Activation of dendritic cells by toll-like receptors and C-type lectins

Optimized peptide nanofibrils as efficient transduction enhancers for in vitro and ex vivo gene transfer

Chimeric antigen receptor (CAR)-T cell therapy is a groundbreaking immunotherapy for cancer. However, the intricate and costly manufacturing process remains a hurdle. Improving the transduction rate is a potential avenue to cut down costs and boost therapeutic efficiency. Peptide nanofibrils (PNFs) serve as one such class of transduction enhancers. PNFs bind to negatively charged virions, facilitating their active engagement by cellular protrusions, which enhances virion attachment to cells, leading to increased cellular entry and gene transfer rates. While first-generation PNFs had issues with aggregate formation and potential immunogenicity, our study utilized in silico screening to identify short, endogenous, and non-immunogenic peptides capable of enhancing transduction. This led to the discovery of an 8-mer peptide, RM-8, which forms PNFs that effectively boost T cell transduction rates by various retroviral vectors. A subsequent structure-activity relationship (SAR) analysis refined RM-8, resulting in the D4 derivative. D4 peptide is stable and assembles into smaller PNFs, avoiding large aggregate formation, and demonstrates superior transduction rates in primary T and NK cells. In essence, D4 PNFs present an economical and straightforward nanotechnological tool, ideal for refining ex vivo gene transfer in CAR-T cell production and potentially other advanced therapeutic applications.

TIRAP, TRAM, and Toll-Like Receptors: The Untold Story

Toll-like receptors (TLRs) are the most studied receptors among the pattern recognition receptors (PRRs). They act as microbial sensors, playing major roles in the regulation of the innate immune system. TLRs mediate their cellular functions through the activation of MyD88-dependent or MyD88-independent signaling pathways. Myd88, or myeloid differentiation primary response 88, is a cytosolic adaptor protein essential for the induction of proinflammatory cytokines by all TLRs except TLR3. While the crucial role of Myd88 is well described, the contribution of other adaptors in mediating TLR signaling and function has been underestimated. In this review, we highlight important results demonstrating that TIRAP and TRAM adaptors are also required for full signaling activity and responses induced by most TLRs.

Innate Immunity Mechanisms in Marine Multicellular Organisms

The innate immune system provides an adequate response to stress factors and pathogens through pattern recognition receptors (PRRs), located on the surface of cell membranes and in the cytoplasm. Generally, the structures of PRRs are formed by several domains that are evolutionarily conserved, with a fairly high degree of homology in representatives of different species. The orthologs of TLRs, NLRs, RLRs and CLRs are widely represented, not only in marine chordates, but also in invertebrates. Study of the interactions of the most ancient marine multicellular organisms with microorganisms gives us an idea of the evolution of molecular mechanisms of protection against pathogens and reveals new functions of already known proteins in ensuring the body’s homeostasis. The review discusses innate immunity mechanisms of protection of marine invertebrate organisms against infections, using the examples of ancient multicellular hydroids, tunicates, echinoderms, and marine worms in the context of searching for analogies with vertebrate innate immunity. Due to the fact that mucous membranes first arose in marine invertebrates that have existed for several hundred million years, study of their innate immune system is both of fundamental importance in terms of understanding molecular mechanisms of host defense, and of practical application, including the search of new antimicrobial agents for subsequent use in medicine, veterinary and biotechnology.

Modulation of the immune response by heterogeneous monocytes and dendritic cells in lung cancer

Different subpopulations of monocytes and dendritic cells (DCs) may have a key impact on the modulation of the immune response in malignancy. In this review, we summarize the monocyte and DCs heterogeneity and their function in the context of modulating the immune response in cancer. Subgroups of monocytes may play opposing roles in cancer, depending on the tumour growth and progression as well as the type of cancer. Monocytes can have pro-tumour and anti-tumour functions and can also differentiate into monocyte-derived DCs (moDCs). MoDCs have a similar antigen presentation ability as classical DCs, including cross-priming, a process by which DCs activate CD8 T-cells by cross-presenting exogenous antigens. DCs play a critical role in generating anti-tumour CD8 T-cell immunity. DCs have plastic characteristics and show distinct phenotypes depending on their mature state and depending on the influence of the tumour microenvironment. MoDCs and other DC subsets have been attracting increased interest owing to their possible beneficial effects in cancer immunotherapy. This review also highlights key strategies deploying specific DC subpopulations in combination with other therapies to enhance the anti-tumour response and summarizes the latest ongoing and completed clinical trials using DCs in lung cancer.

A novel therapeutic modality using CRISPR-engineered dendritic cells to treat allergies

Despite the important roles of dendritic cells (DCs) in airway allergies, current therapeutic strategies such as drugs, allergen immunotherapy and biologics haven't been targeted at them. In this study, we established a promising DC-based therapeutic approach for the alleviation of allergic rhinitis (AR)-associated allergic reactions, using clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-mediated targeted gene disruption. RNA sequencing analysis revealed upregulation of vacuolar protein sorting 37 B (VPS37B) in AR-derived DCs, indicating a novel molecular target. Following antigen presentation, VPS37A and VPS37B enabled endocytosis of the mannose receptor, which recognizes the house dust mite (HDM) allergen Der p 1. DCs with targeted disruption of VPS37A/B alleviated Th2 cytokine production when co-cultured in vitro with allogeneic naïve CD4⁺ T cell from patients with AR. Furthermore, nasal administration of Vps37a/b-disrupted bone marrow DCs to a mouse model of AR resulted in strongly reduced AR-related symptoms. Thus, this novel modality using genetically engineered DCs can provide an effective therapeutic and preventative strategy for allergic diseases.

Candida Pathogenicity and Interplay with the Immune System

Candida species are opportunistic fungal pathogens that are part of the normal skin and mucosal microflora. Overgrowth of Candida can cause infections such as thrush or life-threatening invasive candidiasis in immunocompromised patients. Though Candida albicans is highly prevalent, several non-albicans species are also isolated from nosocomial infections. Candida sp. are over presented in the gut of people with Crohn's disease and certain types of neurological disorders, with hyphal form and biofilms being the most virulent states. In addition, Candida uses several secreted and cell surface molecules such as pH related antigen 1, High affinity glucose transporter, Phosphoglycerate mutase 1 and lipases to establish pathogenicity. A strong innate immune response is elicited against Candida via dendritic cells, neutrophils and macrophages. All three complement pathways are also activated. Production of proinflammatory cytokines IL-10 and IL-12 signal differentiation of CD4⁺ cells into Th1 and Th2 cells, whereas IL-6, IL-17 and IL-23 induce Th17 cells. Importance of T-lymphocytes is reflected in depleted T-cell count patients being more prone to Candidiasis. Anti- Candida antibodies also play a role against candidiasis using various mechanisms such as targeting virulent enzymes and exhibiting direct candidacidal activity. However, the significance of antibody response during infection remains controversial. Furthermore, some of the Candida strains have evolved molecular strategies to evade the sophisticated host attack by proteolysis of components of immune system and interfering with immune signalling pathways. Emergence of several non-albicans species that are resistant to current antifungal agents makes treatment more difficult. Therefore, deeper insight into interactions between Candida and the host immune system is required for discovery of novel therapeutic options.

