is the causative agent of a severe pneumonia called Legionnaires' disease. A single strain of encodes a repertoire of over 300 different effector proteins that are delivered into host cells by the Dot/Icm type IV secretion system during infection. The large number of effectors has been a limiting factor in assessing the importance of individual effectors for virulence. Here, a transposon insertion sequencing technology called INSeq was used to analyze replication of a pool of effector mutants in parallel both in a mouse model of infection and in cultured host cells. Loss-of-function mutations in genes encoding effector proteins resulted in host-specific or broad virulence phenotypes. Screen results were validated for several effector mutants displaying different virulence phenotypes using genetic complementation studies and infection assays. Specifically, loss-of-function mutations in the gene encoding LegC4 resulted in enhanced in the lungs of infected mice but not within cultured host cells, which indicates LegC4 augments bacterial clearance by the host immune system. The effector proteins RavY and Lpg2505 were important for efficient replication within both mammalian and protozoan hosts. Further analysis of Lpg2505 revealed that this protein functions as a metaeffector that counteracts host cytotoxicity displayed by the effector protein SidI. Thus, this study identified a large cohort of effectors that contribute to virulence positively or negatively and has demonstrated regulation of effector protein activities by cognate metaeffectors as being critical for host pathogenesis.

BackgroundThe dose-dependent toxicities of doxorubicin (DOX) limit its clinical applications, particularly in drug-resistant cancers, such as liver cancer. In this study, we investigated the role of quercetin on the antitumor effects of DOX on liver cancer cells and its ability to provide protection against DOX-mediated liver damage in mice.Methodology and ResultsThe MTT and Annexin V/PI staining assay demonstrated that quercetin selectively sensitized DOX-induced cytotoxicity against liver cancer cells while protecting normal liver cells. The increase in DOX-mediated apoptosis in hepatoma cells by quercetin was p53-dependent and occurred by downregulating Bcl-xl expression. Z-VAD-fmk (caspase inhibitor), pifithrin-α (p53 inhibitor), or overexpressed Bcl-xl decreased the effects of quercetin on DOX-mediated apoptosis. The combined treatment of quercetin and DOX significantly reduced the growth of liver cancer xenografts in mice. Moreover, quercetin decreased the serum levels of alanine aminotransferase and aspartate aminotransferase that were increased in DOX-treated mice. Quercetin also reversed the DOX-induced pathological changes in mice livers.Conclusion and SignificanceThese results indicate that quercetin potentiated the antitumor effects of DOX on liver cancer cells while protecting normal liver cells. Therefore, the development of quercetin may be beneficial in a combined treatment with DOX for increased therapeutic efficacy against liver cancer.

PURPOSE Differentiating the irinotecan dose on the basis of the uridine diphosphate glucuronosyltransferase 1A1 ( UGT1A1) genotype improves the pathologic complete response (pCR) rate. In this study, we further investigated preoperative irinotecan combined with capecitabine-based chemoradiotherapy for locally advanced rectal cancer. PATIENTS AND METHODS We conducted this randomized, open-label, multicenter, phase III trial in China. Eligible patients with clinical T3-4 and/or N+ rectal adenocarcinoma, UGT1A1 genotype *1*1 or *1*28 were randomly allocated to the control group: pelvic radiation of 50 Gy/25 fractions with concurrent capecitabine, followed by oxaliplatin and capecitabine; or the experimental group: radiation with capecitabine combined with weekly irinotecan 80 mg/m2 for patients with UGT1A1*1*1 or 65 mg/m2 for patients with UGT1A1*1*28, followed by irinotecan and capecitabine. The primary end point was pCR. This trial was registered with ClinicalTrials.gov (ClinicalTrials.gov identifier: NCT02605265). RESULTS Of the 360 patients initially enrolled, 356 were evaluated as the modified intention-to-treat population (n = 178 in both groups). Surgery was performed in 87% and 88% of patients in the control and experimental groups, respectively. The pCR rates were 15% (n = 27 of 178) and 30% (n = 53 of 178) in the control and experimental groups (risk ratio, 1.96; 95% CI, 1.30 to 2.97; P = .001). Four and 6 patients achieved complete clinical response in the control and experimental groups, respectively. Grade 3-4 toxicities were recorded in 11 (6%) and 68 (38%) patients in the control and experimental groups, respectively ( P < .001). The commonest grade 3-4 toxicities were leukopenia, neutropenia, and diarrhea. The overall surgical complication rate was not significantly different between the two groups (11% v 15%; P < .001). CONCLUSION Adding irinotecan guided by UGT1A1 genotype to capecitabine-based neoadjuvant chemoradiotherapy significantly increased complete tumor response in Chinese patients.

