Combination immunotherapy after ASCT for multiple myeloma using MAGE-A3/Poly-ICLC immunizations followed by adoptive transfer of vaccine-primed and costimulated autologous T cells

PURPOSE

Myeloma-directed cellular immune responses after autologous stem cell transplantation (ASCT) may reduce relapse rates. We studied whether coinjecting the TLR-3 agonist and vaccine adjuvant Poly-ICLC with a MAGE-A3 peptide vaccine was safe and would elicit a high frequency of vaccine-directed immune responses when combined with vaccine-primed and costimulated autologous T cells.

EXPERIMENTAL DESIGN

In a phase II clinical trial (NCT01245673), we evaluated the safety and activity of ex vivo expanded autologous T cells primed in vivo using a MAGE-A3 multipeptide vaccine (compound GL-0817) combined with Poly-ICLC (Hiltonol), granulocyte macrophage colony-stimulating factor (GM-CSF) ± montanide. Twenty-seven patients with active and/or high-risk myeloma received autografts followed by anti-CD3/anti-CD28-costimulated autologous T cells, accompanied by MAGE-A3 peptide immunizations before T-cell collection and five times after ASCT. Immune responses to the vaccine were evaluated by cytokine production (all patients), dextramer binding to CD8(+) T cells, and ELISA performed serially after transplant.

RESULTS

T-cell infusions were well tolerated, whereas vaccine injection site reactions occurred in >90% of patients. Two of nine patients who received montanide developed sterile abscesses; however, this did not occur in the 18 patients who did not receive montanide. Dextramer staining demonstrated MAGE-A3-specific CD8 T cells in 7 of 8 evaluable HLA-A2(+) patients (88%), whereas vaccine-specific cytokine-producing T cells were generated in 19 of 25 patients (76%). Antibody responses developed in 7 of 9 patients (78%) who received montanide and only weakly in 2 of 18 patients (11%) who did not. The 2-year overall survival was 74% [95% confidence interval (CI), 54%-100%] and 2-year event-free survival was 56% (95% CI, 37%-85%).

CONCLUSIONS

A high frequency of vaccine-specific T-cell responses were generated after transplant by combining costimulated autologous T cells with a Poly-ICLC/GM-CSF-primed MAGE-A3 vaccine.

Molecular cloning and functional characterization of peptidoglycan recognition protein 6 in grass carp Ctenopharyngodon idella

Peptidoglycan recognition proteins (PGRPs) are pattern recognition molecules of innate immunity. In this study, a long-form PGRP, designated as gcPGRP6, was identified from grass carp Ctenopharyngodon idella. The deduced amino acid sequence of gcPGRP6 is composed of 464 residues with a conserved PGRP domain at the C-terminus. The gcPGRP6 gene consists of four exons and three introns, spacing approximately 2.7 kb of genomic sequence. Phylogenetic analysis demonstrated that gcPGRP6 is clustered closely with zebrafish PGLYRP6, and formed a long-type PGRP subfamily together with PGLYRP2 members identified in teleosts and mammals. Real-time PCR and Western blotting analyses revealed that gcPGRP6 is constitutively expressed in organs/tissues examined, and its expression was significantly induced in liver and intestine of grass carp in response to PGN stimulation and in CIK cells treated with lipoteichoic acid (LTA), polyinosinic polycytidylic acid (Poly I:C) and peptidoglycan (PGN). Immunofluorescence microscopy and Western blotting analyses revealed that gcPGRP6 is effectively secreted to the exterior of CIK cells. The over-expression of gcPGRP6 in CIK cells leads to the activation of NF-κB and the inhibition of intracellular bacterial growth. Moreover, cell lysates from CIK cells transfected with pTurbo-gcPGRP6-GFP plasmid display the binding activity towards Lys-type PGN from Staphylococcus aureus and DAP-type PGN from Bacillus subtilis. Furthermore, proinflammatory cytokine IL-2 and intracellular PGN receptor NOD2 had a significantly increased expression in CIK cells overexpressed with gcPGRP6. It is demonstrated that the PGRP6 in grass carp has a role in binding PGN, in inhibiting the growth of intracellular bacteria, and in activating NF-κB, as well as in regulating innate immune genes.