Lipopolysaccharide-induced DC-SIGN/TLR4 crosstalk activates NLRP3 inflammasomes via MyD88-independent signaling in gastric epithelial cells

Abnormal pattern recognition receptor (PRR) signaling plays an important role in gastric mucosal damage caused by stomach microbiota; however, the underlying molecular mechanisms remain obscure. Here, we show that DC-SIGN, a surface phenotype marker of dendritic cells, is overexpressed in gastric epithelial cells facing LPS stimulation. NLRP3 expression in gastric epithelial cells are significantly increased and related to the degree of LPS stimulation. Furthermore, DC-SIGN could interact with TLR4, promote NLRP3 and related genes expression via MyD88-independent signaling pathway and regulate the secretion of IL-1β and IL-18 in gastric epithelial cells. The results of flow cytometry analysis show that DC-SIGN primarily mediates Th1 differentiation when co-cultured with gastric epithelial cells. These results reveal that LPS-induced DC-SIGN expression modulates NLRP3 inflammasomes formation via MyD88-independent TLR4 signaling in gastric epithelial cell, and induces a Th1-predominant host immune response,these findings may indicate a new function of DC-SIGN in non-immune cells, and elucidate the diversity role of gastric epithelial cells in mechanism of immune damage caused by microbial flora.

Adhesion molecules facilitate host-pathogen interaction & mediate Mycobacterium tuberculosis pathogenesis

Most of the microorganisms display adhesion molecules on their surface which help them to bind and interact with the host cell during infection. Adhesion molecules help mycobacteria to colonize and invade immune system of the host, and also trigger immune response explicated by the host against the infection. Hence, understanding the signalling pathways illustrated by these molecules to enhance our knowledge on mycobacterial survival and persistence inside the host cell is required. Hence, this review was focussed on the role of adhesion molecules and their receptor molecules. The various mechanisms adopted by adhesion molecules to bind with the specific receptors on the host cell and their role in invasion and persistence of mycobacterium inside the host cell are explained.

Glycans in the roles of parasitological diagnosis and host-parasite interplay

The investigation of the glycan repertoire of several organisms has revealed a wide variation in terms of structures and abundance of glycan moieties. Among the parasites, it is possible to observe different sets of glycoconjugates across taxa and developmental stages within a species. The presence of distinct glycoconjugates throughout the life cycle of a parasite could relate to the ability of that organism to adapt and survive in different hosts and environments. Carbohydrates on the surface, and in excretory-secretory products of parasites, play essential roles in host-parasite interactions. Carbohydrate portions of complex molecules of parasites stimulate and modulate host immune responses, mainly through interactions with specific receptors on the surface of dendritic cells, leading to the generation of a pattern of response that may benefit parasite survival. Available data reviewed here also show the frequent aspect of parasite immunomodulation of mammalian responses through specific glycan interactions, which ultimately makes these molecules promising in the fields of diagnostics and vaccinology.

Clonorchis sinensis adult-derived proteins elicit Th2 immune responses by regulating dendritic cells via mannose receptor

BACKGROUND

Clonorchis sinensis (C. sinensis) is the most widespread human liver fluke in East Asia including China and Korea. Clonorchiasis as a neglected tropical zoonosis, leads to serious economic and public health burden in China. There are considerable evidences for an etiological relation between chronic clonorchiasis and liver fibrosis in human beings. Liver fibrosis is a highly conserved and over-protected response to hepatic tissue injury. Immune cells including CD4+ T cell as well as dendritic cell (DC), and pro-fibrogenic cytokines like interleukin 4 (IL-4), IL-13 have been identified as vital manipulators in liver fibrogenesis. Our previous studies had a mere glimpse of T helper type 2 (Th2) dominant immune responses as key players in liver fibrosis induced by C. sinensis infection, but little is known about the involved mechanisms in this pathological process.

METHODOLOGY/PRINCIPAL FINDINGS

By flow cytometry (FACS), adult-derived total proteins of C. sinensis (CsTPs) down-regulated the expression of surface markers CD80, CD86 and major histocompatibility complex class II (MHC-II) on lipopolysaccharide (LPS) induced DC. ELISA results demonstrated that CsTPs inhibited IL-12p70 release from LPS-treated bone marrow-derived dendritic cells (BMDC). IL-10 level increased in a time-dependent manner in LPS-treated BMDCs after incubation with CsTPs. CD4+ T cells incubated with LPS-treated BMDCs plus CsTPs could significantly elevate IL-4 level by ELISA. Meanwhile, elevated expression of pro-fibrogenic mediators including IL-13 and IL-4 were detected in a co-culture system of LPS-activated BMDCs and naive T cells containing CsTPs. In vivo, CsTPs-immunized mice enhanced expression of type 2 cytokines IL-13, IL-10 and IL-4 in both splenocytes and hepatic tissue. Exposure of BMDCs to CsTPs activated expression of mannose receptor (MR) but not toll like receptor 2 (TLR2), TLR4, C-type lectin receptor DC-SIGN and Dectin-2 on the cell surface by RT-PCR and FACS. Blockade of MR almost completely reversed the capacity of CsTPs to suppress LPS-induced BMDCs surface markers CD80, CD86 and MHC-II expression, and further made these BMDCs fail to induce a Th2-skewed response as well as Th2 cell-associated cytokines IL-13 and IL-4 release in vitro.

CONCLUSIONS/SIGNIFICANCE

Collectively, we validated that CsTPs could suppress the maturation of BMDCs in the presence of LPS via binding MR, and showed that the CsTPs-pulsed BMDCs actively polarized naive T helper cells to Th2 cells though the production of IL-10 instead of IL-12. CsTPs endowed host with the capacity to facilitate Th2 cytokines production including IL-13 and IL-4 in vitro and vivo. The study might provide useful information for developing potential therapeutic targets against the disease.

