Synthesis and Photobiological Activity of Ru(II) Dyads Derived from Pyrrole-2-carboxylate Thionoesters

The synthesis and characterization of a series of heteroleptic ruthenium(II) dyads derived from pyrrole-2-carboxylate thionoesters are reported. Ligands bearing a conjugated thiocarbonyl group were found to be more reactive toward Ru(II) complexation compared to analogous all-oxygen pyrrole-2-carboxylate esters, and salient features of the resulting complexes were determined using X-ray crystallography, electronic absorption, and NMR spectroscopy. Selected complexes were evaluated for their potential in photobiological applications, whereupon all compounds demonstrated in vitro photodynamic therapy effects in HL-60 and SK-MEL-28 cells, with low nanomolar activities observed, and exhibited some of the largest photocytotoxicity indices to date (>2000). Importantly, the Ru(II) dyads could be activated by relatively soft doses of visible (100 J cm^-2, 29 mW cm^-2) or red light (100 J cm^-2, 34 mW cm^-2), which is compatible with therapeutic applications. Some compounds even demonstrated up to five-fold selectivity for malignant cells over noncancerous cells. These complexes were also shown to photocleave, and in some cases unwind, DNA in cell-free experiments. Thus, this new class of Ru(II) dyads has the capacity to interact with and damage biological macromolecules in the cell, making them attractive agents for photodynamic therapy.

Aberrant function of myeloid-derived suppressor cells (MDSCs) in experimental colitis and in inflammatory bowel disease (IBD) immune responses

BACKGROUND AND AIMS

Myeloid-derived suppressor cells (MDSCs) encompass a novel population of suppressor cells and a potential candidate for cell-based therapies in inflammatory diseases. Herein, we investigated their immunomodulatory properties in experimental inflammatory colitis and T cell-mediated immune responses in inflammatory bowel disease (IBD) patients.

METHODS

MDSCs (defined as CD14^-HLA^-DR^-/lowCD33⁺CD15⁺) numbers were determined in peripheral blood (PB) from IBD patients. PB MDSC function was assessed in vitro. Experimental colitis was induced upon 2,4,6-trinitrobenzene sulfonic acid (TNBS) treatment and MDSCs were characterized by flow cytometry. The in vivo suppressive potential of bone marrow (BM)-derived MDSCs (BM-MDSCs) was tested by using both depleting and adoptive transfer strategies.

RESULTS

MDSCs were enriched in the periphery of IBD patients during active disease. TNBS colitis induced amplification of MDSCs, particularly of the granulocytic (Ly6G⁺) subset during the effector phase of disease. Of interest, BM-MDSCs potently suppressed CD4⁺T cell responses under steady state but failed to control colitis-associated immune responses in vivo. Mechanistically, under the colonic inflammatory milieu MDSCs switched phenotype (decreased proportion of Gr1^high and increased numbers of Gr1^low) and downregulated CCAAT/enhancer-binding protein beta (CEBPβ) expression, a critical transcription factor for the suppressive function of MDSCs. In accordance with the murine data, human CD33 ⁺ CD15⁺MDSCs from peripheral blood of IBD patients not only failed to suppress autologous T cell responses but instead enhanced T cell proliferation in vitro.

CONCLUSIONS

Our findings demonstrate an aberrant function of MDSCs in experimental inflammatory colitis and in IBD-associated immune responses in vitro. Delineation of the mechanisms that underlie the loss of MDSCs function in IBD may provide novel therapeutic targets.

Engineered Hydrogen-Bonded Glycopolymer Capsules and Their Interactions with Antigen Presenting Cells

Hollow glycopolymer microcapsules were fabricated by hydrogen-bonded layer-by-layer (LbL) assembly, and their interactions with a set of antigen presenting cells (APCs), including dendritic cells (DCs), macrophages (MACs), and myeloid derived suppressor cells (MDSCs), were investigated. The glycopolymers were obtained by cascade postpolymerization modifications of poly(oligo(2-ethyl-2-oxazoline methacrylate)-stat-glycidyl methacrylate) involving the modification of the glycidyl groups with propargylamine and the subsequent attachment of mannose azide by copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). Multilayer assembly of the hydrogen-bonding pair (glycopolymer/poly(methacrylic acid) (PMA)) onto planar and particulate supports (SiO₂ particles, d = 1.16 μm) yielded stable glycopolymer films upon cross-linking by CuAAC. The silica (SiO₂) particle templates were removed yielding hollow monodisperse capsules, as demonstrated by fluorescence and scanning electron microscopy. Cellular uptake studies using flow cytometry revealed the preferential uptake of the capsules by DCs when compared to MACs or MDSCs. Mannosylated capsules showed a cytokine independent cis-upregulation of CD80 specifically on DCs and a trans-downregulation of PDL-1 on MDSCs. Thus, the glycopolymer capsules may have potential as vaccine carriers, as they are able to upregulate costimulatory molecules for immune cell stimulation on DCs and at the same time downregulate immune inhibitory receptors on suppressor APC such as MDSCs.

ALA-Photodynamic treatment in Lichen sclerosus-clinical and immunological outcome focusing on the assesment of antinuclear antibodies

BACKGROUND

Lichen sclerosus (LS) is a difficult to treat, often relapsing disease with unknown background. Autoimmune diseases also coexist with LS. Over recent years photodynamic therapy (PDT) has been shown to be a noninvasive and successful therapeutic approach for the effective treatment of many conditions. However, the change of immune status of the patients based on ANA antibodies has not been yet reported. Our aim was to observe the clinical response followed by possible changes in autoimmune antibodies levels before and after PDT for LS.

MATERIAL AND METHODS

We enrolled 100 women with Lichen sclerosus with or without a concomitant autoimmune disease. All patients received 10 cycles of PDT (65 treated with DIOMED Light, 35 with PhotoDYN Light). We assessed autoimmune antibodies before and after PDT in addition to the clinical response evaluation.Two-year prospective controlled before-and-after study.

RESULTS

Following PDT, patients showed a significant attenuation in symptoms' intensity (itching, pruritus, vulvar discomfort). After therapy 41% of patients had partial response, 51% of patients had no symptoms and 8% had persistent or worsened symptoms. The most frequent autoimmune disease were thyroid disorders, followed by vitiligo and arthritis. 57% patients with an additional autoimmune disease before PDT had ANA antibodies. The mean level of ANA in this group diminished significantly after PDT treatment (261.74 IU/ml before vs. 123.20 IU/ml after treatment).

CONCLUSION

Based on our results, we assume that PDT may influence the immune status of patients with Lichen sclerosus.