Hepatitis C virus impairs TLR3 signaling and inhibits IFN-λ 1 expression in human hepatoma cell line

Toll-like receptor 3 (TLR3) activation plays an important role in the innate immune responses to viral infections. We show here that the activation of TLR3 signaling pathway by poly I:C, a synthetic mimic of dsRNA, could induce high-level expression of interferon (IFN)-λ1 in a hepatoma cell line. The induced IFN-λ1 contributed to poly I:C-mediated inhibition of hepatitis C virus (HCV) Japanese fulminant hepatitis-1 (JFH-1) replication in Huh7 cells. This inhibitory effect of poly I:C on HCV replication, however, was compromised by HCV infection of Huh7 cells. Investigation of the mechanisms showed that HCV infection suppressed the expression of poly I:C-induced IFN-λ1 and IFN-stimulated genes [IFN-stimulated gene 56 (ISG-56), myxovirus resistance A (MxA) and 2'-5'-oligoadenylate synthetase 1 (OAS-1))], the key antiviral elements in IFN signaling pathway. Among the HCV nonstructural (NS) proteins tested, NS3/4A, NS5A and NS5B had the ability to inhibit poly I:C-induced IFN-λ1 expression in Huh7 cells. These observations provide the experimental evidence that HCV and its proteins impair TLR3 signaling and inhibit intracellular IFN-λ1/ISG expression in a hepatoma cell line, which may account for HCV persistence in the liver.

Increased CXCL10 expression in nasal fibroblasts from patients with refractory chronic rhinosinusitis and asthma

BACKGROUND

Chronic rhinosinusitis (CRS) is characterized by local inflammation of the sinonasal tissues. CRS patients with nasal polyps and asthma often develop acute exacerbation of sinonasal symptoms after upper respiratory tract infections. However, the influence of concomitant asthma on the nasal immune response to viral infection remains unclear.

METHODS

Specimens of nasal polyp and mucosal tissues were obtained from 3 groups of CRS patients (n = 14 per group): 1) patients without asthma (CRS group), 2) patients with aspirin-tolerant asthma (ATA group), and 3) patients with aspirin-intolerant asthma (AIA group). Nasal fibroblasts isolated from the specimens were stimulated with poly I:C. CXCL10 expression was analyzed by the quantitative real-time polymerase chain reaction and enzyme-linked immunoadsorbent assay. Biopsy specimens from CRS patients without asthma were subjected to immunohistochemistry for detection of T-bet and GATA-3 expression in CD3+ T cells by double labeling.

RESULTS

Nasal fibroblasts from the ATA and AIA groups showed significantly enhanced expression of CXCL10 mRNA and protein after poly I:C stimulation compared with cells from the CRS group and the control group (normal nasal mucosa). In addition to T helper (Th)2 cells, there was more abundant infiltration of Th1 cells into tissues from the AIA and ATA groups.

CONCLUSIONS

Our findings suggest that CRS associated with asthma may become intractable through the over-production of CXCL10 in response to viral infection.

Adjuvants and immunization strategies to induce influenza virus hemagglutinin stalk antibodies

The global population remains vulnerable in the face of the next pandemic influenza virus outbreak, and reformulated vaccinations are administered annually to manage seasonal epidemics. Therefore, development of a new generation of vaccines is needed to generate broad and persistent immunity to influenza viruses. Here, we describe three adjuvants that enhance the induction of stalk-directed antibodies against heterologous and heterosubtypic influenza viruses when administered with chimeric HA proteins. Addavax, an MF59-like nanoemulsion, poly(I:C), and an RNA hairpin derived from Sendai virus (SeV) Cantell were efficacious intramuscularly. The SeV RNA and poly(I:C) also proved to be effective respiratory mucosal adjuvants. Although the quantity and quality of antibodies induced by the adjuvants varied, immunized mice demonstrated comparable levels of protection against challenge with influenza A viruses on the basis of HA stalk reactivity. Finally, we present that intranasally, but not intramuscularly, administered chimeric HA proteins induce mucosal IgA antibodies directed at the HA stalk.

Hyaluronic acid oligosaccharides suppress TLR3-dependent cytokine expression in a TLR4-dependent manner