Eutirucallin: A Lectin with Antitumor and Antimicrobial Properties

Eutirucallin is a lectin isolated from the latex of Euphorbia tirucalli, a plant known for its medical properties. The present study explores various characteristics of Eutirucallin including stability, cytotoxicity against tumor cells, antimicrobial and antiparasitic activities. Eutirucallin was stable from 2 to 40 days at 4°C, maintained hemagglutinating activity within a restricted range, and showed optimal activity at pH 7.0–8.0. Eutirucallin presented antiproliferative activity for HeLa, PC3, MDA-MB-231, and MCF-7 tumor cells but was not cytotoxic for non-tumorigenic cells such as macrophages and fibroblasts. Eutirucallin inhibited the Ehrlich ascites carcinoma in vivo and it was also observed that Eutirucallin inhibited 62.5% of Escherichia coli growth. Also, Eutirucallin showed to be effective when tested directly against Toxoplasma gondii infection in vitro. Therefore, this study sheds perspectives for pharmacological applications of Eutirucallin.

Interleukin-10 and prostaglandin E2 have complementary but distinct suppressive effects on Toll-like receptor-mediated dendritic cell activation in ovarian carcinoma

Dendritic cells (DC) have the potential to instigate a tumour-specific immune response, but their ability to prime naïve lymphocytes depends on their activation status. Thus, for tumour immunotherapy to be effective, the provision of appropriate DC activation stimuli such as Toll-like receptor (TLR) agonists is crucial in order to overcome immunosuppression associated with the tumour microenvironment. To address this, we investigated how ovarian carcinoma (OC)-associated ascites impedes activation of DC by TLR agonists. Our results show that ascites reduces the TLR-mediated up-regulation of CD86 and partially inhibits the production of the pro-inflammatory cytokines interleukin 6 (IL-6), IL-12 and tumour necrosis factor α (TNFα) in monocyte-derived DC from healthy controls. We further observe an impaired T cell stimulatory capacity of DC upon activation with TLR agonists in the presence of ascites, indicating that their functionality is affected by the immunosuppressive factors. We identify IL-10 and prostaglandin E2 (PGE₂) as the pivotal immunosuppressive components in OC-associated ascites compromising TLR-mediated DC activation. Interestingly, IL-10 is present in both ascites from patients with malignant OC and in peritoneal fluid from patients with benign ovarian conditions and both fluids have similar ability to reduce TLR-mediated DC activation. However, depletion of IL-10 from ascites revealed that the presence of paracrine IL-10 is not crucial for ascites-mediated suppression of DC activation in response to TLR activation. Unlike IL-10, PGE₂ is absent from peritoneal fluid of patients with benign conditions and selectively reduces TNFα induction in response to TLR-mediated activation in the presence of OC-associated ascites. Our study highlights PGE₂ as an immunosuppressive component of the malignant OC microenvironment rendering PGE₂ a potentially important target for immunotherapy in OC.

Lactobacillus reuteri Surface Mucus Adhesins Upregulate Inflammatory Responses Through Interactions With Innate C-Type Lectin Receptors

The vertebrate gut symbiont Lactobacillus reuteri exhibits strain-specific adhesion and health-promoting properties. Here, we investigated the role of the mucus adhesins, CmbA and MUB, upon interaction of L. reuteri ATCC PTA 6475 and ATCC 53608 strains with human monocyte-derived dendritic cells (moDCs). We showed that mucus adhesins increased the capacity of L. reuteri strains to interact with moDCs and promoted phagocytosis. Our data also indicated that mucus adhesins mediate anti- and pro-inflammatory effects by the induction of interleukin-10 (IL-10), tumor necrosis factor alpha (TNF-α), IL-1β, IL-6, and IL-12 cytokines. L. reuteri ATCC PTA 6475 and ATCC 53608 were exclusively able to induce moDC-mediated Th1 and Th17 immune responses. We further showed that purified MUB activates moDCs and induces Th1 polarized immune responses associated with increased IFNγ production. MUB appeared to mediate these effects via binding to C-type lectin receptors (CLRs), as shown using cell reporter assays. Blocking moDCs with antibodies against DC-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) or Dectin-2 did not affect the uptake of the MUB-expressing strain, but reduced the production of TNF-α and IL-6 by moDCs significantly, in line with the Th1 polarizing capacity of moDCs. The direct interaction between MUB and CLRs was further confirmed by atomic force spectroscopy. Taken together these data suggest that mucus adhesins expressed at the cell surface of L. reuteri strains may exert immunoregulatory effects in the gut through modulating the Th1-promoting capacity of DCs upon interaction with C-type lectins.

The importance of the glycosylation of antimicrobial peptides: natural and synthetic approaches

Glycosylation is one of the most prevalent post-translational modifications of a protein, with a defining impact on its structure and function. Many of the proteins involved in the innate or adaptive immune response, including cytokines, chemokines, and antimicrobial peptides (AMPs), are glycosylated, contributing to their myriad activities. The current availability of synthetic coupling and glycoengineering technology makes it possible to customise the most beneficial glycan modifications for improved AMP stability, microbicidal potency, pathogen specificity, tissue or cell targeting, and immunomodulation.

Ex vivo antigen-pulsed PBMCs generate potent and long lasting immunity to infection when administered as a vaccine

Numerous studies have demonstrated that administration of antigen (Ag)-pulsed dendritic cells (DCs) is an effective strategy for enhancing immunity to tumors and infectious disease organisms. However, the generation and/or isolation of DCs can require substantial time and expense. Therefore, using inactivated F. tularensis (iFt) Ag as a model immunogen, we first sought to determine if DCs could be replaced with peripheral blood mononuclear cells (PBMCs) during the ex-vivo pulse phase and still provide protection against Ft infection. Follow up studies were then conducted using the S. pneumoniae (Sp) vaccine Prevnar ®13 as the Ag in the pulse phase followed by immunization and Sp challenge. In both cases, we demonstrate that PBMCs can be used in place of DCs when pulsing with iFt and/or Prevnar ®13 ex vivo and re-administering the Ag-pulsed PBMCs as a vaccine. In addition, utilization of the i.n. route for Ag-pulsed PBMC administration is superior to use of the i.v. route in the case of Sp immunization, as well as when compared to direct injection of Prevnar ®13 vaccine i.m. or i.n. Furthermore, this PBMC-based vaccine strategy provides a more marked and enduring protective immune response and is also capable of serving as a multi-organism vaccine platform. The potential for this ex-vivo vaccine strategy to provide a simpler, less time consuming, and less expensive approach to DC-based vaccines and vaccination in general is also discussed.