Oncologic Photodynamic Therapy: Basic Principles, Current Clinical Status and Future Directions

Photodynamic therapy (PDT) is a clinically approved cancer therapy, based on a photochemical reaction between a light activatable molecule or photosensitizer, light, and molecular oxygen. When these three harmless components are present together, reactive oxygen species are formed. These can directly damage cells and/or vasculature, and induce inflammatory and immune responses. PDT is a two-stage procedure, which starts with photosensitizer administration followed by a locally directed light exposure, with the aim of confined tumor destruction. Since its regulatory approval, over 30 years ago, PDT has been the subject of numerous studies and has proven to be an effective form of cancer therapy. This review provides an overview of the clinical trials conducted over the last 10 years, illustrating how PDT is applied in the clinic today. Furthermore, examples from ongoing clinical trials and the most recent preclinical studies are presented, to show the directions, in which PDT is headed, in the near and distant future. Despite the clinical success reported, PDT is still currently underutilized in the clinic. We also discuss the factors that hamper the exploration of this effective therapy and what should be changed to render it a more effective and more widely available option for patients.

Transmembrane tumor necrosis factor-α promotes the recruitment of MDSCs to tumor tissue by upregulating CXCR4 expression via TNFR2

Myeloid-derived suppressor cells (MDSCs) accumulated in tumor sites promote immune evasion. We found that TNFR deficiency-induced rejection of transplanted tumor was accompanied with markedly decreased accumulation of MDSCs. However, the mechanism(s) behind this phenomenon is not completely understood. Here, we demonstrated that TNFR deficiency did not affect the amount of MDSCs in bone marrow (BM), but decreased accumulation of Gr-1⁺CD11b⁺ MDSCs in the spleen and tumor tissues. The chemotaxis of Tnfr^-/- MDSCs was prominently decreased in response to both tumor cell culture supernatants and tumor tissue homogenates from Tnfr^-/- and wild-type mice, indicating an effect of TNFR signaling on chemokine receptor expression in MDSCs. We used real-time PCR to detect gene expression for several chemokine receptors in MDSCs from BM and found that CXCR4 was the most affected molecule at the transcriptional level in Tnfr^-/- MDSCs. Neutralizing CXCR4 in wild-type MDSCs by a specific antibody blocked their chemotactic migration. Interestingly, it was tmTNF-α, but not sTNF-α, that induced CXCR4 expression in MDSCs. This effect of tmTNF-α was totally blocked in TNFR2^-/- but not in TNFR1^-/- MDSCs, and partially inhibited by PDTC or SB203580, an inhibitor of NF-κB or p38 MAPK pathway, respectively. Adoptive transfer of wild-type MDSCs restored MDSCs accumulation in tumors of Tnfr^-/- mice, but this could be partially blocked by treatment with a CXCR4 inhibitor AMD3100. Our data suggest that tmTNF-α upregulates CXCR4 expression that promotes chemotaxis of MDSCs to tumor, and give a new insight into a novel mechanism by which tmTNF-α facilitates tumor immune evasion.

Tumor-induced MDSC act via remote control to inhibit L-selectin-dependent adaptive immunity in lymph nodes

Myeloid-derived suppressor cells (MDSC) contribute to an immunosuppressive network that drives cancer escape by disabling T cell adaptive immunity. The prevailing view is that MDSC-mediated immunosuppression is restricted to tissues where MDSC co-mingle with T cells. Here we show that splenic or, unexpectedly, blood-borne MDSC execute far-reaching immune suppression by reducing expression of the L-selectin lymph node (LN) homing receptor on naïve T and B cells. MDSC-induced L-selectin loss occurs through a contact-dependent, post-transcriptional mechanism that is independent of the major L-selectin sheddase, ADAM17, but results in significant elevation of circulating L-selectin in tumor-bearing mice. Even moderate deficits in L-selectin expression disrupt T cell trafficking to distant LN. Furthermore, T cells preconditioned by MDSC have diminished responses to subsequent antigen exposure, which in conjunction with reduced trafficking, severely restricts antigen-driven expansion in widely-dispersed LN. These results establish novel mechanisms for MDSC-mediated immunosuppression that have unanticipated implications for systemic cancer immunity.

DOI:http://dx.doi.org/10.7554/eLife.17375.001

Tropomyosin Receptor Kinase C Targeted Delivery of a Peptidomimetic Ligand-Photosensitizer Conjugate Induces Antitumor Immune Responses Following Photodynamic Therapy

Tropomyosin receptor kinase C (TrkC) targeted ligand-photosensitizer construct, IYIY-diiodo-boron-dipyrromethene (IYIY-I₂-BODIPY) and its scrambled counterpart YIYI-I₂-BODIPY have been prepared. IYIY-I₂-BODIPY binds TrkC similar to neurotrophin-3 (NT-3), and NT-3 has been reported to modulate immune responses. Moreover, it could be shown that photodynamic therapy (PDT) elevates antitumor immune responses. This prompted us to investigate the immunological impacts mediated by IYIY-I₂-BODIPY in pre- and post-PDT conditions. We demonstrated that IYIY-I₂-BODIPY (strong response) and YIYI-I₂-BODIPY (weak response) at 10 mg/kg, but not I₂-BODIPY control, increased the levels of IL-2, IL-4, IL-6 and IL-17, but decreased the levels of systemic immunoregulatory mediators TGF-β, myeloid-derived suppressor cells and regulatory T-cells. Only IYIY-I₂-BODIPY enhanced the IFN-γ⁺ and IL-17⁺ T-lymphocytes, and delayed tumor growth (~20% smaller size) in mice when administrated daily for 5 days. All those effects were observed without irradiation; when irradiated (520 nm, 100 J/cm², 160 mW/cm²) to produce PDT effects (drug-light interval 1 h), IYIY-I₂-BODIPY induced stronger responses. Moreover, photoirradiated IYIY-I₂-BODIPY treated mice had high levels of effector T-cells compared to controls. Adoptive transfer of immune cells from IYIY-I₂-BODIPY-treated survivor mice that were photoirradiated gave significantly delayed tumor growth (~40–50% smaller size) in recipient mice. IYIY-I₂-BODIPY alone and in combination with PDT modulates the immune response in such a way that tumor growth is suppressed. Unlike immunosuppressive conventional chemotherapy, IYIY-I₂-BODIPY can act as an immune-stimulatory chemotherapeutic agent with potential applications in clinical cancer treatment.

Regulation of immunity by Taeniids: lessons from animal models and in vitro studies

Taeniidae is the largest family of the Cyclophyllidea order of parasites despite being composed of just two genera: Taenia spp and Echinococcus spp. These parasites are flatworms with a terrestrial life cycle, having an immature or larval stage called metacestode, which develops into the mature form within the intestine of the primary host after being consumed in raw or poorly cooked meat. Consumed eggs hatch into oncospheres, penetrate the intestinal walls and are transported via the bloodstream to later develop into metacestodes within the muscles and internal organs of secondary and sometimes primary hosts, thereby initiating the cycle again. Larval stages of both Taenia spp and Echinococcus spp are well known to produce tissue-dwelling, long-lasting infections; in this stage, these parasites can reach centimetres (macroparasites) and both genera may cause life-threatening diseases in humans. Establishing such long-term infections requires an exceptional ability to modulate host immunity for long periods of time. In this review, we analyse the immunoregulatory mechanisms induced by these tapeworms and their products, mainly discussing the importance of taeniid strategies to successfully colonize their hosts, such as antigen-presenting cell phenotype manipulation and the consequent induction of T-cell anergy, among others.

