Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “immunization”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 757 records · Page 42

CT584 Is Not a Protective Vaccine Antigen against Respiratory Chlamydial Challenge in Mice

Background: Chlamydia trachomatis is the most prevalent bacterial sexually transmitted pathogen in humans worldwide. Since chlamydial infection is largely asymptomatic with the potential for serious complications, a preventative vaccine is likely the most viable long-term answer to this public health threat. Cell-free protein synthesis (CFPS) utilizes the cellular protein manufacturing machinery decoupled from the requirement for maintaining cellular viability, offering the potential for flexible, rapid, and decentralized production of recombinant protein vaccine antigens. Methods: Here, we use CFPS to produce the full-length putative chlamydial type three secretion system (T3SS) needle-tip protein, CT584, for evaluation as a vaccine antigen in mouse models. High-speed atomic force microscopy (HS-AFM) (RIBM, Tsukuba, Japan) imaging and computer simulations confirm that CFPS-produced CT584 retains a native-like structure prior to immunization. Female mice were primed with CT584 adjuvanted with CpG-1826 intranasally (i.n.) or CpG-1826 + Montanide ISA 720 intramuscularly (i.m.), followed four weeks later by an i.m. boost before respiratory challenge with 10 4 inclusion forming units (IFU) of Chlamydia muridarum. Results: Immunization with CT584 generated robust antibody responses but weak cell-mediated immunity and failed to protect against i.n. challenge as demonstrated by body weight loss, increased lung weights, and the presence of high numbers of IFUs in the lungs. Conclusion: While CT584 was not a protective vaccine candidate, the speed and flexibility with which CFPS can be used to produce other potential chlamydial antigens make it an attractive technique for antigen production.

60 APPLIED LIFE SCIENCES↗

Combined effects of space flight factors and radiation on humans

The probability that a dose of ionizing radiation kills a cell is about 10,000 times the probability that the cell will be transformed to malignancy. On the other hand, the number of cells killed required to significantly impact health is about 10,000 times the number that must be transformed to cause a late malignancy. If these two risks, cell killing and malignant transformation, are about equal, then the risk that occurs during a mission is more significant than the risk that occurs after a mission. The latent period for acute irradiation effects (cell killing) is about 2-4 weeks; the latent period for malignancy is 10-20 years. If these statements are approximately true, then the impact of cell killing on health in the low-gravity environment of space flight should be examined to establish an estimate of risk. The objective of this study is to synthesize data and conclusions from three areas of space biology and environmental health to arrive at rational risk assessment for radiations received by spacecraft crews: (1) the increased physiological demands of the space flight environment; (2) the effects of the space flight environment on physiological systems; and (3) the effects of radiation on physiological systems. One physiological system has been chosen: the immune response and its components, consisting of myeloid and lymphoid proliferative cell compartments. Best-case and worst-case scenarios are considered. In the worst case, a doubling of immune-function demand, accompanied by a halving of immune capacity, would reduce the endangering dose to a crew member to around 1 Gy.

Non-NASA Center↗

Shortwave‐Infrared‐Emitting Nanoprobes for CD8 Targeting and In Vivo Imaging of Cytotoxic T Cells in Breast Cancer

Checkpoint immunotherapy has made great strides in the treatment of solid tumors, but many patients do not respond to immune checkpoint inhibitors. Identification of tumor‐infiltrating cytotoxic T cells (CTLs) has the potential to stratify patients and monitor immunotherapy responses. In this study, the design of cluster of differentiation (CD8 + ) T cell‐targeted nanoprobes that emit shortwave infrared (SWIR) light in the second tissue‐transparent window for noninvasive, real‐time imaging of CTLs in murine models of breast cancer is presented. SWIR‐emitting rare‐earth nanoparticles encapsulated in human serum albumin are conjugated with anti‐CD8α to target CTLs with high specificity. CTL targeting is validated in vitro through binding of nanoprobes to primary mouse CTLs. The potential for the use of SWIR fluorescence intensity to determine CTL presence is validated in two syngeneic mammary fat pad tumor models, EMT6 and 4T1, which differ in immune infiltration. SWIR imaging using CD8‐targeted nanoprobes successfully identifies the presence of CTLs in the more immunogenic EMT6 model, while imaging confirms the lack of substantial immune infiltration in the nonimmunogenic 4T1 model. In this work, the opportunity for SWIR imaging using CD8‐targeted nanoprobes to assess CTL infiltration in tumors for the stratification and monitoring of responders to checkpoint immunotherapy is highlighted.