The release of endogenous molecules from the skin after injury has been proposed to influence inflammation. Recent studies have found that pro-inflammatory signals can be generated by damaged endogenous self-RNA, and this event is detected by TLR3. Conversely, release of endogenous fragments of hyaluronic acid (HA) after injury has been proposed to inhibit LPS induced inflammation driven by TLR4. In this study we investigated if HA oligomers could also influence inflammation mediated by TLR3. A tetramer form of HA (oligo-HA) was added to MH-S cells (mouse alveolar macrophage cell line) that were then activated by poly(I:C). ELISA analysis of culture supernatants showed that the presence of oligo-HA suppressed the poly(I:C) induced release of IL-6 and TNFα. IL-6 mRNA expression was also suppressed as measured by quantitative RT-PCR. To determine the mechanism of action for oligo-HA to inhibit poly(I:C), macrophages derived from wild-type (WT), Tlr2−/− or Tlr4−/− mice were treated with oligo-HA and poly(I:C). Similar to WT cells, Tlr2−/− macrophages were inhibited by oligo-HA and retained suppression of cytokine release. In contrast, Tlr4−/− macrophages lost the capacity to be suppressed by oligo-HA. An increase in Traf1 (TLR negative regulator) mRNA was observed after oligo-HA treatment of WT but not in Tlr4−/− macrophages, and oligo-HA did not suppress cytokine responsiveness in Traf1−/− macrophages. These results show that oligo-HA acts through TLR4 and TRAF1 to inhibit TLR3-dependent inflammation. This observation illustrates the complex immunomodulatory action of endogenous products released after injury.

[Perinatal innate immune activation and neuropsychological development]

Development of animal models is a crucial issue in biological psychiatry for the search of novel drug targets as well as the screening of candidate compounds. Epidemiologic studies suggest that environmental insults, such as prenatal infection and perinatal complication, are involved in the development of schizophrenia. Recently, we have developed a novel mouse model of viral infection during the perinatal stage by injecting polyriboinosinic-polyribocytidilic acid (polyI:C) into neonatal mice. Neonatal treatment of mice with polyI:C, an inducer of innate immune responses via toll-like receptor 3, caused a significant increase in interferon-induced transmembrane protein 3 (IFITM3) levels in the astrocytes of the hippocampus, which resulted in long-lasting brain dysfunction, including cognitive and emotional impairments as well as a deficit in depolarization-evoked glutamate release in the hippocampus in adulthood. Neonatal polyI:C-induced neuronal impairments have not been observed in IFITM3-KO mice. These findings suggest that the induction of IFITM3 expression in astrocytes by the activation of the innate immune system during the early stages of neurodevelopment has non-cell autonomous effects that affect subsequent neurodevelopment, leading to neuropathological impairments and brain dysfunction, by impairing endocytosis in astrocytes.

The DHX33 RNA helicase senses cytosolic RNA and activates the NLRP3 inflammasome

The NLRP3 inflammasome plays a major role in innate immune responses by activating caspase-1, resulting in secretion of interleukin-18 (IL-18) and IL-1β. Although cytosolic double-stranded RNA (dsRNA) and bacterial RNA are known to activate the NLRP3 inflammasome, the upstream sensor is unknown. We investigated the potential function of DExD/H-box RNA helicase family members (previously shown to sense cytosolic DNA and RNA to induce type 1 interferon responses) in RNA-induced NLRP3 inflammasome activation. Among the helicase family members tested, we found that targeting of DHX33 expression by short hairpin RNA efficiently blocked the activation of caspase-1 and secretion of IL-18 and IL-1β in human macrophages that were activated by cytosolic poly I:C, reoviral RNA, or bacterial RNA. DHX33 bound dsRNA via the helicase C domain. DHX33 interacted with NLRP3 and formed the inflammasome complex following stimulation with RNA. We therefore identified DHX33 as a cytosolic RNA sensor that activates the NLRP3 inflammasome.

Interaction between allergy and innate immunity: model for eosinophil regulation of epithelial cell interferon expression

BACKGROUND

Eosinophils in asthmatic airways are associated with risk of exacerbations. The most common cause of asthma exacerbations is viral respiratory infections, particularly human rhinovirus (HRV).

OBJECTIVE

To determine the mechanism by which eosinophils may influence virus-induced responses.

METHODS

We used an in vitro coculture model of primary human eosinophils and the BEAS-2B epithelial cell line either stimulated with HRV1A infection or polyinosinic-polycytidylic acid (poly[I:C]). The messenger RNA (mRNA) expression of interferon (IFN) β1 and IFN-λ1 was assessed by quantitative reverse-transcriptase polymerase chain reaction and the protein level of IFN- λ1 by enzyme-linked immunosorbent assay.

RESULTS

Both poly(I:C) and HRV1A infection induced BEAS-2B expression of IFN-β1 and IFN-λ1 mRNA. Coculture of eosinophils resulted in suppression of poly(I:C)-stimulated IFN-β1 and IFN-λ1 mRNA expression (2.5-fold and 3.6-fold less, respectively). Separation of cells did not block eosinophil regulatory activity. Coculture of eosinophils with HRV1A-infected BEAS-2B cells also suppressed IFN-β1 and IFN-λ1 mRNA (5.7-fold and 5.0-fold less, respectively) and reduced IFN-λ1 protein secretion (1.6-fold decrease). This corresponded to a 34% increase in the quantity of HRV1A virus RNA on coculture with eosinophils. Recombinant transforming growth factor β suppressed IFN-λ1 from HRV1A-infected BEAS-2B cells. Coculture of eosinophils and BEAS-2B cells induced transforming growth factor β secretion, which may mediate suppression of HRV-induced interferon expression.

