热致死发酵乳杆菌对牛乳β-乳球蛋白过敏小鼠的免疫调节作用

目的:观察热致死的发酵乳杆菌对牛乳β-乳球蛋白(BLG)致敏小鼠Th1/Th2细胞平衡、血清抗体水平及T细胞亚群数量的影响,探讨其缓解过敏反应的作用。方法:用牛乳BLG和弗氏佐剂的混合液腹腔注射诱发BALB/c小鼠致敏,建立动物过敏模型。将实验动物随机分为空白组、致敏组和不同剂量的热致死发酵乳杆菌组。采用ELISA法测定各组小鼠血清总IgE、BLG特异性IgE和总IgG含量。体外分离培养各组小鼠脾细胞,采用ELISA法检测细胞上清液中Th1型细胞因子(IL-12、IFN-γ)和Th2型细胞因子(IL-4)水平,采用流式细胞术检测脾淋巴细胞中CD3+、CD4+和CD8+T百分含量。结果:发酵乳杆菌组小鼠脾细胞培养上清液中IFN-γ/IL-4比值为13.53,显著高于致敏组的3.34(P<0.05);血清总IgE、BLG特异性IgE和总IgG水平显著降低(P<0.05);脾细胞中CD3+和CD4+T细胞比例升高,CD4+/CD8+比值趋近正常组。特别是高剂量的热致死发酵乳杆菌组小鼠脾细胞培养上清液中抑制IL-4分泌的效果显著优于致敏组(P>0.05),且该组小鼠血清的抗体水平和CD4+/CD8+比值与空白组相比无差异(P>0.05)。结论:热致死的发酵乳杆菌干预可改善小鼠的BLG过敏症状,其作用可能与促进Th1占优势的Th1/Th2细胞平衡,阻断IgE、IgG分泌及平衡T细胞亚群数量相关。     

乳杆菌对原代淋巴细胞中Th1/Th2细胞平衡的影响

目的:分析7种乳杆菌对原代淋巴细胞增殖和细胞因子(CK)分泌的作用,进而探讨其对Th1/Th2细胞平衡的影响。方法:用不同种属、不同浓度的活的/热致死的乳杆菌体外作用于小鼠脾淋巴细胞培养60 h后,采用MTT比色法检测淋巴细胞的增殖效果。用ELISA法检测Th1型细胞因子(IL-12、IFN-γ)、Th2型细胞因子(IL-4、IL-10)和调节型细胞因子(TGF-β)的分泌量。结果:活的/热致死的乳杆菌单独作用,就能促进淋巴细胞体外增殖并表现出剂量依赖关系(P<0.05)。当菌的浓度为107集落形成单位(CFU)/mL(即细菌与细胞的比例为10∶1)时,热致死的发酵乳杆菌和嗜酸乳杆菌的免疫活性近似于活菌。而且,这两株热致死菌还可适当提高淋巴细胞分泌IL-12和IFN-γ,抑制IL-4、IL-10和TGF-β的分泌,使其IFN-γ/IL-4的比值(代表Th1/Th2细胞平衡)均显著高于刀豆蛋白A(ConA)对照组(P<0.05)。结论:乳杆菌可通过提高淋巴细胞的IFN-γ/IL-4分泌率来促进Th1优势状态的Th1/Th2细胞平衡,并具有菌株特异性。     

一种以虾原肌球蛋白为致敏原的Th2 反应小鼠模型的建立

目的:采用虾原肌球蛋白为致敏原建立Th2 反应小鼠模型。方法:虾原肌球蛋白腹腔注射小鼠6 周诱导Th2反应,ELISA 测定小鼠血清总IgE、sIgE 和sIgG 水平、脾淋巴细胞分泌Th1 和Th2 细胞因子的含量,采用流式细胞术检测血液中嗜碱性粒细胞的活化。结果:与对照组比较,致敏6 周的小鼠血清总IgE、sIgE 和sIgG(sIgG1、sIgG2a 和sIgG2b)均显著升高;脾淋巴细胞在抗原刺激后分泌Th2 细胞因子(IL-4、IL-5、IL-10 和IL-13)增加,而Th1 细胞因子INF-α则出现明显降低;血液中嗜碱性粒细胞表面标志物CD200R 和CD41 表达增强。结论:成功建立一种以虾原肌球蛋白为致敏原的Th2 反应小鼠模型。     