Development of an Ex Vivo Organ Culture Technique to Evaluate Probiotic Utilization in IBD

The consistent technical and conceptual progress in the study of the microbiota has led novel impulse to the research for therapeutical application of probiotic bacteria in human pathologies, such as inflammatory bowel disease (IBD). Considering the heterogenous results of probiotics in clinical studies, the model of translational medicine may lead to a more specific and efficacious utilization of probiotic bacteria in IBD. In this regard, the selection and utilization of appropriate experimental models may drive the transition from pure in vitro systems to practical clinical application. We developed a simple and reproducible ex vivo organ culture method with potential utilization for the evaluation of probiotic bacteria efficacy in IBD patients.

Epigenetic Treatment of Persistent Viral Infections

Preclinical Research Approximately 2,500 years ago, Hippocrates used the word herpes as a medical term to describe lesions that appeared to creep or crawl on the skin, advocating heat as a possible treatment. During the last 50 years, pharmaceutical research has made great strides, and therapeutic options have expanded to include small molecule antiviral agents, protease inhibitors, preventive vaccines for a handful of the papillomaviruses, and even cures for hepatitis C virus infections. However, effective treatments for persistent and recurrent viral infections, particularly the highly prevalent herpesviruses, continue to represent a significant unmet medical need, affecting the majority of the world's population. Exploring the population diversity of the human microbiome and the effects its compositional variances have on the immune system, health, and disease are the subjects of intense investigational research and study. Among the collection of viruses, bacteria, fungi, and single-cell eukaryotes that comprise the human microbiome, the virome has been grossly understudied relative to the influence it exerts on human pathophysiology, much as mitochondria have until recently failed to receive the attention they deserve, given their critical biomedical importance. Fortunately, cellular epigenetic machinery offers a wealth of druggable targets for therapeutic intervention in numerous disease indications, including those outlined above. With advances in synthetic biology, engineering our body's commensal microorganisms to seek out and destroy pathogenic species is clearly on the horizon. This is especially the case given recent breakthroughs in genetic manipulation with tools such as the CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated) gene-editing platforms. Tying these concepts together with our previous work on the microbiome and neurodegenerative and neuropsychiatric diseases, we suggest that, because mammalian cells respond to a viral infection by triggering a cascade of antiviral innate immune responses governed substantially by the cell's mitochondria, small molecule carnitinoids represent a new class of therapeutics with potential widespread utility against many infectious insults. Drug Dev Res 78 : 24-36, 2017.   © 2016 Wiley Periodicals, Inc.

Myeloid-derived suppressor cells expressing a self-antigen ameliorate experimental autoimmune encephalomyelitis

Previous work by our group showed that transferring bone marrow cells transduced with a self-antigen induced immune tolerance and ameliorated experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis (MS). We also found that following retroviral transduction of murine bone marrow (BM) cells, the majority of cells generated and transduced were myeloid-derived suppressor cells (MDSCs). Here, we aimed to determine whether purified antigen-expressing MDSCs have similar therapeutic effects than those of unfractionated BM, and to investigate their potential mechanisms. We performed phenotypic and functional analyses in these cells using the same animal model, and we used purified antigen-expressing MDSCs in preventive and therapeutic approaches. These cells exerted therapeutic effects similar to those of BM cells, which depended upon self-antigen expression. The majority of monocytic (M)-MDSCs expressed the immunosuppressive molecule programmed death ligand-1 (PD-L1), CD80, CD86 and MHC class II molecules. Additionally, the animals infused with antigen-expressing cells exhibited lower percentages of activated T cells and higher percentages of B cells with a regulatory phenotype (B220⁺CD1d^high CD5⁺) in the spleen than their respective controls. MDSCs expressing self-antigens, alloantigens or therapeutic transgenes are tolerogenic and can be exploited therapeutically in autoimmune diseases, transplantation and in gene therapy, respectively.

Gut microbiome alterations in patients with stage 4 hepatitis C

Background

Hepatitis C virus (HCV) causes debilitating liver diseases, which may progress to cirrhosis and cancer, and claims 500,000 annual lives worldwide. While HCV epidemiology, pathophysiology, and therapy are being deeply studied, rare attention is given to reciprocal interactions between HCV infection , HCV-induced chronic liver diseases, and the human gut microbiome. As Egypt has the world’s highest prevalence of HCV infections, we launched this study to monitor differences in the gut microbial community composition of Egyptian HCV patients that may affect, or result from, the patients’ liver state.

Results

To this end, we analyzed stool samples from six stage 4-HCV patients and eight healthy individuals by high-throughput 16S rRNA gene sequencing using Illumina MiSeq. Overall, the alpha-diversity of the healthy persons’ gut microbiomes was higher than those of the HCV patients. Whereas members of phylum Bacteroidetes were more abundant in HCV patients, healthy individuals had higher abundance of Firmicutes, Proteobacteria, and Actinobacteria. Genus-level analysis showed differential abundance of Prevotella and Faecalibacterium (higher in HCV patients) vs. Ruminococcus and Clostridium (healthy group), indicating that the higher abundance of Bacteroidetes in HCV patients is most likely due to Prevotella overabundance. The probiotic genus, Bifidobacterium, was only observed in the microbiotas of healthy individuals.

Conclusions

To the best of our knowledge, this study provides a first overview of major phyla and genera differentiating stage 4-HCV patients from healthy individuals and suggests possible microbiome remodeling in chronic hepatitis C, possibly shaped by bacterial translocation as well as the liver’s impaired role in digestion and protein synthesis. Future studies will investigate the microbiome composition and functional capabilities in more patients while tracing some potential biomarker taxa (e.g., Prevotella, Faecalibacterium vs. Bifidobacterium).

Electronic supplementary material

The online version of this article (doi:10.1186/s13099-016-0124-2) contains supplementary material, which is available to authorized users.

Targeting Antitumor Immune Response for Enhancing the Efficacy of Photodynamic Therapy of Cancer: Recent Advances and Future Perspectives

Photodynamic therapy (PDT) is a minimally invasive therapeutic strategy for cancer treatment, which can destroy local tumor cells and induce systemic antitumor immune response, whereas, focusing on improving direct cytotoxicity to tumor cells treated by PDT, there is growing interest in developing approaches to further explore the immune stimulatory properties of PDT. In this review we summarize the current knowledge of the innate and adaptive immune responses induced by PDT against tumors, providing evidence showing PDT facilitated-antitumor immunity. Various immunotherapeutic approaches on different cells are reviewed for their effectiveness in improving the treatment efficiency in concert with PDT. Future perspectives are discussed for further enhancing PDT efficiency via intracellular targetable drug delivery as well as optimized experimental model development associated with the study of antitumor immune response.