CONCLUSION

Eosinophils suppressed HRV-induced expression of interferons from epithelial cells, resulting in increased quantity of HRV. This represents one mechanism for interaction between allergic inflammation and innate immunity.

Impaired innate interferon induction in severe therapy resistant atopic asthmatic children

Deficient type I interferon-β and type III interferon-λ induction by rhinoviruses has previously been reported in mild/moderate atopic asthmatic adults. No studies have yet investigated if this occurs in severe therapy resistant asthma (STRA). Here, we show that compared with non-allergic healthy control children, bronchial epithelial cells cultured ex vivo from severe therapy resistant atopic asthmatic children have profoundly impaired interferon-β and interferon-λ mRNA and protein in response to rhinovirus (RV) and polyIC stimulation. Severe treatment resistant asthmatics also exhibited increased virus load, which negatively correlated with interferon mRNA levels. Furthermore, uninfected cells from severe therapy resistant asthmatic children showed lower levels of Toll-like receptor-3 mRNA and reduced retinoic acid inducible gene and melanoma differentiation-associated gene 5 mRNA after RV stimulation. These data expand on the original work, suggesting that the innate anti-viral response to RVs is impaired in asthmatic tissues and demonstrate that this is a feature of STRA.

IRF-1 acts as a positive regulator in the transcription of grass carp (Ctenopharyngodon idella) IFN gene

Interferon regulatory factors (IRFs) are well-known to be crucial for modulating the innate immune responses to viral infections. In the present study, the IRF-1 gene of grass carp (Ctenopharyngodon idella) (termed CiIRF-1) was cloned and characterized. The complete genomic sequence of CiIRF-1 was 3150 bp in length and comprised 9 exons and 8 introns. The CiIRF-1 promoter sequence was 558 bp in length. The largest open reading frame (ORF) of the full CiIRF-1 cDNA sequence was 870 bp, and encoded a polypeptide of 289 amino acids. The putative CiIRF-1 was characterized by a conserved N-terminal DBD (113 aa), and included a signature of five conserved tryptophan residues. Phylogenetic relationship analysis revealed that CiIRF-1 was highly homologous to the counterparts of other teleosts and mammalians. CiIRF-1 was expressed at a low constitutive level but was significantly up-regulated following stimulation with either Poly I:C or recombinant grass carp (C. idella) IFN (rCiIFN) in all 6 tested tissues, especially in spleen and gill. The recombinant CiIRF-1 was expressed in BL21 Escherichia coli, and the expressed protein was purified by affinity chromatography with the Ni-NTA His-Bind Resin. Three different fragments of promoter sequences from grass carp type I IFN (CiIFN) gene (GU139255) were amplified. These fragments included the proximal region (CiIFNP2), the distal region (CiIFNP6), and the full length of CiIFN promoter sequences (CiIFNP7). Gel mobility shift assays were employed to analyze the interaction between CiIRF-1 and CiIFN promoter sequences. The results revealed that CiIRF-1 could bind to CiIFN promoter with high affinity in vitro. Subsequently, the recombinant plasmid of pGL3-CiIFNPs and pcDNA3.1-CiIRF-1 were constructed and transiently co-transfected into C. idella kidney (CIK) cells. The impact of CiIRF-1 on CiIFN promoter sequences were measured by luciferase assays. These results demonstrated that CiIRF-1 acts as a positive regulator in the transcription of grass carp IFN gene.

Potent inhibition of Hendra virus infection via RNA interference and poly I:C immune activation

Hendra virus (HeV) is a highly pathogenic zoonotic paramyxovirus that causes fatal disease in a wide range of species, including humans. HeV was first described in Australia in 1994, and has continued to re-emerge with increasing frequency. HeV is of significant concern to human health due to its high mortality rate, increasing emergence, absence of vaccines and limited post exposure therapies. Here we investigate the use of RNA interference (RNAi) based therapeutics targeting HeV in conjunction with the TLR3 agonist Poly I:C and show that they are potent inhibitors of HeV infection in vitro. We found that short interfering RNAs (siRNAs) targeting the abundantly expressed N, P and M genes of HeV caused over 95% reduction of HeV virus titre, protein and mRNA. Furthermore, we found that the combination of HeV targeting siRNA and Poly I:C had an additive effect in suppressing HeV infection. Our results demonstrate for the first time that RNAi and type I interferon stimulation are effective inhibitors of HeV replication in vitro and may provide an effective therapy for this highly lethal, zoonotic pathogen.

