Synthetic Toll-like receptor 7 ligand inhibits porcine reproductive and respiratory syndrome virus infection in primary porcine alveolar macrophages

Porcine ISG15 fused IFN-λ3 as a novel antiviral agent for treating porcine reproductive and respiratory syndrome virus infection in vivo

IFN-λs hold promise as therapeutic candidates against mutable respiratory viruses, but their efficacy against porcine reproductive and respiratory syndrome virus (PRRSV) remains unclear. In this study, we expressed a recombinant fusion protein consisting of porcine ISG15 linked porcine IFN-λ3 (ISG15-IFN-λ3) via a rigid protein linker in Escherichia coli (E. coli). In vitro experiments demonstrated that treatment of porcine alveolar macrophage (PAM)-derived CRL-2843 cells with ISG15-IFN-λ3 induced upregulation of several Interferon-stimulated Genes (ISGs) proteins, including ISG15, ISG56, and HERC5. CRL-2843 cells pretreated with ISG15-IFN-λ3 exhibited heightened resistance to Newcastle disease virus infection, while PRRSV-permissive cells treated with ISG15-IFN-λ3 before and during PRRSV exposure showed significantly inhibited PRRSV replication as well. In animal experiments, at 21 days post-infection, ISG15-IFN-λ3-treated piglets displayed milder lung tissue pathology and significantly reduced serum PRRSV-RNA, indicating enhanced viral clearance and faster recovery. Additionally, PAMs collected from ISG15-IFN-λ3-treated piglets showed significantly reduced mRNA expression of representative cytokines, chemokines, suggesting that ISG15-IFN-λ3 treatment may mitigate pneumonia severity by reducing the levels of these inflammatory mediators. These findings indicate that recombinant ISG15-IFN-λ3 expressed in E. coli may serve as a novel, effective, and affordable agent for treating severe PRRSV infection in piglets, potentially benefiting the pork industry.

Galangin alleviates rheumatoid arthritis in rats by downregulating the phosphatidylinositol 3-kinase/protein kinase B signaling pathway

Rheumatoid arthritis (RA) is a chronic autoimmune disease that greatly affect patients' quality of life. Galangin extract is renowned for its anti-proliferative and anti-oxidative characteristics. However, galangin cytotoxicity studies are presently inadequate. We aimed to investigate the therapeutic potential of galangin on RA by investigating the PI3K/AKT signaling pathway.Fibroblast-like synovial cells (FLSs) were exposed to lipopolysaccharide (LPS) to establish an RA model in vitro. An ELISA assay was used to detect the levels of IL-1β, TNF-α, and IL-6. Cell viability and apoptosis were determined by CCK8/EdU and flow cytometry assays. A western blot assay was used to analyze the protein expression levels. An RA rat model was established to evaluate the function of galangin through histopathological examination. Our results found that galangin induced apoptosis, inhibited cell proliferation, and increased cell invasion of rheumatoid arthritis fibroblast-like synovial cells (RAFLSs). Galangin inactivated the PI3K/AKT signaling pathway and the inflammatory response. An agonist of PI3K signaling, 740Y-P, restored the cellular functions of RAFLSs. Moreover, galangin suppressed the development of RA in vivo. Galangin effected its anti-arthritic influence through the PI3K/AKT signaling pathway. Galangin has potential as an alternative treatment for RA.

Characterization of chicken IFI35 and its antiviral activity against Newcastle disease virus

Interferon-induced protein-35 kDa (IFI35) was an antiviral protein induced by interferon (IFN)-γ, which plays an important role in the IFN-mediated antiviral signaling pathway. Here, we cloned and identified IFI35 in the chicken for the first time. Chicken IFI35 (chIFI35) contains an open reading frame (ORF) of 1,152 bp encoding a protein of 384 amino acids containing two conserved Nmi/IFI35 domain (NID) motifs. Tissue distribution analysis of chIFI35 in healthy and Newcastle disease (ND) virus-infected chickens indicated a positive correlation between chIFI35 mRNA transcription and ND viral loads in various tissues. The role of chIFI35 in regulation NDV replication were further assessed by up- or down-regulated chIFI35 expression in DF-1 cells transfected with plasmid harboring chIFI35, pCMV-3HA-chIFI35 or shRNA targeting chIFI35, pshRNA-chIFI35 plasmids. NDV replications in DF-1 cells were significantly reduced or slightly increased by over- or under-expression of the chIFI35 protein, respectively, indicating the role of chIFI35 in anti-NDV infection. Moreover, chIFI35 also involved in regulation of viral gene transcription and IFNs expression. The collected data were meaningful for research of chicken antiviral immunity and shed light on the pleiotropic antiviral effect of chIFI35 during NDV infection.

