SUMMARY A common thread among conserved lifespan regulators lies within intertwined roles in metabolism and energy homeostasis. We show that heterozygous mutations of adenosine monophosphate (AMP) biosynthetic enzymes extend Drosophila lifespan. The lifespan benefit of these mutations depends upon increased AMP to adenosine triphosphate (ATP) and adenosine diphosphate (ADP) to ATP ratios and adenosine monophosphate-activated protein kinase (AMPK). Transgenic expression of AMPK in adult fat body or adult muscle, key metabolic tissues, extended lifespan, while AMPK RNAi reduced lifespan. Supplementing adenine, a substrate for AMP biosynthesis, to the diet of long-lived AMP biosynthesis mutants reversed lifespan extension. Remarkably, this simple change in diet also blocked the pro-longevity effects of dietary restriction. These data establish AMP biosynthesis, adenosine nucleotide ratios, and AMPK as determinants of adult lifespan, provide a mechanistic link between cellular anabolism and energy sensing pathways, and indicate that dietary adenine manipulations might alter metabolism to influence animal lifespan.

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The failure of Mycobacterium bovis BCG as a TB vaccine against TB reactivation suggests that latency-associated proteins should be included in alternative TB vaccine development. Further, antigens known to generate protective immunity against the strong Th1 stimulatory response to reactivated TB should be included in novel vaccine design. Recent studies have emphasized the importance of Rpfs from Mycobacterium tuberculosis in the reactivation process and cellular immunity. However, little is known about how RpfB mediates protective immunity against M. tuberculosis. Here, we investigated the functional roles and signaling mechanisms of RpfB in DCs and its implications in the development of T cell immunity. DCs treated with RpfB displayed features of mature and functional status, with elevated expression of cell surface molecules (CD80, CD86, and MHC class I and II) and proinflammatory cytokine production (TNF-α, IL-1β, IL-6, and IL-12p70). Activation of DCs was mediated by direct binding of RpfB to TLR4, followed by MyD88/TRIF-dependent signaling to MAPKs and NF-κB signaling pathways. Specifically, we found that the RpfB G5 domain is the most important part in RpfB binding to TLR4. RpfB-treated DCs effectively polarized naïve CD4(+) and CD8(+) T cells to secrete IFN-γ and IL-2. Importantly, RpfB induced the expansion of memory CD4(+)/CD8(+)CD44(high)CD62L(low) T cells in the spleen of M. tuberculosis-infected mice. Our data suggest that RpfB regulates innate immunity and activates adaptive immunity through TLR4, a finding that may help in the design of more effective vaccines.

Evidence suggests that combined gemcitabine-cisplatin chemotherapy extends survival in patients with advanced biliary tract cancer (BTC). We conducted a systematic review in order to collate this evidence and assess whether gemcitabine-cisplatin efficacy is influenced by primary tumor site, disease stage, or geographic region, and whether associated toxicities are related to regimen. MEDLINE (1946-search date), EMBASE (1966-search date), ClinicalTrials. gov (2008-search date), and abstracts from major oncology conferences (2009- search date) were searched (5 Dec 2013) using terms for BTC, gemcitabine, and cisplatin. All study types reporting efficacy (survival, response rates) or safety (toxicities) outcomes of gemcitabine-cisplatin in BTC were eligible for inclusion; efficacy data were extracted from prospective studies only. Evidence retrieved from one meta-analysis (abstract), four randomized controlled trials, 12 nonrandomized prospective studies, and three retrospective studies supported the efficacy and safety of gemcitabine-cisplatin for BTC. Median overall survival ranged from 4.6 to 11.7 months, and response rate ranged from 17.1% to 36.6%. Toxicities were generally acceptable and manageable. Heterogeneity in study designs and data collected prevented formal meta-analysis, however exploratory assessments suggested that efficacy did not vary with primary tumor site (gallbladder vs. others), disease stage (metastatic vs. locally advanced), or geographic origin (Asia vs. other). Incidence of grade 3/4 toxicities was not related to gemcitabine dose or cisplatin frequency. Despite individual variation in study designs, the evidence presented suggests that gemcitabine-cisplatin is effective in patients from a diverse range of countries and with heterogeneous disease characteristics. No substantial differences in toxicity were observed among the different dosing schedules of gemcitabine and cisplatin.