Uncharted Waters: Challenges in the Era of Biologic Therapies for Nasal Polyposis.

Several new, promising, targeted therapies for nasal polyposis are being tested in large-scale clinical trials. These agents target pathways thought to be involved in the disease, including IgE, IL-5, IL-4/IL-13, and others. Designing these trials poses significant challenges: who and when to enroll is not completely clear, optimal dosing is not known, outcome measures are insufficiently robust, there are no validated biomarkers, trial regimens may not comport with how clinicians might use these drugs once approved, and cost-benefit ratios have not been assessed. Thus, there is a need to consider such questions, as trials of these novel treatments continue and these biologics become available. Despite these uncertainties about trial design, there remains a great deal of excitement in the field as we approach the dawn of a new era of therapeutic options for nasal polyposis. In this rostrum, we enumerate these issues and call for a conference that will allow stakeholders in the field to confront them as we enter this new era of opportunity to advance the treatment of nasal polyposis.

Preventing the development of asthma: stopping the allergic march.

PURPOSE OF REVIEW: To describe important precipitants of asthma and allergic disease, to highlight the links between these triggers and modifications within the immune system, and to examine innovative research regarding asthma prevention with focus on attenuating the atopic march. RECENT FINDINGS: Allergen avoidance, allergen immunotherapy, IgE antagonists, prevention and treatment of respiratory infections, as well as management of gastrointestinal and respiratory dysbiosis have been considered as strategies in asthma prevention. Antenatal vitamin D supplementation in expectant mothers and aggressive control of atopic dermatitis to prevent the development of other allergic conditions were carefully studied as well. SUMMARY: Asthma is a major cause of morbidity and lost productivity. Despite the tremendous burden of this disease, the scientific community is still struggling to find an effective means of prevention. The contribution of genetics to the development of atopy cannot be altered, but environmental changes as well as pharmacotherapy have been studied as modifiable risk factors. Many trials to date have been effective only for subjects with certain characteristics. This is likely because asthma is a heterogenous condition, with a variety of triggers and clinical phenotypes. Thus far, a universally effective prevention strategy has eluded us. However, if an intervention can be found to prevent asthma and the allergic march, it will greatly improve quality of life for millions of sufferers and decrease healthcare expenditures.

Tanshinone IIA Attenuates Chronic Pancreatitis-Induced Pain in Rats via Downregulation of HMGB1 and TRL4 Expression in the Spinal Cord.

BACKGROUND: Chronic pancreatitis (CP) is a long-standing inflammation of the exocrine pancreas, which typically results in severe and constant abdominal pain. Previous studies on the mechanisms underlying CP-induced pain have primarily focused on the peripheral nociceptive system. A role for a central mechanism in the mediation or modulation of abdominal pain is largely unknown. Tanshinone IIA (TSN IIA), an active component of the traditional Chinese medicine Danshen, exhibits anti-inflammatory properties via downregulation of the expression of high-mobility group protein B1 (HMGB1), a late proinflammatory cytokine. HMGB1 binds and activates toll-like receptor 4 (TLR4) to induce spinal astrocyte activation and proinflammatory cytokine release in neuropathic pain. OBJECTIVE: In this study, we investigated the effect of TSN IIA on pain responses in rats with trinitrobenzene sulfonic acid (TNBS)-induced CP. The roles of central mechanisms in the mediation or modulation of CP were also investigated. STUDY DESIGN: A randomized, double-blind, placebo-controlled animal trial. METHODS: CP was induced in rats by intrapancreatic infusion of trinitrobenzene sulfonic acid (TNBS). Pancreatic histopathological changes were characterized with semi-quantitative scores. The abdomen nociceptive behaviors were assessed with von Frey filaments. The effects of intraperitoneally administered TSN IIA on CP-induced mechanical allodynia were tested. The spinal protein expression of HMGB1 was determined by western blot. The spinal mRNA and protein expression of proinflammatory cytokines IL-1ß, TNF-α, and IL-6 were determined by RT-PCR and western blot, respectively. The spinal expression of the HMGB1 receptor TRL4 and the astrocyte activation marker glial fibrillary acidic protein (GFAP) were determined by western blot or immunohistological staining after intraperitoneal injection of TSN IIA or intrathecal administration of a neutralizing anti-HMGB1 antibody. RESULTS: TNBS infusion resulted in pancreatic histopathological changes of chronic pancreatitis and mechanical allodynia in rats. TSN IIA significantly attenuated TNBS-induced mechanical allodynia in a dose-dependent manner. TNBS significantly increased the spinal expression of HMGB1 and proinflammatory cytokines IL-1ß, TNF-α, and IL-6. These TNBS-induced changes were significantly inhibited by TSN IIA in a dose-dependent manner. Furthermore, TSN IIA, but not the neutralizing anti-HMGB1 antibody, significantly inhibited TNBS-induced spinal TLR4 and GFAP expression. LIMITATIONS: In addition to TLR4, HMGB1 can also bind to toll-like receptor-2 (TLR2) and the receptor for advanced glycation end products (RAGE). Additional studies are warranted to ascertain whether HMGB1 contributes to CP-induced pain through activation of these receptors. CONCLUSIONS: Our results suggest that spinal HMGB1 contributes to the development of CP-induced pain and can potentially be a therapeutic target. TSN IIA attenuates CP-induced pain via downregulation of spinal HMGB1 and TRL4 expression. Therefore, TSN IIA may be a potential anti-nociceptive drug for the treatment of CP-induced pain.