Screening of Porcine Innate Immune Adaptor Signaling Revealed Several Anti-PRRSV Signaling Pathways

Porcine reproductive and respiratory syndrome virus (PRRSV) causes PRRS and is known to effectively suppress host innate immunity. The current strategies for controlling PRRSV are limited and complete understanding of anti-PRRSV innate immunity is needed. Here, we utilized nine porcine innate immune signaling adaptors which represent all currently known innate immune receptor signaling pathways for screening of anti-PRRSV activity. The analysis of PRRSV N gene transcription and protein expression both suggested that the multiple ectopic adaptors exhibited varying degrees of anti-PRRSV activities, with TRIF and MAVS most effective. To better quantify the PRRSV replication, the GFP signal of PRRSV from reverse genetics were measured by flow cytometry and similarly varying anti-PRRSV activities by different signaling adaptors were observed. Based on the screening data, and considering the importance of viral nucleic acid in innate immune response, endogenous TRIF, MAVS and STING were selected for further examination of anti-PRRSV activity. Agonist stimulation assay showed that MAVS and STING signaling possessed significant anti-PRRSV activities, whereas siRNA knockdown assay showed that TRIF, MAVS and STING are all involved in anti-PRRSV activity, with TLR3-TRIF displaying discrepancy in anti-PRRSV infection. Nevertheless, our work suggests that multiple pattern recognition receptor (PRR) signaling pathways are involved in anti-PRRSV innate immunity, which may have implications for the development of future antiviral strategies.

Nanobody Nb6 fused with porcine IgG Fc as the delivering tag to inhibit porcine reproductive and respiratory syndrome virus replication in porcine alveolar macrophages

Porcine reproductive and respiratory syndrome virus (PRRSV) is a highly contagious virus that has led to enormous economic loss worldwide because of ineffective prevention and treatment. In view of their minimized size, high target specificity and affinity, nanobodies have been extensively investigated as diagnostic tools and treatments of many diseases. Previously, a PRRSV Nsp9-specific nanobody (Nb6) was identified as a PRRSV replication inhibitor. When it was fused with cell-penetrating peptide (CPP) TAT, Nb6-TAT could enter the cells for PRRSV suppression. However, delivery of molecules by CPP lack cell specificity and have a short duration of action. PRRSV has a tropism for monocyte/macrophage lineage, which expresses high levels of Fcγ receptors. Herein, we designed a nanobody containing porcine IgG Fc (Fcγ) to inhibit PRRSV replication in PRRSV permissive cells. Fcγ fused Nb6 chimeric antibody (Nb6-pFc) was assembled into a dimer with interchain disulfide bonds and expressed in a Pichia pastoris system. The results show that Nb6-pFc exhibits a well-binding ability to recombinant Nsp9 or PRRSV-encoded Nsp9 and that FcγR-mediated endocytosis of Nb6-pFc into porcine alveolar macrophages (PAM) was in a dose-dependent manner. Nb6-pFc can inhibit PRRSV infection efficiently not only by binding with Nsp9 but also by upregulating proinflammatory cytokine production in PAM. Together, this study proposes the design of a porcine IgG Fc-fused nanobody that can enter PRRSV susceptible PAM via FcγR-mediated endocytosis and inhibit PRRSV replication. This research reveals that nanobody-Fcγ chimeric antibodies might be effective for the control and prevention of monocyte/macrophage lineage susceptible pathogeneses.