Monocyte-derived hepatocyte-like cells for causality assessment of idiosyncratic drug-induced liver injury

BACKGROUND

Idiosyncratic drug-induced liver injury (iDILI) is a frequent cause of acute liver injury and a serious problem in late stage drug-development. Its diagnosis is one of the most challenging in hepatology, since it is done by exclusion and relies on expert opinion. Until now no reliable in vitro test exists to support the diagnosis of iDILI. In some instances it is impossible to determine the causative drug in polymedicated patients.

AIM

To investigate if monocyte-derived hepatocyte-like (MH) cells might be a tool supporting clinical judgment for iDILI diagnosis and causality assessment.

METHODS

This prospective study included 54 patients with acute liver injury and intake of at least one drug. Thirty-one patients were diagnosed with iDILI based on causality likelihood. MH cells were generated from every patient and in vitro toxicity of the respective drugs was assessed by lactate-dehydrogenase release. The results from MH cells and RUCAM, the most widely used scoring system as methods to support clinical judgement were compared.

RESULTS

MH cells showed enhanced toxicity in 29 of the 31 patients with iDILI, similar to RUCAM score. MH cells exhibited negative results in the 23 non-DILI cases, whereas RUCAM indicated possible iDILI in six cases. Analysis of the comedications also showed superior specificity of MH cells. No MH cell toxicity of the drugs showing toxicity in patients with iDILI was observed in MH cells of healthy donors.

CONCLUSIONS

In this pilot study in vitro testing using MH cells derived from patients with acute liver injury was able to identify patients with iDILI with an excellent sensitivity and a higher specificity than RUCAM, the most widely used current causality assessment score. Therefore, MH cells could be useful to identify the causative drugs even in polymedicated patients by adding objective data to causality assessment.

TRIAL REGISTRATION NUMBER

NCT02353455.

Current trends in topical therapies for chronic rhinosinusitis: update and literature review

INTRODUCTION

Chronic rhinosinusitis (CRS) affects millions of patients worldwide. The disease is multifactorial with influences including anatomic factors, immunological disturbances, and altered sinonasal microbiome. Although oral medications are effective in controlling some symptoms, they are associated with side effects and long-term use is not ideal. Thus, topical therapies have emerged as an alternative delivery method for localized, high-concentration medication with less side effects. Areas covered: This is a review of the various topical therapies available or under investigation for the management of CRS. Common medications such as saline, steroids, and antimicrobials will be discussed. Furthermore, additives including manuka honey, xylitol, surfactant, N-chlorotaurine, Dead Sea salt, and sodium hyaluronate will be addressed. Innovations in topical therapies, such as drug-eluting biomaterials and photodynamic therapy, will also be reviewed. Expert opinion: Although topical therapies provide a high dose of active substance at the site of disease, their efficacy in CRS is not clear. Topical saline and intranasal steroids appear to consistently demonstrate therapeutic benefits. However, other topical medications require further investigation to determine long-term clinical efficacy and safety. A better understanding of their effects on the sinonasal mucociliary system is needed before they become the standard of care in CRS.

The potential of photodynamic therapy (PDT)-Experimental investigations and clinical use

Photodynamic therapy (PDT) is an intensively studied part of medicine based on free radicals. These reactive species, extremely harmful for whole human organism, are used for eradication numerous diseases. Specific structure of ill tissues causes accumulation free radicals inside them without attack remaining healthy tissues. A rapid development of medicine and scientific research has led to extension of PDT towards treatment many diseases such as cancer, herpes, acne and based on antimicrobials. The presented review article is focused on the aforementioned disorders with accurate analysis of the newest available scientific achievements. The discussed cases explicitly indicate on high efficacy of the therapy. In most cases, free radicals turned out to be solution of many afflictions. Photodynamic therapy can be considered as promising treatment with comparable effectiveness but without side effects characteristic for chemotherapy.

The Skin Microbiome: Is It Affected by UV-induced Immune Suppression?

Human skin apart from functioning as a physical barricade to stop the entry of pathogens, also hosts innumerable commensal organisms. The skin cells and the immune system constantly interact with microbes, to maintain cutaneous homeostasis, despite the challenges offered by various environmental factors. A major environmental factor affecting the skin is ultraviolet radiation (UV-R) from sunlight. UV-R is well known to modulate the immune system, which can be both beneficial and deleterious. By targeting the cells and molecules within skin, UV-R can trigger the production and release of antimicrobial peptides, affect the innate immune system and ultimately suppress the adaptive cellular immune response. This can contribute to skin carcinogenesis and the promotion of infectious agents such as herpes simplex virus and possibly others. On the other hand, a UV-established immunosuppressive environment may protect against the induction of immunologically mediated skin diseases including some of photodermatoses such as polymorphic light eruption. In this article, we share our perspective about the possibility that UV-induced immune suppression may alter the landscape of the skin’s microbiome and its components. Alternatively, or in concert with this, direct UV-induced DNA and membrane damage to the microbiome may result in pathogen associated molecular patterns (PAMPs) that interfere with UV-induced immune suppression.

A HER2 selective theranostic agent for surgical resection guidance and photodynamic therapy

In many cancers early intervention involves surgical resection of small localised tumour masses. Inadequate resection leads to recurrence whereas overzealous treatment can lead to organ damage. This work describes production of a HER2 targeting antibody Fab fragment dual conjugated to achieve both real time near-infrared fluorescent imaging and photodynamic therapy. The use of fluorescence emission from a NIR-dye could be used to guide resection of tumour bulk, for example during endoscopic diagnosis for oesophago-gastric adenocarcinoma, this would then be followed by activation of the photodynamic therapeutic agent to destroy untreated localised areas of cancer infiltration and tumour infiltrated lymph nodes. This theranostic agent was prepared from the Fab fragment of trastuzumab initially by functional disulfide re-bridging and site-specific click reaction of a NIR-dye. This was followed by further reaction with a novel pre-activated form of the photosensitiser chlorin e6 with the exposed fragments' lysine residues. Specific binding of the theranostic agent was observed in vitro with a HER2 positive cell line and cellular near-infrared fluorescence was observed with flow cytometry. Specific photo-activity of the conjugates when exposed to laser light was observed with HER2 positive but not HER2 negative cell lines in vitro, this selectivity was not seen with the unconjugated drug. This theranostic agent demonstrates that two different photo-active functions can be coupled to the same antibody fragment with little interference to their independent activities.

Assessment of free fatty acids and cholesteryl esters delivered in liposomes as novel class of antibiotic

BACKGROUND

Healthcare associated infections (HAI) with multidrug-resistant (MDR) bacteria continue to be a global threat, highlighting an urgent need for novel antibiotics. In this study, we assessed the potential of free fatty acids and cholesteryl esters that form part of the innate host defense as novel antibacterial agents for use against MDR bacteria.