Shah, Jay V.↗

Mercury immunotoxicity in the brown watersnake ( Nerodia taxispilota ): An in vitro study

Mercury (Hg) is a heavy metal that enters the environment through natural and anthropogenic means. Once in the environment, Hg can biomagnify in food webs and is known to cause immunotoxic effects to wildlife. Compared with other vertebrates, knowledge of the reptilian immune system is lacking, especially in snakes. Further, even less is known about the impact of environmental contaminants on snake immunity. This gap in knowledge is largely due to an absence of established immune-based assays or specific reagents for these species. In this study, brown watersnakes (Nerodia taxispilota; n = 23) were captured on the Savannah River (Augusta, Georgia, USA), weighed, measured, bled, and released. Peripheral blood leukocytes (24 h old) were enriched and evaluated with an established mammalian in vitro lymphocyte proliferation assay. Enriched leukocytes were then exposed to mercury chloride (HgCl2) at 3.75, 37.5, and 75 μM. Total mercury (THg) in whole blood was also quantified. Snake peripheral blood leukocyte enrichment yielded >90% lymphocytes with viabilities averaging >70%. Exposure to HgCl 2 resulted in significant dose-dependent suppression of proliferative responses relative to spontaneous proliferation at 37.5 and 75 μM (both p ≤ 0.01) but not 3.75 μM (p = 0.99). Mean ± 1 SE concentration of THg in whole blood was 0.127 ± 0.027 mg/kg (wet weight). Based on the in vitro findings with HgCl 2 , snakes in systems with heavy Hg pollution may be at risk of immunosuppression, but N. taxispilota at the site in this study appear to be at low risk.

59 BASIC BIOLOGICAL SCIENCES↗

Defatted microalgae ( Nannochloropsis sp.) from biorefinery as a potential feed protein source to replace fishmeal in European sea bass diets

Here, the present work focuses on the use of defatted biomass of the microalga Nannochloropsis sp. from the biodiesel industry, as a partial substitute of fish meal (FM) in diets for European sea bass. The effects of increasing inclusion levels of microalgal meal on growth performance, body composition, nutrient utilization, gut morphology, and innate immunity were evaluated after 93 days. A reference alga-free diet was the control (CTRL) diet, and the three experimental diets contained 5 (MA5), 10 (MA10), and 15% (MA15) of the microalgal meal. The microalga-rich diets were supplemented with DL-methionine to assure sea bass dietary requirement. Overall, nutrient apparent digestibilities (ADCs) of the diets were not altered by the microalgal inclusion, but energy ADC was highest in fish fed the CTRL diet (90% vs 88%). At the end of the trial, fish growth performance was similar among dietary treatments (DGI of 1.0), but fish fed MA10 had a significantly higher feed conversion ratio than those fed CTRL and MA5. Final whole body composition and nutrient gain of fish fed the different diets were similar. No significant differences were detected in gut morphology among treatments. Innate immune parameters (lysozyme, alternative complement pathway—ACH50, and peroxidase) were examined, and ACH50 of the fish fed MA15 was significantly lower than those fed MA10, suggesting a dose-dependent stimulation of the innate immune response. The present results indicate that defatted microalgal meal can replace fishmeal in European sea bass diets—at inclusion levels of up to 15%—contributing to a circular economy approach.

