The IL-1 receptor 1 is critical for Th2 cell type airway immune responses in a mild but not in a more severe asthma model

IL-1 alpha and IL-1 beta are potent pro-inflammatory cytokines that regulate many physiological systems by binding and signaling to the same receptor termed IL-1 receptor type 1 (IL-1R1). We have investigated the role of IL-1 for pulmonary immune responses in models of allergic asthma using IL-1R1-deficient (IL-1R1(-/-)) mice. In a model of mild asthma, based on repeated sensitization of mice with low doses of ovalbumin in the absence of any adjuvant and multiple intranasal challenges, the pulmonary eosinophilic inflammation and goblet cell hyperplasia were strongly reduced in IL-1R1(-/-) as compared to control BALB/c mice. Moreover, priming of CD4(+) T cells in bronchial lymph nodes and their recruitment to the lung was affected in IL-1R1(-/-) mice associated with impaired antibody responses including IgG, IgE, and IgA. In contrast, sensitization of mice in the presence of alum adjuvant, a more severe asthma model, rendered the IL-1 pathway dispensable for the development of pulmonary allergic Th2 responses, as eosinophilic inflammation, antibody responses, and CD4(+) T cell priming in lymph nodes were comparable between IL-1R1(-/-) and wild-type mice. These results suggest a critical role of IL-1/IL-1R1 for development of allergic Th2 responses, but its requirement can be overcome by using alum as adjuvant for sensitization.     

Environmental pollutant tributyltin promotes Th2 polarization and exacerbates airway inflammation

It has been shown that a relatively high dose of tributyltin (TBT), which is recognized as a particularly notable environmental pollutant, exerts immunotoxic effects such as thymic atrophy via induction of T cell apoptosis. However, the effect of low doses of TBT on the immune responses remains unknown. Here we show that environmentally relevant doses of TBT promoted strong Th2 polarization via suppression and augmentation of Th1 and Th2 development, respectively, from naive CD4(+) T cells primed with anti-CD3 and splenic antigen-presenting cells (APC). TBT-induced Th2 polarization was indirect, working through APC via suppression of IL-12 production by macrophages/DC and the augmentation of IL-10 production by B cells. Th2 polarization was also induced in mice treated with TBT and immunized with OVA or infected with Nippostrongylus brasiliensis. Furthermore, airway inflammation in mice sensitized and challenged with OVA was exacerbated by the administration of TBT with concomitant augmentation of Th2-type immunity. Our results highlight the fact that an important environmental pollutant TBT may present significant risk for the induction of allergic diseases via promotion of Th2 polarization.     

Endocrine disruptors that deplete glutathione levels in APC promote Th2 polarization in mice leading to the exacerbation of airway inflammation

Endocrine-disrupting chemicals (EDC) are ubiquitous in environment and may have various undesirable effects on human health. In the present study, we have shown that some EDC [benzophenone, p-octylphenol, and tributyltin chloride (TBT)] promoted strong Th2 polarization via suppression and augmentation of Th1 and Th2 development, respectively, from naive CD4+ T cells primed with anti-CD3 and splenic antigen-presenting cells (APC). The effect was indicated to be indirect via suppression of IL-12 production and augmentation of IL-10 production of APC, which are critical for the Th1 and Th2 development, respectively. Such modulation of cytokine production by EDC was associated with reduction of intracellular glutathione levels in APC. IL-10 deprivation or the addition of N-acetylcysteine, which replenishes intracellular glutathione level during priming, cancelled the effect of EDC on the promotion of Th2 polarization. Oral administration of TBT, which most effectively promoted Th2 polarization in vitro, exacerbated airway inflammation in a murine model of allergic asthma with concomitant enhancement of Th2-type immunity. Collectively these results suggest that EDC such as benzophenone, p-octylphenol, and TBT promote Th2 polarization indirectly via the depletion of glutathione in APC and subsequent modulation of IL-10 and IL-12 production that might result in the exacerbation of allergic diseases.     

