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Bacterial translocation from the gut and subsequent immune activation are hallmarks of HIV infection and are thought to determine disease progression. Intestinal barrier integrity is impaired early in acute retroviral infection, but levels of plasma lipopolysaccharide (LPS), a marker of bacterial translocation, increase only later. We examined humanized mice infected with HIV to determine if disruption of the intestinal barrier alone is responsible for elevated levels of LPS and if bacterial translocation increases immune activation. Treating uninfectedmice with dextran sodiumsulfate (DSS) induced bacterial translocation, but did not result in elevated plasma LPS levels. DSS-induced translocation provoked LPS elevation only when phagocytic cells were depleted with clodronate liposomes (clodrolip). Macrophages of DSS-treated, HIV-negative mice phagocytosedmore LPS ex vivo than those of control mice. In HIV-infected mice, however, LPS phagocytosis was insufficient to clear the translocated LPS. These conditions allowed higher levels of plasma LPS and CD8+ cell activation, which were associated with lower CD4+/CD8+ cell ratios and higher viral loads. LPS levels reflect both intestinal barrier and LPS clearance. Macrophages are essential in controlling systemic bacterial translocation, and this function might be hindered in chronic HIV infection. [ABSTRACT FROM AUTHOR]

Phagocytosis of fine particles (1 μm) by macrophages is a ligand-receptor–mediated, actin-based process, whereas the entering of smaller particles (≤ 0.2 μm) in macrophages occurs also by other mechanisms. Virosomes with a diameter of 0.12–0.18 μm are widely used as carrier systems for drugs, vectors, and plasmids in cancer therapy or for vaccines. We investigated their interactions with airway cells, in particular penetration into monocyte-derived macrophages. The microscopic analysis of phagocytic cells incubated with virosomes and polystyrene particles showed that virosomes and particles penetrated cells even in the presence of cytochalasin D, a drug inhibiting actin-based phagocytosis. The charge of the virosomes and particles did not influence their penetration. Also, different inhibitors of endocytotic pathways did not prevent the particles and virosomes from penetrating into the cells. Additionally, to study the ability of virosomes to overcome the epithelial airway barrier, a triple cell co-culture model composed of epithelial cells, monocyte-derived macrophages and dendritic cells of the respiratory tract was used. We found virosomes and polystyrene particles in both populations of antigen-presenting cells, monocyte-derived macrophages, and dendritic cells, in the latter even if they were not directly exposed. In conclusion, virosomes are readily taken up by monocyte-derived macrophages, both by conventional phagocytosis and by actin-independent mechanisms. Further, they can penetrate the airway barrier and reach resident dendritic cells. Therefore, virosomes are promising vaccine candidates. [ABSTRACT FROM AUTHOR]

Why and how HIV makes people sick is highly debated. Recent evidence implicates heightened immune activation due to breakdown of the gastrointestinal barrier as a determining factor of lentiviral pathogenesis. HIV-mediated loss of Th17 cells from the gut-associated lymphoid tissue (GALT) impairs mucosal integrity and innate defense mechanisms against gut microbes. Translocation of microbial products from the gut, in turn, correlates with increased immune activation in chronic HIV infection and may further damage the immune system by increasing viral and activation-induced T cell death, by reducing T cell reconstitution due to tissue scarring, and by impairing the function of other cell types, such as γδ T cells and epithelial cells. Maintaining a healthy GALT may be the key to reducing the pathogenic potential of HIV. [ABSTRACT FROM AUTHOR]

Rectal transmission is one of the main routes of infection by human immunodeficiency virus type 1 (HIV-1). To efficiently study transmission mechanisms and prevention strategies, a small animal model permissive for rectal transmission of HIV is mandatory. We tested the susceptibility of RAG2-/-γc-/- mice transplanted with human cord blood hematopoietic stem cells to rectal infection with HIV. We rectally exposed these humanized mice to cell-free and cell-associated HIV. All mice remained HIV negative as assessed by plasma viral load. The same mice infected intraperitoneally showed high levels of HIV replication. In the gut-associated lymphatic tissue, we found disproportionately smaller numbers of human cells than in other lymphoid organs. This finding may explain the observed resistance to rectal transmission of HIV. To increase the numbers of local HIV target cells and the likelihood of HIV transmission, we treated mice with different proinflammatory stimuli: local application of interleukin-1β, addition of seminal plasma to the inoculum, or induction of colitis with dextran sodium sulfate. These procedures attracted some human leukocytes, but the transmission rate was still very low. The humanized mice showed low levels of human engraftment in the intestinal tract and seem to be resistant to rectal transmission of HIV, and thus they are an unsuitable model for this application. [ABSTRACT FROM AUTHOR]

Focuses on the impact of Condorcet's views on reason, knowledge and education on the educational system of France during the eighteenth century. Importance of the free use of reason; Objectives of the instruction publique; Contrast between instruction publique and instruction nationale; Demand for freedom and equality in education.