肾怡对狼疮小鼠免疫器官内Th1/Th2细胞比例的调节作用

目的：探讨复方中药肾怡对MRL/lpr小鼠免疫器官内Th1/Th2细胞比例的调节作用。方法：将MRL/lpr狼疮小鼠随机分成对照组和中药治疗组，从12周观察到28周后于实验终点处死小鼠。通过流式细胞术分别检测胸腺和脾脏中CD4^ CD30^-(Th1)、CD4^ CD30^ (Th2)淋巴细胞所占百分比，进一步对脾细胞进行CD^ T淋巴细胞分选，并于体外利用PHA—P进行刺激后，通过RT—PCR方法检测IL-4(Th2细胞因子)和IFN—γ(Th1细胞因子)的表达丰度，比较二者的比值在对照组和中药治疗组之间的差别。结果：胸腺中几乎检测不到CD4^ CD30^ T淋巴细胞；脾脏中虽可检测到CD4^ CD30^ T淋巴细胞，但在未加入PHA-P的条件下，CD4^ CD30^ T淋巴细胞在对照组和中药治疗组中所占的比例没有显著差异；经PHAP刺激后对照组和治疗组脾细胞中CD4^ CD30^ T淋巴细胞所占百分比均明显增加，但治疗组中CD4^ CD30^ T淋巴细胞所占百分比的增加程度明显低于对照组；将脾细胞中CD4^ T淋巴细胞分选出来后进行RT-PCR检测，结果显示中药治疗组CD^ T淋巴细胞所表达IL-4／IFN—γ(Th2／Th1)比值明显低于对照组。结论：复方中药肾怡能够纠正MRL/lpr狼疮小鼠脾脏中CD^ T淋巴细胞在PHA-P刺激的条件下朝向Th2过度分化的倾向性。     

口服乳酸菌对尘螨致敏小鼠脾细胞的免疫调节作用

目的探讨口服乳酸菌对尘螨致变应性气道炎症小鼠脾细胞免疫调节功能的影响。方法雌性C57BL/6小鼠分为对照组(N组),尘螨组(M组),尘螨+乳酸乳球菌组(L组)和尘螨+植物乳杆菌组(P组)。脾细胞分离培养,检测培养上清IL-4、IL-5、IFN-γ和IL-10水平(ELISA法),脾细胞增殖情况(Brd U法),流式细胞术检测分泌IL-4/IFN-γ的CD3+CD4+细胞比例。结果在基础状态下,L组和P组脾细胞合成释放IL-4、IL-5及IFN-γ水平均明显低于M组,同时IL-10生成显著增加(P<0.05),以L组更明显。螨刺激下,L组脾细胞IL-4、IL-5的释放率要明显低于M组(P<0.05),IL-10的释放率则明显高于其余3组(P<0.05);细胞增殖试验示L组与P组细胞Brd U掺入量明显低于M组(P<0.001),与N组无差异;流式细胞术显示L组和P组,分泌IL-4的CD4+细胞减少的同时(23.1%&23.7%),总CD4+细胞比例反而增高(51.6%&43.9%),以L组为明显。结论口服乳酸菌诱导了小鼠脾细胞CD4+调节性T细胞亚群的增殖,主要通过释放IL-10下调Th1/Th2细胞因子水平,进而抑制了尘螨致变应性气道炎症。     