A C-type lectin that inhibits bacterial infection and facilitates viral invasion in black rockfish, Sebastes schlegelii

C-type lectins (CTLs) are important pattern recognition receptors (PRRs) that play vital roles in innate immunity. In teleosts, a number of CTLs have been reported, but their in vivo effects on host defense are still limited. In this study, a CTL homolog (SsLec1) was identified from black rockfish, Sebastes schlegelii, and its structure, expression and biological function was analyzed. The open reading frame of SsLec1 is 633 bp, with a 5'- untranslated region (UTR) of 36 bp and a 3'- UTR of 117 bp. The deduced amino acid sequence of SsLec1 shares the highest overall identity (73.20%) with the CTL of Oplegnathus fasciatus. SsLec1 possesses conserved CTL features, including a carbohydrate-recognition domain, four disulfide bond-forming cysteine residues, the mannose-type carbohydrate-binding motif, the conserved calcium binding sites and a putative signal peptide. The expression of SsLec1 was highest in liver and could be induced by experimental infection with Listonella anguillarum. Recombinant SsLec1 (rSsLec1) purified from E. coli was able to bind and agglutinate the Gram-negative fish pathogens Vibrio ichthyoenteri and Vibrio vulnificus. The agglutinating ability of rSsLec1 was abolished in the presence of mannose or ethylenediaminetetraacetic acid. Further analysis showed that rSsLec1 could enhance phagocytosis by macrophages. In vivo experiments indicated that rSsLec1 could inhibit bacterial infection and promote viral invasion. Taken together, these results suggest that SsLec1 is a novel CTL that possesses apparent immunoregulation property and plays a critical role in host defense against pathogens invasion.

Differential innate responses of chickens and ducks to low-pathogenic avian influenza

Ducks and chickens are hosts of avian influenza virus, each with distinctive responses to infection. To understand these differences, we characterized the innate immune response to low-pathogenicity avian influenza virus H7N1 infection in chickens and ducks. Viral RNA was detected in the lungs of chickens from day 0.8 to 7, in ducks mainly at day 4. In both species, viral RNA was detected in the bursa and gut. Infection in chickens resulted in up-regulation of interferon (IFN)-α and IFN-β mRNA, while in the ducks IFN-γ mRNA was strongly up-regulated in the lung and bursa. In chickens and ducks, all investigated pathogen recognition receptor (PRR) mRNAs were up-regulated; however, in the chicken lung Toll-like receptor (TLR)7 and melanoma differentiation-associated protein (MDA)-5 mRNA were strongly induced. TLR3, TLR7 and MDA-5 responses correlated with IFN-α and IFN-β responses in chickens, but in ducks a correlation between IFN-α and TLR7, retinoic acid-inducible gene-I and MDA-5 was absent. We studied the responses of duck and chicken splenocytes to poly(I:C) and R848 analogues to analyse the regulation of PRRs without the interfering mechanisms of the influenza virus. This revealed IFN-α and IFN-γ responses in both species. MDA-5 was only strongly up-regulated in chicken splenocytes, in which time-related PRR responses correlated with the IFN-α and IFN-β response. This correlation was absent in duck splenocytes. In conclusion, chickens and ducks differ in induction of MDA-5, TLR7 and IFN-α mRNA after an influenza virus infection in vivo and after in vitro stimulation with TLR antagonists.

Immunogenicity of protein therapeutics: The key causes, consequences and challenges

The immunogenicity of protein therapeutics has so far proven to be difficult to predict in patients, with many biologics inducing undesirable immune responses directed towards the therapeutic resulting in reduced efficacy, anaphylaxis and occasionally life threatening autoimmunity. The most common effect of administrating an immunogenic protein therapeutic is the development of a high affinity anti-therapeutic antibody response. Furthermore, it is clear from clinical studies that protein therapeutics derived from endogenous human proteins are capable of stimulating undesirable immune responses in patients, and as a consequence, the prediction and reduction of immunogenicity has been the focus of intense research. This review will outline the principle causes of the immunogenicity in protein therapeutics, and describe the development of pre-clinical models that can be used to aid in the prediction of the immunogenic potential of novel protein therapeutics prior to administration in man.

Combatting infectious diseases; nanotechnology as a platform for rational vaccine design

Currently, several successful vaccines are available. However, for pathogens with a highly variable genetic composition, and for which serum IgG antibodies are not a useful correlate of protection, effective vaccines are yet to be developed. This is due to a lack of both the understanding of the immunological pathways leading to long-term protection and the ability to translate the available knowledge into a suitable vaccine formulation. Regarding the latter, nanoparticles can be an attractive platform for vaccine development, as they offer multiple options for improving safety and efficacy. For example, side effects might be decreased upon encapsulation of the adjuvant and the concomitant delivery of antigen and adjuvant is a very promising tool for increasing efficacy. In addition to the many promises, the use of nanoparticles as vaccine carriers should be implemented with caution: the more sophisticated a particle, the more parameters need to be controlled during production and storage.

Selective activation of human dendritic cells by OM-85 through a NF-kB and MAPK dependent pathway

OM-85 (Broncho-Vaxom®, Broncho-Munal®, Ommunal®, Paxoral®, Vaxoral®), a product made of the water soluble fractions of 21 inactivated bacterial strain patterns responsible for respiratory tract infections, is used for the prevention of recurrent upper respiratory tract infections and acute exacerbations in chronic obstructive pulmonary disease patients. OM-85 is able to potentiate both innate and adaptive immune responses. However, the molecular mechanisms responsible for OM-85 activation are still largely unknown. Purpose of this study was to investigate the impact of OM-85 stimulation on human dendritic cell functions. We show that OM-85 selectively induced NF-kB and MAPK activation in human DC with no detectable action on the interferon regulatory factor (IRF) pathway. As a consequence, chemokines (i.e. CXCL8, CXCL6, CCL3, CCL20, CCL22) and B-cell activating cytokines (i.e. IL-6, BAFF and IL-10) were strongly upregulated. OM-85 also synergized with the action of classical pro-inflammatory stimuli used at suboptimal concentrations. Peripheral blood mononuclear cells from patients with COPD, a pathological condition often associated with altered PRR expression pattern, fully retained the capability to respond to OM-85. These results provide new insights on the molecular mechanisms of OM-85 activation of the immune response and strengthen the rational for its use in clinical settings.