The article reports on the study that determines the role of RNA interference (RNAi) influencing infection of human cells with bacterial and viral pathogens. It details the method of the study in which the authors designed synthetic siRNAs that promote seed sequence. It also outlines the result of the study which indicates that small interferring (siRNA) screens should be carefully evaluated as important determinants of pathogen infection.

The article reports on the study that determines a bacterial marker that can be used as diagnostic and prognostic tool in identifying the pathogenies of Crohn's disease. It provides overview of the background of Chrohn's disease and the method of the study, which analyzes mucosal biopsy and faecal samples from 447 children. It also mentions the result of the study which reveals the association of specific bacterial taxa with the disease.

The article cites a research study by R.K. Grover and colleagues, published in the online edition of the journal "Nature Reviews Microbiology," which analyzed an antibody-binding protein in Mycoplasma spp. The mycoplasmal protein has a unique structure which allows it to broadly bind to human antibodies and inhibit their engagement with antigens.

The article discusses two research studies about HIV-1 infection. A study revealed that the death of bystander cells in an HIV-positive person is caused by abortive infection of CD4 T cells followed by pyroptosis. Meanwhile, another study showed the binding of inflammasome activator interferon-γ-inducible protein 16 to HIV-1 DNA.

The article reports on a study which examines the gut microbiome in the maternal immune activation (MIA) mouse model. An analysis was conducted to prove the speculation regarding the capacity of Bacteroides fragilis treatment to reverse MIA pathology. Findings show the partial correction of dysbiosis in MIA mice that received Bacteroides fragilis treatment and the therapy's potential to be used in neurodevelopmental disorders.

The article focuses on a study regarding bacterial and viral component of the human microbiome. It reveals that the viral component in plasma grows substantially during immunosuppressive therapy, suggesting that virome dynamics can be applied in predicting immunocompetence. Information about the Anelloviridae, a newly discovered virus family, is provided.

The article reports on the results of a study which determined the common ancestor of Melainabacteria and Cyanobacteria. It cites that the study describe a candidate sibling phylum, Melainabacteria, by searching for sequences that are related to Cyanobacterial genes from sequenced DNA, human faecal samples, and groundwater aquifer. It notes that Melainabacteria and Cyanobacteria are closely related but distinct in terms of the capacity to fix nitrogen, photosynthetic genes, and protein coding.

The article presents a study which indicates that the process if selfing can result to phenotypic diversity through the production of aneuploid progeny based on the analysis over the replication and mating of genetically identical Cryptococcus neoformans (C. neoformans) cells.

The article reports on studies which identified an HIV restriction factor, the antiviral cytokine interferon (IFNa)-inducible myxovirus resistance 2 (MX2) protein. It refers to the identification of 14 IFN-induced genes that were upregulated in responsive HIV-resistant cells through transcriptional profiling. Results suggests that MX2 has reduced the levels of terminal repeat circular DNA and has integrated viral DNA indicating that MX2 could also decrease the stability of viral replication.

The article reports on a study presented by Smith and colleagues regarding the proofreading activity of polymerase of RNA viruses. It states that in the case of severe acute respiratory syndrome coronavirus (SARS-CoV), the exoribonuclease domain (ExoN) provides proofreading activity that prevents virus from mutagenesis. It notes that the research study aims to describe the hypotheses that ExoN is a proofreading enzyme.

The article discusses the research about the physiology of Bacillus subtilis (BsIA) biofilms. It references the study "BsIA is a self-assembling bacterial hydrophobin that coats the Bacillus subtilis biolfim," by L. Hobley and colleagues in the 2013 issue. It states that BsIA biofilms acts as water-repellent and defend bacterial colonies formed on plant roots from environmental threats.

The article explores the metagenomic studies on single-cell genomics to enhance the archael genomes and bacterial recover from uncultured environment. It notes the phylogenetic analysis on single-cell genomes which contains parvarchaeota and two bacterial lineages. It examines the cultured marine microorganisms of uncultured bacterioplankton lineages in marine ecosystems. It also adds that the studies used single-cell genomics approach to identify the relationship among phylogenetic genomes.

The article discusses a study which examines the composition of the human gut virome and its variation in bacterial colonizations. It mentions the method of the study collected the viral DNA and amplication of an adult male for 2.5 years. It found that human gut virome is comprised of long-term resident phages that contribute to individual variation.

