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Alzheimer's disease (AD) is the first most common neurodegenerative disease. Despite a large amount of research, the pathogenetic mechanism of AD has not yet been clarified. The two hallmarks of the pathology of AD are the extracellular senile plaques (SPs) of aggregated amyloid-beta (Aβ) peptide and the accumulation of the intracellular microtubule-associated protein tau into fibrillar aggregates. Heat shock proteins (HSPs) play a key role in preventing protein misfolding and aggregation, and Hsp90 can be viewed as a ubiquitous molecular chaperone potentially involved in AD pathogenesis. A role of Hsp90 regulates the activity of the transcription factor heat shock factor-1 (HSF-1), the master regulator of the heat shock response. In AD, Hsp90 inhibitors may redirect neuronal aggregate formation, and protect against protein toxicity by activation of HSF-1 and the subsequent induction of heat shock proteins, such as Hsp70. Therefore, we review here to further discuss the recent advances and challenges in targeting Hsp90 for AD therapy. [ABSTRACT FROM AUTHOR]

The hallmarks of the immune response to viral infections are the expansion of antigen-specific CD8+ cytotoxic T lymphocytes (CTLs) after they encounter antigen-presenting cells in the lymphoid tissues and their subsequent redistribution to nonlymphoid tissues to deal with the pathogen. Control mechanisms exist within CTL activation pathways to prevent inappropriate CTL responses against disseminating infections with a broad distribution of pathogen in host tissues. This is demonstrated during overwhelming infection with the noncytolytic murine lymphocytic choriomeningitis virus, in which clonal exhaustion (anergy and/or deletion) of CTLs prevents immune-mediated pathology but allows persistence of the virus. The mechanism by which the immune system determines whether or not to mount a full response to such infections is unknown. Here we present data showing that the initial encounter of specific CTLs with infected cells in lymphoid tissues is critical for this decision. Whether the course of the viral infection is acute or persistent for life primarily depends on the degree and kinetics of CTL exhaustion in infected lymphoid tissues. Virus-driven CTL expansion in lymphoid tissues resulted in the migration of large quantities of CTLs to nonlymphoid tissues, where they persisted at stable levels. Surprisingly, although virus-specific CTLs were rapidly clonally exhausted in lymphoid tissues under conditions of chronic infection, a substantial number of them migrated to nonlymphoid tissues, where they retained an effector phenotype for a long time. However, these cells were unable to control the infection and progressively lost their antiviral capacities (cytotoxicity and cytokine secretion) in a hierarchical manner before their eventual physical elimination. These results illustrate the differential tissue-specific regulation of antiviral T-cell responses during chronic infections and may help us to understand the dynamic relationship between antigen and T-cell populations in many persistent infections in humans. [ABSTRACT FROM AUTHOR]

25 at. % Rare-earth (RE)-doped ceria samples (RE=Sm, Dy, Y, and Yb) were examined using transmission electron microscopy and electron energy loss spectroscopy, from which the oxygen vacancy ordering in nanosized domains was confirmed. The relationships of the dopant type, oxygen vacancy ordering, and ionic conductivity of doped ceria were established. It is found that the ordering of oxygen vacancies depends strongly on the dopant type, and the development of nanosized domains with a higher degree of ordering can lead to a more dramatic decrease of ionic conductivity in doped ceria. [ABSTRACT FROM AUTHOR]

