Nasal delivery of H5N1 avian influenza vaccine formulated with GenJet™ or in vivo-jetPEI® induces enhanced serological,cellular and protective immune responses

Avian influenza virus infection is a serious public health threat and preventive vaccination is the most cost-effective public health intervention strategy. Unfortunately, currently available unadjuvanted avian influenza vaccines are poorly immunogenic and alternative vaccine formulations and delivery strategies are in urgent need to reduce the high risk of avian influenza pandemics. Cationic polymers have been widely used as vectors for gene delivery in vitro and in vivo. In this study, we formulated H5N1 influenza vaccines with GenJet? or in vivo-jetPEI^®, and showed that these formulations significantly enhanced the immunogenicity of H5N1 vaccines and conferred protective immunity in a mouse model. Detailed analyses of adaptive immune responses revealed that both formulations induced mixed T_H1/T_H2 antigen-specific CD4 T-cell responses, antigen-specific cytotoxic CD8 T-cell and memory B-cell responses. Our findings suggest that cationic polymers merit future development as potential adjuvants for mucosal delivery of poorly immunogenic vaccines.     

Retinoid-related orphan receptor γt is a potential therapeutic target for controlling inflammatory autoimmunity

Retinoid-related orphan receptor gamma t (RORγt) is a member of the nuclear receptor family that is specifically expressed in T cell compartments. RORγt regulates the development of T cells in the thymus and the differentiation of effector T cells in the periphery. During T cell development, RORγt enhances CD4⁺CD8⁺ double positive thymocyte survival by upregulating Bcl-x_L. In the periphery, RORγt regulates IL-17 production and dictates the differentiation of pro-inflammatory T helper 17 (T_H17) cells that play a critical role in inflammatory conditions and autoimmunity. RORγt-deficient T cells fail to differentiate into T_H17 cells, whereas forced expression of RORγt is sufficient to induce naive T cells to produce IL-17. T_H17 cells are believed to be the major inflammatory cells in autoimmune diseases. Therefore, inhibition of RORγt activity could potentially alleviate the symptoms associated with the T_H17-dependent inflammatory autoimmune diseases. RORγt is thus potentially an excellent therapeutic target for the intervention of inflammatory autoimmunity.     

Obesity enhances eosinophilic inflammation in a murine model of allergic asthma

Background and purpose:

Obesity is associated with deterioration in asthma outcomes. Although airways eosinophil accumulation is characteristic of lung allergic diseases, little is known about the influence of obesity on the allergic eosinophil trafficking from bone marrow to lung tissues, and recruitment to airways lumen. Here, we have assessed the effects of diet-induced obesity on allergic eosinophilic inflammation in mice, examining eosinophil trafficking from bone marrow to airways, and production of T_H1/T_H2 cytokines.

Experimental approach:

C57BL/6 mice fed for 10 weeks with standard chow or high-fat diet were sensitized and challenged with ovalbumin. At 24–96 h post-ovalbumin challenge, bronchoalveolar lavage (BAL) fluid, lung tissue and bone marrow were examined.

Key results:

The high-fat-fed mice exhibited increased body weight and epididymal fat, glucose intolerance and alterations in lipid profile compared with the lean mice. Obesity markedly elevated serum leptin and lowered adiponectin levels. Ovalbumin challenge in obese mice promoted a markedly higher eosinophil accumulation in bone marrow and connective tissue surrounding the bronchial and bronchiolar segments. Eosinophil number in BAL fluid of obese mice was lower at 24 and 48 h. Levels of interleukin (IL)-5, eotaxin, tumour necrosis factor-α and IL-10 in BAL fluid of obese mice were significantly higher than in lean mice.

Conclusions and implications:

Diet-induced obesity enhanced eosinophil trafficking from bone marrow to lung tissues, and delayed their transit through the airway epithelium into the airway lumen. Consequently, eosinophils remain longer in lung peribronchiolar segments due to overproduction of T_H1/T_H2 cytokines and chemokines.     