In this article the author focuses on the first metatranscriptomic analysis of sub-seafloor communities. In this, the author used an optimized microRNA extraction and amplification technique to study anaerobic sediments from the Peru Margin, covering depths of 5159 meter below the sea floor. The author further mentions the turnover of the microbial biomass in the deep biosphere.

The article discusses research regarding the commensal bacterium Akkermansia muciniphila in the intestinal mucus layer. It references the study "Cross-talk between Akkermansia muciniphila and intestinal epithelium controls diet-induced obesity" by A. Everard in the May 13, 2013 issue of the journal "Proceedings of the National Academy of Sciences." It cites the research done on a mice with a high-fat diet, A. Muciniphila, and lipopolysaccharide.

The article discusses the research findings on Hepatitis A virus (HAV) that virions circulating in the blood are enclosed by host cell-derived membranes. It mentions that HAV is a common cause of food-borne hepatitis which is a member of the Picornaviridae family and sorted as a non-enveloped virus. It notes that cloaking virions with host-derived membranes protects HAV from neutralizing antibodies in the blood but not in infected cells.

The article presents a research conducted by author Adam P. Arkin and colleagues on the cultured wild-type and transposon-mutant pools of the metal-reducing bacterium Shewanella oneidensis str. MR-1. It mentions that the group studied the S. oneidensis in 15 different conditions such as differing carbon sources, aerobic versus anaerobic growth or the presence of toxic compounds. It notes that the group found that the detrimental genes were more highly expressed than other genes.

The article discusses research being done on polyunsaturated fatty acid (PUFA)-derived lipids for the treatment of influenza virus. It references the study "The lipid mediator protectin D1 inhibits influenza virus replication and improves severe influenza," by M. Morita and colleagues in the March 7, 2013 issue. It says that the anti-viral potential of PUFA-derived metabolites was tested by the authors in influenza virus-infected human lung cells.

The article presents the study conducted by B. Dreier and colleagues on a new adapter-based targeting strategy for natural adenovirus tropism and retargets viruses to the desired tissue. It says that they developed an adapter for mutated human adenovirus serotype Ad5 knob based on fusion of two designed anykrin repeat proteins (DARPins). Result showed that DARPin adapters can be used to target adenoviral vectors to various tissue by simply changing the specificity of the cell-targeting DARPin.

The article cites a research study by S.A. Leiman and colleagues, published in the "Journal of Bacteriology," which examines how d-amino acids indirectly inhibit biofilm formation in Bacillus subtilis.

The article cites a research study by M. Worobey and colleagues, published in the online edition of the journal "Nature Reviews Microbiology," which analyzes the internal genes of modern avian influenza virus. They studied full-length influenza virus genomes from humans, birds, horses and pigs. They found that all viruses share a common ancestor that branched off into the equine H7N7 subtype.

The article cites a research study by T. Loot and colleagues published online, which examined the effects of in-feed antibiotics on the composition of the luminal and mucosa-associated communities in the small and large intestines of pig.

The article discusses research being done on viral infection. It references the study "Bacterial lipopolysaccharide binding enhances virion stability and promotes environmental fitness of an enteric virus," by C. M. Robinson, P. R. Jesudhasan, and J. K. Pfeiffer in the 2014 issue of the journal "Cell Host Microbe." The results of the study show that poliovirus can bind to bacterial lipopolysaccharide (LPS).

The article discusses various studies which references several articles regarding vibrio cholerae, staphylococcus aureus, and phage attack on flamingo food chain.

The article discusses the study regarding bacterial vesicles in the marine ecology. It references the study "Bacterial vesicles in marine ecosystems," by S. Biller and colleagues in the 2014 issue in the same issue. It mentions that the study founds extracellular vesicles in cultures from Prochlorococcus species through nanoparticle-tracking analysis and transmission electron microscopy.

The article discusses research being done on bacterial secretion which references the study "Release of protein A from the cell wall of Staphylococcus aureus," by P. Peduzzi and colleagues in the 2014 issue of the journal "Proceedings of the National Academy of Sciences of the United States."

The article discusses research being done on microbial ecology which references the study "The virus's tooth: cyanophages affect an African flamingo population in a bottom-up cascade," by P. Peduzzi and colleagues in the 2014 issue of the "International Society for Microbial Ecology Journal" (ISME J).

The article focuses on a research which aims to identify a potential role for the intestinal bacterium Prevotella copri in the pathogenesis of rheumatoid arthritis, noted to be one of the most common autoimmune diseases. It reveals that rheumatoid arthritis is characterized by joint inflammation and suggests that the gut microbiota has the potential to trigger inflammation in the context of pre-existing autoimmunity. Information about Prevotella copri is provided.