59 BASIC BIOLOGICAL SCIENCES↗

Cancer Treatment-Associated Pericardial Disease: Epidemiology, Clinical Presentation, Diagnosis, and Management

Purpose of Review: Cancer therapeutics have seen tremendous growth in the last decade and have been effective in the treatment of several cancer types. However, with advanced therapies like kinase inhibitors and immunotherapies, there have been unintended consequences of cardiotoxicities. While traditional chemotherapy and radiation-induced cardiotoxicity have been well studied, further research is needed to understand the adverse effects of newer regimens. Recent Findings: Both immune-mediated and non-immune-medicated cytotoxicity have been noted with targeted therapies such as tyrosine kinase inhibitors and immune checkpoint inhibitors. In this manuscript, we describe the pericardial syndromes associated with cancer therapies and propose management strategies. Pericardial effusion and pericarditis are common presentations in cancer patients and often difficult to diagnose. Concomitant myocarditis may also present with pericardial toxicity, especially with immunotherapies. In addition to proper history and physical, additional testing such as cardiovascular imaging and tissue histology need to be obtained as appropriate. Holding the offending oncology drug, and institution of anti-inflammatory medications, and immunosuppressants such as steroids are indicated. Summary: A high index of suspicion, use of standardized definitions, and comprehensive evaluation are needed for early identification, appropriate treatment, and better outcomes for patients with cancer treatment-associated pericardial disease. Further research is needed to understand the pathophysiology and to evaluate how the management of pericardial conditions in these patients differ from traditional management and also evaluate new therapies.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Clinicians’ and Pharmacists’ Reported Implementation of Vaccination Practices for Adults

Introduction: Despite the proven effectiveness of immunization in preventing morbidity and mortality, adult vaccines remain underutilized. The objective of this study was to describe clinicians’ and pharmacists’ self-reported implementation of the Standards for Adult Immunization Practice (“the Standards”; i.e., routine assessment, recommendation, and administration/referral for needed vaccines, and documentation of administered vaccines, including in immunization information systems). Methods: Two Internet panel surveys (one among clinicians and one among pharmacists) were conducted during February–March 2017 and asked respondents about their practice’s implementation of the Standards. T-tests assessed associations between clinician medical specialty, vaccine type, and each component of the Standards (March–August 2017). Results: Implementation of the Standards varied substantially by vaccine and provider type. For example, >80.0% of providers, including obstetrician/gynecologists and subspecialists, assessed for and recommended influenza vaccine. However, 24.3% of obstetrician/gynecologists and 48.9% of subspecialists did not stock influenza vaccine for administration. Although zoster vaccine was recommended by >89.0% of primary care providers, <58.0% stocked the vaccine; by contrast, 91.6% of pharmacists stocked zoster vaccine. Vaccine needs assessments, recommendations, and stocking/referrals also varied by provider type for pneumococcal; tetanus, diphtheria, acellular pertussis; tetanus diphtheria; human papillomavirus; and hepatitis B vaccines. Conclusions: This report highlights gaps in access to vaccines recommended for adults across the spectrum of provider specialties. Greater implementation of the Standards by all providers could improve adult vaccination rates in the U.S. by reducing missed opportunities to recommend vaccinations and either vaccinate or refer patients to vaccine providers.

