Serum IL-4 as a marker of immunological response to sublingual immunotherapy

Allergic rhinitis (AR) is characterized by a Th2 polarized immune response. Specific Immunotherapy modifies this bias restoring a physiologic Th1 profile. Sublingual immunotherapy (SLIT) is widely prescribed, but there is no early, simple marker of response. This study was undertaken in order to determine whether serum IL-4 might be a possible marker of SLIT immunological response in order to quickly and easily detect responder patients. Thirty-nine AR patients with a pollen allergy assumed preseasonal SLIT for 3 months. VAS for symptoms and medication efficacy were evaluated. Serum IL-4 was assessed before and 3 and 6 months after SLIT initiation. Eighty-two percent of patients (32/39) showed a clinical response to SLIT. Serum IL-4 significantly decreased at 6 months post-therapy in responders, whereas it increased in non-responders. In conclusion, these results may be considered clinically relevant proof that SLIT treatment induces a quick reduction in Th2 polarization. Serum IL-4 appears to be an early marker of immunological response to SLIT.     

Immune response to sublingual immunotherapy in children allergic to mites

Allergic rhinitis (AR) is characterized by Th2 polarized immune response. Specific immunotherapy modifies this arrangement restoring a physiologic Th1 profile. Sublingual immunotherapy (SLIT) is widely prescribed, but there is no early marker of response. The aim of this study is to investigate possible marker of SLIT effectiveness. Thirty children with mite allergy were studied: 15 were treated with drugs alone, 15 with SLIT and drugs on demand. The study lasted 2 years. Visual analogue scale (VAS) for symptoms and medication score were evaluated. Serum cytokines (IL-2, IL-4, IL-6, IL-8, IL-10, IFN-gamma, MCP-1, and TNF-alpha) were assessed by ELISA before and after 1 and 2 year SLIT. SLIT-treated children obtained a significant improvement of symptoms and a reduction of drug use, whereas children treated with a drug alone did not obtained any change. IL-10 significantly increased, whereas Th2-dependent and pro-inflammatory cytokines significantly decreased. In conclusion, the present study demonstrates that 2-year SLIT is capable of inducing immunologic hyporeactivity to mites.     

Serum IL-9 levels and sublingual immunotherapy: preliminary report

Th9 is a new T cell subset characterized by IL-9 production. It has been reported that serum IL-9 levels are related with symptom severity in patients with allergic rhinitis (AR). This study is aimed at investigating whether serum IL-9 may be modulated by sublingual immunotherapy (SLIT) in patients with persistent AR due to Parietaria allergy. Twenty-one AR patients (9 males, median age 41 years) successfully treated with SLIT and 52 AR patients (25 males, median age 34 years) treated only with drugs were evaluated during the pollen season. Serum IL-9 was dosed in all patients. SLIT-treated patients showed significantly lower serum IL-9 levels than untreated AR patients (p <0.0001). In conclusion, this preliminary study shows that a single pre-seasonal SLIT course might modulate serum IL-9.     

Preventive actions of allergen immunotherapy: the facts and the effects in search of evidence

Allergen immunotherapy (AIT) is the only treatment that works on the causes of allergy. Available AIT nowadays are subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) for allergic rhinitis and asthma, while for allergy to Hymenoptera venom only subcutaneous route is recommended. A bulk of trials and meta-analyses demonstrated that efficacy and safety of AIT in decreasing allergic clinical symptoms and use of rescue medications, while its preventive capacity is yet under investigation. The most important of these effects is the prevention of potentially fatal anaphylactic reactions to Hymenoptera stings by venom immunotherapy (VIT). A certain number of studies thus far available showed that AIT, in both forms, is able to prevent the progress of allergic rhinitis into asthma and the development of new sensitizations. These effects should be related to the mechanisms of action of AIT. In fact, it has been demonstrated that both SCIT and SLIT are able to modify the allergen presentation by dendritic cells, with result in modification of the phenotype of allergen-specific T cells, switching from the typical of allergic inflammation Th2-type response to a Th1-type one. Also allergen-specific T regulatory (Treg) cells play a pivotal role by producing suppressive cytokines, such as IL-10 and TGF-beta. However, the only plain evidence of a preventive effect concerns VIT, while the other outcomes need to be furtherly investigated.     