METHODS

Liposomes of six different phospholipid mixtures were employed as carrier for six different fatty acids and four different cholesteryl esters. Using a modified MIC assay based on DNA quantification with the fluoroprobe Syto9, formulations were tested against Gram-positive and Gram-negative bacteria implicated in HAI. Formulations with MIC values in the low μg/mL range were further subjected to determination of minimal bactericidal activity, hemolysis assay with sheep erythrocytes, and cytotoxicity testing with the human liver cell line HepG2. The potential for synergistic activity with a standard antibiotic was also probed.

RESULTS

Palmitic acid and stearic acid prepared in carrier 4 (PA4 and SA4, respectively) were identified as most active lipids (MIC against MDR Staphylococcus epidermidis was 0.5 and 0.25 μg/mL, respectively; MIC against vancomycin resistant Enterococcus faecalis (VRE) was 2 and 0.5 μg/mL, respectively). Cholesteryl linoleate formulated with carrier 3 (CL3) exhibited activity against the S. epidermidis strain (MIC 1 μg/mL) and a Pseudomonas aeruginosa strain (MIC 8 μg/mL) and lowered the vancomycin MIC for VRE from 32-64 μg/mL to as low as 4 μg/mL. At 90 μg/mL PA4, SA4, and CL3 effected less than 5 % hemolysis over 3 h and PA4 and CL3 did not exhibit significant cytotoxic activity against HepG2 cells when applied at 100 μg/mL over 48 h.

CONCLUSIONS

Our results showed that selected fatty acids and cholesteryl esters packaged with phospholipids exhibit antibacterial activity against Gram-positive and Gram-negative bacteria and may augment the activity of antibiotics. Bactericidal activity could be unlinked from hemolytic and cytotoxic activity and the type of phospholipid carrier greatly influenced the activity. Thus, fatty acids and cholesteryl esters packaged in liposomes may have potential as novel lipophilic antimicrobial agents.

Interaction of acid ceramidase inhibitor LCL521 with tumor response to photodynamic therapy and photodynamic therapy-generated vaccine

Acid ceramidase has been identified as a promising target for cancer therapy. One of its most effective inhibitors, LCL521, was examined as adjuvant to photodynamic therapy (PDT) using mouse squamous cell carcinoma SCCVII model of head and neck cancer. Lethal effects of PDT, assessed by colony forming ability of in vitro treated SCCVII cells, were greatly enhanced when combined with 10 µM LCL521 treatment particularly when preceding PDT. When PDT-treated SCCVII cells are used to vaccinate SCCVII tumor-bearing mice (PDT vaccine protocol), adjuvant LCL521 treatment (75 mg/kg) resulted in a marked retardation of tumor growth. This effect can be attributed to the capacity of LCL521 to effectively restrict the activity of two main immunoregulatory cell populations (Tregs and myeloid-derived suppressor cells, MDSCs) that are known to hinder the efficacy of PDT vaccines. The therapeutic benefit with adjuvant LCL521 was also achieved with SCCVII tumors treated with standard PDT when using immunocompetent mice but not with immunodeficient hosts. The interaction of LCL521 with PDT-based antitumor mechanisms is dominated by immune system contribution that includes overriding the effects of immunoregulatory cells, but could also include a tacit contribution from boosting direct tumor cell kill.

Extra-hepatic infection of hepatitis C virus in the colon tissue and its relationship with hepatitis C virus pathogenesis

Extra-hepatic compartments might contribute to hepatitis C virus (HCV) persistence and extra-hepatic manifestations. Therefore, we investigated HCV infection in colonic tissue in patients with chronic hepatitis C (CHC) and its relationship with HCV pathogenesis. Colonic biopsies were collected from three groups with CHC infection: treatment naïve (TN; n=12), non-responders (NR; n=10) to anti-HCV therapy (pegylated interferon-α and ribavirin) and sustained virologic response (SVR; n=10) and from a fourth healthy control group (n=10). Liver biopsies were examined to assess inflammation and fibrosis. HCV infection and colonic T regulatory (Treg) frequency were detected by immunohistochemistry. HCV core and NS3 proteins were detected in B cells and macrophage/monocytes of 42 % and 25 % of TN and 50 % and 30 % of NR, respectively, but not in SVR or control group. The numbers of cells expressing HCV proteins were positively correlated with both HCV viral load and colonic Treg frequency. A significant negative correlation between HCV-expressing cells with both liver inflammation and fibrosis was identified. Our study provides evidence that HCV can infect B cells and macrophages of the colon. The correlations between HCV infection in colonic tissue and HCV viral load and liver pathology underline the significance of this extra-hepatic infection in HCV pathogenesis and response to therapy.

Beyond adjuvants: Antagonizing inflammation to enhance vaccine immunity

Since the development of the first vaccine over 200 years ago, vaccines have saved millions of lives and have become the most cost-effective modern medical intervention. However, over 70 years ago, Freund recognized that the effectiveness of the vaccine-induced immune responses could be vastly improved via the co-delivery of inflammation-induced agents, giving birth to the adjuvant field. Since the first description of adjuvants, revolutionary discoveries, including the discovery of dendritic cells and pattern recognition receptors, that drive remarkably different biological profiles, have opened the landscape of opportunities for the development of novel adjuvants able to trigger a remarkably diverse inflammatory profiles, thereby qualitatively and quantitatively skewing adaptive immunity in a tailored manner against target pathogens. However, mounting data point to a critical role for pre-existing inflammation as a predictor of vaccine responsiveness. Thus, in this review we will discuss novel opportunities by which pre-existing inflammation may be modulated, skewed, or tuned via next-generation vaccine approaches to enhanced vaccine-induced immunity in the elderly, immunocompromised, or subjects with chronic diseases.

Repurposing Drugs in Oncology (ReDO)-diclofenac as an anti-cancer agent

Diclofenac (DCF) is a well-known and widely used non-steroidal anti-inflammatory drug (NSAID), with a range of actions which are of interest in an oncological context. While there has long been an interest in the use of NSAIDs in chemoprevention, there is now emerging evidence that such drugs may have activity in a treatment setting. DCF, which is a potent inhibitor of COX-2 and prostaglandin E2 synthesis, displays a range of effects on the immune system, the angiogenic cascade, chemo- and radio-sensitivity and tumour metabolism. Both pre-clinical and clinical evidence of these effects, in multiple cancer types, is assessed and summarised and relevant mechanisms of action outlined. Based on this evidence the case is made for further clinical investigation of the anticancer effects of DCF, particularly in combination with other agents - with a range of possible multi-drug and multi-modality combinations outlined in the supplementary materials accompanying the main paper.