Th2 cells shape the differentiation of developing T cell responses during interactions with dendritic cells in vivo

During priming, naive CD4(+) Th cells differentiate into cells that produce either IFN-gamma or IL-4. Even though the cascade of pathways that induces IL-4-producing Th2 cells has been determined in vitro, the signals promoting Th2 differentiation under physiological conditions remain enigmatic, especially the natural role of the single most important Th2-inducing signal,IL-4. Using Th2 and naive Th cells, each expressing a distinct transgenic TCR, here we show that Th2 cells migrate with the same dynamics as naive Th cells in draining lymph nodes and bind to the same DC, when driven by antigen in complete Freund's adjuvant (CFA). Th2-cell-derived IL-4 deviates CFA-induced Th1 development toward a Th2 phenotype, if both cell populations co-localize in the same T cell area, and are activated simultaneously. Thus, intranodal Th2 cells directly influence Th cell differentiation in vivo, but only under restricted conditions. These findings have implications for the design of cytokine-based therapies and explain the spreading of Th2 responses to multiple aeroallergens in allergic asthma, where naive Th and Th2 cells co-localize in lung-draining lymph nodes.     

Th1/Th2 cytokine responses following HIV-1 immunization in seronegative volunteers

The Th1/Th2 profile that follows human vaccination may profoundly influence the subsequent course of disease after infection. However, the ability to detect IL-4 has been limited outside trials of live vaccination. By using methods in which memory effector cells are allowed to antigenically expand by short term culture, followed by low-dose mitogenic stimulation, we have been able to follow the Th1/Th2 profile in HIV-1^?volunteers enrolled in two phase I studies of HIV immunogens (a recombinant gp120 and a multivalent, octomeric V3 loop peptide). Antigen-specific interferon-gamma (IFN-γ) could be detected in primary stimulation, but IL-4 was observed only after antigenic expansion and restimulation. In both of these studies the responses after initial immunizations were dominated by IFN-γ, with IL-4 appearing only after multiple rounds of immunization, and IL-4 was temporally related to antibody production. Concomitant with the IL-4 production, the amount of supernatant IFN-γ declined. Antigen-specific IL-10 was not detected in either study. Such techniques, which have been shown to correlate with outcomes in immunotherapy, may prove useful as future surrogates of human vaccine response.     

T-bet重组腺病毒对哮喘小鼠Thl/Th2免疫平衡的调节

目的探讨静脉应用T-bet重组腺病毒（AdT-bet）对哮喘模型小鼠过敏性气道炎症及Th1／Th2免疫失衡的影响。方法36只C57BL/6小鼠随机分为AdT-bet治疗组（A组）、模型对照组（B组）、正常组（C组）。以卵蛋白（OVA）、氢氧化铝免疫建立哮喘模型，A组激发前尾静脉注射100μL的AdT-bet（1×10^8 PFU/μL），各组激发后肺泡灌洗分析细胞组份，分离肺淋巴细胞测定细胞因子分泌水平，以流式细胞仪检测CD3^＋、CD4^＋ T细胞比例及表达IFNγ和IL-4的比例，比较各组肺组织学改变。结果静脉应用AdT-bet组与对照组相比：①可明显抑制抗原激发后气道内嗜酸性粒细胞的浸润（P〈0．01）；②明显抑制肺淋巴细胞产生IL-4、IL-5，增加了IFNγ的产生；③肺脏淋巴细胞CD4^＋ IFNγ百分比及IFNγ^＋/IL-4^＋明显升高（P〈0．01），而CD4^＋ IL-4^＋百分比则明显下降；④明显抑制哮喘鼠气道内及肺泡内的过敏性炎症反应。结论激发前静脉用AdT-bet对哮喘小鼠过敏性气道炎症有明显的防治作用，其机制可能与表达的T-bet上调Th1／Th2比值，从而调整了免疫平衡有关。     

PLGA为佐剂的OVA纳米疫苗皮下注射可预防小鼠过敏反应性气道炎症和调节Th1/Th2反应

目的 探讨聚乳酸.羟基乙酸共聚物[poly（D,L-lactic-co-glycolic）acid,PLGA]包裹的卵清蛋白（OVA）纳米癌苗（POM）对哮喘小鼠的免疫治疗效果.方法 包裹不同剂量（低、中、高）的OVA纳米粒子和对照（OVA、空白纳米粒子、PBS）通过皮下注射给予小鼠,再用OVA进行致敏和激发,通过肺组织学、支气管肺泡灌洗液（BALF）细胞计数、测定BALF和脾细胞培养上清液中细胞因子的含量,观察小鼠呼吸道炎症和免疫学改变.结果 肺部组织学和BALF中细胞计数结果显示,与PBS对照组相比,OVA治疗组、中剂量和高剂量OVA纳米组的肺部嗜酸性浸润显著减轻,BALF中总细胞和嗜酸性细胞显著减少.卸胞因子测定结果显示,与PBS对照组相比,中、高剂量OVA纳米组的BALF和脾细胞培养上清液中IFN-γ显著升高,Ⅱ,4水平显著降低.OVA治疗组中IL-4水平显著下降,而IFN-γ水平无显著差异.结论 OVA纳米疫苗可预防哮喘嗜酸性气道炎症,其可能的机制之一是调节了过敏性哮喘的Th1/Th2失平衡反应.     