变应性鼻炎舌下特异性免疫治疗前后主客观指标、生活质量改变及疗效影响因素分析

目的:分析舌下特异性免疫治疗变应性鼻炎(AR)临床疗效及其影响因素。方法:以我院2012年1月~2014年1月诊治的100例变应性鼻炎患者为研究对象,均接受舌下特异性免疫治疗,以治疗2年为研究终点,比较治疗前、治疗2年后症状及体征评分、视觉模拟量表(VAS)评分及生活质量变化,评价治疗2年疗效及不良反应,同时对可能影响舌下特异性免疫治疗2年疗效的相关因素行多元线性回归分析。结果:治疗2年总有效率高达72.00%;与治疗前比较,治疗2年后症状及体征积分、VAS评分、鼻结膜炎生存质量调查问卷(RQLQ)中文版各项评分均显著下降,差异有统计学意义(P0.05)。多元线性回归分析显示舌下特异性免疫治疗AR 2年疗效的影响因素为病程、治疗前VAS评分及患者用药依从性。结论:舌下特异性免疫治疗AR疗效明确,不良反应少,能有效缓解患者症状及体征,改善其生活质量。同时其疗效与AR患者病程长、治疗前VAS评分高、用药依从性差有关。     

Oral administration of Lactiplantibacillus plantarum NR16 isolated from Kimchi ameliorates murine allergic rhinitis

Allergic rhinitis (AR) is a type I hypersensitivity mediated by dominant T helper 2 (Th2) response over the Th1 response after re-exposure to a specific allergen. Currently, socio-economic cost evoked by AR is quickly increasing since the prevalence of AR is gradually increasing in all ages worldwide. Several probiotic Lactobacillus strains have been described with potential immunomodulatory effects against type I hypersensitivity such as AR. Thus, the aim of the present work was to characterize basic probiotic property and immunomodulatory role of newly isolated Lactobacillus strains from Kimchi, a traditional fermented Korean food, in AR. Among the identified strains, Lactiplantibacillus plantarum NR16 revealed to be a powerful Th1 inducer since immune cells co-cultured with NR16 produced the highest quantity of interferon-γ (IFN-γ) and interleukin-12 (IL-12) but secreted a low amount of IL-4 in vitro. Therefore, NR16 was selected for the following assays conducted with mice with birch pollen–induced AR. Oral administration of NR16 reduced airway hyperresponsiveness and leukocyte infiltration in lesions of mice. In conclusion, oral administration of NR16 may mitigate symptoms of AR by inducing Th1 immune response, which might rebalance Th2/Th1 ratio by decreasing Th2 cytokine production in specific lesions of mucosa.     

Pharmacoeconomics of sublingual immunotherapy with the 5-grass pollen tablets for seasonal allergic rhinitis

Allergic rhinitis has a very high burden regarding both direct and indirect costs. This makes essential in the management of AR to reduce the clinical severity of the disease and thus to lessen its costs. This particularly concerns allergen immunotherapy (AIT), that, based on its immunological action on the causes of allergy, extends its benefit also after discontinuation of the treatment. From the pharmacoeconomic point of view, any treatment must be evaluated according to its cost-effectiveness, that is, the ratio between the cost of the intervention and its effect. A favorable cost-benefit ratio for AIT was defined, starting from the first studies in the 1990s on subcutaneous immunotherapy (SCIT) in AR patients, that highlighted a clear advantage on costs over the treatment with symptomatic drugs. Such outcome was confirmed also for sublingual immunotherapy (SLIT), that has also the advantage on SCIT to be free of the cost of the injections. Here we review the available literature on pharmacoeconomic data for SLIT with the 5-grass pollen tablets.     