Effect of age on the pathogenesis of DHV-1 in Pekin ducks and on the innate immune responses of ducks to infection

Duck hepatitis virus (DHV) affects 1-week-old but not 3-week-old ducks, and it causes a more severe disease in the younger ducks. These differences may be partially due to the host response to DHV infection. In order to understand this difference, we characterized the pathobiology of and innate immune response to DHV infection in 1-day-old (1D) and 3-week-old (3 W) ducks. Viral RNA was detected in duck livers at 24, 36 and 72 h after inoculation with DHV at a dose of 10(3) LD50. Virus-induced pathology ranged from no clinical signs to severe disease and death, and it was more severe in the 1D ducks. Infection with DHV induced up-regulation of gene expression of Toll-like receptor (TLR)-7, TLR3, retinoic-acid-inducible gene I (RIG-I), melanoma differentiation-associated gene 5 (MDA-5), interleukin (IL)-6, interferon (IFN)-α, interferon-induced transmembrane protein 1 (IFITM1), interferon-stimulated gene 12 (ISG12), and 2'-5' oligoadenylate synthetase-like gene (OASL) in the livers of 3 W ducks. Of these, IL-6, OASL and ISG12 mRNA levels were more than 100-fold higher in infected 3 W ducks than in mock-infected ducks of the same age. These genes were induced much less in infected 1D ducklings. We present evidence that a lower level of viral replication in the hepatocytes of 3 W ducks, whose basal level of cytokines is higher than that in 1D ducklings, may be related to the strong innate immunity induced. From our data, we conclude that duck age plays an important role in the pathogenicity of and innate immune responses to DHV.

Effect of vasoactive intestinal peptide (VIP) on NKG2D signal pathway and its contribution to immune escape of MKN45 cells

Objective. To investigate VIP effect on the cytotoxicity of NK cell to gastric cancer cells in vitro and the relation between the effect with the NKG2D signal molecules in NK cells. Material and Methods. NK cells were purified from peripheral blood mononuclear cells (PBMC). Before and after NK cells were incubated with VIP or its antagonist (D-p-Cl-Phe6,Leu17)-VIP, we detected the cytotoxicity of NK cells to MKN45 gastric cancer cells by MTT and detected the expressions of NKG2D, DAP10, and NF-κB proteins and mRNAs in NK cells by immunocytochemistry and RT-PCR in those conditions. Then we analyzed the effect of VIP and its antagonist on the cytotocicity of NK cell to gastric cancer cells and on expressions of NKG2D, DAP10, and NF-κB signal molecules in NK cells. Results. VIP could inhibit the cytotoxicity of NK cells to MKN45 cells and could inhibit the expressions of NKG2D, DAP10, and NF-κB in NK cells. However, (D-p-Cl-Phe6, Leu17)-VIP could reverse those effects. Conclusions. The VIP inhibited the cytotoxicity of NK cell to MKN45 cells which might get through inhibiting the expressions of NKG2D signal molecules in NK cells. This may be one mechanism of gastric cancer cells escaping organism immune clearance.

An increased number of CD4+CD25+ cells induced by an oral administration of Lactobacillus plantarum NRIC0380 are involved in antiallergic activity

BACKGROUND

Our previous study showed that an oral administration of Lactobacillus plantarum NRIC0380 inhibited immunoglobulin E (IgE) production in a murine model, and that orally administered NRIC0380 induced CD4+CD25+ Foxp3+ T, i.e. regulatory T (Treg), cells in the spleen and Peyer's patch of mice. Although it has been reported that Treg cells might suppress the allergic symptoms, the involvement of the cells in the antiallergic activity of lactic acid bacteria has not been clearly demonstrated. We therefore examined in detail the antiallergic activity of Treg cells obtained from mice that had been fed NRIC0380.

METHODS

Treg cells were obtained from mice that had been fed NRIC0380. The T cell-suppressive effect of the cells was analyzed by coculturing the cells with splenocytes of β-lactoglobulin-immunized mice and β-lactoglobulin. The effects of the Treg cells on the IgE production and cutaneous anaphylaxis reaction were then analyzed by transferring the cells into another mouse.

RESULTS

The Treg cells obtained from the mice that had been fed NRIC0380 showed similar T cell-suppressive activity to those cells obtained from the control mice. The Treg cells obtained from the mice fed NRIC0380 significantly inhibited the IgE production and active cutaneous anaphylaxis reaction when transferred into another mouse that was subsequently immunized with the antigen. Furthermore, the Treg cells also significantly suppressed the passive cutaneous anaphylaxis reaction when cotransferred with the IgE antibody into another mouse.

CONCLUSIONS

The induction of Treg cells by the oral administration of NRIC0380 would be involved in the antiallergic activity of NRIC0380.

Effects of antigen-expressing immunostimulatory liposomes on chemotaxis and maturation of dendritic cells in vitro and in human skin explants

PURPOSE

Antigen-Expressing Immunostimulatory Liposomes (AnExILs) represent a novel DNA vaccination platform based on the production of protein antigens from DNA templates inside liposomes mediated by an in vitro transcription and translation (IVTT) mix. The aim of this study was to analyze the effects of AnExILs on different dendritic cells (DCs) models and to better understand the role of the different components of this formulation on its adjuvanticity.

METHODS

The effect of β-galactosidase-expressing AnExILs on maturation and particle uptake by murine DC cell line, fresh human monocyte-derived DCs or human dermal DCs in skin explants was investigated and compared to the effects of either plain liposomes or IVTT mix alone.

RESULTS

AnExILs induced efficient DC chemotaxis and promoted up-regulation of maturation markers on murine DCs, due to the presence of IVTT in the formulation. Furthermore, the amount of active βGal associated with DCs was higher for AnExILs than for free βGal expressed in IVTT or βGal encapsulated into non-adjuvanted liposomes. Most interestingly, the same trend was observed with human DCs.

CONCLUSIONS

Both IVTT mix and liposomal vehicles were shown to be key components of the AnExIL formulation responsible for its adjuvanticity. AnExILs combine antigen production, adjuvanticity and delivery in one system, and can efficiently activate both murine and human DCs.

Differences in highly pathogenic avian influenza viral pathogenesis and associated early inflammatory response in chickens and ducks

We studied the immunological responses in the lung, brain and spleen of ducks and chickens within the first 7 days after infection with H7N1 highly pathogenic avian influenza (HPAI). Infection with HPAI caused significant morbidity and mortality in chickens, while in ducks the infection was asymptomatic. The HPAI viral mRNA load was higher in all investigated tissues of chickens compared with duck tissues. In the lung, brain and spleen of HPAI-infected chickens, a high, but delayed, pro-inflammatory response of IL-6 and IL-1β mRNA was induced, including up-regulation of IFN-β, IFN-γ, TLR3 and MDA-5 mRNA from 1 day post infection (p.i.). Whereas in ducks already at 8 h p.i., a quicker but lower response was found for IL-6, IL-1β and iNOS mRNA followed by a delayed activation of TLR7, RIG-I, MDA5 and IFN-γ mRNA response. Virus-infected areas in the lung of chickens co-localized with KUL-01⁺ (macrophages, dendritic cells), CD4⁺, and CD8α⁺ cells, during the first day after infection. However, only KUL-01⁺ cells co-localized with the virus after 1 day p.i. In ducks, CVI-ChNL-68.1⁺ (macrophage-like cells), CD4⁺ and CD8α⁺ cells and apoptosis co-localized with the virus within 8 h p.i. Apoptosis was detected in the brain and lung of HPAI-infected chickens after 2 days p.i. and apoptotic cells co-localized with virus-infected areas. In conclusion, excessive delayed cytokine inflammatory responses but inadequate cellular immune responses may contribute to pathogenesis in chickens, while ducks initiate a fast lower cytokine response followed by the activation of major pattern recognition receptors (TLR7, RIG-I, MDA5) and a persistent cellular response.