A characteristic feature in the immune response to many persistent viral infections is the dysfunction or deletion of antigen-specific T cells (exhaustion). This down-regulation of virus-specific T-cell response represents a critical control mechanism that exists within T-cell activation pathways to prevent lethal disease by inappropriate responses against disseminating virus infections. However, the molecular mechanisms by which the immune system determines whether to mount a full response to such infections remain largely unexplored. Here, we have established that in the murine lymphocytic choriomeningitis virus (LCMV) model, induction of the T-cell receptor signaling inhibitor molecule E3 ligase Cbl-b is critically involved in this decision. In particular, our data revealed that Cbl-b controls the program responsible for T-cell tolerance (exhaustion) induction during a chronic viral infection. Thus, Cbl-b-/- mice infected with a low dose of LCMV Docile mount a strong CD8+ T-cell response that rapidly clears the infection, and the animals remain healthy; in contrast, down-regulation of the epitope-specific CD8+ T-cell population in persistently infected Cbl-b-/- mice, compared to that in chronically infected B6 mice, was significantly delayed, and this was associated with increased morbidity and eventual death in nearly 20% of the animals. Interestingly, infection of Cbl-b-/- mice with a moderate virus dose resulted in rapid death with 100% mortality by 7 to 8 days after infection, caused by a dysregulated antiviral T-cell response, whereas the infected B6 mice survived and remained healthy. In conclusion, our results suggest that Cbl-b is critically involved in T-cell exhaustion and prevention of lethal disease. [ABSTRACT FROM AUTHOR]

The migration of activated antigen-specific immune cells to the target tissues of virus replication is controlled by the expression of adhesion molecules on the vascular endothelium that bind to ligands on circulating lymphocytes. Here, we demonstrate that the adhesion pathway mediated by vascular cell adhesion molecule 1 (VCAM-1) plays a role in regulating T-cell-mediated inflammation and pathology in nonlymphoid tissues, including the central nervous system (CNS) during viral infection. The ablation of VCAM-1 expression from endothelial and hematopoietic cells using a loxP-Cre recombination strategy had no major effect on the induction or overall tissue distribution of antigen-specific T cells during a systemic infection with lymphocytic choriomeningitis virus (LCMV), except in the case of lung tissue. However, enhanced resistance to lethal LCM and the significantly reduced magnitude and duration of footpad swelling observed in VCAM-1 mutant mice compared to B6 controls suggest a significant role for VCAM-1 in promoting successful local inflammatory reactions associated with efficient viral clearance and even life-threatening immunopathology under particular infection conditions. Interestingly, analysis of the infiltrating populations in the brains of intracerebrally infected mice revealed that VCAM-1 deletion significantly delayed migration into the CNS of antigen-presenting cells (macrophages and dendritic cells), which are critical for optimal stimulation of migrating virus-specific CD8+ T cells initiating a pathological cascade. We propose that the impaired migration of these accessory cells in the brain may explain the improved clinical outcome of infection in VCAM-1 mutant mice. Thus, these results underscore the potential role of VCAM-1 in regulating the immune response and inflammatory reactions against viral infections. [ABSTRACT FROM AUTHOR]

Antigenic variation is a viral strategy exploited to promote survival in the face of the host immune response and represents a major challenge for efficient vaccine development. Influenza viruses are pathogens with high transmissibility and mutation rates, enabling viral escape from immunity induced by prior infection or vaccination. Intense selection from neutralizing antibody drives antigenic changes in the surface glycoproteins, resulting in emergence of new strains able to reinfect hosts immune to previously circulating viruses. CD8+ cytotoxic T cells (CTLs) also provide protective immunity from influenza virus infection and may contribute to the antigenic evolution of influenza viruses. Utilizing mice transgenic for an influenza virus NP366-374 peptide-specific T-cell receptor, we demonstrated that the respiratory tract is a suitable site for generation of escape variants of influenza virus selected by CTL in vivo. In this report the contributions of the perforin and Fas pathways utilized by influenza virus-specific CTLs in viral clearance and selection of CTL escape variants have been evaluated. While transgenic CTLs deficient in either perforin- or Fas-mediated pathways are efficient in initial pulmonary viral control, variant virus emergence was observed in all the mice studied, although the spectrum of viral CTL escape variants selected varied profoundly. Thus, a less-restricted repertoire of escape variants was observed in mice with an intact perforin cytotoxic pathway compared with a limited variant diversity in perforin pathway-deficient mice, although maximal variant diversity was observed in mice having both Fas and perforin pathways intact. We conclude that selection of viral CTL escape variants reflects coordinate action between the tightly controlled perforin/granzyme pathway and the more promiscuous Fas/FasL pathway. [ABSTRACT FROM AUTHOR]