舌下特异性免疫治疗变应性鼻炎的临床疗效评价

目的：评价舌下特异性免疫治疗变应性鼻炎（allergicrhinitis,AR）的临床疗效,探讨提高AR疗效的治疗措施。方法：选择同期门诊及住院治疗的AR患者76例,在患者自愿的前提下,将患者分为对照组（n=40例）和观察组（n=36例）,对照组患者给予常规药物治疗措施,观察组患者在上述治疗措施的基础上加行舌下特异性免疫治疗,治疗12个月后比较两组患者变异性鼻炎症状评分、变异性鼻炎体征评分、临床疗效及不良反应的发生情况。结果：治疗前,两组患者变异性鼻炎症状评分与体征评分比较。差异均无统计学意义（P〉0．05）;治疗12个月后,两组患者变异性鼻炎症状评分与体征评分均较治疗前显著降低,差异具有统计学意义（P〈0．05）,且观察组患者变异性鼻炎症状评分与体征评分显著低于对照组,差异具有统计学意义（P〈0．05）。对照组和观察组的治疗总有效率分别为为87．5％和100．0％,差异具有统计学意义（P〈0．05）。此外,两组治疗期间不良反应的发生率比较差异无统计学意义（P〉0．05）。结论：舌下特异性免疫治疗治疗AR,其临床疗效确切且安全可靠,值得推广和深入研究。     

Effects of glucan treatment on the Th1/Th2 balance in patients with allergic rhinitis: a double-blind placebo-controlled study

BACKGROUND: Allergic rhinitis (AR) is a disease characterized by IgE-mediated, allergic inflammation of the nasal mucosa. T helper (Th) 2 cells play an important role in the development of IgE-mediated diseases such as AR, with local overproduction of Th2 cytokines (IL-4, IL-5 and IL-13) at the site of allergic inflammation. Th1 cytokines (IL-12 and IFN-gamma) are known to suppress this Th2 immune response, aiding the treatment of these diseases. Beta-1,3-1,6-glucan (Glucan) is an immunomodulator stimulating particularly the antitumor response. An efficient antitumor stimulation can be achieved through a Th1-mediated immune response. OBJECTIVE: The aim of this study was to investigate the effects of Glucan on the immunopathogenic processes in the microenvironment to determine if it reverses the Th2-mediated immune response in AR to Th1-mediated response. METHODS: 24 Olea europea mono-sensitized patients with AR were randomized into Glucan and placebo groups. The Glucan group consisted of 12 patients who received Glucan treatment for 12 weeks, while the placebo group of 12 patients received placebo during the same period. A nasal provocation test (NPT) with Olea europea was performed at the beginning and end of treatment, and nasal lavage followed the positive NPT. IL-4, IL-5, IFN-gamma and IL-12 levels and the eosinophil count (%) were measured in nasal lavage fluid (NLF) samples. Simultaneously, peripheral blood eosinophil % values were measured. RESULTS: After treatment, IL-4 and IL-5 levels in NLF from the Glucan group were found to have decreased significantly (p = 0.027, p = 0.04; respectively), while IL-12 levels were found to have significantly increased (p = 0.008). However, IFN-gamma levels had not changed. On the other hand, none of the cytokine levels had changed significantly in the placebo group following treatment. Moreover, the percentage of eosinophils in the NLF was found to have decreased significantly after treatment in the Glucan group (p = 0.01), while that of the placebo group did not change. Peripheral blood percentage eosinophil levels had not changed significantly in any group. CONCLUSION: Th2-originated IL-4 and IL-5 levels responsible for the allergic inflammatory response in the microenvironment of patients with AR, are decreased with Glucan while levels of Th1-originated IL-12 are increased. Moreover, eosinophils, which are important effector cells of the inflammatory response, are decreased in the microenvironment. As a result, Glucan may have a role as an adjunct to standard treatment in patients with AR.     