Tolerogenic dendritic cell therapy for rheumatoid arthritis: where are we now?

Dendritic cells with tolerogenic function (tolDC) have become a promising immunotherapeutic tool for reinstating immune tolerance in rheumatoid arthritis (RA) and other autoimmune diseases. The concept underpinning tolDC therapy is that it specifically targets the pathogenic autoimmune response while leaving protective immunity intact. Findings from human in-vitro and mouse in-vivo studies have been translated into the development of clinical grade tolDC for the treatment of autoimmune disorders. Recently, two tolDC trials in RA and type I diabetes have been carried out and other trials are in progress or are imminent. In this review, we provide an update on tolDC therapy, in particular in relation to the treatment of RA, and discuss the challenges and the future perspectives of this new experimental immunotherapy.

B cell infection and activation by rabies virus-based vaccines

Replication-deficient rabies viruses (RABV) are promising rabies postexposure vaccines due to their prompt and potent stimulation of protective virus neutralizing antibody titers, which are produced in mice by both T-dependent and T-independent mechanisms. To promote such early and robust B cell stimulation, we hypothesized that live RABV-based vaccines directly infect B cells, thereby activating a large pool of antigen-presenting cells (APCs) capable of providing early priming and costimulation to CD4(+) T cells. In this report, we show that live RABV-based vaccine vectors efficiently infect naive primary murine and human B cells ex vivo. Infection of B cells resulted in the significant upregulation of early markers of B cell activation and antigen presentation, including CD69, major histocompatibility complex class II (MHC-II), and CD40 in murine B cells or HLA-DR and CD40 in human B cells compared to mock-infected cells or cells treated with an inactivated RABV-based vaccine. Furthermore, primary B cells infected with a live RABV expressing ovalbumin were able to prime and stimulate naive CD4(+) OT-II T cells to proliferate and to secrete interleukin-2 (IL-2), demonstrating a functional consequence of B cell infection and activation by live RABV-based vaccine vectors. We propose that this direct B cell stimulation by live RABV-based vaccines is a potential mechanism underlying their induction of early protective T cell-dependent B cell responses, and that designing live RABV-based vaccines to infect and activate B cells represents a promising strategy to develop a single-dose postexposure rabies vaccine where the generation of early protective antibody titers is critical.

Immune system targeting by biodegradable nanoparticles for cancer vaccines

The concept of therapeutic cancer vaccines is based on the activation of the immune system against tumor cells after the presentation of tumor antigens. Nanoparticles (NPs) have shown great potential as delivery systems for cancer vaccines as they potentiate the co-delivery of tumor-associated antigens and adjuvants to dendritic cells (DCs), insuring effective activation of the immune system against tumor cells. In this review, the immunological mechanisms behind cancer vaccines, including the role of DCs in the stimulation of T lymphocytes and the use of Toll-like receptor (TLR) ligands as adjuvants will be discussed. An overview of each of the three essential components of a therapeutic cancer vaccine - antigen, adjuvant and delivery system - will be provided with special emphasis on the potential of particulate delivery systems for cancer vaccines, in particular those made of biodegradable aliphatic polyesters, such as poly(lactic-co-glycolic acid) (PLGA) and poly-ε-caprolactone (PCL). Some of the factors that can influence NP uptake by DCs, including size, surface charge, surface functionalization and route of administration, will also be considered.

Memory CD4+ T cells are required for optimal NK cell effector functions against the opportunistic fungal pathogen Pneumocystis murina

Little is known about the role of NK cells or their interplay with other immune cells during opportunistic infections. Using our murine model of Pneumocystis pneumonia, we found that loss of NK cells during immunosuppression results in substantial Pneumocystis lung burden. During early infection of C57B/6 CD4(+) T cell-depleted mice, there were significantly fewer NK cells in the lung tissue compared with CD4(+) T cell-intact animals, and the NK cells present demonstrated decreased upregulation of the activation marker NKp46 and production of the effector cytokine, IFN-γ. Furthermore, coincubation studies revealed a significant increase in fungal killing when NK cells were combined with CD4(+) T cells compared with either cell alone, which was coincident with a significant increase in perforin production by NK cells. Finally, however, we found through adoptive transfer that memory CD4(+) T cells are required for significant NK cell upregulation of the activation marker NK group 2D and production of IFN-γ, granzyme B, and perforin during Pneumocystis infection. To the best of our knowledge, this study is the first to demonstrate a role for NK cells in immunity to Pneumocystis pneumonia, as well as to establish a functional relationship between CD4(+) T cells and NK cells in the host response to an opportunistic fungal pathogen.

Development and characterization of a monoclonal antibody against porcine CD205

The aim of this work was to develop mAbs against porcine CD205 and to conduct a comparative analysis of the CD205 protein expression on lymphoid tissues, monocyte-derived dendritic cells (DCs) and DCs isolated from the porcine skin. To conduct this study, we generated a monoclonal antibody, designated 1.F6F6, against the C-type lectin-like domain-5 of the porcine CD205 and showed that it recognizes a protein band of ∼200 kDa by Western Blot analysis in mesenteric lymph nodes cells. Flow cytometric analysis showed that the mAb 1.F6F6 recognized 28.5%, 28.1% and 34.1% of cells from tonsil, inguinal and mesenteric lymph nodes, respectively, and 6% of cells from thymus. Analysis of monocyte-derived DCs showed that approximately 20% were positive and activation of the cells with LPS increased the positive population to 36%. Analysis of DCs isolated from the porcine skin showed that approximately 70% of the cell population expressed the CD205 receptor. The development of a monoclonal antibody capable of recognizing the CD205 receptor in swine opens up possibilities of applying new strategies for enhancing vaccine efficacy by using the anti-CD205 antibody for DC antigen-targeting to enhance priming of immune responses.