Programmed death-1 blockade enhances the antitumor effects of peptide vaccine-induced peptide-specific cytotoxic T lymphocytes.

Novel treatment modalities are required urgently in patients with hepatocellular carcinoma (HCC). A vaccine that induces cytotoxic T lymphocytes (CTLs) is an ideal strategy for cancer, and glypican-3 (GPC3) is a potential option for HCC. Blocking the programmed death-1 (PD-1)/PD-L1 pathway is a rational strategy to overcome tumor escape and tolerance toward CTLs. In the present study, we investigated whether anti-PD-1 blocking antibodies (αPD-1 Ab) enhanced the number of vaccine-induced peptide-specific CTLs in peripheral blood mononuclear cells (PBMCs) following the administration of GPC3 peptide vaccine to both patients and in a mouse model. The inhibitory receptor PD-1 was highly expressed in ex vivo GPC3-specific CTLs isolated from the PBMCs of vaccinated HCC patients. In vitro, interferon-γ induced PD-L1 expression in liver cancer cell lines. In addition, PD-1 blockade increased the number of GPC3-specific CTLs, which degranulate against liver cancer cell lines. In vivo experiments using tumor-bearing mouse models showed that the combination therapy of peptide vaccine and αPD-1 Ab suppressed tumor growth synergistically. PD-1 blockade increased the number of peptide-specific tumor-infiltrating T cells (TILs) and decreased the expression of inhibitory receptors on TILs. This study demonstrated that PD-1/PD-L1 blockade augmented the antitumor effects of a peptide vaccine by increasing the immune response of vaccine-induced CTLs, and provided a foundation for the clinical development of a combination therapy using a GPC3 peptide vaccine and αPD-1 Ab.

Depletion of tumor-associated macrophages enhances the anti-tumor immunity induced by a Toll-like receptor agonist-conjugated peptide.

It has been reported that lipopeptides can be used to elicit cytotoxic T lymphocyte (CTL) responses against viral diseases and cancer. In our previous study, we determined that mono-palmitoylated peptides can enhance anti-tumor responses in the absence of adjuvant activity. To investigate whether di-palmitoylated peptides with TLR2 agonist activity are able to induce anti-tumor immunity, we synthesized a di-palmitic acid-conjugated long peptide that contains a murine CTL epitope of HPV E749-57 (Pam2IDG). Pam2IDG stimulated the maturation of bone marrow-derived dendritic cells (BMDCs) through TLR2/6. After immunization, Pam2IDG induced higher levels of T cell responses than those obtained with its non-lipidated counterpart (IDG). In the prophylactic model, Pam2IDG immunization completely inhibited tumor growth, whereas IDG immunization was unable to inhibit tumor growth. However, Pam2IDG immunization could not effectively inhibit the growth of established tumors. Therefore, we further investigated whether the depletion of immunosuppressive factors could improve the therapeutic effects of Pam2IDG. Our data indicate that treatment with Pam2IDG combined with clodronate/liposome delays tumor growth and increases the survival rate. We also observed that the therapeutic effects of Pam2IDG are improved by diminishing the function of tumor-associate macrophages (TAMs) and through the use of an IL10 receptor blocking antibody or a Cyclooxygenase 2 (Cox-2) inhibitor. In conclusion, the depletion of TAMs may enhance the anti-tumor immunity of a TLR2 agonist-conjugated peptide.

At the bench: preclinical rationale for CTLA-4 and PD-1 blockade as cancer immunotherapy.

Tumors can avoid immune surveillance by stimulating immune inhibitory receptors that function to turn off established immune responses. By blocking the ability of tumors to stimulate inhibitory receptors on T cells, sustained, anti-tumor immune responses can be generated in animals. Thus, therapeutic blockade of immune inhibitory checkpoints provides a potential method to boost anti-tumor immunity. The CTLA-4 and PD-1Rs represent two T cell-inhibitory receptors with independent mechanisms of action. Preclinical investigations revealed that CTLA-4 enforces an activation threshold and attenuates proliferation of tumor-specific T lymphocytes. In contrast, PD-1 functions primarily as a stop signal that limits T cell effector function within a tumor. The unique mechanisms and sites of action of CTLA-4 and PD-1 suggest that although blockade of either has the potential to promote anti-tumor immune responses, combined blockade of both might offer even more potent anti-tumor activity. See related review At the Bedside: CTLA-4 and PD-1 blocking antibodies in cancer immunotherapy.