PcDNA3.0/p27~(kip1)真核表达质粒对小鼠哮喘模型Th1/Th2的影响

目的:探讨细胞周期负性调控蛋白PcDNA3.0/p27kip1重组真核表达质粒转染小鼠哮喘模型对Th1/Th2比例失衡的调节作用。方法:小鼠各10只分为A组(正常对照组)、B组(哮喘模型组)、C组(质粒治疗组)三组。用卵蛋白致敏法构建小鼠哮喘模型,以本实验室构建的PcDNA3.0/p27kip1重组真核表达质粒经静脉转染小鼠哮喘模型,36小时后Western blot检测肺组织中p27蛋白表达量;流式细胞仪分析小鼠脾CD4+、CD8+T细胞比例;ELISA检测小鼠血清IL-4、IL-5、IL-13、IFN-γ水平。结果:B组与A组比较,哮喘发病后肺p27蛋白表达量明显降低;脾CD4+T细胞显著增高而CD8+T细胞显著降低;血清IL-4、IL-5、IL-13水平明显升高而IFN-γ明显降低。C组与B组比较,肺p27蛋白表达量明显增加,脾CD4+T细胞比例显著降低而CD8+T细胞显著升高;血清IL-4、IL-5、IL-13水平明显降低而IFN-γ明显升高。结论:PcDNA3.0/p27kip1静脉给药可在哮喘模型肺组织中表达,并通过基因干预调控细胞周期的方式调节Th1/Th2比例失衡,为哮喘防治提出了新思路。     

细粒棘球蚴早期感染促进小鼠体内IL-22的产生

目的探讨小鼠腹腔细粒棘球蚴感染早期主要产生IL-22的CD4~+T细胞Th1、Th17和Th22细胞以及IL-22R1的表达情况。方法建立小鼠腹腔细粒棘球蚴感染模型,分别在感染后第3、6、9、12天收集外周血、小鼠脾淋巴细胞以及肝脏和肠管组织。ELISA检测外周血IFN-γ和IL-17、IL-22的蛋白表达量;qRT-PCR检测脾淋巴细胞中Th1细胞相关因子(Ifng、Tbx21基因)、Th17细胞相关因子(IL-17、Rorc基因)、Th22细胞相关因子(IL-22、Ahr基因)以及肝脏和肠管组织中IL-22R1的mRNA表达水平;流式细胞术检测脾淋巴细胞中Th1细胞(CD4~+IFN-γ~+)、Th17细胞(CD4~+IFN-γ~-IL-22~+IL-17~+)及Th22细胞(CD4~+IFN-γ~-IL-22~+IL-17~-)的百分比情况。结果与对照组相比,ELISA、qRT-PCR和流式细胞术检测细粒棘球蚴感染后Th1细胞、Th17细胞、Th22细胞增高:qRT-PCR检测细粒棘球蚴感染后肝脏和肠管IL-22R1的表达增高。结论细粒棘球蚴感染小鼠早期,主要产生IL-22的CD4~+T细胞Th1、Th17、Th22细胞比例以及IL-22R1表达增加,可能参与了宿主的免疫防御反应。     

Th17淋巴细胞及相关细胞因子加重哮喘小鼠气道炎症

目的:研究Th17淋巴细胞及其相关的细胞因子在加重哮喘小鼠气道炎症中的作用机制.方法:20只小鼠随机均分为哮喘组和正常对照组.哮喘组用卵白蛋白(OVA)致敏与激发建立小鼠哮喘模型.对照组致敏与激发均以生理盐水代替.HE染色观察小鼠气道及肺组织病理变化;光学显微镜下观察小鼠支气管肺泡灌洗液(BALF)中细胞分类及计数;酶联免疫吸附试验(ELISA)检测小鼠BALF上清中IL-4、IFN-γ及IL-17的含量,流式细胞技术(FCM)检测小鼠外周血Th1、Th2及Th17淋巴细胞占CD4+细胞百分率情况.将外周血各T淋巴细胞亚群与BALF的中性粒细胞数作相关性分析.结果:哮喘组小鼠BALF中细胞数及中性粒细胞、嗜酸性粒细胞、淋巴细胞百分率均显著高于对照组(P＜0.05),BALF上清中IL-4和IL-17的水平显著增高(P＜0.05),而IFN-γ的水平显著降低(P＜0.05),外周血Th2、Th17淋巴细胞占CD4+细胞百分比显著增高(P＜0.05),而Th1淋巴细胞占CD4+细胞百分比显著降低(P＜0.05).相关性分析显示Th1淋巴细胞与BALF的中性粒细胞数呈显著负相关(rThl=-0.446,P＜0.05),Th17淋巴细胞与BALF的中性粒细胞数呈显著正相关(rTh17=0.394,P＜0.05).结论:Th17淋巴细胞可促进中性粒细胞及炎性介质在哮喘小鼠气道内的聚集,加重气道炎症.     