The Changing Landscape of Renal Inflammation

Kidney inflammation is a major contributor to progressive renal injury, leading to glomerulonephritis (GN) and chronic kidney disease. We review recent advances in our understanding of leukocyte accumulation in the kidney, emphasizing key chemokines involved in GN. We discuss features of renal inflammation such as the evolving concept of immune cell plasticity. We also describe certain aspects of organ-specific tissue microenvironments in shaping immune cell responses, as well as the current knowledge of how regulatory T lymphocytes impact on other immune effector cell populations to control inflammation. It is clear that present and future research in these areas may contribute to the development of novel targeted therapeutics, with the hope of alleviating the burden of end-stage renal disease (ESRD).

Defective DNA methylation in salivary gland epithelial acini from patients with Sjögren's syndrome is associated with SSB gene expression, anti-SSB/LA detection, and lymphocyte infiltration

The pathogenesis of primary Sjögren's syndrome (pSS) is complex, in part due to DNA methylation abnormalities. This study was undertaken to evaluate the importance of global DNA methylation ((5m)C) as determined in minor salivary glands (MSG) from well characterized pSS patients. Twenty-two pSS patients and ten controls were selected, and MSG were stained with anti-(5m)C, anti-(5m)C/anti-cytokeratin (KRT)19, or with anti-SSB/La antibodies (Ab). The DNA methylation status at the SSB gene promoter P1 and P1' was evaluated by methylation-sensitive restriction enzymes (MSRE) coupled with PCR. The effect of the DNA demethylating drug 5 azacytidine (5-Aza) was tested in the human salivary gland (HSG) cell line. In pSS, the reduction of global DNA methylation ((5m)C) was associated with lymphocyte infiltration, the emergence of (5m)C(low) and KRT19(high) acini, and the detection of circulating anti-SSB/La Ab, but not with disease activity (ESSDAI). Next, treating HSG cells with 5-Aza was effective in inducing SSB expression. Finally in pSS patients positive for anti-SSB/La Ab, we further observed DNA demethylation at the SSB gene promoter P1 with consequent SSB overexpression at both the transcriptional and protein levels in salivary gland epithelial cells. In conclusion, our results highlight the importance of DNA methylation in the pathophysiology of pSS and to the emergence of anti-SSB/La Ab.

Contributions of neutrophils to the adaptive immune response in autoimmune disease

Neutrophils are granulocytic cytotoxic leukocytes of the innate immune system that activate during acute inflammation. Neutrophils can also persist beyond the acute phase of inflammation to impact the adaptive immune response during chronic inflammation. In the context of the autoimmune disease, neutrophils modulating T and B cell functions by producing cytokines and chemokines, forming neutrophil extracellular traps, and acting as or priming antigen presentation cells. Thus, neutrophils are actively involved in chronic inflammation and tissue damage in autoimmune disease. Using rheumatoid arthritis as an example, this review focuses on functions of neutrophils in adaptive immunity and the therapeutic potential of these cells in the treatment of autoimmune disease and chronic inflammation.

The chemical, genetic and immunological basis of idiosyncratic drug–induced liver injury

Idiosyncratic drug reactions can be extremely severe and are not accounted for by the regular pharmacology of a drug. Thus, the mechanism of idiosyncratic drug–induced liver injury (iDILI), a phenomenon that occurs with many drugs including β-lactams, anti-tuberculosis drugs and non-steroidal anti-inflammatories, has been difficult to determine and remains a pressing issue for patients and drug companies. Evidence has shown that iDILI is multifactorial and multifaceted, which suggests that multiple cellular mechanisms may be involved. However, a common initiating event has been proposed to be the formation of reactive drug metabolites and covalently bound adducts. Although the fate of these metabolites are unclear, recent evidence has shown a possible link between iDILI and the adaptive immune system. This review highlights the role of reactive metabolites, the recent genetic innovations which have provided molecular targets for iDILI, and the current literature which suggests an immunological basis for iDILI.

miR-223 Inhibits Lipid Deposition and Inflammation by Suppressing Toll-Like Receptor 4 Signaling in Macrophages

Atherosclerosis and its complications rank as the leading cause of death with the hallmarks of lipid deposition and inflammatory response. MicroRNAs (miRNAs) have recently garnered increasing interests in cardiovascular disease. In this study, we investigated the function of miR-223 and the underlying mechanism in atherosclerosis. In the atherosclerotic ApoE^−/− mice models, an obvious increase of miR-223 was observed in aortic atherosclerotic lesions. In lipopolysaccharide (LPS) activated macrophages, its expression was decreased. The miR-223 overexpression significantly attenuated macrophage foam cell formation, lipid accumulation and pro-inflammatory cytokine production, which were reversed by anti-miR-223 inhibitor transfection. Mechanism assay corroborated that miR-223 negatively regulated the activation of the toll-like receptor 4 (TLR4)-nuclear factor-κB (NF-κB) pathway. Pretreatment with a specific inhibitor of NF-κB (pyrrolidinedithiocarbamate, PDTC) strikingly abrogated miR-223 silence-induced lipid deposition and inflammatory cytokine production. Furthermore, PI3K/AKT was activated by miR-223 up-regulation. Pretreatment with PI3K/AKT inhibitor LY294002 strikingly ameliorated the inhibitory effects of miR-223 on the activation of TLR4 and p65, concomitant with the increase in lipid deposition and inflammatory cytokine production. Together, these data indicate that miR-223 up-regulation might abrogate the development of atherosclerosis by blocking TLR4 signaling through activation of the PI3K/AKT pathway, and provides a promising therapeutic avenue for the treatment of atherosclerosis.

Association of colonic regulatory T cells with hepatitis C virus pathogenesis and liver pathology

BACKGROUND AND AIM

Forkhead box protein P3 (FoxP3)(+) regulatory T (Treg ) cells play a fundamental role in maintaining the balance between the tissue-damaging and protective immune response to chronic hepatitis C (CHC) infection. Herein, we investigated the frequency of Treg cells in the colon and their potential relationship to the various CHC outcomes and hepatic histopathology.

METHODS

Colonic biopsies were collected from three groups with CHC: treatment naïve (TN; n = 20), non-responders (NR; n = 20), sustained virologic response (SVR; n = 20), and a fourth healthy control group (n = 10). The plasma viral loads and cytokines levels were determined by quantitative real-time polymerase chain reaction, and ELISA, respectively. Liver biopsies were examined to assess inflammatory score and fibrosis stage. Colonic Treg frequency was estimated by immunohistochemistry using confocal microscopy.

RESULTS

A significant increase in the frequency of colonic Treg was found in TN, and NR groups compared with the control and SVR group. The frequency of colonic Treg , plasma interleukin (IL)-10 and IL-4 levels were significantly positively correlated with viral load and negatively correlated with METAVIR inflammatory score, and fibrosis stages.

CONCLUSION

Colonic Treg cells are negatively correlated with liver inflammation and hepatitis C virus (HCV) viral load, which suggests a strong linkage between gut-derived Treg cell populations and HCV infection.