Mesenchymal stem cells combined with traditional Chinese medicine (qi-fang-bi-min-tang) alleviates rodent allergic rhinitis

Mesenchymal stem cells (MSCs) have been proved to exert anti-inflammatory effects and regulate immune reactions. Traditional Chinese medicine (TCM), qi-fang-bi-min-tang, is effective for some patients with allergic diseases. However, it remains unclear whether MSCs combined with TCM could benefit the treatment of allergic rhinitis (AR). In this study, we reported an additional effect of TCM (qi-fang-bi-min-tang) on the therapy of AR under MSCs treatment. Intriguingly, we observed that TCM-treated MSCs significantly inhibited the symptoms of AR and reduced the pathological changes of nasal mucosa in ovalbumin (OVA)-induced rats. The expression levels of interferon γ (IFN-γ), interleukin-17 (IL-17), and IL-4 were significantly decreased in the plasma of AR rats after injection of TCM-treated MSCs. TCM-treated MSCs reduced the levels of histamine secreted by mast cells and immunoglobulin E (IgE) secreted by plasma cells. In addition, we found that MSCs combined with TCM had a better therapeutic effect than TCM alone on AR in an OVA-induced mouse model. After OVA induction, MSCs combined with TCM significantly reduced the ratio of T helper type 1 (Th1), Th2, and Th17, but increased the proportion of Treg in the spleen of mice. Consistently, the expression levels of IFN-γ, IL-4, and IL-17 were significantly decreased, but transforming growth factor-β1 was significantly increased in the plasma of AR mice after treated with TCM and MSCs. Our results from both rats and mice indicated that the effects of TCM combined with MSCs on the AR might be through regulating the secretion of Th1, Th2, and Th17 cytokines. This study suggested that TCM (qi-fang-bi-min-tang)-treated MSCs could be used in the clinical therapy of AR.     

IFN-gamma production by Th1 cells generated from naive CD4+ T cells exposed to norepinephrine

During activation in vivo, naive CD4(+) T cells are exposed to various endogenous ligands, such as cytokines and the neurotransmitter norepinephrine (NE). To determine whether NE affects naive T cell differentiation, we used naive CD4(+) T cells sort-purified from either BALB/c or DO11.10 TCR-transgenic mouse spleens and activated these cells with either anti-CD3/anti-CD28 mAbs or APC and OVA(323-329) peptide, respectively, under Th1-promoting conditions. RT-PCR and functional assays using selective adrenergic receptor (AR) subtype antagonists showed that naive CD4(+) T cells expressed only the beta 2AR subtype to bind NE and that stimulation of this receptor generated Th1 cells that produced 2- to 4-fold more IFN-gamma. This increase was due to more IFN-gamma produced per cell upon restimulation instead of more IFN-gamma-secreting cells, as determined by IFN-gamma-specific immunofluorescence and enzyme-linked immunospot. In contrast, Th1 cell differentiation was unaffected when naive T cells were exposed to NE and activated either in the presence of a neutralizing anti-IL-12 mAb or by APC from IL-12-deficient mice. Moreover, the addition of IL-12 to the IL-12-deficient APC cultures restored the ability of NE to increase Th1 differentiation. Taken together, these results indicate that a possible link may exist between the signaling pathways used by NE and IL-12 to increase naive CD4(+) T cell differentiation to a Th1 cell.     

变应性鼻炎患者外周血中Tr1/Th3细胞的检测和分析

目的:检测变应性鼻炎(Allergic rhinitis,AR)患者和健康对照者外周血中IL-10+CD4+T细胞、TGF-β+CD4+T细胞(分别代表Tr1细胞和Th3细胞的特性)的比例,并探讨其在AR发病中的意义,为AR的治疗提供临床参考。方法:分离19例对粉尘螨过敏的AR患者和19例健康对照者外周血单个核细胞(PBMCs),采用流式细胞术分别检测外周血中IL-10+CD4+T细胞、TGF-β+CD4+T细胞的比例。结果:同健康对照者相比,AR患者外周血中IL-10+CD4+T细胞的比例显著降低[(1.66±0.48)%vs.(3.80.92)%,t=-9.08,P0.01)],AR患者外周血中TGF-β+CD4+T细胞的比例降低[(1.92±0.54)%vs.(4.76±1.12)%,t=-9.94,P0.01)]。结论:外周血中IL-10+CD4+T(Tr1)细胞比例的降低可能是AR发病的一个重要因素,提高AR患者外周血中分泌IL-10的Tr1细胞的比例可能在AR的治疗中具有重要意义。外周血中TGF-β1+CD4+T(Th3)细胞的比例显著降低,可能是AR发病的一个重要因素。但TGF-β1与AR关系的研究较少,特别是外周血中TGF-β1水平与AR的关系研究较少,需进一步研究。     