八肽胆囊收缩素对经钥孔戚血蓝蛋白免疫小鼠T淋巴细胞亚群的影响

目的：探讨八肽胆囊收缩素（CCK-8）对经钥孔戚血蓝蛋白（KLH）免疫小鼠T淋巴细胞亚群的影响。方法：雌性BALB/c小鼠KLH免疫同时分别给予不同剂量CCK-8。流式细胞法检测小鼠外周血及脾细胞中CD4+、CD8+T细胞阳性百分率；RT-PCR法检测脾细胞中Th1型细胞因子IFN-γ、Th2型细胞因子IL-4 mRNA表达；ELISA法检测其培养上清中IFN-γ、IL-4水平；HE染色观察小鼠肺组织病理变化。结果：CCK-8下调KLH免疫小鼠外周血及脾细胞中上升的CD4+、CD8+T细胞阳性百分率，降低CD4+/CD8+比值；进一步提高其IFN-γ mRNA表达和培养上清中IFN-γ分泌量，同时下调上升的IL-4 mRNA表达和培养上清中IL-4分泌量；减轻KLH免疫所致小鼠肺部炎症。结论：CCK-8可调节适应性免疫应答，抑制T细胞尤其是CD4+T细胞活性；抑制Th2功能，提高Th1功能，因此可能在变态反应性疾病的发病和防治中具有一定作用。     

白细胞介素23在小鼠乳腺癌中的抗肿瘤作用及其免疫机制

目的: 研究白细胞介素23(IL-23)在小鼠乳腺癌中的抗肿瘤作用及其免疫功能变化.方法: 将逆转录病毒介导转染IL-23基因的小鼠乳腺癌细胞(IL-23/MA-891)、转染逆转录病毒空载体的小鼠乳腺癌细胞(LXSN/ MA-891)及亲代小鼠乳腺癌细胞(MA-891)分别接种于小鼠皮下, 观察小鼠成瘤及肿瘤生长情况; 30 d时取3组小鼠脾脏和肿瘤组织, 用ELISA法检测3组小鼠脾细胞在MA-891诱导下IFN-?、 TNF-á、 IL-12和IL-4的产生情况; 用流式细胞术(FCM)检测肿瘤组织细胞表面分子MHC-Ⅰ、 MHC-Ⅱ、 CD80、 CD86的表达, 检测脾细胞中CD11c阳性细胞的比率, 并对脾细胞中CD4 、 CD8 淋巴细胞进行分选; 用免疫组织化学技术对3组肿瘤组织中CD4 、 CD8 淋巴细胞浸润情况进行检测.结果: IL-23基因转染组小鼠皮下结节生长速度明显慢于接种空载体转染组及未转染组; 接种IL-23/MA-891细胞的小鼠脾细胞可产生较水平的IFN-γ、 TNF-á和IL-12等Th1类及相关细胞因子, 与接种LXSN/MA-891细胞和MA-891细胞2组小鼠的脾细胞相比明显增高(P<0.01), 而Th2类细胞因子IL-4的水平却无统计学意义(P>0.05); 接种IL-23/MA-891细胞组小鼠脾细胞中CD11c阳性细胞率、 CD4 、 CD8 淋巴细胞比率以及肿瘤组织中CD4 、 CD8 淋巴细胞浸润程度均较LXSN/MA-891、 MA-891组明显增加(P<0.01); IL-23/MA-891细胞组小鼠肿瘤组织细胞表面MHC-Ⅰ、 MHC-Ⅱ、 CD80、 CD86分子的表达明显提高(P<0.01).结论: 转染IL-23基因的小鼠乳腺癌细胞所分泌的IL-23具有生物学活性, 增强了细胞免疫功能, 在小鼠体内发挥了明显的抗肿瘤作用.     