The article provides information regarding the risks and benefits of vaccines.

The article reports on the results of a study which explain LukED-mediated killing of neutrophils. The study revealed that leukotoxin ED (LukED) targets CXC-chemokine receptor 1 (CXCR1) and CXCR2 and efficiently kills neutrophils, which are the most important cell type for Staphylococcus aureus infection control. The study found that DR4- nor DR5- mutated LukE combined with LukD could kill neutrophils while killing of CCR5-positive cells was abolished by DR5-mutated LukE.

Genetic strategies to block expression of CCR5, the major co-receptor of human immunodeficiency virus type 1 (HIV-1), are being developed as anti-HIV therapies. For example, human hematopoietic stem/precursor cells (HSPC) can be modified by the transient expression of CCR5-targeted zinc finger nucleases (ZFNs) to generate CCR5-negative cells, which could then give rise to HIV-resistant mature CD4+ T cells following transplantation into patients. The safety and anti-HIV effects of such treatments can be evaluated by transplanting ZFN-treated HSPC into immunodeficient mice, where the extent of human cell engraftment, lineage differentiation and anti-HIV activity arising from the engineered HSPC can be examined. In this way, humanized mice are providing a powerful small animal model for pre-clinical studies of novel anti-HIV therapies. [ABSTRACT FROM AUTHOR]

Genetic strategies to block expression of CCR5, the major co-receptor of human immunodeficiency virus type 1 (HIV-1), are being developed as anti-HIV therapies. For example, human hematopoietic stem/precursor cells (HSPC) can be modified by the transient expression of CCR5-targeted zinc finger nucleases (ZFNs) to generate CCR5-negative cells, which could then give rise to HIV-resistant mature CD4(+) T cells following transplantation into patients. The safety and anti-HIV effects of such treatments can be evaluated by transplanting ZFN-treated HSPC into immunodeficient mice, where the extent of human cell engraftment, lineage differentiation and anti-HIV activity arising from the engineered HSPC can be examined. In this way, humanized mice are providing a powerful small animal model for pre-clinical studies of novel anti-HIV therapies. [ABSTRACT FROM AUTHOR]

The article focuses on the badgers which was suspected of spreading the Mycobacterium bovis, bacteria causing tuberculosis (TB) in cattle, in the farms in Great Britain.

The article reports that the detection of antibodies for the virus in dromedary camels and of viral sequences in tomb bats, and in patients with Middle East respiratory syndrome coronavirus (MERS-CoV) proposes that the two animals serve as the MERS-CoV reservoirs.

The article reports that the reticuloendotheliosis viruses (REVs) and endogenous viral elements (EVEs) came from a mammalian retrovirus which infected the ancestor of mongooses.

The article reports on a study which examines the role of cyclic guanosine monophosphate (cGMP) as a bacterial signalling molecule and in the regulation of bacterial phytopathogenesis.

The article reports on a study which shows that infection of listeria monocytogenes results to the deacetylation of H3 lysine, which depends on the nuclear translocation of the host histone deacetylase SIRT2.

The article reports on a study which found that Dictyostelium discoideum clone QS161 carries two strains of Pseudomonas fluorescens which produce an antifungal pyrrolnitrin and a compound called chromene.

The article focuses on a study which shows the CUG codes ambiguity in Candida albicans leads to more genetic and phenotypic diversity that allows the fungus to adapt its environment. The study found that the genetic changes that occur in response to genetic ambiguity allow C. albicans to adapt to environmental factors such as host immune responses and antifungal drugs.

The article offers information on the Middle East respiratory syndrome coronavirus (MERS-CoV) wherein World Health Organization (WHO) chief Margaret Chan indicated the need for global response to cope with the disease.

The article focuses on the cases of drug-resistant H7N9 influenza virus infection in Shanghai, China which can only be treated by antiviral drugs.

The article discusses research on the transmission of toxoplasma gondii. It references the study "Motile invaded neutrophils in the small intestine of Toxoplasma gondii-infected mice reveal a potential mechanism for parasite spread," by J. L. Coombes and colleagues in the May 6, 2013 issue of "Proceedings of the National Academy of Sciences." It says that neutrophils were used by T. gondii to spread through the intestinal lumen.

The article discusses research on HIV vaccine, which references the study "Cytomegalovirus vectors violte CD8+ T cell epitope recognition paradigms," by S. G. Hansen and colleagues in the 2013 issue of "Science."