Anti-tumor immunity of BAM-SiPc-mediated vascular photodynamic therapy in a BALB/c mouse model

In recent decades, accumulating evidence from both animal and clinical studies has suggested that a sufficiently activated immune system may strongly augment various types of cancer treatment, including photodynamic therapy (PDT). Through the generation of reactive oxygen species, PDT eradicates tumors by triggering localized tumor damage and inducing anti-tumor immunity. As the major component of anti-tumor immunity, the involvement of a cell-mediated immune response in PDT has been well investigated in the past decade, whereas the role of humoral immunity has remained relatively unexplored. In the present investigation, using the photosensitizer BAM-SiPc and the CT26 tumor-bearing BALB/c mouse model, it was demonstrated that both cell-mediated and humoral adaptive immune components could be involved in PDT. With a vascular PDT (VPDT) regimen, BAM-SiPc could eradicate the tumors of ∼70% of tumor-bearing mice and trigger an anti-tumor immune response that could last for more than 1 year. An elevation of Th2 cytokines was detected ex vivo after VPDT, indicating the potential involvement of a humoral response. An analysis of serum from the VPDT-cured mice also revealed elevated levels of tumor-specific antibodies. Moreover, this serum could effectively hinder tumor growth and protect the mice against further re-challenge in a T-cell-dependent manner. Taken together, these results show that the humoral components induced after BAM-SiPc-VPDT could assist the development of anti-tumor immunity.

Is the use of IL28B genotype justified in the era of interferon-free treatments for hepatitis C?

In 2009, several groups reported that interleukin-28B (IL28B) genotypes are associated with the response to peginterferon plus ribavirin therapy for chronic hepatitis C virus (HCV) infection in a genome-wide association study, although the mechanism of this association is not yet well understood. However, in recent years, tremendous progress has been made in the treatment of HCV infection. In Japan, some patients infected with HCV have the IL28B major genotype, which may indicate a favorable response to interferon-including regimens; however, certain patients within this group are also interferon-intolerant or ineligible. In Japan, interferon-free 24-wk regimens of asunaprevir and daclatasvir are now available for HCV genotype 1b-infected patients who are interferon-intolerant or ineligible or previous treatment null-responders. The treatment response to interferon-free regimens appears better, regardless of IL28B genotype. Maybe other interferon-free regimens will widely be available soon. In conclusion, although some HCV-infected individuals have IL28B favorable alleles, importance of IL28B will be reduced with availability of oral interferon free regimen.

T-cell mediated anti-tumor immunity after photodynamic therapy: why does it not always work and how can we improve it?

Photodynamic therapy (PDT) uses the combination of non-toxic photosensitizers and harmless light to generate reactive oxygen species that destroy tumors by a combination of direct tumor cell killing, vascular shutdown, and activation of the immune system. It has been shown in some animal models that mice that have been cured of cancer by PDT, may exhibit resistance to rechallenge. The cured mice can also possess tumor specific T-cells that recognize defined tumor antigens, destroy tumor cells in vitro, and can be adoptively transferred to protect naïve mice from cancer. However, these beneficial outcomes are the exception rather than the rule. The reasons for this lack of consistency lie in the ability of many tumors to suppress the host immune system and to actively evade immune attack. The presence of an appropriate tumor rejection antigen in the particular tumor cell line is a requisite for T-cell mediated immunity. Regulatory T-cells (CD25+, Foxp3+) are potent inhibitors of anti-tumor immunity, and their removal by low dose cyclophosphamide can potentiate the PDT-induced immune response. Treatments that stimulate dendritic cells (DC) such as CpG oligonucleotide can overcome tumor-induced DC dysfunction and improve PDT outcome. Epigenetic reversal agents can increase tumor expression of MHC class I and also simultaneously increase expression of tumor antigens. A few clinical reports have shown that anti-tumor immunity can be generated by PDT in patients, and it is hoped that these combination approaches may increase tumor cures in patients.

Photodynamic therapy in colorectal cancer treatment--The state of the art in preclinical research

BACKGROUND

Photodynamic therapy (PDT) is used in many different oncologic fields. Also in gastroenterology, where have been a few attempts to treat both the premalignant lesion and advanced colorectal cancer (CRC). This review aims to give a general overview of preclinical photodynamic studies related to CRC cells and animal studies of photodynamic effects related to CRC treatment to emphasize their potential in study of PDT mechanism, safety and efficiency to translate these results into clinical benefit in CRC treatment.

MATERIALS AND METHOD

Literature on in vitro preclinical photodynamic studies related to CRC cells and animal studies of photodynamic effects related to CRC treatment with the fallowing medical subject headings search terms: colorectal cancer, photodynamic therapy, photosensitizer(s), in vitro, cell culture(s), in vivo, animal experiment(s). The articles were selected by their relevance to the topic.

RESULTS

The majority of preclinical studies concerning possibility of PDT application in colon and rectal cancer is focused on phototoxic action of photosensitizers toward cultured colorectal tumor cells in vitro. The purposes of animal experiments are usually elucidation of mechanisms of observed photodynamic effects in scale of organism, estimation of PDT safety and efficiency and translation of these results into clinical benefit.

CONCLUDING REMARKS

In vitro photodynamic studies and animal experiments can be useful for studies of mechanisms and efficiency of photodynamic method as a start point on PDT clinical research. The primary disadvantage of in vitro experiments is a risk of over-interpretation of their results during extrapolation to the entire CRC.

Hepatocyte-Specific Expression of Human Lysosome Acid Lipase Corrects Liver Inflammation and Tumor Metastasis in lal(-/-) Mice

The liver is a major organ for lipid synthesis and metabolism. Deficiency of lysosomal acid lipase (LAL; official name Lipa, encoded by Lipa) in mice (lal(-/-)) results in enlarged liver size due to neutral lipid storage in hepatocytes and Kupffer cells. To test the functional role of LAL in hepatocyte, hepatocyte-specific expression of human LAL (hLAL) in lal(-/-) mice was established by cross-breeding of liver-activated promoter (LAP)-driven tTA transgene and (tetO)7-CMV-hLAL transgene with lal(-/-) knockout (KO) (LAP-Tg/KO) triple mice. Hepatocyte-specific expression of hLAL in LAP-Tg/KO triple mice reduced the liver size to the normal level by decreasing lipid storage in both hepatocytes and Kupffer cells. hLAL expression reduced tumor-promoting myeloid-derived suppressive cells in the liver of lal(-/-) mice. As a result, B16 melanoma metastasis to the liver was almost completely blocked. Expression and secretion of multiple tumor-promoting cytokines or chemokines in the liver were also significantly reduced. Because hLAL is a secretory protein, lal(-/-) phenotypes in other compartments (eg, blood, spleen, and lung) also ameliorated, including systemic reduction of myeloid-derived suppressive cells, an increase in CD4(+) and CD8(+) T and B lymphocytes, and reduced B16 melanoma metastasis in the lung. These results support a concept that LAL in hepatocytes is a critical metabolic enzyme in controlling neutral lipid metabolism, liver homeostasis, immune response, and tumor metastasis.