Novel histamine H4 receptor ligands and their potential therapeutic applications: an update

Introduction: Histamine H₄ receptor (H₄R) has been shown to be involved in various inflammatory conditions. Ligands acting on H₄R show therapeutic potential in various diseases. For the first time, the positive proof-of-concept clinical trials of the H₄ antagonist JNJ39758979 have demonstrated this potential in histamine-induced pruritus. Besides role of H₄R in inflammatory conditions, preclinical results in cancer, neuropathic pain, vestibular disorders and type 2 diabetes show the diverse signaling network modulated by H₄R. This suggests further potential for H₄ ligands in such diseases.

Areas covered: In this review, we have summarized patent applications and papers of the H₄R field published between 2012 and 2014. Additionally, we have analyzed the quality of the already described H₄ ligands in terms of their ligand efficiency, lipophilic ligand efficiency and lipophilicity-corrected ligand efficiency.

Expert opinion: We demonstrate that the number of published patent applications reached a maximum in 2009 and showed some decrease in the last few years. On the other hand, the field is still very lively, reflected by the numerous publications on novel potential therapeutic applications. The favorable property profile of H₄ ligands in development shows promise for the upcoming human clinical trials.     

Targeting the toll-like receptor 7 pathway in asthma: a potential immunomodulatory approach?

In allergic airways, as in asthma, inflammation and impaired functioning of toll-like receptor 7 (TLR7) has been found. The augmentation of this receptor with agonist compounds resulted in bronchodilation and a switch of the T_H2 inflammatory pattern, specific for allergic conditions, to T_H1 inflammation, characterised by an increased production of interferon-γ. This was a preclinical study evaluating the effects of two TLR7 agonists, imiquimod and resiquimod, on the isolated guinea pig trachea. The TLR7-related downstream signalling pathways were also assessed. Both TLR7 agonists were shown to reduce serotonin-induced bronchoconstriction, which is possibly exerted via the p38MAPK and NF-κB pathways. Therapeutic targeting of TLR7 with specific agonists might represent a promising immunomodulatory approach in asthma, especially if systemic exposure is minimised with inhaled formulations.     

Development of WT1 peptide cancer vaccine against hematopoietic malignancies and solid cancers

Wild-type Wilms' tumor gene WT1 is highly expressed not only in hematopoietic malignancies, including leukemia and myelodysplastic syndromes (MDS), but also in various kinds of solid tumors. Human cytotoxic T lymphocytes (CTLs) which could specifically lyse WT1-expressing tumor cells with HLA class I restriction were generated in vitro. We have also demonstrated that mice immunized with the WT1 peptide or WT1 cDNA rejected challenges by WT1-expressing tumor cells and survived with no signs of auto-aggression to normal organs which physiologically expressed WT1 in prophylactic and therapeutic models. Furthermore, we and others detected IgM and IgG WT1 antibodies in the patients with hematopoietic malignancies, indicating that WT1 protein was highly immunogenic, and that immunoglobulin class-switch-inducing WT1-specific cellular immune responses were elicited in the patients. CD8+ WT1-specific CTLs were also detected in peripheral blood or tumor-draining lymph nodes of cancer patients. These results provided us with the rationale for elicitation of CTL responses targeting the WT1 product for cancer immunotherapy. On the basis of the findings mentioned above, we performed a phase I clinical trial of WT1 peptide cancer vaccine for the patients with malignant neoplasms. These results strongly suggested that WT1 peptide cancer vaccine had efficacy in the clinical setting, because clinical responses, including reduction of leukemic blast cells or regression of tumor masses, were observed after the WT1 vaccination in patients with hematopoietic malignancies or solid cancers. The power of TAA-derived cancer vaccine may be enhanced by combination with stronger adjuvants, helper peptide, or conventional treatments such as molecular-target-based drugs.     

