Background:Anti-PD-1 monoclonal antibodies, nivolumab and pembrolizumab, and anti-CTLA-4 antibody ipilimumab are being in clinic trials to treat melanoma. Here, we performed a meta-analysis to evaluate the efficacy and toxicity of them against advanced melanoma.Methods:Eleven reports from 6 randomized control trials on treating metastatic melanoma, which were divided into 3 subgroups, nivolumab/pembrolizumab versus chemotherapy, nivolumab versus ipilimumab, and nivolumab-plus-ipilimumab versus ipilimumab, were included and the meta-analysis was performed for each subgroup. The outcome measures were objective response rates (ORR), median progression free survival (PFS), 1-year overall survival rates (OS), and toxicity estimated by grade 3 to 4 adverse events.Results:For nivolumab/pembrolizumab versus chemotherapy, nivolumab versus ipilimumab, and nivolumab-plus-ipilimumab versus ipilimumab, the pooled risk ratios (RR) of the ORR were 3.43 (95% CI: 2.57–4.58), 2.51 (95% CI: 2.03–3.09), and 3.28 (95% CI: 2.58–4.17), respectively. The pooled HR of PFS were 0.42 (95% CI: 0.36–0.49), 0.58 (95% CI: 0.50–0.66), and 0.41 (95% CI: 0.30–0.52), respectively. The pooled RR of 1-year OS was 1.37 (95% CI: 1.08–1.74) and 1.54 (95% CI: 0.90–2.63) for nivolumab versus ipilimumab and nivolumab-plus-ipilimumab versus ipilimumab. These results suggested that anti-PD-1 monotherapy and nivolumab-plus-ipilimumab therapy had ORR and PFS benefit compared with the control group. Anti-PD-1 treatment increased 1-year OS for patients compared with ipililumab treatment. But there is no significantly difference on 1-year OS between the nivolumab-plus-ipilimumab treatment and the ipilimumab treatment group. The toxicity analysis showed that there is less risk of adverse events in the anti-PD-1 treatment group compared with the chemotherapy and ipilimumab group. Combining nivolumab with ipilimumab increased the risk for high-grade adverse events compared with ipilimumab alone but the adverse events were generally manageable.Conclusions:Anti-PD-1 monotherapy and nivolumab-plus-ipilimumab therapy improved ORR and prolonged PFS of patients with advanced melanoma and the adverse events are generally manageable. The therapy is indeed a promising approach for treatment of advanced melanoma.

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Persister cells are metabolically quiescent multi-drug tolerant fraction of a genetically sensitive bacterial population and are thought to be responsible for relapse of many persistent infections. Persisters can be formed naturally in the stationary phase culture, and also can be induced by bacteriostatic antibiotics. However, the molecular basis of bacteriostatic antibiotic induced persister formation is unknown. Here, we established a bacteriostatic antibiotic induced persister model and screened the Escherichia coli single gene deletion mutant library for mutants with defect in rifampin or tetracycline induced persistence to ofloxacin. Thirsty-seven and nine genes were found with defects in rifampin- and tetracycline-induced persister formation, respectively. Six mutants were found to overlap in both rifampin and tetracycline induced persister screens: recA, recC, ruvA, uvrD, fis, and acrB. Interestingly, four of these mutants (recA, recC, ruvA, and uvrD) mapped to DNA repair pathway, one mutant mapped to global transcriptional regulator (fis) and one to efflux (acrB). The stationary phase culture of the identified mutants and parent strain BW25113 were subjected to different antibiotics including ofloxacin, ampicillin, gentamicin, and stress conditions including starvation and acid pH 4.0. All the six mutants showed less tolerance to ofloxacin, but only some of them were more sensitive to other specific stress conditions. Complementation of five of the six common mutants restored the persister level to that of the parent strain in both stationary phase and static antibiotic-induced conditions. In addition to the DNA repair pathways shared by both rifampin and tetracycline induced persisters, genes involved in rifampin-induced persisters map also to transporters, LPS biosynthesis, flagella biosynthesis, metabolism (folate and energy), and translation, etc. These findings suggest that persisters generated by different ways may share common mechanisms of survival, and also shed new insight into the molecular basis of static antibiotic induced antagonism of cidal antibiotics.

To search for more effective tuberculosis (TB) subunit vaccines, antigens expressed in different growth stages of Mycobacterium tuberculosis (M. tuberculosis), such as RpfE (Rv2450c) produced in the stage of resuscitation, Mtb10.4 (Rv0288), Mtb8.4 (Rv1174c), ESAT6 (Rv3875), Ag85B (Rv1886c) mainly secreted by replicating bacilli, and HspX (Rv2031c) highly expressed in dormant bacilli, were selected to construct six fusion proteins: ESAT6-Ag85B-MPT64190-198-Mtb8.4 (EAMM), Mtb10.4-HspX (MH), ESAT6-Mtb8.4, Mtb10.4-Ag85B, ESAT6-Ag85B, and ESAT6-RpfE. The six fusion proteins were separately emulsified in an adjuvant composed of N,N’-dimethyl-N, N’-dioctadecylammonium bromide (DDA), polyribocytidylic acid (poly I:C) and gelatin to construct subunit vaccines, and their protective effects against M. tuberculosis infection were evaluated in C57BL/6 mice. Furthermore, the boosting effects of EAMM and MH in the adjuvant of DDA plus trehalose 6,6'-dimycolate (TDM) on BCG-induced immunity were also evaluated. It was found that the six proteins were stably produced in E. coli and successfully purified by chromatography. Among them, EAMM presented the most effective protection against M. tuberculosis. Interestingly, the mice that received EAMM+MH had significantly lower bacterial counts in the lungs and spleens than the single protein vaccinated groups, and had the same effect as those that received BCG. In addition, EAMM and MH could improve BCG-primed protective efficacy against M. tuberculosis infection in mice. In conclusion, the combination of EAMM and MH containing antigens from both replicating and dormant stages of the bacilli could induce robust immunity against M. tuberculosis infection in mice and may serve as promising subunit vaccine candidate.