Immunological effects of sublingual immunotherapy: clinical efficacy is associated with modulation of programmed cell death ligand 1, IL-10, and IgG4

Sublingual immunotherapy (SLIT) is an alternate route of administration of allergen-specific immunotherapy with an improved safety profile; to clarify the immune mechanisms elicited by this therapy, we analyzed the clinical and immunologic effects of SLIT in patients with a clinical history of ragweed sensitization. To analyze possible difference among immunotherapeutic protocols, we also compared patients receiving preseasonal, seasonal, or prolonged sublingual therapy (≥ 3 y); patients receiving symptomatic therapy alone were enrolled as well in the study. Clinical and immunological parameters were measured twice in and out of the pollination period. Clinical benefits, as measured by the visual analog scale for symptoms and for use of drugs, were evident in all three groups of individuals receiving immunotherapy, but were significantly better in patients undergoing prolonged SLIT. Immunologically, SLIT resulted in increased IL-10 production, programmed cell death ligand 1 expression, and concentration of allergen-specific IgG4, as well as in the reduction of CD80 and CD86 expression and IL-4 production. SLIT, thus, is associated with modulation of programmed cell death ligand 1 expression and IL-10 synthesis and favors the production of allergen-specific IgG4. These effects are evident from the first pollen season, independently from therapeutic regimen (preseasonal or seasonal) even if a prolonged treatment is necessary to obtain full clinical efficacy. A more detailed understanding of the interaction of allergen and APCs within the oral mucosa will allow improved targeting of allergy vaccine.     

Effects of CD80 and CD86 on cytokine production in patients with wasp-venom allergy who receive venom immunotherapy

Several studies have provided evidence that activation of antigen-specific T cells requires interactions between CD28 on T cells and its ligands, CD80 and CD86, on antigen-presenting cells (APCs). However, the effects of CD80 and CD86 on cytokine production in patients with Hymenoptera venom allergy who receive venom immunotherapy remain unclear. We examined the effects of CD80 and CD86 on Th1- and Th2-cytokine production before and after venom immunotherapy in patients with wasp-venom allergy. Peripheral blood mononuclear cells (PBMCs) were isolated from patients with wasp-venom allergy before and after three months of venom immunotherapy. CD4+ T cells and monocytes were isolated as APCs from PBMCs and were cocultured with wasp venom in the presence of anti-CD80 or -CD86 blocking antibodies. Interleukin (IL)-4, IL-10, and interferon (IFN)-gamma were measured by enzyme-linked immunosorbent assay. The expression of CD80 and CD86 on CD14+ PBMCs was detected by fluorescence-activated cell-sorter analysis. The expression of CD86, but not that of CD80, on CD14+ PBMCs cocultured with venom increased after three months of venom immunotherapy, but not before venom immunotherapy. Blockade of CD86 reduced IL-10 production after three months of venom immunotherapy. IL-10 production promoted by CD86 costimulation may be involved in the mechanism of venom immunotherapy in patients with venom allergy.     

Low-dose lymphocyte immunotherapy rebalances the peripheral blood Th1/Th2/Treg paradigm in patients with unexplained recurrent miscarriage

Background

The published results regarding lymphocytes immunotherapy for unexplained recurrent miscarriage (uRM) patients are conflicting due to different screening criteria and therapeutic protocols. The objective of the present study is to evaluate the effectiveness of immunotherapy using low-dose lymphocytes in patients with uRM and Th1/Th2/Treg paradigm disorders.

Methods

Sixty-four uRM patients who received low-dose lymphocytes immunotherapy served as the immunotherapy group, while the other 35 women who did not receive the treatment served as the control group. The proportions of peripheral blood Th1 cells, Th2 cells and Treg cells; and the concentration of TGF-β1 in serum were detected by flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively, before and after the immunotherapy.