Molecular cloning, expression and functional analysis of ISG15 in orange-spotted grouper, Epinephelus coioides

Interferon-stimulated gene 15 (ISG15) is an ubiquitin homolog that is significantly induced by type I interferons or viral infections. Groupers, Epinephelus spp. being maricultured in China and Southeast Asian countries, always suffer from virus infection, including iridovirus and nodavirus. To date, the roles of grouper genes, especially interferon related genes in virus infection remained largely unknown. Here, the ISG15 homolog (EcISG15) was cloned from grouper Epinephelus coioides and its immune response to Singapore grouper iridovirus (SGIV) and grouper nervous necrosis virus (GNNV) was investigated. The full-length EcISG15 cDNA was composed of 948 bp and encoded a polypeptide of 155 amino acids with 37-68% identity with the known ISG15 homologs from other fish species. Amino acid alignment analysis indicated that EcISG15 contained two ubiquitin-like (UBL) domains and an Ub-conjugation domain (LRGG). Expressional analysis showed that EcISG15 was dramatically induced by GNNV infection, poly I:C or poly dA-dT treatment, but no obvious changes were observed during SGIV infection. Immunofluorescence assay showed that EcISG15 localized mainly in the cytoplasm of grouper cells in response to poly I:C stimulation or GNNV infection, but not in mock or SGIV infected cells. Western blot analysis indicated that the ISGylation was absent in SGIV-infected cells, but significantly enhanced in GNNV-infected or poly I:C transfected cells, suggesting that EcISG15 might play different roles in SGIV and GNNV infection. Furthermore, overexpression of EcISG15 in vitro inhibited the transcription of GNNV genes significantly. Taken together, the results indicated that fish ISG15 might exert important roles against RNA virus infection.

Interleukin-17 in pearl oyster (Pinctada fucata): molecular cloning and functional characterization

IL-17 from pearl oyster Pinctada fucata, one of mollusk, was identified and characterized, and its genomic structure and promoter were analyzed. The full-length cDNA of P. fucata IL-17 (PfIL-17) is 907 bp with an open reading frame of 585 bp encoding a putative protein of 194 amino acids. The deduced PfIL-17 contains a 19 amino acid signal peptide and a conserved IL-17 domain. Multiple sequence alignments and phylogenetic analysis revealed that PfIL-17 has lower similarity with other invertebrate IL-17 and was clustered with CgIL-17, but not clustered with other invertebrate IL-17. Gene expression analysis indicated that PfIL-17 took part in the immune response to LPS and poly(I:C) stimulation, and dual-luciferase reporter assays showed that PfIL-17 could active vertebrate target genes containing the NF-κB binding site and involve NF-κB signal pathway in HEK293 cells. Combined with the results mentioned above, it is suggested that PfIL-17 might involve and activate NF-κB signal pathway against extracellular pathogens.

Molecular characterisation and biological activity of a novel CXC chemokine gene in rock bream (Oplegnathus fasciatus)

Chemokines are chemoattractant cytokines defined by the presence of four conserved cysteine residues. In mammals, these cytokines can be divided into four subfamilies depending on the arrangement of the first two conserved cysteines in the sequence, and include the CXC(α), CC(β), C(γ), and CX3C(δ) classes. We identified CXC chemokine cDNA, designated RbCXC, isolated using expressed sequence tag analysis of a lipopolysaccharide (LPS)-stimulated rock bream liver cDNA library. The full-length RbCXC cDNA (742 bp) contained an open reading frame of 342 bp encoding 114 amino acids. Results from phylogenetic analysis showed that RbCXC was strictly separated into a distinct clade compared to other known CXC chemokine subgroups. RbCXC was significantly expressed in the trunk kidney, liver, spleen, gill, peripheral blood leukocytes (PBLs), and head kidney. Rock bream PBLs were stimulated with several mitogens, including LPS and polyinosinic-polycytidylic acid (poly I:C), which significantly induced the expression of RbCXC mRNA. RbCXC mRNA expression was examined in several tissues under conditions of bacterial and viral challenge. Experimental challenges revealed that all examined tissues from fish infected with Edwardsiella tarda and red sea bream iridovirus showed significant increases in RbCXC expression compared to the control. In the case of Streptococcus iniae infection, RbCXC mRNA expression was markedly upregulated in the kidney, spleen, and liver. In addition, a maltose binding protein fusion recombinant RbCXC (~53 kDa) was produced in an Escherichia coli expression system and purified. Subsequently, the addition of purified recombinant RbCXC (rRbCXC) to kidney leukocytes was examined to investigate the impact of proliferative and chemotactic activity. The rRbCXC induced significant kidney leukocyte proliferation and attraction at concentrations ranging from 10 to 300 μg/mL, suggesting that it can be utilised as an immune stimulant and/or molecular adjuvant to enhance the immunological effects of vaccines.