The emergence of the novel coronavirus disease 2019 (COVID-19) is a serious global public health problem. The mystery around the causative agent was revealed on 7 January 2020 when the pathogen was isolated by Chinese scientists and named as novel coronavirus-2019 (2019-nCoV). With quicker reaction to the contagion, the number of scholarly research publications have increased exponentially, which calls for bibliometric analysis and review of the incipient studies. Therefore on 7 Feb 2020, the English language and Chinese publications on COVID-19 were retrieved from PubMed and CNKI (China National Knowledge Infrastructure). A retrospective bibliometric analysis was performed to gauge the output, language, document type, journal, authorship, geographical distribution, research focus, resulting in a total of 154 papers comprising 100 papers in English and another 54 in Chinese. There were 30 journals published at least 2 papers, and the Journal of Medical Virology published the most papers (11). China and USA were the most productive countries, and there were 24 international collaborative papers. Fudan University contributed the most papers. Isaac I. Bogoch, Kunling Shen, Xingguang LI, Hongzhou Lu were the most active authors as first authors, with 2 papers respectively. Among the 154 publications, 35 were opinions papers, and 30 were research articles. Papers were categorized by research areas, and five research foci were identified. Our study offers an overview of the incipient publications and quantitative information for future research on coronavirus. Besides, Chinese publications were also retrieved for an integrated data analysis and diversity comparison. [ABSTRACT FROM AUTHOR]

Interleukin-33 (IL-33), a newly-discovered cytokine belonging to the IL-1 family, serves an important role in inflammation. However, it is not clear whether IL-33 is of clinical significance in hepatocarcinogenesis. The present study was designed to investigate the role of IL-33 during oncogenesis and development of hepatocellular carcinoma (HCC). IL-33 protein expression was detected in 76 HCC (including 36 para-carcinoma), 33 cirrhosis, 30 hepatitis, and 20 normal liver tissues using immunohistochemistry. IL-33 mRNA expression in carcinoma and para-carcinoma tissues was evaluated by reverse transcription-polymerase chain reaction (RT-PCR). The possible correlation between IL-33 and clinicopathological parameters of HCC was also analyzed. Significant differences in IL-33 expression were not observed among normal, hepatic, and cirrhotic tissues (P>0.05), whereas the level of protein positive rate was markedly reduced in HCC tissues (P<0.01). Positive staining of IL-33 in non-cancerous liver (NCL) tissues (i.e. normal, hepatitis, and liver cirrhosis) was located predominantly in the nucleus and occasionally in the cytoplasm of hepatocytes; however, the expression in HCC tissues was mostly restricted to the cytoplasm. A significant alteration in protein localization was observed in HCC tissues as compared with NCL tissues (P<0.01). In comparison with HCC tissues, cytoplasmic staining of IL-33 was increased in para-carcinoma tissues. RT-PCR assay further confirmed relatively high mRNA expression levels of IL-33 in para-carcinoma tissues. IL-33 expression was significantly negatively associated with tumor histological grade (r=-0.279, P=0.015), but not with year, gender, tumor size, clinical stage, HCC with hepatitis and cirrhosis background, lymph node metastasis or intrahepatic vascular embolism (P>0.05). Therefore, the aberrant expression of IL-33 is associated with oncogenesis and progression of HCC and the cytoplasmic accumulation of the protein may serve a role in hepatocarcinogenesis. [ABSTRACT FROM AUTHOR]