Results

The proportion of Th1 cells was significantly decreased while the proportions of Th2 cells and Treg cells were significantly increased in immunotherapy group patients after treatment. In addition, the concentration of TGF-β1 in serum was significantly higher after immunotherapy than before. Forty-three uRM patients achieved pregnancy after receiving immunotherapy and 5 patients underwent miscarriages in the immunotherapy group (11.6%, 5/43), while 8 of the 23 pregnant patients experienced a miscarriage in the control group (34.8%, 8/23; p?<?0.05).

Conclusions

Low-dose lymphocyte immunotherapy is beneficial for restoring balance in the Th1/Th2/Treg paradigm and improving pregnancy outcome in uRM patients.

Trial registration

NCT03081325. ClinicalTrials.gov. Retrospectively registered July 2015.

     

Angelica gigas extract ameliorates allergic rhinitis in an ovalbumin-induced mouse model by inhibiting Th2 cell activation

BackgroundAllergic rhinitis (AR) is a well-documented type 2 helper T (Th2) cell-mediated allergic disease that is accompanied by symptoms such as nasal rubbing, sneezing, itching, and rhinorrhea. Angelica gigas (AG) is traditional oriental medicine, and its dried root is widely used for the treatment of anemia, as a sedative, and as a blood tonic.PurposeThe effects of AG on allergic diseases including AR are currently unclear; therefore, we aimed to investigate the effects of AG extract (AG-Ex) in ameliorating AR.Study design/methodsThe cytotoxicity of AG-Ex was analyzed by EZ-Cytox or MTS assay in splenocytes, differentiated Th2 cells, and human nasal epithelial cells (HNEpC). The changes of Th2 cells activation were determined by the secretion levels of cytokines and chemokines using cytometric bead array in splenocytes and differentiated Th2 cells. The expression levels of eotaxin-3 and periostin were analyzed using an ELISA. AR was induced by ovalbumin in BALB/c mice and the ameliorating effects of AG-Ex were assessed by their clinical symptoms.ResultsThe secretion of Th2 cytokines such as IL-4, IL-5, and IL-13 was inhibited by the AG-Ex treatment in the splenocytes and differentiated Th2 cells. The treatment also suppressed allergic responses including the secretion of eotaxin-3 and periostin in human nasal epithelial cells (HNEpC). Moreover, the administration of AG-Ex to the OVA-induced AR mice improved their clinical symptoms, including behavioral tests, immune cell counts, histopathological analysis, and changes in serum parameters.ConclusionThe results of this study suggest that AG-Ex ameliorates AR by inhibiting Th2 cell activation and could thus be utilized as a treatment for Th2-mediated allergic diseases in the future.     

Effects of specific allergen immunotherapy on biological markers and clinical parameters in asthmatic children: a controlled-real life study

Background

Allergen-specific immunotherapy (AIT) is the only treatment able to change the natural course of allergic diseases. We aimed at investigating the clinical efficacy of SLITOR (Serbian registered vaccine for sublingual allergen specific immunotherapy).

Methods

7–18 years old children with allergic asthma and rhinitis were enrolled and addressed to the active (AIT plus pharmacological treatment) or control (standard pharmacological treatment only) group. Clinical and medications scores, lung function and exhaled FeNO were measured at baseline and at every follow-up.

Results

There was a significant improvement in both nasal and asthma symptom scores as well as in medication score in SLIT group. SLIT showed an important influence on lung function and airway inflammation.

Conclusions

Our data showed that SLITOR was effective not only in terms of patient reported outcomes but an improvement of pulmonary function and decrease of lower airway inflammation were also observed.