Immune activation of human brain microvascular endothelial cells inhibits HIV replication in macrophages

There is limited information about the role of blood-brain barrier (BBB) endothelial cells (ECs) in the central nervous system (CNS) and their innate immunity against HIV. We examined whether brain ECs can be immunologically activated to produce antiviral factors that inhibit HIV replication in macrophages. Human brain microvascular ECs expressed functional toll-like receptor 3 (TLR3) that could be activated by polyinosinic-polycytidylic acid (PolyI:C), resulting in the induction of endogenous interferon-β (IFN-β) and IFN-λ. The TLR3 activation of ECs also induced the phosphorylation of interferon regulatory transcription factor 3 (IRF3) and IRF7, the key regulators of IFN signaling pathway. When supernatant (SN) of PolyI:C-activated EC cultures was applied to infected macrophage cultures, HIV replication was significantly suppressed. This SN action of ECs on HIV was mediated through both IFN-β and IFN-λ because antibodies to their receptors could neutralize the SN-mediated anti-HIV effect. The role of IFNs in EC-mediated anti-HIV activity is further supported by the observation that treatment with SN from EC cultures induced the expression of IFN-stimulated genes (ISGs: ISG56, OAS-1, and MxA) in macrophages. These observations indicate that brain microvascular ECs may be a key regulatory bystander, playing a crucial role in the BBB innate immunity against HIV infection.

Inhibition of both BRAF and MEK in BRAF(V600E) mutant melanoma restores compromised dendritic cell (DC) function while having differential direct effects on DC properties

PURPOSE

Dendritic cells (DCs) can induce strong tumor-specific T-cell immune responses. Constitutive upregulation of the mitogen-activated protein kinase (MAPK) pathway by a BRAF(V600) mutation, which is present in about 50 % of metastatic melanomas, may be linked to compromised function of DCs in the tumor microenvironment. Targeting both MEK and BRAF has shown efficacy in BRAF(V600) mutant melanoma.

METHODS

We co-cultured monocyte-derived human DCs with melanoma cell lines pretreated with the MEK inhibitor U0126 or the BRAF inhibitor vemurafenib. Cytokine production (IL-12 and TNF-α) and surface marker expression (CD80, CD83, and CD86) in DCs matured with the Toll-like receptor 3/Melanoma Differentiation-Associated protein 5 agonist polyI:C was examined. Additionally, DC function, viability, and T-cell priming capacity were assessed upon direct exposure to U0126 and vemurafenib.

RESULTS

Cytokine production and co-stimulation marker expression were suppressed in polyI:C-matured DCs exposed to melanoma cells in co-cultures. This suppression was reversed by MAPK blockade with U0126 and/or vemurafenib only in melanoma cell lines carrying a BRAF(V600E) mutation. Furthermore, when testing the effect of U0126 directly on DCs, marked inhibition of function, viability, and DC priming capacity was observed. In contrast, vemurafenib had no effect on DC function across a wide range of dose concentrations.

CONCLUSIONS

BRAF(V600E) mutant melanoma cells modulate DC through the MAPK pathway as its blockade can reverse suppression of DC function. MEK inhibition negatively impacts DC function and viability if applied directly. In contrast, vemurafenib does not have detrimental effects on important functions of DCs and may therefore be a superior candidate for combination immunotherapy approaches in melanoma patients.

Interferon-ε protects the female reproductive tract from viral and bacterial infection

The innate immune system senses pathogens through pattern-recognition receptors (PRRs) that signal to induce effector cytokines, such as type I interferons (IFNs). We characterized IFN-ε as a type I IFN because it signaled via the Ifnar1 and Ifnar2 receptors to induce IFN-regulated genes. In contrast to other type I IFNs, IFN-ε was not induced by known PRR pathways; instead, IFN-ε was constitutively expressed by epithelial cells of the female reproductive tract (FRT) and was hormonally regulated. Ifn-ε-deficient mice had increased susceptibility to infection of the FRT by the common sexually transmitted infections (STIs) herpes simplex virus 2 and Chlamydia muridarum. Thus, IFN-ε is a potent antipathogen and immunoregulatory cytokine that may be important in combating STIs that represent a major global health and socioeconomic burden.