A nano-liposome vaccine carrying E75, a HER-2/neu-derived peptide,exhibits significant antitumour activity in mice

E75 (HER-2/neu-369–377), is an immunogenic peptide which is highly expressed in breast cancer patients. The purpose of this study was to develop an effective vaccine delivery/adjuvant system by attachment of this peptide to the surface of liposomes consisting of phospholipids including distearoylphosphocholine (DSPC) and distearoyl phosphoglycerol (DSPG) with high transition temperature (Tm) and dioleoylphosphatidylethanolamine (DOPE) (a pH-sensitive lipid for cytosolic antigen delivery) to improve antitumour immune activity against the E75 peptide. For this purpose, the E75 peptide was incorporated into liposomes consisting of DSPC/DSPG/cholesterol (Chol)/DOPE (15/2/3/5 molar ratio) through conjugation with distearoylphosphoethanolamine-N-[maleimide(polyethylene glycol)-2000] (maleimide-PEG₂₀₀₀-DSPE). Immunization of BALB/c mice was performed three times with different forms of liposomal formulations at 2-week intervals and antitumour immunity responses were evaluated. Results of ELISpot and flow cytometry analysis showed that mice vaccinated with DSPC/DSPG/Chol/DOPE/E75 have significantly enhanced the antigen-specific IFN-γ response of CD8⁺ T cells and generated cytotoxic T lymphocytes (CTL) antitumour responses. CTL responses induced by this formulation resulted in inhibition of tumour progression and longer survival time in the mice TUBO tumour model. The results revealed that the liposomes consist of DSPC/DSPG/Chol/DOPE could be suitable candidates for vaccine delivery of E75 peptide for the prevention and therapy of HER2-positive breast cancer and merit further investigation.     

抗CD40抗体增强宫颈癌肽疫苗的治疗作用

目的：探讨抗CD40抗体对宫颈癌肽疫苗治疗作用的影响。方法将乳头状病毒结构性蛋白 E7表位肽（ E749－57,H－2Db限制性,CD8 T细胞表位）与Toll样受体7配体（Gardiquimod）组成疫苗,C57BL／6小鼠给予疫苗及抗CD40抗体免疫后取得外周血及脾组织CD8 T细胞,利用流式细胞仪分析特异性CD8 T细胞数量,Elisa检测CD8 T细胞与TC－1细胞（表达HPV E7蛋白的小鼠宫颈癌细胞）共孵育后干扰素（ INF－γ）表达水平。另取15只皮下荷瘤小鼠,监测免疫后肿瘤生长速度。结果与单用疫苗组相比,抗 CD40抗体明显增加小鼠外周血肿瘤特异性 CD8 T细胞数量（16．50±0．8185％ vs 9．747±1．834％,P＝0．0282）,且内源性CD8 T细胞体外与TC－1细胞共孵育可以分泌INF－γ,体内显著抑制皮下肿瘤生长（ P＜0．001）。结论抗CD40抗体增强肽疫苗诱发的免疫应答,有潜力成为一种良好的佐剂。     

Loading dendritic cells with gold nanoparticles (GNPs) bearing HIV-peptides and mannosides enhance HIV-specific T cell responses

Gold nanoparticles (GNPs) decorated with glycans ameliorate dendritic cells (DC) uptake, antigen-presentation and T-cells cross-talk, which are important aspects in vaccine design. GNPs allow for high antigen loading, DC targeting, lack of toxicity and are straightforward prepared and easy to handle. The present study aimed to assess the capacity of DC to process and present HIV-1-peptides loaded onto GNPs bearing high-mannoside-type oligosaccharides (P1@HM) to autologous T-cells from HIV-1 patients. The results showed that P1@HM increased HIV-specific CD4⁺ and CD8⁺ T-cell proliferation and induced highly functional cytokine secretion compared with HIV-peptides alone. P1@HM elicits a highly efficient secretion of pro-T_H1 cytokines and chemokines, a moderate production of pro-T_H2 and significant higher secretion of pro-inflammatory cytokines such as TNF‐α and IL-1β. Thus, co-delivery of HIV-1 antigens and HM by GNPs is an excellent vaccine delivery system inducing HIV-specific cellular immune responses in HIV+ patients, being a promising approach to improve anti-HIV-1 vaccines.     

