higher counts of both circulating CCL5(+)CD14(+) monocytes and intragraft CD14(+) monocyte-derived macrophages in immunohistochemistry of postperfusion and early post-ITx biopsies from the test and an independent replication cohort. Donor-specific alloreactivity measured with CD154(+) T-cytotoxic memory cells correlated with the CCL5 gene and intragraft CD14+ monocyte-derived macrophages at graft reperfusion and early post-ITx. CCL5 gene up-regulation and CD14+ macrophages likely prime cellular ITx rejection. Infiltration of reperfused intestine allografts with CD14+ macrophages may predict rejection events. (Am Pathol 2011, 179:1929-1938. DOI: 10.1016/j.ajpath.2011.06.040)