GSH-ZnS Nanoparticles Exhibit High-Efficiency and Broad-Spectrum Antiviral Activities via Multistep Inhibition Mechanisms

Despite the good biocompatibility and antibacterial activity of zinc sulfide nanoparticles (ZnS NPs), whether they possess antiviral activity is still unclear. Here, GSH-modified ZnS NPs (GSH-ZnS NPs) were synthesized and their significant antiviral activity was demonstrated using the Arteriviridae family RNA virus, porcine reproductive and respiratory syndrome virus (PRRSV), as a model. Mechanistically, GSH-ZnS NPs were shown to reduce PRRSV-induced ROS production to prevent PRRSV multiplication, with no activating effect on the interferon (IFN) signal pathway, the first defense line against virus infection. Furthermore, isobaric tags for relative and absolute quantification (iTRAQ)-based quantitative proteomic analysis of GSH-ZnS NP-treated cells revealed the involvement of numerous crucial proteins in virus proliferation, with vitronectin (VTN) being confirmed as an efficient PRRSV antagonist here. Furthermore, GSH-ZnS NPs were found to have potent antiviral effects on the Herpesviridae family DNA virus, pseudorabies virus (PRV), the Coronaviridae family positive-sense RNA virus, porcine epidemic diarrhea virus (PEDV), and the Rhabdoviridae family negative-stranded RNA virus, vesicular stomatitis virus (VSV), indicating their broad-spectrum antiviral activity against viruses from different families with various genome types. Overall, GSH-ZnS NP is a prospective candidate for the development of antiviral nanomaterials and may serve as a model for investigation of potential host restriction factors in combination with proteomics.

Methionine enkephalin inhibits influenza A virus infection through upregulating antiviral state in RAW264.7 cells

MENK, as an immune adjuvant, has potential immune-regulatory activity on innate and adaptive immune cells. The aim of this work was to investigate the antiviral effect of MENK on influenza virus-infected murine macrophage cells (RAW264.7) and its underlying mechanisms. The results showed that MENK markedly inhibited influenza A virus (H1N1) replication in pre- and post-MENK treatment, especially in pre-MENK treatment. The mechanisms exploration revealed that MENK (10 mg/mL) significantly inhibited the nucleoprotein (NP) of influenza virus and up-regulated levels of IL-6, TNF-α and IFN-β compared with those in H1N1 control group. Further experiments confirmed that antiviral effects of MENK was associated with promotion of opioid receptor (MOR) as well as activation of NF-κB p65 inducing cellular antiviral status. The data suggest that MENK should be potential candidate for prophylactic or therapeutic treatment against H1N1 influenza virus.

Direct Interaction Between CD163 N-Terminal Domain and MYH9 C-Terminal Domain Contributes to Porcine Reproductive and Respiratory Syndrome Virus Internalization by Permissive Cells

Porcine reproductive and respiratory syndrome virus (PRRSV) has a highly restricted tropism for cells of the monocyte-macrophage lineage, including porcine alveolar macrophages (PAMs). PRRSV entry into permissive cells involves several mediators in addition to two required host cell receptors, CD163 and MYH9. It is unknown whether CD163 directly interacts and/or cooperates with MYH9 to facilitate PRRSV infection. In this study, CD163 and MYH9 were co-immunoprecipitated from PAMs regardless of PRRSV infection status. Further truncation analysis indicated that the CD163 N-terminal region, containing scavenger receptor cysteine-rich domains 1 to 4 (SRCR1-4), directly interacts with the MYH9 C-terminal domain region without involvement of other adaptor proteins. Meanwhile, non-permissive HEK293T cells that stably expressed truncated swine CD163 SRCR1-4 domain did not support virus attachment. However, virus attachment to cells stably expressing SRCR5-CT domain was demonstrated to occur without appreciable virus internalization. The involvement of the SRCR1-4 domain in virus internalization was further demonstrated by the fact that incubation of recombinant SRCR1-4 protein with PAMs abolished subsequent virus internalization by permissive cells. These results demonstrated that CD163 SRCR1-4 interacts with the MYH9 C–terminal domain to facilitate PRRSV virion internalization in permissive cells, thus expanding our understanding of PRRSV cell-invasion mechanisms.