“Low T3-syndrome” in acute myocardial infarction — Relationship to beta-adrenergic blockade and clinical course

Summary Serum levels of T₄, T₃ rT₃ and resin T₃ uptake were followed for 5 days in 40 patients with acute myocardial infarction (AMI) allocated to early treatment either with alprenolol or placebo. There was a significant fall in T₃ (P<0.05) and an increase in rT₃ (P<0.05) without any significant difference between the alprenolol — (n=19) and placebo — (n=21) treated groups. The risk of missing a further 20% change in se-T₃ and se-rT₃ after alprenolol compared to placebo treatment () was <0.10 and <0.50, respectively. In patients with a severe clinical course, the fall in T₃ and increase in rT₃ was significantly greater than in patients without complications. No change in T₄ was observed either with respect to the clinical course nor following alprenolol. The data suggest that alprenolol can be given in the acute phase of myocardial infarction without causing any additional disturbance in the serum levels of T₃ and T₄.     

License to kill: Formulation requirements for optimal priming of CD8(+) CTL responses with particulate vaccine delivery systems

Induction of CD8(+) T-cell responses is critical for the immunological control of a variety of diseases upon vaccination. Modern subunit vaccines are based on highly purified recombinant proteins. The high purity represents a major advancement in terms of vaccine safety compared to previous vaccination strategies with live attenuated or whole killed pathogens, but typically renders vaccine antigens poorly immunogenic and insufficient in mobilizing protective immunity. Adjuvants are therefore needed in vaccine formulations to enhance, direct and maintain the immune response to vaccine antigens. However, a weakness of many adjuvants is the lack of induction of CD8(+) T-cell responses against protein antigens, which are required for protection against challenging and difficult infectious diseases such as AIDS and for therapeutic cancer vaccination. Within the last decade, adjuvant systems that can induce CD8(+) T-cell responses have been developed and the first clinical trials demonstrating the clinical relevance of such formulations have been performed. This paper reviews the current status of lipid- and polymer-based particulate antigen delivery systems capable of stimulating CD8(+) T-cell immunity with special focus on mechanisms of priming and pharmaceutical requirements for optimal activation of cytotoxic T-lymphocytes that can kill virus-infected or abnormal (cancer) cells.     

Clinical trials of active cancer immunotherapy

Active immunotherapy of cancer needs its own clinical trials' methodology. The standard methodology paradigm for clinical trials in oncology was developed for cytotoxic drugs, which differ dramatically from cancer vaccines in their mode of action and toxicity profile. To minimize the risk of overlooking benefits for patients, Mackiewicz and Nawrocki invite to open discussion on vaccine trials' methodology. Our point of view is based on several Phase I and II trials with hundreds of melanoma patients treated with allogenic cellular vaccine genetically modified with cytokine genes. We feel that a simplified two-stage clinical trial design without a separate Phase I is justified. In the first stage, preliminary efficacy together with proof-of-principle and feasibility issues could be addressed. For real efficacy assessment, careful consideration of end points is necessary. Immunologic responses and objective clinical responses are not the best measures of vaccine efficacy for many patients who benefit from treatment. Randomized single institution studies with time-to-event end points are probably well suited for such combined Phase I/II studies. In the second stage trial (Phase III), the final efficacy analysis with comparator arm is needed.     