PLGA为佐剂的OVA纳米疫苗皮下注射可预防小鼠过敏反应性气道炎症和调节Thl/Th2反应

目的 探讨聚乳酸.羟基乙酸共聚物[poly(D,L-lactic-co-glycolic)acid,PLGA]包裹的卵清蛋白(OVA)纳米癌苗(POM)对哮喘小鼠的免疫治疗效果.方法 包裹不同剂量(低、中、高)的OVA纳米粒子和对照(OVA、空白纳米粒子、PBS)通过皮下注射给予小鼠,再用OVA进行致敏和激发,通过肺组织学、支气管肺泡灌洗液(BALF)细胞计数、测定BALF和脾细胞培养上清液中细胞因子的含量,观察小鼠呼吸道炎症和免疫学改变.结果 肺部组织学和BALF中细胞计数结果显示,与PBS对照组相比,OVA治疗组、中剂量和高剂量OVA纳米组的肺部嗜酸性浸润显著减轻,BALF中总细胞和嗜酸性细胞显著减少.卸胞因子测定结果显示,与PBS对照组相比,中、高剂量OVA纳米组的BALF和脾细胞培养上清液中IFN-γ显著升高,Ⅱ,4水平显著降低.OVA治疗组中IL-4水平显著下降,而IFN-γ水平无显著差异.结论 OVA纳米疫苗可预防哮喘嗜酸性气道炎症,其可能的机制之一是调节了过敏性哮喘的Th1/Th2失平衡反应.     

Exacerbated Th2-mediated airway inflammation and hyperresponsiveness in autoimmune diabetes-prone NOD mice: a critical role for CD1d-dependent NKT cells

The NOD mouse has proved to be a relevant model of insulin-dependent diabetes mellitus, closely resembling the human disease. However, it is unknown whether this strain presents a general biastoward Th1-mediated autoimmunity or remains capable of mounting complete Th2-mediated responses. Here, we show that NOD mice have the capacity to develop a typical Th2-mediated disease, namely experimental allergic asthma. In contrast to what might have been expected, they even developed a stronger Th2-mediated pulmonary inflammatory response than BALB/c mice, a strain that shows a typical Th2 bias in this model. Thus, after allergen sensitization and intra-nasal challenge, the typical features of experimental asthma were exacerbated in NOD mice, including enhanced bronchopulmonary responsiveness, mucus production and eosinophilic inflammation in the lungs as well as specific IgE titers in serum. These hallmarks of allergic asthma were associated with increased IL-4, IL-5, IL-13 and eotaxin production in the lungs, as compared with BALB/c mice. Notwithstanding their quantitative and functional defect in NOD mice, CD1d-dependent NKT cells contribute to aggravate the disease, since in OVA-immunized CD1d(-/-) NOD mice, which are deficient in this particular T cell subset, airway eosinophilia was clearly diminished relative to NOD littermates. This is the first evidence that autoimmune diabetes-prone NOD mice can also give rise to enhanced Th2-mediated responses and might thus provide a useful model for the study of common genetic and cellular components, including NKT cells that contribute to both asthma and type 1 diabetes.     