     

Sublingual Immunotherapy as an Alternative to Induce Protection Against Acute Respiratory Infections

Sublingual route has been widely used to deliver small molecules into the bloodstream and to modulate the immune response at different sites. It has been shown to effectively induce humoral and cellular responses at systemic and mucosal sites, namely the lungs and urogenital tract. Sublingual vaccination can promote protection against infections at the lower and upper respiratory tract; it can also promote tolerance to allergens and ameliorate asthma symptoms. Modulation of lung’s immune response by sublingual immunotherapy (SLIT) is safer than direct administration of formulations by intranasal route because it does not require delivery of potentially harmful molecules directly into the airways. In contrast to intranasal delivery, side effects involving brain toxicity or facial paralysis are not promoted by SLIT. The immune mechanisms underlying SLIT remain elusive and its use for the treatment of acute lung infections has not yet been explored. Thus, development of appropriate animal models of SLIT is needed to further explore its potential advantages. This work shows how to perform sublingual administration of therapeutic agents in mice to evaluate their ability to protect against acute pneumococcal pneumonia. Technical aspects of mouse handling during sublingual inoculation, precise identification of sublingual mucosa, draining lymph nodes and isolation of tissues, bronchoalveolar lavage and lungs are illustrated. Protocols for single cell suspension preparation for FACS analysis are described in detail. Other downstream applications for the analysis of the immune response are discussed. Technical aspects of the preparation of Streptococcus pneumoniae inoculum and intranasal challenge of mice are also explained.SLIT is a simple technique that allows screening of candidate molecules to modulate lungs’ immune response. Parameters affecting the success of SLIT are related to molecular size, susceptibility to degradation and stability of highly concentrated formulations.     

Vaccination with heat-killed Listeria as adjuvant reverses established allergen-induced airway hyperreactivity and inflammation: role of CD8+ T cells and IL-18

Asthma is a respiratory disorder characterized by airway hyperreactivity (AHR) and inflammation and is associated with high serum IgE and overproduction of IL-4, IL-5, and IL-13 by allergen-specific Th2 cells. Our previous studies demonstrated that heat-killed Listeria monocytogenes (HKL) as an adjuvant in immunotherapy successfully reversed ongoing Ag-specific Th2-dominated responses toward Th1-dominated responses, but it was unclear if such immune modulation could reverse ongoing, established disease in target organs such as the lung. In this paper we show that a single dose of Ag plus HKL as adjuvant significantly reduced AHR in a murine model for asthma and reversed established AHR when given late after allergen sensitization. HKL as adjuvant also dramatically inhibited airway inflammation, eosinophilia, and mucus production, significantly reduced Ag-specific IgE and IL-4 production, and dramatically increased Ag-specific IFN-gamma synthesis. The inhibitory effect of HKL on AHR depended on the presence of IL-12 and CD8+ T cells and was associated with an increase of IL-18 mRNA expression. Thus, our results demonstrate that HKL as an adjuvant for immunotherapy mediates immune deviation from a pathological Th2-dominated response toward a protective immune response in peripheral lymphoid tissues and in the lungs and may be clinically effective in the treatment of patients with established asthma and allergic disease.     

The efficacy of immunotherapy in an experimental murine model of allergic asthma is related to the strength and site of T cell activation during immunotherapy

In the present study, the relation between the efficacy of immunotherapy, and the strength and site of T cell activation during immunotherapy was evaluated. We used a model of allergic asthma in which OVA-sensitized and OVA-challenged mice display increased airway hyperresponsiveness, airway inflammation, and Th2 cytokine production by OVA-specific T cells. In this model, different immunotherapy strategies, including different routes of administration, or treatment with entire OVA or the immunodominant T cell epitope OVA(323-339), or treatment with a peptide analogue of OVA(323-339) with altered T cell activation capacity were studied. To gain more insight in how immunotherapy affects allergen-specific T cells, the site of Ag-specific T cell activation and the magnitude of the T cell response induced during different immunotherapy strategies were determined using an adoptive transfer model. Our data suggest that amelioration of airway hyperresponsiveness and inflammation is associated with the induction of a strong, synchronized, and systemic T cell response, resulting in a decreased OVA-specific Th2 response. In contrast, deterioration of the disease after immunotherapy is associated with the induction of a weak nonsynchronized T cell response, resulting in the enhancement of the OVA-specific Th2 response after challenge.