Identification of endothelial H1, vascular H2 and cardiac presynaptic H3 receptors in the pithed rat

Summary In pithed and vagotomized rats the effects of the H₃ receptor agonist R-(–)--methylhistamine, the H₁ receptor agonist 2-(2-thiazolyl)ethylamine and the H₂ receptor agonist dimaprit on basal diastolic blood pressure, basal heart rate and the electrically induced rise in heart rate were examined.Basal diastolic blood pressure was not altered by low, but increased by high doses of R-(–)--methylhistamine; the latter effect was not affected by selective H₁, H₂ or H₃ receptor antagonists and by prazosin, but was attenuated by rauwolscine. Rauwolscine also unmasked a vasodepressor response to R-(–)--methylhistamine not affected by the H₃ receptor antagonist thioperamide, but counteracted by the H₁ receptor antagonist dimetindene or the H₂ receptor antagonist ranitidine. The vasodepressor responses to 2-(2-thiazolyl)ethylamine and dimaprit were antagonized by dimetindene and ranitidine, respectively. The vasodepressor response to 2-(2-thiazolyl)ethylamine was not altered by indomethacin, but reduced by an inhibitor of endothelial nitric oxide synthase, N-nitro-L-arginine methyl ester (which, by itself, markedly increased blood pressure). Both drug tools did not alter the effect of dimaprit. Basal heart rate was not affected by 2-(2-thiazolyl)ethylamine (examined after administration of propranolol), dimaprit and R-(–)--methylhistamine. The electrically induced increase in heart rate (studied in animals which had received rauwolscine) was decreased by R-(–)--methylhistamine but not affected by 2-(2-thiazolyl)ethylamine and dimaprit. The effect of R-(–)--methylhistamine was abolished by thioperamide. R-(–)--methylhistamine did not influence the increase in heart rate produced by isoprenaline.In conclusion, the pithed rat offers the opportunity to study cardiac presynaptic H₃ receptors, endothelial H₁ receptors and vascular H₂ receptors in the same experimental model. Cardiac presynaptic H₁ and H₂ receptors as well as postsynaptic H₃ receptors in the heart and in the resistance vessels were not found. R-(–)--methylhistamine is a weak agonist at ₂, H₁ and H₂ receptors.Correspondence to E. Schlicker at the above address     

Effects of activation of central nervous histamine receptors in cardiovascular regulation; studies in H<Subscript>1</Subscript> and H<Subscript>2</Subscript> receptor gene knockout mice

To elucidate the central roles of histamine receptors in cardiovascular regulatory system, systolic, mean, and diastolic blood pressures (BPs) and heart rate (HR) were examined in conscious H₁ receptor gene knockout (H₁KO) mice, H₂ receptor gene knockout (H₂KO) mice, H₁ and H₂ receptor gene double knockout (DKO) mice, and their respective control mice by the tail-cuff system. Histamine, histamine-trifluoromethyl-toluidine derivative (HTMT, an H₁ agonist), dimaprit (an H₂ agonist), and immepip (an H₃ agonist) were intrathecally administered to these KO mice and control mice. Basal BPs and HR were not different among these three KO mice and their control or wild-type mice. Intrathecal administration of histamine significantly increased BPs and decreased HR in control mice. The increases in BPs were produced by histamine in H₁KO and H₂KO mice and by HTMT and dimaprit in C57BL mice. The pressor responses by HTMT and dimaprit in C57BL mice were greater than those by histamine in H₁KO and H₂KO mice, although the same decreases in HR were induced by histamine in C57BL and H₁KO mice and by dimaprit in C57BL mice. The selective stimulation of H₃ receptors by immepip produced a consistent decrease in BPs in control mice. These results obtained with the exogenous selective agonists of three histamine receptors suggest that the pressor responses to histamine are mediated through the stimulation of both H₁ and H₂ receptors, whereas the atropine-sensitive decrease in heart rate is mainly due to H₂ receptors which activate the vagal output to the heart.     

The evolving role of telomerase inhibitors in the treatment of cancer

SUMMARY

Telomerase is a ribonucleoprotein that maintains telomeres and is essential for cellular immortality and tumour growth. The differential expression of telomerase in cancer cells makes it an attractive therapeutic target. Anti-sense oligonucleotides directed against the RNA template of hTR and small molecules that can interact and stabilise the G-quadruplex represent promising therapeutic strategies. Human trials investigating the potential role of the catalytic subunit hTERT as a universal cancer vaccine have already commenced. Alternative lengthening of telomeres (ALT) and efficacy delay remain important limitations to anti-telomerase therapy.     