Human airway and peripheral blood eosinophils enhance Th1 and Th2 cytokine secretion

BACKGROUND: The effector function of eosinophils involves their release of toxic granule proteins, reactive oxygen species, cytokines, and lipid mediators. Murine studies have demonstrated that eosinophils can also enhance T cell function. Whether human eosinophils, in particular, airway eosinophils, have similar immunoregulatory activity has not been fully investigated. The aim of this study was to determine whether human blood and airway eosinophils can contribute to Th1 and Th2 cytokine generation from CD4+ T cells stimulated with superantigen. METHODS: Eosinophils were obtained from blood or bronchoalveolar lavage fluid 48 h after segmental allergen bronchoprovocation. Purified eosinophils were co-cultured with autologous CD4+ blood T cells in the presence of staphylococcal enterotoxin B (SEB). Cytokine levels in the supernatant fluid were determined by enzyme-linked immunosorbent assay (ELISA). Eosinophil expression of major histocompatibility complex (MHC) class II and co-stimulatory molecules was assessed by flow cytometry before culture, 24 h after granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulation, and 24 h after co-culture with CD4+ T cells and SEB. RESULTS: Interleukin (IL)-5, IL-13, and interferon (IFN)-gamma generation increased when CD4+ T cells were co-cultured with either blood or airway eosinophils in the presence of SEB. The ability of eosinophils to enhance cytokine generation was independent of their source (blood vs airway), activation by GM-CSF, or detectable expression of human leukocyte antigen (HLA)-DR, CD80, or CD86. CONCLUSION: Our data demonstrate that SEB-induced generation of Th1 and Th2 cytokines is increased in the presence of human blood and airway eosinophils. Thus, eosinophils can have an immunoregulatory function in pathogen-associated allergic diseases such as atopic dermatitis, chronic sinusitis, and asthma exacerbations.     

Prevention of allergen-specific IgE production and suppression of an established Th2-type response by immunization with DNA encoding hypoallergenic allergen derivatives of Bet v 1, the major birch-pollen allergen

In atopic patients, programming towards a preferential Th2 immunity leads to IgE antibody production and cellular Th2 immunity against otherwise harmless antigens. We report the development of prophylactic and therapeutic DNA vaccines for the major birch-pollen allergen, Bet v 1. We constructed three DNA vaccines, coding for the complete cDNA, coding for two hypoallergenic fragments or coding for a hypoallergenic Bet v 1 mutant. The protective effect was studied in mice pretreated by intradermal DNA injections, then sensitized with Bet v 1 protein. Mice pretreated with any of the three Bet v 1-specific DNA vaccines were protected against allergic sensitization to Bet v 1. Protection was characterized by a lack of Bet v 1-specific IgE production, a lack of basophil activation and an enhanced IFN-gamma expression. DNA vaccines with wild-type Bet v 1 induced strong Bet v 1-specific antibody responses whereas DNA vaccines with hypoallergenic Bet v 1 derivatives induced no (fragments) or only transient (mutant) Bet v 1-specific antibody responses. A therapeutic approach with the fragment-DNA vaccine reduced IgE production and stimulated a sustained Th1 cytokine milieu. Our results demonstrate that DNA vaccines with hypoallergenic forms of the allergen specifically protect against sensitization and suppress established Th2-type responses. This concept may be applied for the development of safe and specific DNA vaccines for the prophylaxis and therapy of allergic diseases.     

An essential role for Rxr alpha in the development of Th2 responses

A viable hypomorphic allele of mouse retinoid X receptor α (Rxrα) was created by random germline mutagenesis. The mutation (I273N) alters the ligand binding and heterodimerization domain, and causes a 90% decline in ligand‐inducible transactivation. Homozygotes develop progressive alopecia and dermal cysts, and progressive exaggeration of Th1 and loss of Th2 responses to antigen. Th1 skewing is directly caused by aberrant function of both antigen‐presenting cells and naïve CD4 T cells; the predominant Th1 response to antigen is attributable to decreased suppression of regulatory T cells in mutant mouse. Dietary depletion of vitamin A in Th2‐prone wild‐type mice mimics the immune phenotype caused by the mutation. Hence, RXRα plays an important post‐developmental role in the regulation of adaptive immune responses, and provides a plausible link between nutritional environment and the type of adaptive response that results from immunization. See accompanying commentary http://dx.doi.org/10.1002/eji.200535588     

CD44 is critical for airway accumulation of antigen-specific Th2, but not Th1, cells induced by antigen challenge in mice