Toll-like receptor agonists as adjuvants for inactivated porcine reproductive and respiratory syndrome virus (PRRSV) vaccine

Toll-like receptor (TLR) agonists can effectively stimulate antigen-presenting cells (APCs) and are anticipated to be promising adjuvants in combination with inactivated vaccines. In this study, the adjuvant potential of three different TLR-agonists were compared with an oil-in-water (O/W) adjuvant in combination with inactivated porcine reproductive and respiratory syndrome virus (iPRRSV) applied by different administration routes: intramuscular (i.m.) or into the skin using dissolving microneedle (DMN) patches. Pigs received a prime vaccination followed by a booster vaccination four weeks later. TLR1/2 (Pam3Cys), TLR7/8 (R848) or TLR9 (CpG ODN) agonists were used as adjuvant in combination with iPRRSV strain 07V063. O/W adjuvant (Montanide™) was used as reference control adjuvant and one group received a placebo vaccination containing diluent only. All animals received a homologous challenge with PRRSV three weeks after the booster vaccination. Antibody and IFN-γ production, serum cytokines and viremia were measured at several time-points after vaccination and/or challenge, and lung pathology at necropsy. Our results indicate that a TLR 1/2, 7/8 or 9 agonist as adjuvant with iPRRSV does not induce a detectable PRRSV-specific immune response, independent of the administration route. However, the i.m. TLR9 agonist group showed reduction of viremia upon challenge compared to the non-vaccinated animals, supported by a non-antigen-specific IFN-γ level after booster vaccination and an anamnestic antibody response after challenge. Montanide™-adjuvanted iPRRSV induced antigen-specific immunity after booster combined with reduction of vireamia. Skin application of TLR7/8 agonist, but not the other agonists, induced a local skin reaction. Further research is needed to explore the potential of TLR agonists as adjuvants for inactivated porcine vaccines with a preference for TLR9 agonists.

A Nanobody Targeting Viral Nonstructural Protein 9 Inhibits Porcine Reproductive and Respiratory Syndrome Virus Replication

Porcine reproductive and respiratory syndrome (PRRS) is of great concern to the swine industry due to pandemic outbreaks of the disease, current ineffective vaccinations, and a lack of efficient antiviral strategies. In our previous study, a PRRSV Nsp9-specific nanobody, Nb6, was successfully isolated, and the intracellularly expressed Nb6 could dramatically inhibit PRRSV replication in MARC-145 cells. However, despite its small size, the application of Nb6 protein in infected cells is greatly limited, as the protein itself cannot enter the cells physically. In this study, a trans-activating transduction (TAT) peptide was fused with Nb6 to promote protein entry into cells. TAT-Nb6 was expressed as an inclusion body in Escherichia coli, and indirect enzyme-linked immunosorbent assays and pulldown assays showed that E. coli-expressed TAT-Nb6 maintained the binding ability to E. coli-expressed or PRRSV-encoded Nsp9. We demonstrated that TAT delivered Nb6 into MARC-145 cells and porcine alveolar macrophages (PAMs) in a dose- and time-dependent manner, and TAT-Nb6 efficiently inhibited the replication of several PRRSV genotype 2 strains as well as a genotype 1 strain. Using a yeast two-hybrid assay, Nb6 recognition sites were identified in the C-terminal part of Nsp9 and spanned two discontinuous regions (Nsp9_aa454-551 and Nsp9_aa599-646). Taken together, these results suggest that TAT-Nb6 can be developed as an antiviral drug for the inhibition of PRRSV replication and controlling PRRS disease.IMPORTANCE The pandemic outbreak of PRRS, which is caused by PRRSV, has greatly affected the swine industry. We still lack an efficient vaccine, and it is an immense challenge to control its infection. An intracellularly expressed Nsp9-specific nanobody, Nb6, has been shown to be able to inhibit PRRSV replication in MARC-145 cells. However, its application is limited, because Nb6 cannot physically enter cells. Here, we demonstrated that the cell-penetrating peptide TAT could deliver Nb6 into cultured cells. In addition, TAT-Nb6 fusion protein could suppress the replication of various PRRSV strains in MARC-145 cells and PAMs. These findings may provide a new approach for drug development to control PRRS.