Maternal abstention from cow milk and egg in allergy risk pregnancies

To study the possibility of intrauterine sensitization, 212 women were enrolled on a voluntary basis into a prospective, randomized study, comparing the effects of an elimination diet and normal food during late pregnancy. The diet group took no cow milk and no egg from week 28 to delivery, and extra calcium and casein hydrolysate (Nutramigen) supplement was given to fill the nutritional needs of mother and child. The control group took normal food, including approximately 1/2 liter of milk/day and 3-5 eggs/week. All families had a history of allergy in mother, father, or sibling. Maternal weight gain during pregnancy was significantly lower in the diet group. Birth weights showed no significant difference between the two main groups, but smokers in the elimination diet group had significantly smaller babies. IgE antibodies to cow milk and egg were significantly higher in atopic than in non-atopic women before the trial. The diet caused a significant fall in IgG-antibodies to cow milk and egg in both atopic and non-atopic subjects. Cord blood IgE determination revealed no significant difference between the groups. No IgE antibodies to cow milk or egg were detected in any of the cord sera. The participating babies are being followed up until 18 months of age.     

Clinical research of specific IgE and IgG4 antibody in allergic children. Correlation specific IgE antibody to specific IgG4 antibody to food allergen

We analysed the correlation specific IgE antibodies to specific IgG4 antibodies to food allergens in 150 asthmatic children by Multiple Factor Analysis-Type II and examined the role of both antibodies. The following results were obtained. 1) Of soybean, there was the stronger influence power between specific IgE and IgG4 antibody than the other 2 food allergens. 2) IgE antibody to soybean had the strong influence power to IgG4 antibodies to egg white and cow's milk and IgG4 antibody to soybean had same influence power to IgE antibodies to egg white and cow's milk. So, the specific IgE and IgG4 antibodies to soybean may be play the role of "the bride" between specific IgE antibody group and specific IgG4 antibody group of food allergens.     

Prolonged type of food allergy]

OBJECT: Prevalence of food allergy is the most frequent during infancy, and it is gradually decreasing with age. We can not distinguish patients developing tolerance from those with persistent food allergy, therefore we are unable to advice patients accelerating the development of tolerance. To clarify the factors developing tolerance or intolerance, we conducted the following study. METHOD: Patients who were diagnosed as food allergy to hen's egg, or cow's milk or wheat in infancy by the definitive history of positive food allergic reactions or food provocation tests were recruited to this study. Patients were divided into two groups; one (prolonged group, n=27) is those who needed to eliminate some of the main offending foods even at the age of 6 years old and the other (tolerized group, n=37) is those who had released all main offending foods by the age of 6 years old. RESULT: The factors which distinguished the prolonged group from the tolerized group were the positive clinical history of the atopic dermatitis and its prolonged clinical course, past history of anaphylactic shock, and maximum number of offending foods in the past clinical history. The specific IgE against main antigens such as egg white, cow's milk and wheat in the tolerized group was lower compared to that in the prolonged group, whereas no significant difference was found in non specific IgE value, peripheral eosinophil counts, and specific IgE against other antigens. CONCLUSION: We could find the clinical factors discriminating food allergy patients against three major food allergen among children developing tolerance by the age of 6 years old form those without tolerance.     

Total serum IgE level influences oral food challenge tests for IgE‐mediated food allergies

Probability curves predicting oral food challenge test (OFC) results based on specific IgE levels are widely used to prevent serious allergic reactions. Although several confounding factors are known to affect probability curves, the main factors that affect OFC outcomes are currently unclear. We hypothesized that an increased total IgE level would reduce allergic reactivity. Medical records of 337 and 266 patients who underwent OFCs for 3.5 g boiled hen's egg white and 3.1 ml raw cow's milk, respectively, were examined retrospectively. We subdivided the patients into three groups based on total IgE levels and age by percentile (<25th, 25–75th, and >75th percentiles), and logistic regression analyses were performed on each group. Patients with higher total IgE levels were significantly less responsive. In addition, age did not significantly affect the OFC results. Therefore, total IgE levels should be taken into account when predicting OFC results based on food‐specific IgE levels.     