CD44 is a cell adhesion molecule involved in lymphocyte infiltration of inflamed tissues. We previously demonstrated that CD44 plays an important role in the development of airway inflammation in a murine model of allergic asthma. In this study, we investigated the role of CD44 expressed on CD4(+) T cells in the accumulation of T-helper type 2 (Th2) cells in the airway using CD44-deficient mice and anti-CD44 monoclonal antibodies. Antigen-induced Th2-mediated airway inflammation and airway hyperresponsiveness (AHR) in sensitized mice were reduced by CD44-deficiency. These asthmatic responses induced by the transfer of antigen-sensitized splenic CD4(+) T cells from CD44-deficient mice were weaker than those from WT mice. Lack of CD44 failed to induce AHR by antigen challenge. Expression level and hyaluronic acid receptor activity of CD44, as well as Neu1 sialidase expression on antigen-specific Th2 cells, were higher than those on antigen-specific Th1 cells. Anti-CD44 antibody preferentially suppressed the accumulation of those Th2 cells in the airway induced by antigen challenge. Our findings indicate that CD44 expressed on CD4(+) T cells plays a critical role in the accumulation of antigen-specific Th2 cells, but not Th1 cells, in the airway and in the development of AHR induced by antigen challenge.     

Tim-1 stimulation of dendritic cells regulates the balance between effector and regulatory T cells

We show that the T-cell immunoglobalin mucin, Tim-1, initially reported to be expressed on CD4(+) T cells, is constitutively expressed on dendritic cells (DCs) and that its expression further increases after DC maturation. Tim-1 signaling into DCs upregulates costimulatory molecule expression and proinflammatory cytokine production, thereby promoting effector T-cell responses, while inhibiting Foxp3(+) Treg responses. By contrast, Tim-1 signaling in T cells only regulates Th2 responses. Using a high-avidity/agonistic anti-Tim-1 antibody as a co-adjuvant enhances the immunogenic function of DCs, decreases the suppressive function of Tregs, and substantially increases proinflammatory Th17 responses in vivo. The treatment with high- but not low-avidity anti-Tim-1 not only worsens experimental autoimmune encephalomyelitis (EAE) in susceptible mice but also breaks tolerance and induces EAE in a genetically resistant strain of mice. These findings indicate that Tim-1 has an important role in regulating DC function and thus shifts the balance between effector and regulatory T cells towards an enhanced immune response. By understanding the mechanisms by which Tim-1 regulates DC and T-cell responses, we may clarify the potential utility of Tim-1 as a target of therapy against autoimmunity, cancer, and infectious diseases.     

Cytotoxic T lymphocyte antigen 4 immunoglobulin modified dendritic cells attenuate allergic airway inflammation and hyperresponsiveness by regulating the development of T helper type 1 (Th1)/Th2 and Th2/regulatory T cell subsets in a murine model of asthma

T helper type 2 (Th2) and regulatory T cells (T(reg) ) have been postulated to have critical roles in the pathogenesis of allergic asthma. Cytotoxic T lymphocyte antigen 4 immunoglobulin (CTLA4Ig) gene-modified dendritic cells (DC-CTLA4Ig) have the potential to reduce Th2 cells and induce T(reg) cells. In the present study, we evaluated the therapeutic effects and potential mechanisms of the adoptive transfer of DC-CTLA4Ig into mice in an experimental model of asthma. BALB/c mice were sensitized with ovalbumin (OVA) and challenged with aerosolized OVA for 7 days. Just prior to the first challenge, DC-CTLA4Ig, DCs or DCs infected with DC-green fluorescent protein (GFP) were injected intravenously into mice. The administration of DC-CTLA4Ig reduced airway hyperresponsiveness, relieved asthmatic airway inflammation and decreased the numbers of esosinophils in the BALF in OVA-sensitized/challenged mice. In addition, DC-CTLA4Ig altered the balance of Th1/Th2 cytokine production in the lungs with increased interferon (IFN)-γ levels and decreased interleukin (IL)-4 levels, decreased the percentage of Th2 and increased both the percentage of Th1 and T(reg) cells in the lungs of OVA-sensitized/challenged mice. This research demonstrates that DC-CTL4Ig reduces airway hyperresponsiveness effectively and prevents airway inflammation in OVA-sensitized/challenged mice, which is due most probably to attenuated secretion of Th2 cytokines and increased secretion of Th1 cytokines in the local airway, and the correction of the pulmonary imbalance between Th1/Th2 cells and Th2/T(reg) cells.     