60 APPLIED LIFE SCIENCES↗

MCPIP1 is a positive regulator of type I interferons antiviral activity

Highlights: • MCPIP1 promotes innate antiviral immunity independently of its RNase activity. • MCPIP1 enhances IFN-I mediated antiviral activity. • MCPIP1 is an IFN-induced positive feedback signal for IFN signaling activation. • MCPIP1 promotes ISRE promoter activity and ISGs expression in IFN signaling. Type-I interferons (IFN-I) are widely used for antiviral immunotherapy in clinic. Therefore, identification of the regulators of IFN-I antiviral activity is important for developing novel targets for IFN-based antiviral therapy. Monocyte chemoattractant protein 1-induced protein 1 (MCPIP1) is critical for cellular inflammatory responses. However, the roles of MCPIP1 in interferons (IFNs)-mediated antiviral immunity are unexplored. In this study, we demonstrate for the first time that MCPIP1 is an important positive regulator of IFNs antiviral activity. We found that MCPIP1 can promote innate antiviral immunity independently of both its RNase and deubiquitinase activity. Furthermore, we reveal that MCPIP1 is an IFN-induced positive feedback signal molecule which promotes IFN-I-mediated antiviral efficacy. Mechanistically, MCPIP1 does not affect the activation of JAK/STAT upstream of IFN-I signaling, but significantly promotes IFN-I signaling by enhancing ISRE promoter activity and expression of interferon-stimulated genes (ISGs). And MCPIP1-mediated activation of IFN-I signaling is independently of its RNase and deubiquitinase activity. These findings uncover a novel innate antiviral mechanism mediated by the IFN-MCPIP1 axis, and may provide potential targets for enhancing IFNs antiviral therapy.

60 APPLIED LIFE SCIENCES↗

Substance P preserves pancreatic β-cells in type 1 and type 2 diabetic mice

Highlights: • Substance P preserved β-cells in nonobese diabetic mice with type 1 diabetes. • Substance P preserved β-cells in db/db mice with type 2 diabetes. • Substance P inhibited the activation of pancreatic stellate cells. Preservation of pancreatic β-cells is required for the development of therapies for type 1 and type 2 diabetes (T1D and T2D, respectively). Our previous study demonstrated that substance P (SP) preserves β-cell populations in mice with streptozotocin-induced T1D. Here, we demonstrated that chronic systemic treatment with SP restored the mass of β-cells both in nonobese diabetic (NOD) mice with T1D or db/db mice with T2D. SP delayed the onset of T1D in NOD mice via immune modulation. SP inhibited immune infiltration into islets and the salivary glands of NOD mice. In db/db mice, SP treatment rescued glucose intolerance. Moreover, SP inhibited apoptosis, as well as the activation of pancreatic stellate cells in pancreatic islets of db/db mice. SP downregulated the number of α-smooth muscle actin (α-SMA) expressing cells in db/db pancreatic islets. Cleaved-caspase-3 expression was reduced in islets of SP-treated db/db mice compared to that in the control. Therefore, these results suggested that SP may preserve pancreatic β-cells through immune modulation and protection from the stimulated activation of pancreatic stellate cells and apoptosis in T1D and T2D, respectively.

60 APPLIED LIFE SCIENCES↗

Orai1 downregulation impairs lymphocyte function in type 2 diabetes mellitus

Highlights: • Diabetes can affect immune function, increasing the risk of various infections in patients. • Changes in Ca{sup 2+} signal in diabetic lymphocytes and its underlined mechanism(s) are not clear. • The results demonstrate a reduced store-operated Ca{sup 2+} entry (SOCE) though downregulation of Orai1 expression. • This study provides additional insight into the disordered immune function in T cells. It has been suggested that diabetes is associated with immune dysfunction, in which Ca{sup 2+} signaling malfunction in lymphocyte may contributes most. However, the pattern of the Ca{sup 2+} signal disorder and the mechanism(s) that explains the change are unclear. Here, in this study we aimed to investigate possible changes and mechanism(s) accounting for the internal Ca{sup 2+} signals in diabetic T lymphocyte upon stimulation.

60 APPLIED LIFE SCIENCES↗

Activation of TLR3 and its adaptor TICAM-1 increases miR-21 levels in extracellular vesicles released from human cells