Cow's milk stimulated lymphocyte proliferation and TNFalpha secretion in hypersensitivity to cow's milk protein

Although there is no reliable single laboratory test available for the diagnosis of cow's milk allergy, if an allergic mechanism is suspected, a number of laboratory studies may be useful in delineating specific proteins responsible for these disorders. In the current study we analyzed in vitro lymphocyte proliferation assays, specific secretion of TNFalpha in supernatant cultures and specific IgE, IgG, and IgA in a group of patients with hypersensitivity to cow's milk antigens. The stimulation index against a cow's milk antigen mixture, alpha-lactalbumin, beta-lactoglobulin, and casein was significant higher in the group of patients maintained on cow's milk-free diet for less than 4 months compared with the values observed in the control group and in the group of patients without a close contact to cow's milk proteins. A significant increase in TNF-alpha secretion was observed in supernatants from patients with close contact to cow's milk (CM). Specific IgE was detected in 59.3% of the patients, with higher specific IgE levels in patients who were not positive for the proliferation assay, suggesting a clear difference in the two mechanisms proposed as effectors in this disease. No differences in specific IgG and IgA levels were observed between the patient group and the control group, with a great dispersion among individuals in all groups tested. We conclude that a combination of the assays tested in this study, such as proliferative assay of peripheral blood mononuclear cells to CM, the quantitation of TNFalpha in culture supernatants, and serum specific IgE determination, are useful laboratory tests to identify cow's milk allergy among patients with immediate and non immediate adverse reactions, reducing the need for food allergen challenges in young children.     

Adoptive transfer of dendritic cells from allergic mice induces specific immunoglobulin E antibody in naïve recipients in absence of antigen challenge without altering the T helper 1/T helper 2 balance

Dendritic cells (DCs) are important in the regulation of immune responses and it has been proposed that these cells play an important role in asthma; however, their role in food allergy is still largely unknown. Our aim was to study specific immunoglobulin E (IgE) and immunoglobulin G (IgG) responses in naïve recipients following adoptive transfer of myeloid DCs from allergic and control mice. The phenotypic features and lymphokine production of DCs were also investigated. CD11c ^{+ /hi} B220^? DCs isolated from spleen and Peyer's patches (PP) of cow's milk (CM) allergic and control mice were transferred intravenously (i.v.) into naïve syngeneic recipients, and IgE‐ and IgG‐specific responses were evaluated. Experiments were also carried out to determine the levels of interferon‐γ (IFN‐γ) and interleukin (IL)‐4 produced by splenocytes from naïve recipients following the adoptive transfer, and CD40 ligand (CD40L)‐mediated IL‐10 production by DCs from allergic and control mice. DCs isolated from spleen and PP of allergic mice, but not control groups, induced CM‐specific IgG and IgE antibody production in naïve recipients in the absence of previous immunization, but did not modify the T helper 1 (Th1) and T helper 2 (Th2) balance. Furthermore, although no difference was observed in the expression of canonical DC surface markers, PP DCs from allergic mice produced less IL‐10 than DCs from controls. We interpret these data as showing that DCs play a pivotal role in allergen‐specific IgE responses and that a Th2‐skewed response may not be involved in the early phase of allergic responses. The identification of the mechanisms underlying these events may help to design novel strategies of therapeutic intervention in food allergy.     

Clinical symptoms and IgE responses to common food proteins in atopic and healthy children

The appearance of symptoms suggestive of allergy through the first 4 years of life was studied prospectively in eighty-six healthy newborn babies. Blood samples were obtained at birth, at 3,8,25 and 48 months of age and analyzed for levels of total serum IgE and for IgE antibodies to some common foods. The occurrence of IgE antibodies was related to atopic manifestations and to a detailed history of infant feeding and family history of allergy. All infants with elevated cord blood IgE (more than 1.3 kU/1) developed manifestations of atopy. Specific IgE antibodies against egg, cow's milk and soy were demonstrated at 3, 8, 25 and 48 months in nine, twenty-three, six and two children respectively. Egg was a more potent sensitizing agent than cow's milk, IgE antibodies to egg being present in thirty-one samples, to cow's milk in eleven and to soy in five samples. Nine infants developed IgE antibodies to eggs or cow's milk before the introduction of these nutrients into the food. The IgE antibody levels were generally low in healthy non-atopic children and did, with one exception, not reach RAST class 1. In contrast, the levels of IgE antibodies to egg or cow's milk were higher in eleven blood samples from atopic children. We conclude that transient low IgE antibody responses to food proteins appear relatively often even in healthy infants. High concentrations of IgE antibodies however are almost exclusively seen in infants with atopic disease. Sensitization may appear early in infancy sometimes even before the offending food has been introduced into the diet.     