CD8(+) T cells regulate immune responses in a murine model of allergen-induced sensitization and airway inflammation

The role of CD8(+) T cells in the development of allergic airway disease is controversial. On the one hand, CD8(+) T cells are known to inhibit the development of airway hyperreactivity (AHR) in murine models of asthma. In humans, IL-10-producing CD8(+) T cells were shown to act as regulatory cells, inhibiting both proliferation and cytokine secretion of T cells. On the other hand, CD8(+) T cells can promote IL-5-mediated eosinophilic airway inflammation and the development of AHR in animal models. To examine this, we investigated the role of CD8(+) T cells during the induction of allergen-induced AHR and demonstrated a protective effect of CD8(+) T cells. Depletion of CD8(+) T cells prior to the immunization led to increased Th2 responses and increased allergic airway disease. However, after development of AHR, CD8(+) T cells that infiltrated the lungs secreted high levels of IL-4, IL-5 and IL-10, but little IFN-gamma, whereas CD8(+) T cells in the peribronchial lymph nodes or spleen produced high levels of IFN-gamma, but little or no Th2 cytokines. These data demonstrate protective effects of CD8(+)T cells against the induction of immune responses and show a functional diversity of CD8(+) T cells in different compartments of sensitized mice.     

Thioredoxin suppresses airway inflammation independently of systemic Th1/Th2 immune modulation

Oxidative stress plays an important role in the pathogenesis of asthma via the upregulation of local inflammatory mediators and/or promoting Th2‐skewing during Ag sensitization. Thioredoxin (TRX), a 12 kDa redox‐active protein with antioxidative property, has been recently shown to play a protective role in various inflammatory diseases. Using a mouse model of asthma, we show here that IL‐13 and eotaxin production are decreased in TRX‐Tg mice leading to reduced eosinophils recruitment and mucus metaplasia. The reduction in airway inflammation occurs without the attenuation of systemic Th2 immunity in that comparable levels of Th2‐type cytokines and Ig were detected in LN and serum, respectively, from TRX‐Tg and WT mice. Likewise, CD4⁺ T cells from both strains of mice developed similar Th1 and Th2 responses in vitro. Asthmatic lungs of TRX‐Tg and WT mice contained similar amounts of GATA‐3⁺ and Foxp3⁺ T cells. Finally, production of MIF, an upstream modulator of airway inflammation, was significantly reduced in the lungs of TRX‐Tg mice. Our data suggest that TRX suppresses airway inflammation by inhibiting MIF production thereby limiting the downstream recruitment of eosinophils to the lung independently of modulating systemic Th1/Th2 immunity.     

大鼠发育早期接触变应原对Th1/Th2亚群功能及哮喘发生的影响

目的探讨妊娠期母鼠及其子代接触尘螨点刺液（Derp）对发育后期个体Th1/Th2平衡及哮喘发生的影响。方法Wistar大鼠根据母体妊娠期及新生早期是否接触Derp随机分为对照组、母Derp-仔Derp-组（母鼠和其子代均未接触Derp）、母Derp＋仔Derp＋组（母鼠和其子代均接触Derp）和母Derp＋仔Derp-组（母鼠接触Derp,其子代未接触Derp）,分别皮下注射Derp或生理盐水,30d龄时除对照组外,其余3组以卵白蛋白（OVA）为变应原致敏并雾化吸入,诱发哮喘发生。取血浆检测OVA特异性IgE抗体、收集外周血单个核细胞（PBMC）用ELISA法检测培养上清中细胞因子IL-4和IFN-γ水平,行支气管肺泡灌洗记录支气管肺泡灌洗液（BALF）中嗜酸性粒细胞的计数,留取肺组织行病理学检查。结果母Derp＋仔Derp＋组在哮喘建模后PBMC培养上清中IFN-γ水平显著低于母Derp-仔Derp-组,IL-4水平显著升高,IL-4/IFN-γ比值升高,OVA特异性IgE、BALF中嗜酸性粒细胞计数显著高于母Derp-仔Derp-组;母Derp＋仔Derp-组与母Derp-仔Derp-组IL-4和IFN-γ水平差异均无统计学意义,OVA特异性IgE水平虽有增高,但差异不具统计学意义,BALF中嗜酸性粒细胞计数差异无统计学意义。母Derp＋仔Derp＋组Th2优势显著高于母Derp＋仔Derp-组。结论胎鼠对于Derp跨胎盘的致敏作用可通过母体妊娠期间的免疫来完成,这一过程会根本上导致Th2优势免疫的发生,增加了变态反应性疾病的危险性。