Highlights: • Activation of TLR3 increases miR-21 levels in extracellular vesicles. • TLR3 requires TICAM-1 adaptor to increase miR-21 levels in extracellular vesicles. • YBX-1 is involved in TLR3-mediated increase of miR-21 levels. Pattern-recognition receptors (PRRs) recognizes viral RNAs and trigger the innate immune responses. Toll-like receptor 3 (TLR3), a PRR, recognizes viral double-stranded RNA (dsRNA) in endolysosomes, whereas cytoplasmic dsRNA is sensed by another PRR, MDA5. TLR3 and MDA5 utilize TICAM-1 and MAVS, respectively, to trigger the signal for inducing innate immune responses. Extracellular vesicles (EVs) include the exosomes and microvesicles; an accumulating body of evidence has shown that EVs delivers functional RNA, such as microRNAs (miRNAs), to other cells and thus mediate intercellular communications. Therefore, EVs carrying miRNAs affect innate immune responses in macrophages and dendritic cells. However, the mechanism underlying the regulation of miRNA levels in EVs remains unclear. To elucidate the mechanism, we sought to reveal the pathway that control miRNA expression levels in EVs. Here, we found that TLR3 stimulation increased miR-21 levels in EVs released from various types of human cells. Ectopic expression of the TLR3 adaptor, TICAM-1, increased miR-21 levels in EVs but not intracellular miR-21 levels, suggesting that TICAM-1 augmented sorting of miR-21 to EVs. In contrast, the MDA5 adaptor, MAVS, did not increase miR-21 levels in EVs. The siRNA for TICAM-1 reduced EV miR-21 levels after stimulation of TLR3. Collectively, our data indicate a novel role of the TLR3-TICAM-1 pathway in controlling miR-21 levels in EVs.

60 APPLIED LIFE SCIENCES↗

Distinct notch signaling expression patterns between nucleoside and nucleotide analogues treatment for hepatitis B virus infection

Highlights: • Notch signaling inhibited by nucleoside analogues treatment under HBV infection. • Upregulation of Notch signaling after nucleotide analogues administration. • Reduction of Foxp3 expression by both nucleotide and nucleoside analogues treatment. • Activation of phosphorylated mTORC2–Akt cascade after nucleotide analogue treatment. Nucleos(t)ide analogues therapies are currently approved for the treatment of chronic hepatitis B virus (HBV) infection, which effectively suppress HBV replication and correlate with the anti-HBV-specific immune response. Notch signaling serves pleiotropic roles in the immune system that also contribute to virus-specific immunity. In this study, we assessed Notch signal-related gene expression after administrating nucleoside or nucleotide analogues to HBV-replicating cells and clinical liver tissues. We found distinct Notch signaling expression patterns under nucleos(t)ide analogues therapies, with high expression for nucleotide analogues (adefovir pivoxil or tenofovir disoproxil fumarate) and low expression for nucleoside analogues (lamivudine or entecavir) in the presence of HBV infection. Furthermore, activation of mammalian target of rapamycin (mTOR)-Akt (Ser473) phosphorylation was also observed after nucleotide analogue treatment. In conclusion, nucleoside and nucleotide analogues displayed different patterns of Notch signaling activity under HBV infection, and the induction of mTORC2-Akt (Ser473) phosphorylation may contribute to nucleotide analogues-mediated Notch signaling activation.

60 APPLIED LIFE SCIENCES↗

Identification of immunodominant CD8 epitope in the stalk domain of influenza B viral hemagglutinin

Highlights: • The HA2 subunit of influenza hemagglutinin is highly conserved and could be a potential candidate for a universal vaccine. • CD8 T cells are important for influenza viral clearance from the lungs. • Assessment of CD8 T cell-induced immunity is critical for vaccine evaluation. • Immunodominant H-2K{sup d}-restricted peptide, YYSTAASSL, was found to effectively induce cell-mediated immune responses. • YYSTAASSL induces high levels of IL-2, TNF-α and cytotoxic CD8 T cells. Human infections by type B influenza virus constitute about 25% of all influenza cases. The viral hemagglutinin is comprised of two subunits, HA1 and HA2. While HA1 is constantly evolving in an unpredictable fashion, the HA2 subunit is highly conserved, making it a potential candidate for a universal vaccine. However, immunodominant epitopes in the HA2 subunit remain largely unknown. To delineate MHC Class I epitopes, we first identified 9-mer H-2K{sup d}-restricted CD8 T cell epitopes in the HA2 domain by in silico analyses, followed by evaluating the immunodominance of these peptides in mice challenged with the virus. Of three peptides selected through in silico analysis, the universally conserved peptide, YYSTAASSL (B/HA2-190), possessed the highest predicted binding affinity to MHC Class I and was most effective in inducing IL-2 and TNF-α in mouse splenocytes. Importantly, the peptide demonstrated best capability of stimulating peptide-specific ex-vivo cytotoxicity against target cells. Taken together, this finding would be of value for assessment of cell-mediated immune responses elicited by vaccines based on the highly conserved HA2 stalk domain.