Generating CTLs against the subdominant EBV LMP antigens by transient expression of an A20 inhibitor with EBV LMP proteins in human DCs

Epstein-Barr virus (EBV) infection leads to Hodgkin’s disease (HD) in some immunocompetent hosts. The malignant Reed-Sternberg cells of HD only express a limited array of subdominant EBV antigens to evade preexisting immune responses to EBV. The EBV-encoded latent membrane proteins (LMP1 and LMP2), which are expressed by HD and various EBV-associated malignancies, have been proposed as a potential target for CTL-based therapy. However, the precursor frequency for LMP-specific CTL is generally low in healthy EBV-infected hosts, and immunotherapy based on these antigens is often compromised by the poor immunogenicity and the oncogenic potential. In the present study, we report that transitively expressing an inhibitor of A20, a key negative regulator of inflammatory signaling pathways, together with the LMP antigens (truncated LMP1 and full-length LMP2) greatly enhances maturation and cytokine production of human (h) monocyte-derived dendritic cells (DCs). As a consequence, LMP1/2-expressed, A20-silenced hDCs have an enhanced potency to prime LMP-specific T cell response. When the in vitro primed T cells are adoptively transferred into tumor-xenografted, severe combined immunodeficient (SCID) mice, some of the xenografted tumors approach complete regression. Thus, the study may provide an available resource of LMP-specific T cells for T cell immunotherapy.

The type I interferon response during viral infections: a "SWOT" analysis

The type I interferon (IFN) response is a strong and crucial moderator for the control of viral infections. The strength of this system is illustrated by the fact that, despite some temporary discomfort like a common cold or diarrhea, most viral infections will not cause major harm to the healthy immunocompetent host. To achieve this, the immune system is equipped with a wide array of pattern recognition receptors and the subsequent coordinated type I IFN response orchestrated by plasmacytoid dendritic cells (pDCs) and conventional dendritic cells (cDCs). The production of type I IFN subtypes by dendritic cells (DCs), but also other cells is crucial for the execution of many antiviral processes. Despite this coordinated response, morbidity and mortality are still common in viral disease due to the ability of viruses to exploit the weaknesses of the immune system. Viruses successfully evade immunity and infection can result in aberrant immune responses. However, these weaknesses also open opportunities for improvement via clinical interventions as can be seen in current vaccination and antiviral treatment programs. The application of IFNs, Toll-like receptor ligands, DCs, and antiviral proteins is now being investigated to further limit viral infections. Unfortunately, a common threat during stimulation of immunity is the possible initiation or aggravation of autoimmunity. Also the translation from animal models to the human situation remains difficult. With a Strengths-Weaknesses-Opportunities-Threats ("SWOT") analysis, we discuss the interaction between host and virus as well as (future) therapeutic options, related to the type I IFN system.

Analysis of the acute phase responses of serum amyloid a, haptoglobin and type 1 interferon in cattle experimentally infected with foot-and-mouth disease virus serotype O

A series of challenge experiments were performed in order to investigate the acute phase responses to foot-and-mouth disease virus (FMDV) infection in cattle and possible implications for the development of persistently infected "carriers". The host response to infection was investigated through measurements of the concentrations of the acute phase proteins (APPs) serum amyloid A (SAA) and haptoglobin (HP), as well as the bioactivity of type 1 interferon (IFN) in serum of infected animals. Results were based on measurements from a total of 36 infected animals of which 24 were kept for observational periods exceeding 28 days in order to determine the carrier-status of individual animals. The systemic host response to FMDV in infected animals was evaluated in comparison to similar measurements in sera from 6 mock-inoculated control animals.

There was a significant increase in serum concentrations of both APPs and type 1 IFN in infected animals coinciding with the onset of viremia and clinical disease. The measured parameters declined to baseline levels within 21 days after inoculation, indicating that there was no systemically measurable inflammatory reaction related to the carrier state of FMD. There was a statistically significant difference in the HP response between carriers and non-carriers with a lower response in the animals that subsequently developed into FMDV carriers. It was concluded that the induction of SAA, HP and type 1 IFN in serum can be used as markers of acute infection by FMDV in cattle.

Transcriptomic analysis of the temporal host response to skin infestation with the ectoparasitic mite Psoroptes ovis

Background

Infestation of ovine skin with the ectoparasitic mite Psoroptes ovis results in a rapid cutaneous immune response, leading to the crusted skin lesions characteristic of sheep scab. Little is known regarding the mechanisms by which such a profound inflammatory response is instigated and to identify novel vaccine and drug targets a better understanding of the host-parasite relationship is essential. The main objective of this study was to perform a combined network and pathway analysis of the in vivo skin response to infestation with P. ovis to gain a clearer understanding of the mechanisms and signalling pathways involved.

Results

Infestation with P. ovis resulted in differential expression of 1,552 genes over a 24 hour time course. Clustering by peak gene expression enabled classification of genes into temporally related groupings. Network and pathway analysis of clusters identified key signalling pathways involved in the host response to infestation. The analysis implicated a number of genes with roles in allergy and inflammation, including pro-inflammatory cytokines (IL1A, IL1B, IL6, IL8 and TNF) and factors involved in immune cell activation and recruitment (SELE, SELL, SELP, ICAM1, CSF2, CSF3, CCL2 and CXCL2). The analysis also highlighted the influence of the transcription factors NF-kB and AP-1 in the early pro-inflammatory response, and demonstrated a bias towards a Th2 type immune response.

Conclusions

This study has provided novel insights into the signalling mechanisms leading to the development of a pro-inflammatory response in sheep scab, whilst providing crucial information regarding the nature of mite factors that may trigger this response. It has enabled the elucidation of the temporal patterns by which the immune system is regulated following exposure to P. ovis, providing novel insights into the mechanisms underlying lesion development. This study has improved our existing knowledge of the host response to P. ovis, including the identification of key parallels between sheep scab and other inflammatory skin disorders and the identification of potential targets for disease control.

Human myeloid dendritic cells for cancer therapy: does maturation matter?

Dendritic cells form the connection between innate and adoptive mechanisms of the immune system. As antigen-presenting cells, dendritic cells are capable of presenting tumour antigen and effectively stimulating immune response targeted against a tumour. A number of preclinical and clinical studies document dendritic cells' potential in anti-cancer treatment. Increasing knowledge of dendritic cell biology is leading to improved methods for their preparation for clinical application. Unfortunately, there is to date no consensus specifying optimal conditions for dendritic cell preparation in vitro. This review summarizes the methods used for preparing myeloid dendritic cells derived from monocytic precursors while focusing on cytokine cocktails used for their growth, maturation, and functional adjustment.