Evaluation of intravenous regional perfusion with amphotericin B and dimethylsulfoxide to treat horses for pythiosis of a limb

BACKGROUND

Treatment for horses with pythiosis of a limb is challenging. This study aims to evaluate the effects of administering amphotericin B in a 10 % solution of dimethylsulfoxide by intravenous regional limb perfusion (IRLP) to treat horses for cutaneous pythiosis of a limb.

RESULTS

All 15 of the horses treated had complete resolutions of their lesion between 6 to 9 weeks after a single IRLP treatment. No complications were observed at the site of venipuncture for IRLP. Before initiation of treatment, there was anemia and marked leucocytosis which resolved following treatment. Serum biochemistry showed no significant changes.

CONCLUSIONS

IRLP administration of amphotericin B in a 10 % DMSO solution was easily performed, relatively inexpensive and an effective treatment for treating horses for pythiosis of a limb and resolved the infection with no complications.

GM-CSF: An immune modulatory cytokine that can suppress autoimmunity

GM-CSF was originally identified as a colony stimulating factor (CSF) because of its ability to induce granulocyte and macrophage populations from precursor cells. Multiple studies have demonstrated that GM-CSF is also an immune-modulatory cytokine, capable of affecting not only the phenotype of myeloid lineage cells, but also T-cell activation through various myeloid intermediaries. This property has been implicated in the sustenance of several autoimmune diseases like arthritis and multiple sclerosis. In contrast, several studies using animal models have shown that GM-CSF is also capable of suppressing many autoimmune diseases such as Crohn's disease, Type-1 diabetes, Myasthenia gravis and experimental autoimmune thyroiditis. Knockout mouse studies have suggested that the role of GM-CSF in maintaining granulocyte and macrophage populations in the physiological steady state is largely redundant. Instead, its immune-modulatory role plays a significant role in the development or resolution of autoimmune diseases. This is mediated either through the differentiation of precursor cells into specialized non-steady state granulocytes, macrophages and dendritic cells, or through the modulation of the phenotype of mature myeloid cells. Thus, outside of myelopoiesis, GM-CSF has a profound role in regulating the immune response and maintaining immunological tolerance.

Natural interferon-beta treatment for patients with chronic hepatitis C in Japan

Chronic hepatitis C virus (HCV) infection can cause liver cirrhosis and hepatocellular carcinoma (HCC). Several studies have demonstrated that the eradication of HCV reduces the occurrence of HCC. In Japan, as many people live to an advanced age, HCV-infected patients are also getting older, and the age at HCC diagnosis has also increased. Although older HCV-infected patients have a risk of developing HCC, the treatment response to peginterferon-alpha plus ribavirin therapy is relatively poor in these patients because of drop-out or discontinuation of this treatment due to adverse events. It is established that the mechanism of action between interferon-alpha and interferon-beta is slightly different. Short-term natural interferon-beta monotherapy is effective for patients with acute hepatitis C and patients infected with HCV genotype 2 and low viral loads. Natural interferon-beta plus ribavirin for 48 wk or for 24 wk are also effective for some patients with HCV genotype 1 or HCV genotype 2. Natural interferon-beta plus ribavirin has been used for certain "difficult-to-treat" HCV-infected patients. In the era of direct-acting anti-virals, natural interferon-beta plus ribavirin may be one of the therapeutic options for special groups of HCV-infected patients. In the near future, signal transduction pathways of interferon-beta will inform further directions.

The G2019S LRRK2 mutation increases myeloid cell chemotactic responses and enhances LRRK2 binding to actin-regulatory proteins

The Leucine rich repeat kinase 2 (LRRK2) gene is genetically and biochemically linked to several diseases that involve innate immunity. LRRK2 protein is highly expressed in phagocytic cells of the innate immune system, most notably in myeloid cells capable of mounting potent pro-inflammatory responses. Knockdown of LRRK2 protein in these cells reduces pro-inflammatory responses. However, the effect of LRRK2 pathogenic mutations that cause Parkinson's disease on myeloid cell function is not clear but could provide insight into LRRK2-linked disease. Here, we find that rats expressing G2019S LRRK2 have exaggerated pro-inflammatory responses and subsequent neurodegeneration after lipopolysaccharide injections in the substantia nigra, with a marked increase in the recruitment of CD68 myeloid cells to the site of injection. While G2019S LRRK2 expression did not affect immunological homeostasis, myeloid cells expressing G2019S LRRK2 show enhanced chemotaxis both in vitro in two-chamber assays and in vivo in response to thioglycollate injections in the peritoneum. The G2019S mutation enhanced the association between LRRK2 and actin-regulatory proteins that control chemotaxis. The interaction between G2019S LRRK2 and actin-regulatory proteins can be blocked by LRRK2 kinase inhibitors, although we did not find evidence that LRRK2 phosphorylated these interacting proteins. These results suggest that the primary mechanism of G2019S LRRK2 with respect to myeloid cell function in disease may be related to exaggerated chemotactic responses.

Oral administration of Lactobacillus paracasei alleviates clinical symptoms of colitis induced by dextran sulphate sodium salt in BALB/c mice

The aim of this study was to investigate the alleviating effect of Lactobacillus paracasei subsp. paracasei LC-01 (LC-01) on the murine model of colitis induced by dextran sulphate sodium (DSS). 50 pathogen-free, 6-week-old male BALB/c mice were divided randomly into 5 groups, including a control group and four DSS-LC-01-treated groups (DSS, DSS-106, DSS-108, and DSS-1010 with 0, 1×106, 1×108 and 1×1010 cfu/ml LC-01, respectively). To test the effectiveness of LC-01 as a prophylactic it was administered for 7 days before the onset of the disease in DSS-LC-01-treated mice. After 7 days, colitis was induced by administration of 2.5% (w/v) DSS in drinking water for a further 7 days. The disease activity index (DAI), histological score, myeloperoxidase (MPO) activity and the level of the pro-inflammatory cytokines interleukin-1β (IL-1β) and tumour necrosis factor α (TNF-α) were measured. DAI, histological scores and MPO activity of mice treated with a medium or high dose of LC-01 were significantly lower compared to a low-dose of LC-01 and DSS treatment alone (P<0.05). Colon length shortening could be prevented with increasing dose of LC-01. In addition, the levels of IL-1β and TNF-α were suppressed significantly by treatment with a medium and high dose of LC-01. However, no significant difference in the indices mentioned above were observed between a low dose of LC-01 and treatment with DSS alone (P≯0.05). An appropriate dose of LC-01 can prevent intestinal damage in mice with DSS-induced colitis. The expression of inflammatory cytokines related to pathogenesis of DSS-induced colitis decreased following treatment with LC-01.