60 APPLIED LIFE SCIENCES↗

Cell adhesion properties of human defensins

Highlights: • Human α-Defensin 5 and Human Neutrophil Peptide 1 directly bind to fibronectin. • Human α-Defensin 5 and Human Neutrophil Peptide 1 modulate cell adhesion and cellto-cell interactions. • These properties do not extend to other human defensin peptides. Effector peptides of innate immunity play an important role in host defense. They act directly by inactivating microbes but also link innate to adaptive immunity. A variety of innate immune functions has been described for these peptides, including chemoattraction and cytokine release. In this study, we describe the effect on cell morphology and cell adhesion of human defensins. We find that Human Defensin 5, the major product of specialized gut epithelial cells, causes changes in cell morphology. HD-5 induces cell adhesion, binds to fibronectin and facilitates binding of T cells to intestinal epithelial cells. These effects were found also for a second prominent defensing, termed Human Neutrophil peptide-1, but not for other human defensins.

60 APPLIED LIFE SCIENCES↗

Foot-and-mouth disease virus non-structural protein 2B negatively regulates the RLR-mediated IFN-β induction

Highlights: • FMDV 2B is a negatively regulator of type I interferon induction. • FMDV 2B can inhibit the phosphorylation of TBK1 and IRF3. • FMDV 2B inhibited the expression of the RIG-I and MDA5. Foot-and-mouth disease virus (FMDV) is the causative agent of Foot-and-mouth disease (FMD), which is an acute and highly contagious disease affecting pigs, cattle and other cloven-hoofed animals. Several studies have shown that FMDV has evolved multiple strategies to evade the host innate immune response, but the underlying mechanisms for immune evasion are still not fully understood. In the current research, we have demonstrated that FMDV utilizes its non-structural protein 2B to sabotage the host immune response. Over-expression of the FMDV 2B inhibited Poly(I:C)-induced or SeV-triggered up-regulation of IFN-β, IL-6 as well as ISG15. When HEK293T cells were transfected with FMDV 2B, the phosphorylation of TBK1 and IRF3 was inhibited. Co-immunoprecipitation and pull-down experiments indicated that FMDV 2B protein could interact with host RIG-I and MDA5. Moreover, FMDV 2B also inhibited the expression of the RIG-I and MDA5. Thus, FMDV 2B negatively regulates the RLR-mediated IFN-β induction by targeting RIG-I and MDA5.

60 APPLIED LIFE SCIENCES↗

Production and characterization of monoclonal antibody against a triple negative breast cancer cell line

Highlights: • Discovery of potential biomarkers that can predict tumor behavior is essential in breast cancer. • A panel of monoclonal antibodies was produced by hybridoma technology. • MAbs that reacted with surface antigens of immunizing cell line but not normal cells were selected. • Target was identified as NCAM1 by immunoprecipitation and mass spectrometry. • The anti-NCAM1 antibody has potential application in cancer diagnosis. Breast cancer is the most prevalent malignancy among women around the world such that more than 1,400,000 new cases are being diagnosed each year. Despite immense studies over many years on diagnosis and treatment of breast cancer, about 30% of treated patients will relapse and require subsequent therapy. By development of hybridoma technology, murine monoclonal antibodies (MAbs) against several human tumor-associated antigens have been produced and characterized in many laboratories. The purpose of these studies is to generate effective monoclonal antibodies that could be useful in tumor diagnosis and therapy. In this study, splenic lymphocytes of immunized BALB/c mouse with a new established breast cancer cell line (Pari-ICR cell line, established in Shiraz Institute for Cancer Research) were fused with the mouse myeloma cell line SP2/0 in the presence of polyethylene glycol. We generated a panel of monoclonal antibodies against the newly established cell line. The hybrid cultures were screened by flow cytometry. Hybridomas that produced antibody to surface antigens of immunizing cell line but not to Human Gingival Fibroblasts, adipose stem cells, and leucocytes isolated from peripheral blood were selected and cloned by limiting dilution method. The 1E3 clone (IgG2a type) that displayed clonal stability was further analyzed for specificity by flow cytometry. MAb 1E3 showed weak to strong reactivity to other cell lines compared with Pari-ICR cell line. Antigen identification was performed by a workflow consisting of immunoaffinity purification, SDS-PAGE, Western blotting, and mass spectrometry analysis. The target of 1E3 mAb was identified as NCAM1. In conclusion, using the antibody-based strategy we identified NCAM1 as a potential therapeutic target and biomarker for breast cancer.