Dendritic cells transfected with Her2 antigen-encoding RNA replicons cross-prime CD8 T cells and protect mice against tumor challenge

Antigen-specific T cells can be induced by direct priming and cross-priming. To investigate cross-priming as a vaccination approach dendritic cells were transfected with cytopathogenic viral RNA-replicons that expressed domains of the tumor-associated Her2-antigen and injected into MHC-discordant mice that did not allow direct priming. Upon tumor challenge 75% of the vaccinated, but none of the mock-vaccinated mice remained tumor-free. The anti-tumor effect required T cells and correlated with the vigor of the cross-primed CD8 T cell response. Her2-specific antibodies were not detected. This study highlights the potential of T cell cross-priming in cancer immunotherapy.

Identification and molecular analysis of a novel C-type lectin from Scophthalmus maximus

C-type lectins are calcium-dependent carbohydrate-binding proteins that play important roles in innate immunity. In this study, a C-type lectin homologue (SmLec1) was identified from turbot (Scophthalmus maximus) and analyzed at expression and functional levels. The open reading frame of SmLec1 is 504 bp, with a 5'-untranslated region (UTR) of 101 bp and a 3'-UTR of 164 bp. The deduced amino acid sequence of SmLec1 shares 34%-38% overall identities with the C-type lectins of several fish species. In silico analysis identified in SmLec1 conserved C-type lectin features, including a carbohydrate-recognition domain, four disulfide bond-forming cysteine residues, and the mannose-type carbohydrate-binding motif. In addition, SmLec1 possesses a putative signal peptide sequence and is predicted to be localized in the extracellular. Expression of SmLec1 was highest in liver and responded positively to experimental challenges with fish pathogens. Recombinant SmLec1 (rSmLec1) purified from yeast was able to agglutinate the Gram-negative fish pathogen Listonella anguillarum but not the Gram-positive pathogen Streptococcus iniae. The agglutinating ability of rSmLec1 was abolished in the presence of mannose and ethylenediaminetetraacetic acid and by elevated temperature (65 degrees C). Further analysis showed that rSmLec1 could stimulate kidney lymphocyte proliferation and enhance the killing of bacterial pathogen by macrophages. Taken together, these results suggest that SmLec1 is a unique mannose-binding C-type lectin that possesses apparent immunomodulating property and is likely to be involved in host defense against bacterial infection.

Dendritic cells: bridging innate and adaptive immunity in atopic dermatitis

Much knowledge has been gained about the multifaceted functions of dendritic cells (DCs). The central role of various DC subtypes as bridges between innate and adaptive immunity has become more and more evident. However, a high number of differences exist in the expression of pattern-recognition receptors, the first sensors of the innate immune system, in particular Toll-like receptors (TLRs) by distinct DC subtypes (including myeloid and plasmacytoid DCs), their maturation stage, and tissue distribution, as well as state of health or disease. Furthermore, a plethora of variations in human and murine model systems have to be considered. This review sheds some light on this complex and rapidly growing field. It summarizes the most recent findings and deals with the role of TLR-expressing DCs as promoters of chronic inflammatory immune responses in patients with atopic dermatitis, as well as tolerogenic pathways. Therefore TLR-bearing DCs represent promising targets, which might help to improve tolerance induction during immunotherapeutic approaches in the future.

Glycan gimmickry by parasitic helminths: a strategy for modulating the host immune response?

Parasitic helminths (worms) co-evolved with vertebrate immune systems to enable long-term survival of worms in infected hosts. Among their survival strategies, worms use their glycans within glycoproteins and glycolipids, which are abundant on helminth surfaces and in their excretory/ secretory products, to regulate and suppress host immune responses. Many helminths express unusual and antigenic (nonhost-like) glycans, including those containing polyfucose, tyvelose, terminal GalNAc, phosphorylcholine, methyl groups, and sugars in unusual linkages. In addition, some glycan antigens are expressed that share structural features with those in their intermediate and vertebrate hosts (host-like glycans), including Le(X) (Galbeta1-4[Fucalpha1-3]GlcNAc-), LDNF (GalNAcbeta1-4[Fucalpha1-3]GlcNAc-), LDN (GalNAcbeta1-4GlcNAc-), and Tn (GalNAcalpha1-O-Thr/Ser) antigens. The expression of host-like glycan determinants is remarkable and suggests that helminths may gain advantages by synthesizing such glycans. The expression of host-like glycans by parasites previously led to the concept of "molecular mimicry," in which molecules are either derived from the pathogen or acquired from the host to evade recognition by the host immune system. However, recent discoveries into the potential of host glycan-binding proteins (GBPs), such as C-type lectin receptors and galectins, to functionally interact with various host-like helminth glycans provide new insights. Host GBPs through their interactions with worm-derived glycans participate in shaping innate and adaptive immune responses upon infection. We thus propose an alternative concept termed "glycan gimmickry," which is defined as an active strategy of parasites to use their glycans to target GBPs within the host to promote their survival.

Effects of Lansoprazole on the Lipopolysaccharide-Stimulated Toll-Like Receptor 4 Signal Transduction Systems: A Study Using the 293hTLR4/MD2-CD14 Cells

The present study was undertaken to evaluate the effects of lansoprazole (LPZ) on lipopolysaccharide (LPS)-stimulated toll-like receptor 4 (TLR4) signal transduction systems using the 293hTLR4/MD2-CD14 cells. The cells were incubated and then divided into the following groups: (a) untreated group, (b) non-LPZ treated (1h) group, (c) LPZ-treated (1h) plus non LPS-stimulated (1h) group, (d) LPZ-treated (1h) plus non LPS-stimulated (6h) group, (e) LPZ-treated (1h) plus LPS-stimulated (1h) group, (f) LPZ-treated (1h) plus LPS-stimulated (6h) group, (g) non LPZ-treated (1h) plus LPS-stimulated (1h) group and (h) non LPZ-treated (1h) plus LPS-stimulated (6h) group. Samples from each group were subjected to western blotting for analysis of IkB phosphorylation, intranuclear transfer of NF-kB, phosphorylation of MAP kinase (MAPK), intranuclear transfer of interferon regulatory factor 5 (IRF5), and expression of suppressor of cytokine signaling-1 (SOCS1). In the LPZ-treated groups, neither phosphorylation of MAPK nor intranuclear transfer of IRF5 was suppressed under stimulation with LPS, and enhanced intranuclear transfer of NF-kB and increased expression of SOCS1 were noted by comparison with the group treated with LPS alone. These results suggest that LPZ stimulates the expression of SOCS1 and regulates protein phosphorylation through its activity on TLR4 signal transduction under LPS stimulation.