Porcine FcεRI Mediates Porcine Reproductive and Respiratory Syndrome Virus Multiplication and Regulates the Inflammatory Reaction

Porcine reproductive and respiratory syndrome virus (PRRSV) shows characteristic antibody-dependent enhancement (ADE) of infection and causes porcine systemic inflammation, which is similar to a type I allergic reaction; however, the role of porcine FcεRI in ADE is still unclear. In this study, the expression of different Fc receptors (FcRs) on macrophages was investigated in a PRRSV 3D4/21 cell infection model in the presence or absence of PRRSV antibody. The transcription level of FcγII and FcεRI was significantly up-regulated under PRRSV-antibody complex infection. Internalization and proliferation of PRRSV were promoted by the ADE mechanism when FcεRI was expressed in permissive 3D4/21 cells and the non-permissive cell line HEK 293T. Transcriptome sequencing data showed that the expression levels of AKT, ERK and other signal molecules in the anti-inflammatory pathway were significantly increased, especially in the cells infected with the PRRSV-antibody immune complex. Inflammatory regulatory molecules such as PLA2G6, LOX, TRPM8 and TRPM4 were significantly up-regulated following PRRSV infection but significantly down-regulated in the cells infected with the PRRSV-antibody immune complex. Our results demonstrated that FcεRI could be involved in PRRSV ADE, the antigen presenting process and regulation of the inflammatory response during PRRSV infection, which provides new insights into PRRSV infection mediated by FcεRI and the PRRSV-antibody immune complex.

Generation of murine macrophage-derived cell lines expressing porcine CD163 that support porcine reproductive and respiratory syndrome virus infection

Background

Porcine reproductive and respiratory syndrome virus (PRRSV) exhibits a highly restricted tropism for cells of the monocyte-macrophage lineage, utilizing porcine CD163 (pCD163) as an indispensable cellular receptor for infection. Transfection the gene of pCD163 into several non-permissive cell lines followed by protein expression confers susceptibility to PRRSV. A lack of specialized porcine antibody tools for use with existing porcine-derived primary cells and cell lines has hampered studies of both PRRSV pathogenesis and virus triggering of immune response cascades. Therefore, we constructed PRRSV-susceptible murine alveolar macrophage-derived MH-S and peritoneal macrophage-like RAW264.7 cell lines by achieving pCD163 cell surface expression in these cells. We then evaluated PRRSV susceptibility and cytokine expression patterns induced upon PRRSV infection of these pCD163-expressing cell lines.

Results

Growth of MH-S^CD163 and RAW264.7^CD163 cells was indistinguishable from growth of un-transfected parental cell lines. Meanwhile, various stages of the PRRSV replication cycle, including viral particle attachment, internalization, disassembly and infection were confirmed in both pCD163-transfected cell lines. Analysis of PRRSV replication using immunofluorescence staining of virus and viral titration of cell lysates demonstrated that both MH-S^CD163 and RAW264.7^CD163 cells supported replication of various genotype 2 PRRSV isolates. Moreover, PRRSV replication in MH-S^CD163 cells was similar to that observed in porcine alveolar macrophages (PAMs) and was more efficient than in RAW264.7^CD163 cells. However, peak virus titers in MH-S^CD163 cells were attained at 60 h post-infection (pi) versus 48 hpi in PAMs. Analysis of cytokine expression showed that post-PRRSV infection, mRNA expression patterns of anti-inflammatory cytokines (IL-4 and IL-10) and pro-inflammatory cytokines (TNF-α and IFN-γ) in MH-S^CD163 cells were more similar to those observed in PAMs versus levels in RAW264.7^CD163 cells.

Conclusions

MH-S and RAW264.7 cells were not susceptible to PRRSV infection until transfection and subsequent expression of pCD163 were achieved in these cell lines. The PRRSV-susceptible MH-S^CD163 cell line efficiently supported viral replication of various genotype 2 PRRSV isolates and exhibited similar cytokine expression patterns as observed in PAMs. In conclusion, this work describes the development of new tools to further understand PRRSV pathogenesis and immune response mechanisms to PRRSV infection.

