The TLR9 agonist MGN1703 triggers a potent type I interferon response in the sigmoid colon.

Toll-like receptor 9 (TLR9) agonists are being developed for treatment of colorectal and other cancers, yet the impact of these drugs on human intestines remains unknown. This, together with the fact that there are additional potential indications for TLR9 agonist therapy (e.g., autoimmune and infectious diseases), led us to investigate the impact of MGN1703 (Lefitolimod) on intestinal homeostasis and viral persistence in HIV-positive individuals. Colonic sigmoid biopsies were collected (baseline and week four) from 11 HIV+ individuals on suppressive antiretroviral therapy, who received MGN1703 (60 mg s.c.) twice weekly for 4 weeks in a single-arm, phase 1b/2a study. Within sigmoid mucosa, global transcriptomic analyses revealed 248 modulated genes (false discovery rate<0.05) including many type I interferon (IFN)-stimulated genes. MGN1703 increased the frequencies of cells exhibiting MX1 (P=0.001) and ISG15 (P=0.014) protein expression. No changes were observed in neutrophil infiltration (myeloperoxidase; P=0.97). No systematic effect on fecal microbiota structure was observed (analysis of similarity Global R=-0.105; P=0.929). TLR9 expression at baseline was inversely proportional to the change in integrated HIV DNA during MGN1703 treatment (P=0.020). In conclusion, MGN1703 induced a potent type I IFN response, without a concomitant general inflammatory response, in the intestines.

Antiviral gene expression in psoriasis.

BACKGROUND: Psoriasis patients have relatively infrequent cutaneous viral infections compared to atopic dermatitis patients. Increased expression of four antiviral proteins (MX1, BST2, ISG15 and OAS2) has been reported in psoriatic skin and genetic studies of psoriasis have identified susceptibility genes in antiviral pathways. OBJECTIVE: To determine if psoriasis is associated with pervasive expression of antiviral genes in skin and blood. METHODS: We performed RNA sequencing on skin samples of 18 subjects with chronic plaque psoriasis and 16 healthy controls. We examined the expression of a predefined set of 42 antiviral genes, each of which has been shown in previous studies to inhibit viral replication. In parallel, we examined antiviral gene expression in atopic dermatitis, non-lesional psoriatic skin and psoriatic blood. We performed HIV-1 infectivity assays in CD4+ peripheral blood T cells from psoriatic and healthy individuals. RESULTS: We observed significant overexpression of 16 antiviral genes in lesional psoriatic skin, with a greater than two-fold increase in ISG15, RSAD2, IRF7, MX2 and TRIM22 (P < 1E-07). None of these genes was overexpressed in atopic dermatitis skin (P < 0.0001) or non-lesional psoriatic skin. In contrast to the skin compartment, no differences in antiviral gene expression were detected in the peripheral blood of psoriasis cases compared to healthy controls. CD4+ T cells from both psoriatic and healthy patients supported HIV-1 infection at a similar rate. CONCLUSION: Our findings highlight psoriasis as an inflammatory disease with cutaneous but not systemic immune activation against viral pathogens.

Daptomycin In Vitro Activity against Methicillin-Resistant Staphylococcus aureus Is Enhanced by d-Cycloserine in a Mechanism Associated with a Decrease in Cell Surface Charge.

The killing activity of daptomycin against an isogenic pair of daptomycin-susceptible and daptomycin-nonsusceptible (DNS) methicillin-resistant Staphylococcus aureus (MRSA) strains was enhanced by the addition of certain cell wall agents at 1× MIC. However, when high inocula of the DNS strain were used, no significant killing was observed in our experiments. Cytochrome c binding assays revealed d-cycloserine as the only agent associated with a reduction in the cell surface charge for both strains at the concentrations used.

Protective effects of Ocimum sanctum on lipid peroxidation and antioxidant status in streptozocin-induced diabetic rats.

The antioxidant effects of Ocimum sanctum in experimental streptozocin-induced diabetic rats was evaluated in this study. Streptozocin, 55 mg kg(-1) body weight, was injected intraperitoneally once daily for 30 days to induce diabetes mellitus in rats. Streptozocin-induced diabetic rats were orally treated with an aqueous extract of O. sanctum once daily for 30 days. After the experimental period, thiobarbituric acid reacting substances (TBARS) and antioxidant enzymes such as catalase, superoxide dismutase (SOD) and glutathione peroxidase were measured. Administration of O. sanctum to streptozocin-induced diabetic rats for 30 days significantly reduced the plasma level of TBARS and improved the status of the antioxidant enzymes catalase, SOD and glutathione peroxidase in vital organs such as the liver and kidney. These results confirmed that the Indian medicinal plant O. sanctum has a protective effect and it may be useful in controlling complications resulting from diabetes.

Estimating selection pressures on HIV-1 using phylogenetic likelihood models.