Cytosolic DNA sensing is an important process during the innate immune response that activates the stimulator of interferon genes (STING) adaptor and induces IFN-I. STING incites spontaneous immunity during immunogenic tumor growth and accordingly, STING agonists induce regression of therapy-resistant tumors. However DNA, STING agonists, and apoptotic cells can also promote tolerogenic responses via STING by activating immunoregulatory mechanisms such as indoleamine 2,3 dioxygenase (IDO). Here, we show that IDO activity induced by STING activity in the tumor microenvironment (TME) promoted the growth of Lewis lung carcinoma (LLC). Although STING also induced IDO in tumor-draining lymph nodes (TDLN) during EL4 thymoma growth, this event was insufficient to promote tumorigenesis. In the LLC model, STING ablation enhanced CD8+ T-cell infiltration and tumor cell killing while decreasing myeloidderived suppressor cell infiltration and IL10 production in the TME. Depletion of CD8+ T cells also eliminated the growth disadvantage of LLC tumors in STING-deficient mice, indicating that STING signaling attenuated CD8+ T-cell effector functions during tumorigenesis. In contrast with native LLC tumors, STING signaling neither promoted growth of neoantigen-expressing LLC, nor did it induce IDO in TDLN. Similarly, STING failed to promote growth of B16 melanoma or to induce IDO activity in TDLN in this setting. Thus, our results show how STING-dependent DNA sensing can enhance tolerogenic states in tumors characterized by low antigenicity and how IDO inhibition can overcome this state by attenuating tumor tolerance. Furthermore, our results reveal a greater complexity in the role of STING signaling in cancer, underscoring how innate immune pathways in the TME modify tumorigenesis in distinct tumor settings, with implications for designing effective immunotherapy trials. [ABSTRACT FROM AUTHOR]

The effect of dry-curing salt content (4% low salt (LS), 8% high salt (HS)) on lipolysis, lipid oxidation and volatile compounds in dry-cured goose was investigated in our study. The activities of acid lipase and neutral lipase increased during dry-curing, while phospholipase reached its maximum at the end of marinating. Lipoxygenase (LOX) and thiobarbituric acid reactive substances (TBARS) values increased during dry-curing and marinating then decreased during dry-ripening. Total free fatty acids (TFFA) increased at dry-curing and dry-ripening points and decreased during marinating. Total peak area of lipids derived volatile compounds (TPALDVC) and total peak area increased during entire stages. Compared to LS, HS group has higher lipolytic and LOX activities, TBARS, TFFA, unsaturated fatty acids and TPALDVC. The higher TPALDVC in HS could be attributed to higher lipid hydrolysis and oxidation during processing. [ABSTRACT FROM AUTHOR]

Defect clusters with ordered structures in Gd-doped ceria have been verified by transmission electron microscopy. Atomistic simulation validates further the ordered structures and related pathway for cluster growth. A unique dumbbell structure formed with six oxygen vacancies in a ceria matrix has been identified as the building block for detect cluster growth and sequentially for the evolution from a F- to C-type lattice. As such, the phase transformation as established on the atomic scale occurs through this defect cluster growth. [ABSTRACT FROM AUTHOR]

We constructed a peptide consisting of a staphylococcal AgrD1 pheromone fused to the channel-forming domain of colicin Ia and named it pheromonicin. This fusion peptide had bactericidal effects against methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA, respectively), but not against Staphylococcus epidermidis or Streptococcus pneumoniae. Growth rates, vital staining and colony forming unit (CFU) counts showed that pheromonicin did not merely suppress growth but killed S. aureus cells. The specificity of pheromonicin was shown by the absence of bactericidal effects against an accessory gene regulator (agr) locus knockout of S. aureus, and a dose-dependent inhibition of the bactericidal effects of pheromonicin by competition with corresponding free AgrD pheromone. In vivo, all pheromonicin-treated mice survived administration of MRSA that was lethal to controls. No toxicity was detectable in human liver or renal cells in culture, or in livers, kidneys or spleens of pheromonicin-treated mice. The results suggest that these types of chimeric peptides may be of value as antibiotics against specific bacterial infections. [ABSTRACT FROM AUTHOR]

Presents a correction to the article "An Engineered Multidomain Bactericidal Peptide As a Model for Targeted Antibiotics Against Specific Bacteria," that was previously published in the 2003 issue of the journal "Nature Biotechnology."