Interleukin-19 blockade attenuates collagen-induced arthritis in rats.

OBJECTIVES: RA is the most common form of inflammatory arthritis. IL-19 acts as a pro-inflammatory cytokine involved in the pathogenesis of RA. We investigated whether anti-IL-19 antibody treatment would modulate the severity of the disease in a CIA rat model. METHODS: We generated a CIA model by immunizing rats with bovine type II collagen. CIA rats were s.c. treated with anti-IL-19 antibody 1BB1. The effects of 1BB1 on CIA rats were determined by hind-paw thickness, severity score, bone destruction, BMD and cytokine production, which were evaluated using radiological scans, micro-CT, real-time quantitative PCR and ELISA. To analyse gene regulation by IL-19, rat synovial fibroblasts (SFs) were isolated and analysed for the expression of TNF-α, IL-1ß and RANK ligand (RANKL). RESULTS: In vivo, IL-19 was highly expressed in the synovial tissue and SFs isolated from CIA rats. 1BB1 significantly ameliorated the severity of arthritis by decreasing hind-paw thickness and swelling; prevented bone destruction and bone loss; inhibited the expression of TNF-α, IL-1ß, IL-6 and RANKL in synovial tissue; and decreased the production of IL-6 in serum. In vitro, IL-19-induced TNF-α, IL-1ß, IL-6 and RANKL expression in CIA SFs. CONCLUSIONS: Specifically blocking IL-19 inhibited pro-inflammatory cytokine production and prevented bone destruction in CIA rats. These findings provide evidence that IL-19 is a novel target, and that anti-IL-19 antibody may be a potential target to ameliorate the severity of RA.

Immunological aspects of scorpion toxins: current status and perspectives.

Significant progress has been made in immunological studies of scorpion toxins and several formats of antibodies directed against scorpion toxins have been reported. Some of these are commonly used in a specific treatment against envenoming; others are primarily used for immuno-biochemical characterizations. The preparation protocol of the antibody or its fragments can be substantially different from one laboratory to another, which complicates a direct comparison of the potency of the antivenom. The use of immune sera, the total immunoglobulin fraction or Fab and Fab'2 fragments as the therapeutic agent is widespread. A number of monoclonal antibodies have also been reported and used for engineering of Fv, ScFv or Fab fragments. Recently, a novel antibody format - known as nanobodies - derived from HCAbs of camelids and selected after phage display shows great potential to provide a more efficient therapy against scorpion envenoming. Subsequent bispecific derivatives have been designed and their pharmacokinetics have been studied. Distinct advantages and disadvantages have been attributed to these equine, murine or camelid antibodies and their derived fragments. Some fragments are easily amenable into next generation therapeutics after proper manufacturing and provide an ensured availability of the product to the medical community. Through examples, we will show how the comparison of the serotherapeutic effectiveness is compromised due to the absence of standardization, on the preparation of immunogens, production processes and / or nature of the products. We will report on recent advances in the field.

Small-molecule inhibitors of vascular adhesion protein-1 reduce the accumulation of myeloid cells into tumors and attenuate tumor growth in mice.

Vascular adhesion protein-1 (VAP-1) is an endothelial, cell surface-expressed oxidase involved in leukocyte traffic. The adhesive function of VAP-1 can be blocked by anti-VAP-1 Abs and small-molecule inhibitors. However, the effects of VAP-1 blockade on antitumor immunity and tumor progression are unknown. In this paper, we used anti-VAP-1 mAbs and small-molecule inhibitors of VAP-1 in B16 melanoma and EL-4 lymphoma tumor models in C57BL/6 mice. Leukocyte accumulation into tumors and neoangiogenesis were evaluated by immunohistochemistry, flow cytometry, and intravital videomicroscopy. We found that both anti-VAP-1 Abs and VAP-1 inhibitors reduced the number of leukocytes in the tumors, but they targeted partially different leukocyte subpopulations. Anti-VAP-1 Abs selectively inhibited infiltration of CD8-positive lymphocytes into tumors and had no effect on accumulation of myeloid cells into tumors. In contrast, the VAP-1 inhibitors significantly reduced only the number of proangiogenic Gr-1(+)CD11b(+) myeloid cells in melanomas and lymphomas. Blocking of VAP-1 by either means left tumor homing of regulatory T cells and type 2 immune-suppressing monocytes/macrophages intact. Notably, VAP-1 inhibitors, but not anti-VAP-1 Abs, retarded the growth of melanomas and lymphomas and reduced tumor neoangiogenesis. The VAP-1 inhibitors also reduced the binding of Gr-1(+) myeloid cells to the tumor vasculature. We conclude that tumors use the catalytic activity of VAP-1 to recruit myeloid cells into tumors and to support tumor progression. Small-molecule VAP-1 inhibitors therefore might be a potential new tool for immunotherapy of tumors.