Human immunodeficiency virus (HIV-1) can rapidly evolve due to selection pressures exerted by HIV-specific immune responses, antiviral agents, and to allow the virus to establish infection in different compartments in the body. Statistical models applied to HIV-1 sequence data can help to elucidate the nature of these selection pressures through comparisons of non-synonymous (or amino acid changing) and synonymous (or amino acid preserving) substitution rates. These models also need to take into account the non-independence of sequences due to their shared evolutionary history. We review how we have developed these methods and have applied them to characterize the evolution of HIV-1 in vivo. To illustrate our methods, we present an analysis of compartment-specific evolution of HIV-1 env in blood and cerebrospinal fluid and of site-to-site variation in the gag gene of subtype C HIV-1.

Rational peptide selection to detect human immunodeficiency virus type 1-specific T-cell responses under resource-limited conditions.

Understanding human immunodeficiency virus type 1 (HIV-1)-specific cytotoxic T-lymphocyte responses is important for the development of vaccines and therapies. We describe a novel method for the rational selection of peptides that target stable regions of the HIV-1 genome, rich in epitopes specifically recognized by the study population. This method will be of particular use under resource/sample-limited conditions.

Maintenance of Nef-mediated modulation of major histocompatibility complex class I and CD4 after sexual transmission of human immunodeficiency virus type 1.

Viruses encounter changing selective pressures during transmission between hosts, including host-specific immune responses and potentially varying functional demands on specific proteins. The human immunodeficiency virus type 1 Nef protein performs several functions potentially important for successful infection, including immune escape via down-regulation of class I major histocompatibility complex (MHC-I) and direct enhancement of viral infectivity and replication. Nef is also a major target of the host cytotoxic T-lymphocyte (CTL) response. To examine the impact of changing selective pressures on Nef functions following sexual transmission, we analyzed genetic and functional changes in nef clones from six transmission events. Phylogenetic analyses indicated that the diversity of nef was similar in both sources and acutely infected recipients, the patterns of selection across transmission were variable, and regions of Nef associated with distinct functions evolved similarly in sources and recipients. These results weighed against the selection of specific Nef functions by transmission or during acute infection. Measurement of Nef function provided no evidence that the down-regulation of either CD4 or MHC-I was optimized by transmission or during acute infection, although rare nef clones from sources that were impaired in these activities were not detected in recipients. Nef-specific CTL activity was detected as early as 3 weeks after infection and appeared to be an evolutionary force driving the diversification of nef. Despite the change in selective pressure between the source and recipient immune systems and concomitant genetic diversity, the majority of Nef proteins maintained robust abilities to down-regulate MHC-I and CD4. These data suggest that both functions are important for the successful establishment of infection in a new host.

Genetic composition of human immunodeficiency virus type 1 in cerebrospinal fluid and blood without treatment and during failing antiretroviral therapy.

Human immunodeficiency virus (HIV) infection of the central nervous system (CNS) is a significant cause of morbidity. The requirements for HIV adaptation to the CNS for neuropathogenesis and the value of CSF virus as a surrogate for virus activity in brain parenchyma are not well established. We studied 18 HIV-infected subjects, most with advanced immunodeficiency and some neurocognitive impairment but none with evidence of opportunistic infection or malignancy of the CNS. Clonal sequences of C2-V3 env and population sequences of pol from HIV RNA in cerebrospinal fluid (CSF) and plasma were correlated with clinical and virologic variables. Most (14 of 18) subjects had partitioning of C2-V3 sequences according to compartment, and 9 of 13 subjects with drug resistance exhibited discordant resistance patterns between the two compartments. Regression analyses identified three to seven positions in C2-V3 that discriminated CSF from plasma HIV. The presence of compartmental differences at one or more of the identified positions in C2-V3 was highly associated with the presence of discordant resistance (P = 0.007), reflecting the autonomous replication of HIV and the independent evolution of drug resistance in the CNS. Discordance of resistance was associated with severity of neurocognitive deficits (P = 0.07), while low nadir CD4 counts were linked both to the severity of neurocognitive deficits and to discordant resistance patterns (P = 0.05 and 0.09, respectively). These observations support the study of CSF HIV as an accessible surrogate for HIV virions in the brain, confirm the high frequency of discordant resistance in subjects with advanced disease in the absence of opportunistic infection or malignancy of the CNS, and begin to identify genetic patterns in HIV env associated with adaptation to the CNS.

Prevalence of the fsr locus in Enterococcus faecalis infections.

The fsr locus of Enterococcus faecalis confers virulence in animal models. A retrospective analysis of fsr prevalence in diverse E. faecalis clinical isolates demonstrated fsr in all endocarditis isolates versus 53% of stool isolates (P = 0.005). This supports a role for fsr-mediated virulence in the pathogenesis of enterococcal infections in humans.

An efficient solid-phase strategy for the construction of chemokines.

Synthesis of chemokines via stepwise SPPS approaches has been shown to be a challenge. Herein, a complete study of different coupling methods, solvents and temperature combined with a continuous-flow synthesizer equipped with feedback monitoring was carried out. The results from this study indicate that this family of molecules can be prepared using an Fmoc/Bu(t) chemical approach and provide a general method to apply for the elongation of other difficult sequences.