T-cell epitope analogues from carcinoembryonic antigen for vaccination against cancer: WO2009002418

Background: Cancer is one of the leading causes of death in the Western world. Therapeutic vaccination to target minimal residual disease or prevent tumor recurrence represents an interesting and novel alternative for treatment of tumor diseases. T-cell peptide epitopes are commonly used as vaccine candidates for the induction of antitumor immune responses. By modifying the amino-acid sequence of the peptide at certain, so-called anchor positions, the binding affinity to MHC class I and the immunogenicity of the peptide can be improved. Vaccination with the modified peptide analogue can then be used to induce an immune response to the wild-type epitope. Method: The present application concerns the use of peptides representing wild-type T-cell epitopes and analogues from carcinoembryonic antigen for vaccination against cancer. The stated claims also include the use of these epitopes in several other vaccine modalities, including RNA, DNA and adenoviral vector vaccines. Conclusion: Although the available data clearly support the basic claims that some of the peptide analogues indeed are able to induce a potent immune response in mice to the corresponding wild-type epitopes, the lack of in vivo antitumor data for any of the covered vaccine modalities prevents a thorough evaluation of the stated claims.     

Polyactin A is a novel and potent immunological adjuvant for peptide-based cancer vaccine

Synthetic peptide cancer vaccines are poorly immunogenic sub-unit vaccines and thus essentially need adjuvants in their formulations to increase the efficacy by enhancing the peptide-specific immune response. However, aluminum-based compounds are almost dependent for clinical use at present. Therefore, the increasing use of peptide-based vaccines makes the need for novel and potent adjuvants. Polyactin A (PAA) has been used for the clinical treatment of impaired immunity in China for over 30 years. To figure out the adjuvant effects of PAA for E75 peptide breast cancer vaccine (Her2 p369-p377), the generation of mature dendritic cells (DCs) from peripheral blood monocytes (PBMCs) cultured with PAA, IL-4 and TNF-α was assessed by morphologic features and the expressions of special surface markers using flow cytometry. Then the functional features of PBMCs-derived DCs cultured with PAA, IL-4 and TNF-α were investigated by inducing E75-specific cytotoxicity. Finally, C57BL/6-Tg(HLA-A2.1)1Enge/J transgenic mice were immunized with E75 and various amounts of PAA, and splenic lymphocyte proliferation and the IFN-γ level were determined. The results showed that PAA, just like granulocyte-macrophage colony stimulating factor, with IL-4 and TNF-α efficiently induced mature DCs from PBMCs, and these DCs could trigger a potent E75 peptide-specific CD8⁺ T-cell response in vitro. Immunization with E75 and PAA significantly increased positive rates of CD4⁺ and CD8⁺ T lymphocytes, and enhanced splenocytes proliferation and levels of IFN-γ in splenocytes when induced by E75. Our results indicated that PAA could efficiently induce E75-specific immunologic responses in vitro and in vivo. Therefore, PAA possesses potent adjuvant effect on peptide-based cancer vaccine. Our study provides a safe, effective and novel adjuvant for clinical use.     

The evolving role of telomerase inhibitors in the treatment of cancer

Telomerase is a ribonucleoprotein that maintains telomeres and is essential for cellular immortality and tumour growth. The differential expression of telomerase in cancer cells makes it an attractive therapeutic target. Anti-sense oligonucleotides directed against the RNA template of hTR and small molecules that can interact and stabilise the G-quadruplex represent promising therapeutic strategies. Human trials investigating the potential role of the catalytic subunit hTERT as a universal cancer vaccine have already commenced. Alternative lengthening of telomeres (ALT) and efficacy delay remain important limitations to anti-telomerase therapy.     

Novel Benzamide-Based Histamine H3 Receptor Antagonists: The Identification of Two Candidates for Clinical Development

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