Management of yellow oleander poisoning.

BACKGROUND: Poisoning due to deliberate self-harm with the seeds of yellow oleander (Thevetia peruviana) results in significant morbidity and mortality each year in South Asia. Yellow oleander seeds contain highly toxic cardiac glycosides including thevetins A and B and neriifolin. A wide variety of bradyarrhythmias and tachyarrhythmias occur following ingestion. Important epidemiological and clinical differences exist between poisoning due to yellow oleander and digoxin; yellow oleander poisoning is commonly seen in younger patients without preexisting illness or comorbidity. Assessment and initial management. Initial assessment and management is similar to other poisonings. No definite criteria are available for risk stratification. Continuous ECG monitoring for at least 24 h is necessary to detect arrhythmias; longer monitoring is appropriate in patients with severe poisoning. Supportive care. Correction of dehydration with normal saline is necessary, and antiemetics are used to control severe vomiting. Electrolytes. Hypokalemia worsens toxicity due to digitalis glycosides, and hyperkalemia is life-threatening. Both must be corrected. Hyperkalemia is due to extracellular shift of potassium rather than an increase in total body potassium and is best treated with insulin-dextrose infusion. Intravenous calcium increases the risk of cardiac arrhythmias and is not recommended in treating hyperkalemia. Oral or rectal administration of sodium polystyrene sulfonate resin may result in hypokalemia when used together with digoxin-specific antibody fragments. Unlike digoxin toxicity, serum magnesium concentrations are less likely to be affected in yellow oleander poisoning. The effect of magnesium concentrations on toxicity and outcome is not known. Hypomagnesaemia should be corrected as it can worsen cardiac glycoside toxicity. Gastric decontamination. The place of emesis induction and gastric lavage has not been investigated, although they are used in practice. Gastric decontamination by the use of single dose and multiple doses of activated charcoal has been evaluated in two randomized controlled trials, with contradictory results. Methodological differences (severity of poisoning in recruited patients, duration of treatment, compliance) between the two trials, together with differences in mortality rates in control groups, have led to much controversy. No firm recommendation for or against the use of multiple doses of activated charcoal can be made at present, and further studies are needed. Single-dose activated charcoal is probably beneficial. Activated charcoal is clearly safe. Arrhythmia management. Bradyarrhythmias are commonly managed with atropine, isoprenaline, and temporary cardiac pacing in severe cases, although without trial evidence of survival benefit, or adequate evaluation of possible risks. Accelerating the heart rate with atropine or beta-adrenergic agents theoretically increases the risk of tachyarrhythmias, and it has been claimed that atropine increases tachyarrhythmic deaths. Further studies are required. Tachyarrhythmias have a poor prognosis and are more difficult to treat. Lidocaine is the preferred antiarrhythmic; the role of intravenous magnesium is uncertain. Digoxin-specific antibody fragments. Digoxin-specific antibody fragments are effective in reverting life-threatening cardiac arrhythmias; prospective observational studies show a beneficial effect on mortality. High cost and lack of availability limit the widespread use of digoxin-specific antibody fragments in developing countries. CONCLUSIONS: Digoxin-specific antibody fragments remain the only proven therapy for yellow oleander poisoning. Further studies are needed to determine the place of activated charcoal, the benefits or risks of atropine and isoprenaline, the place and choice of antiarrhythmics, and the effect of intravenous magnesium in yellow oleander poisoning.

[Nerium oleander self poisoning treated with digoxin-specific antibodies]. / Traitement par anticorps antidigitalique d'une intoxication volontaire par laurier rose.

A chronically depressed 44-year-old man was rescued by the French medicalised ambulance service four hours after the ingestion of Nerium oleander leaves in a suicide attempt. Cardiotoxicity was evidenced by the presence of bradycardia with mental confusion and vomiting. The patient was empirically treated in the prehospital phase with a single dose of digoxin-specific Fab antibody fragments (Digidot). In spite of this treatment, the patient presented a new episode of important bradycardia (25 b/minute). Thereafter, the patient's rhythm stabilized and neurological signs and vomiting resolved. The patient recovered uneventfully and was discharged from the intensive care unit two days later.