Legionella pneumophila, a causative agent of pneumonia, utilizes the Type 4B secretion (T4BS) system to translocate over 300 effectors into the host cell during infection. T4BS systems are encoded by a large gene cluster termed dot/icm, three components of which, DotL, DotM, and DotN, form the “coupling complex”, which serves as a platform for recruitment of effector proteins. One class of effectors includes proteins containing Glu-rich/E-block sequences at their C terminus. However, the protein or region of the coupling complex mediating recruitment of such effectors is unknown. Here we present the crystal structure of DotM. This all alpha-helical structure exhibits patches of positively charged residues. We show that these regions form binding sites for acidic Glu-rich peptides and that mutants targeting these patches are defective in vivo in the translocation of acidic Glu-rich motif-containing effectors. We conclude that DotM forms the interacting surface for recruitment of acidic Glu-rich motif-containing Legionella effectors.

GC patients with an elevated CTGF expression have more lymph node metastases and a shorter survival time. CTGF seems to be an independent prognostic factor for the successful differentiation of high-risk GC patients staging I + II + III. Over-expression of CTGF in human GC cells results in an increased aggressive ability.

No abstract

Some studies suggest that the histaminergic system plays an important role in learning and memory. However, the results seem to be controversial in many behavioral tasks. In the present study, we used HDC knockout (HDC-KO) mice to investigate the effects of long-term histamine deficiency on learning and memory in contextual fear conditioning. We found that HDC-KO mice exhibited improved contextual fear from 1 day after training and this lasted for at least 14 days when compared with the wild-type (WT) controls. Cued fear was also improved 2 days after training in HDC-KO mice. Moreover, injection of histamine (intracerebroventricularly, 10 microg/mouse) immediately after training reversed the improvement in contextual fear conditioning when tested 1 day after training. Electrophysiological data showed that hippocampal CA1 long-term potentiation (LTP) in HDC-KO mice was much greater than that in WT mice, and paired-pulse facilitation decreased 2 h after LTP induction in HDC-KO mice. In contrast, HDC-KO mice showed smaller LTP than did WT mice 1 day after training. Hippocampal glutamate levels significantly increased in HDC-KO mice 1 and 4 days after training. The results indicated that histamine deficiency may improve consolidation of contextual fear conditioning. This improvement may be due to the increased hippocampal CA1 LTP, and presynaptic glutamate release. The relationship between behavior and synaptic plasticity provides support for the involvement of activity-dependent LTP in learning and memory.

It has been reported that in patients with operable stage I non-small cell lung cancer (NSCLC), overall survival (OS) is better in those who undergo hypofractionated stereotactic radiation therapy (HSRT) than in those who undergo surgery. However, the reason that HSRT has a better OS has not been fully explored. Here, we analyzed reconstitution kinetics in immune cells in the peripheral blood of NSCLC patients after HSRT. We found that HSRT increased the frequency of total T cells, especially the proportion of CD8+ T cells, but decreased the frequency of inhibitory Tregs. Intracellular staining showed that after HSRT, peripheral CD8+ T cells were transformed into activated T cells, which express high levels of TNF-α, IFN-γ, granzyme B and IL-2. HSRT also increased the production of IL-2, TNF-α, and IFN-γ but down-regulated the production of TGF-β in CD4+ T cells. The frequencies of naïve B cells and double-negative B cells were lower, while the proportions of MZ-like B cells, transitional B cells and plasmablast cells were higher after HSRT. Collectively, our results demonstrate that HSRT activates the peripheral immune response and indicate the dynamic variation in peripheral lymphocytes after HSRT, which is very important for optimizing combination treatments in clinical practice.