60 APPLIED LIFE SCIENCES↗

A strategy of targeting B10 cell by CD19scFv-IL10R for tumor therapy

Highlights: • PcCD19scFv-IL10R had bispecific ability to target IL-10 and CD19 molecules. • Injecting mice with pcCD19scFv-IL-10R plasmid inhibited carcinoma growth. • Mice treated with pcCD19scFv-IL-10R showed a significant reduction in B10 cells and regulatory T (Treg) cells, but an increase in the anti-tumor Th1 immune response and the cytotoxic CD8{sup +} T cell response. IL-10 producing B (B10) cells, a subset of regulatory B (Breg) cells, produce IL-10 and play immunosuppressive roles in antitumor immunity. B10 cells are associated with enhanced tumor-aggressiveness and a poorer prognosis. To specifically inhibit the IL-10 secreted by B cells, we constructed the recombinant plasmid pcCD19scFv-IL10R, which contained the gene of anti-CD19 single-chain variable fragment (CD19scFv) and the extracellular domain of IL-10R1. Soluble CD19scFv-IL10R protein was identified in vitro and in vivo after the cells were transfected with pcCD19scFv-IL10R plasmid or the mice were injected with the plasmid. The fusion protein had the bispecific ability to target both IL-10 and CD19 molecules in vitro. Intramuscularly (i.m.) injecting mice with pcCD19scFv-IL-10R plasmid inhibited hepatocellular carcinoma growth in vivo. Mice treated with pcCD19scFv-IL-10R showed a significant reduction in B10 cells and regulatory T (Treg) cells, but an increase in the anti-tumor Th1 immune response and the cytotoxic CD8{sup +} T cell response. Thus, targeting B10 cells by CD19scFv-IL10R molecule may offer a new avenue for tumor therapy.

60 APPLIED LIFE SCIENCES↗

Suppression of hepatitis B virus through therapeutic activation of RIG-I and IRF3 signaling in hepatocytes

Hepatitis B virus (HBV) mediates persistent infection, chronic hepatitis, and liver disease. HBV covalently closed circular (ccc)DNA is central to viral persistence such that its elimination is considered the cornerstone for HBV cure. Inefficient detection by pathogen recognition receptors (PRRs) in the infected hepatocyte facilitates HBV persistence via avoidance of innate immune activation and interferon regulatory factor (IRF)3 induction of antiviral gene expression. We evaluated a small molecule compound, F7, and 5'-triphosphate-poly-U/UC pathogen-associated-molecular-pattern (PAMP) RNA agonists of RIG-I, a PRR that signals innate immunity, for ability to suppress cccDNA. F7 and poly-U/UC PAMP treatment of HBV-infected cells induced RIG-I signaling of IRF3 activation to induce antiviral genes for suppression of cccDNA formation and accelerated decay of established cccDNA, and were additive to the actions of entecavir. Our study shows that activation of the RIG-I pathway and IRF3 to induce innate immune actions offers therapeutic benefit toward elimination of cccDNA.

60 APPLIED LIFE SCIENCES↗