Electronic supplementary material

The online version of this article (10.1186/s12896-017-0399-5) contains supplementary material, which is available to authorized users.

Curcumin is a promising inhibitor of genotype 2 porcine reproductive and respiratory syndrome virus infection

Background

Porcine reproductive and respiratory syndrome virus (PRRSV) could lead to pandemic diseases and huge financial losses to the swine industry worldwide. Curcumin, a natural compound, has been reported to serve as an entry inhibitor of hepatitis C virus, chikungunya virus and vesicular stomatitis virus. In this study, we investigated the potential effect of curcumin on early stages of PRRSV infection.

Results

Curcumin inhibited infection of Marc-145 cells and porcine alveolar macrophages (PAMs) by four different genotype 2 PRRSV strains, but had no effect on the levels of major PRRSV receptor proteins on Marc-145 cells and PAMs or on PRRSV binding to Marc-145 cells. However, curcumin did block two steps of the PRRSV infection process: virus internalization and virus-mediated cell fusion.

Conclusions

Our results suggested that an inhibition of genotype 2 PRRSV infection by curcumin is virus strain-independent, and mainly inhibited by virus internalization and cell fusion mediated by virus. Collectively, these results demonstrate that curcumin holds promise as a new anti-PRRSV drug.

Improved Vaccine against PRRSV: Current Progress and Future Perspective

Porcine reproductive and respiratory syndrome virus (PRRSV), one of the most economically significant pathogens worldwide, has caused numerous outbreaks during the past 30 years. PRRSV infection causes reproductive failure in sows and respiratory disease in growing and finishing pigs, leading to huge economic losses for the swine industry. This impact has become even more significant with the recent emergence of highly pathogenic PRRSV strains from China, further exacerbating global food security. Since new PRRSV variants are constantly emerging from outbreaks, current strategies for controlling PRRSV have been largely inadequate, even though our understanding of PRRSV virology, evolution and host immune response has been rapidly expanding. Meanwhile, practical experience has revealed numerous safety and efficacy concerns for currently licensed vaccines, such as shedding of modified live virus (MLV), reversion to virulence, recombination between field strains and MLV and failure to elicit protective immunity against heterogeneous virus. Therefore, an effective vaccine against PRRSV infection is urgently needed. Here, we systematically review recent advances in PRRSV vaccine development. Antigenic variations resulting from PRRSV evolution, identification of neutralizing epitopes for heterogeneous isolates, broad neutralizing antibodies against PRRSV, chimeric virus generated by reverse genetics, and novel PRRSV strains with interferon-inducing phenotype will be discussed in detail. Moreover, techniques that could potentially transform current MLV vaccines into a superior vaccine will receive special emphasis, as will new insights for future PRRSV vaccine development. Ultimately, improved PRRSV vaccines may overcome the disadvantages of current vaccines and minimize the PRRS impact to the swine industry.

A Novel Agonist of the TRIF Pathway Induces a Cellular State Refractory to Replication of Zika, Chikungunya, and Dengue Viruses