Molecular cloning and characterization of sea bass (Dicentrarchus labrax, L.) MHC class I heavy chain and β2-microglobulin

In this work, the gene and cDNA of sea bass (Dicentrarchus labrax) β2-microglobulin (Dila-β2m) and several cDNAs of MHC class I heavy chain (Dila-UA) were characterized. While Dila-β2m is single-copy, numerous Dila-UA transcripts were identified per individual with variability at the peptide-binding domain (PBD), but also with unexpected diversity from the connective peptide (CP) through the 3' untranslated region (UTR). Phylogenetic analysis segregates Dila-β2m and Dila-UA into each subfamily cluster, placing them in the fish class and branching Dila-MHC-I with lineage U. The α1 domains resemble those of the recently proposed L1 trans-species lineage. Although no Dila-specific α1, α2 or α3 sub-lineages could be observed, two highly distinct sub-lineages were identified at the CP/TM/CYT regions. The three-dimensional homology model of sea bass MHC-I complex is consistent with other characterized vertebrate structures. Furthermore, basal tissue-specific expression profiles were determined for both molecules, and expression of β2m was evaluated after poly I:C stimulus. Results suggest these molecules are orthologues of other β2m and teleost classical MHC-I and their basic structure is evolutionarily conserved, providing relevant information for further studies on antigen presentation in this fish species.

Molecular characterisation of porcine miR-155 and its regulatory roles in the TLR3/TLR4 pathways

MiR-155 plays very important roles in host inflammation and immunity. However, few studies have focused on miR-155 in livestock. In this study, the molecular characterisation of miR-155 and its functional roles in TLR3/TLR4 signalling pathways were investigated in pigs. The results indicated that miR-155 was highly expressed in the spleen and fat tissues of the pig. In PK-15 cells, miR-155 was up-regulated 4h after LPS stimulation and up-regulated 12h and 24h after poly (I:C) stimulation. Furthermore, the overexpression of miR-155 significantly activated the TLR3/TLR4 signalling pathways, and the inhibition of miR-155 suppressed these pathways. Thus, miR-155 played positive regulatory roles in TLR3/TLR4 signalling pathways. Additionally, one T/C SNP of miR-155 was significantly associated with basophil percentage (BA%), absolute eosinophili value (EO) and the distribution width of the least squares mean of CD3-CD4-CD8+ T cells (DWT) in pigs. Our study offers new evidence on the immune function of miR-155 in pigs.

Implication of double-stranded RNA signaling in the etiology of autoimmune myasthenia gravis

OBJECTIVE

Myasthenia gravis (MG) is an autoimmune disease mediated mainly by anti-acetylcholine receptor (AChR) antibodies. The thymus plays a primary role in MG pathogenesis. As we recently showed an inflammatory and antiviral signature in MG thymuses, we investigated whether pathogen-sensing molecules could contribute to an anti-AChR response.

METHODS

We studied the effects of toll-like receptor agonists on the expression of α-AChR and various tissue-specific antigens (TSAs) in human thymic epithelial cell (TEC) cultures. As polyinosinic-polycytidylic acid (poly[I:C]), which mimics double-stranded RNA (dsRNA), stimulated specifically α-AChR expression, the signaling pathways involved were investigated. In parallel, we analyzed the expression of dsRNA-signaling components in the thymus of MG patients, and the relevance of our data was investigated in vivo in poly(I:C)-injected mice.

RESULTS

We demonstrate that dsRNA signaling induced by poly(I:C) specifically triggers the overexpression of α-AChR in TECs and not of other TSAs. A poly(I:C) effect was also observed on MG TECs. This induction is mediated through toll-like receptor 3 (TLR3) and protein kinase R (PKR), and by the release of interferon (IFN)-β. In parallel, human MG thymuses also display an overexpression of TLR3, PKR, and IFN-β. In addition, poly(I:C) injections specifically increase thymic expression of α-AChR in wild-type mice, but not in IFN-I receptor knockout mice. These injections also lead to an anti-AChR autoimmune response characterized by a significant production of serum anti-AChR antibodies and a specific proliferation of B cells.