The ongoing concurrent outbreaks of Zika, Chikungunya, and dengue viruses in Latin America and the Caribbean highlight the need for development of broad-spectrum antiviral treatments. The type I interferon (IFN) system has evolved in vertebrates to generate tissue responses that actively block replication of multiple known and potentially zoonotic viruses. As such, its control and activation through pharmacological agents may represent a novel therapeutic strategy for simultaneously impairing growth of multiple virus types and rendering host populations resistant to virus spread. In light of this strategy's potential, we undertook a screen to identify novel interferon-activating small molecules. Here, we describe 1-(2-fluorophenyl)-2-(5-isopropyl-1,3,4-thiadiazol-2-yl)-1,2-dihydrochromeno[2,3-c]pyrrole-3,9-dione, which we termed AV-C. Treatment of human cells with AV-C activates innate and interferon-associated responses that strongly inhibit replication of Zika, Chikungunya, and dengue viruses. By utilizing genome editing, we investigated the host proteins essential to AV-C-induced cellular states. This showed that the compound requires a TRIF-dependent signaling cascade that culminates in IFN regulatory factor 3 (IRF3)-dependent expression and secretion of type I interferon to elicit antiviral responses. The other canonical IRF3-terminal adaptor proteins STING and IPS-1/MAVS were dispensable for AV-C-induced phenotypes. However, our work revealed an important inhibitory role for IPS-1/MAVS, but not TRIF, in flavivirus replication, implying that TRIF-directed viral evasion may not occur. Additionally, we show that in response to AV-C, primary human peripheral blood mononuclear cells secrete proinflammatory cytokines that are linked with establishment of adaptive immunity to viral pathogens. Ultimately, synthetic innate immune activators such as AV-C may serve multiple therapeutic purposes, including direct antimicrobial responses and facilitation of pathogen-directed adaptive immunity.IMPORTANCE The type I interferon system is part of the innate immune response that has evolved in vertebrates as a first line of broad-spectrum immunological defense against an unknowable diversity of microbial, especially viral, pathogens. Here, we characterize a novel small molecule that artificially activates this response and in so doing generates a cellular state antagonistic to growth of currently emerging viruses: Zika virus, Chikungunya virus, and dengue virus. We also show that this molecule is capable of eliciting cellular responses that are predictive of establishment of adaptive immunity. As such, this agent may represent a powerful and multipronged therapeutic tool to combat emerging and other viral diseases.

Immunomodulatory and Antitumor Effects of a Novel TLR7 Agonist Combined with Lapatinib

As new treatment approaches, both immunotherapy and targeted treatments have been used in the clinical treatment of cancers. These therapies are different from traditional surgery, chemotherapy and radiotherapy. Use of a combination of immunotherapy and targeted treatments may improve tumor clearance. We investigated the feasibility of combining tyrosine kinase inhibitors (TKIs, targeted drugs) and SZU-101 (a novel TLR7 agonist synthesized by our laboratory). Thirteen different TKIs were combined with or without SZU-101 and studied to determine their effects on immunocytes. On the basis of the distinctive results, lapatinib and sunitinib were selected for further tumor-inhibition investigation and determination of the underlying mechanism. Interestingly, we found lapatinib to work better with SZU-101, enhancing tumor clearance in vivo, without affecting the TLR7-NF-κB pathway activated by the TLR7 agonist in mouse spleen lymphocytes and bone marrow dendritic cells (BMDCs).

CpG Oligodeoxynucleotides Induce Differential Cytokine and Chemokine Gene Expression Profiles in Dapulian and Landrace Pigs

Oligodeoxynucleotides containing unmethylated CpG motifs (CpG ODN) mimic the immunostimulatory activity of microbial DNA by interacting with Toll-like receptor 9 (TLR9) to activate both the innate and adaptive immune responses in different species. However, few studies have been published to compare the effects of CpG ODN on different pig breeds. Therefore, in this study, whole blood gene expression profiles of DPL and Landrace pigs treated with CpG ODN were studied using RNA-seq technology. Five Hundred differentially expressed genes (DEGs) were identified between the two breeds. DPL pigs had significantly higher number of immune-relevant DEGs than the Landrace pigs after CpG ODN treatment. Pathway analysis showed that cytokine-cytokine receptor interaction and chemokine signaling pathway were the major enriched pathways of the immune-relevant DEGs. Further in vitro experiments showed that PBMCs of the DPL pigs had significantly higher levels of TLR9 mRNA than those of the Landrace pigs, both before and after CpG ODN stimulation. Cytokine and chemokine induction in the PBMCs of both breeds were also measured after CpG ODN stimulation. Our data showed that mRNA levels of cytokines (IFNα, IL8, IL12 p40) and chemokines (CXCL9, CXCL13) were significantly higher in the PBMCs of the DPL pigs than those of the Landrace pigs. Taken together, our data provide new information regarding the pig breed difference in response to CpG ODN stimulation and that higher levels of TLR9 mRNA in DPL pigs may be a major contributor for disease resistance.