INTERPRETATION

Because anti-AChR antibodies are highly specific for MG and are pathogenic, dsRNA-signaling activation could contribute to the etiology of MG.

Interferon induction and suppression in swine testicle cells by porcine parvovirus and its proteins

Porcine parvovirus (PPV) is a major causative agent of reproductive failure in swine, which currently affects the swine industry worldwide. Although PPV was identified several years ago, little is known about how it overcomes host innate immunity. In this study, we used quantitative real-time PCR and a luciferase reporter assay to determine whether PPV infection induces type I interferon (IFN-α and IFN-β) and whether PPV infection blocks dsRNA-induced IFN-β promoter activation in cell cultures. The results indicate that PPV does not induce type I interferon and that the NS2 protein of PPV could blocks dsRNA-induced IFN-β promoter activation.

Pre-clinical assessment of autologous DC-based therapy in ovarian cancer patients with progressive disease

Dendritic cell-based vaccines offer promise for therapy of ovarian cancer. Previous studies have demonstrated that oxidation of several antigens, including ovarian cancer cells, using hypochlorous acid strongly enhances their immunogenicity and their uptake and presentation by dendritic cells. The response of T cells and dendritic cells to autologous tumour from patients with active disease has not previously been investigated. Monocyte-derived dendritic cells were generated from patients with active disease and activated by co-culture with oxidised tumour cells and the TLR agonist poly I:C. The dendritic cells showed an activated phenotype, but secreted high levels of TGFβ. Co-culture of the antigen-loaded dendritic cells with autologous T cells generated a population of effector T cells that showed a low level of specific lytic activity against autologous tumour, as compared to autologous mesothelium. The addition of neutralising antibody to TGFβ in DC/T cell co-cultures increased the levels of subsequent tumour killing in three samples tested. Co-culture of monocytes from healthy volunteers with the ovarian cell line SKOV-3 prior to differentiation into dendritic cells reduced the ability of dendritic cells to stimulate cytotoxic effector cells. The study suggests that co-culture of dendritic cells with oxidised tumour cells can generate effector cells able to kill autologous tumour, but that the high tumour burden in patients with active disease may compromise dendritic cell and/or T cell function.

[Effects on chemotactic factor expression in bronchial epithelial cells by co-stimulation of poly(I:C) and lipopolysaccharide and the underlying mechanism]

AIM

To investigate the effect of co-stimulation of mimic viral infection [polyinosinic: polycytidylic acid, poly(I:C)] and endotoxin (lipopolysaccharide, LPS) on chemotactic factors production of human bronchial epithelial cells and explore its related mechanism.

METHODS

Human bronchial epithelial cells (16HBE) were challenged by co-stimulation of different concentrations of poly(I:C) and LPS. Some other 16HBE cells, before the co-stimulation of poly(I:C) and LPS, were pretreated with dexamethasone and p38MAPK specific inhibitor (SB203580), respectively. The levels of IL-8/CXCL8 and IP-10/CXCL1 mRNA transcription were detected by RT-PCR after 6 h challenge. The contents of IL-8 and IP-10 proteins were detected by ELISA after 24 h challenge.

RESULTS

(1) The mRNA and protein expression of IL-8, not IP-10, increased under 10 μg/mL LPS stimulation compared with control group. The mRNA and protein expressions of both IL-8 and IP-10 were elevated significantly by the co-stimulation of LPS and 0.1 μg/mL poly (I:C) compared with control group and simple LPS groups. (2) The mRNA and protein expressions of IL-8 and IP-10 increased under the challenge of different concentrations of poly(I:C) (0.001, 0.01, 0.1 μg/mL) in a concentration-dependent manner, which showed no change after adding 10 μg/mL LPS. (3) Dexamethasone (1 μmol/L) and SB203580 (20 μmol/L) significantly decreased both the mRNA and protein production of IL-8 and IP-10 induced by co-stimulation of 0.1 μg/mL poly (I:C) and 10 μg/mL LPS compared with the control group and control+DMSO group respectively (P<0.01 and P<0.05). Inhibitive effect of dexamethasone was stronger than that of p38MAPK inhibitor.

CONCLUSIONS

The co-stimulation of poly(I:C) and LPS can induce chemokine expression of airway epithelial cells. Poly(I:C) enhances the IL-8 expression induced by single LPS challenge, which suggests that viral infection could enhance the inflammation resulted from bacterial colonization in airway. Glucocorticoid has the greater effect on the inhibition of chemotactic factors production than p38MAPK inhibitor. These two drugs have a potential therapeutic effect on AECOPD caused by viral infection.