Oral administration of recombinant Lactococcus lactis expressing bovine β-lactoglobulin partially prevents mice from sensitization

BACKGROUND: The use of probiotics such as Lactococcus lactis and other lactic acid bacteria (LAB) has been proposed for the management of food allergy. However, no experimental study has clearly demonstrated any preventive or therapeutic inhibition of an allergen-specific IgE response. OBJECTIVE: We aimed to study the immunomodulatory effect of recombinant L. lactis expressing bovine beta-lactoglobulin (BLG), a major cow's milk allergen, in a validated mouse model of allergy. METHODS: Six-week-old female Balb/c mice received five repeated doses of BLG, of L. lactis plus BLG, or of recombinant L. lactis by gavage. Different recombinant strains were inoculated, which corresponded to BLG doses ranging from 4 to 70 microg/mice. Mice were then sensitized by intra-peritoneal injection of BLG emulsified in incomplete Freund's adjuvant to induce high IgE concentrations. RESULTS: Pre-treatment with natural L. lactis plus BLG allowed induction of BLG-specific T-helper type 1 (Th1) response, and abrogated the oral tolerance induced by BLG alone, demonstrating the adjuvant effect of this non-colonizing LAB. Moreover, pre-treatment with some of the recombinant strains favoured the development of a Th1 response inhibiting the Th2 one: it induced a significant decrease of specific IgE response, and an intense increase of specific IgG2a and IFN-gamma productions. The most efficient strains that inhibited the IgE response were those producing the highest amounts of the BLG protein. CONCLUSION: Oral administration of some recombinant L. lactis was demonstrated to induce a specific Th1 response down-regulating a further Th2 one. Prophylaxis protocols will thus be evaluated using the most efficient strains.     

Intolerance to hydrolysed cow's milk proteins in infants: clinical characteristics and dietary treatment.

BACKGROUND: Multiple food intolerance in infants, including intolerance to extensively hydrolysed proteins (HP), is often difficult to treat. However, few data have been reported on clinical outcome and dietary treatment of these patients. AIMS: To evaluate the clinical characteristics of patients with HP-intolerance and the long-term outcome of treatment with ass' milk. PATIENTS AND METHODS: This study included 21 HP-intolerant infants (15 males, median age at diagnosis 2 months) treated with an ass' milk-based diet and 70 cow's milk (CM) intolerant infants (40 males, median age at diagnosis 3 months) treated with casein hydrolysate milk-based diet. All patients were followed-up for a median period of 4 years. Both HP-intolerance and intolerance to other foods were diagnosed according to the double-blind placebo-controlled procedure. Formal CM-challenges were conducted at yearly intervals until tolerance was demonstrated. At diagnosis and after one year of the respective diets, the following growth parameters were determined: relative weight for sex and age, relative weight for height and height z-score. RESULTS: During the study period, multiple food intolerance was documented in 21/21 HP-intolerant infants (ass' milk group) and in 20/70 infants with CM-intolerance but tolerating HP (casein hydrolysate group) (P < 0.0001). In the ass' milk group, the more frequent food intolerances were toward soya, oranges, tomatoes and fish; goat's milk intolerance was demonstrated in five out of six patients receiving this food, and sheep's milk derivatives intolerance in four out of seven; these patients tolerated ass' milk. During the study period 3/21 patients in the ass' milk group became ass' milk intolerant; they showed vomiting (one cases) or diarrhoea (two cases). A lower percentage (52%) of patients in the ass' milk group became CM-tolerant during the study period than in the casein hydrolysate group (78%) (P < 0.01) and the age of the children at CM-tolerance was higher in the ass' milk than in the casein hydrolysate-treated children (P < 0.05). At diagnosis, a higher frequency of cases with elevated serum total IgE and specific IgE to CM antigens (P < 0.01) was observed in the ass' milk group. No difference was recorded between the two treatment groups in any of the growth parameters considered either at diagnosis or during the follow-up. CONCLUSIONS: HP-intolerant patients showed a higher frequency of persistent food intolerance and of multiple food intolerance than patients tolerating casein hydrolysate. Ass' milk feeding was confirmed as a safe and valid treatment of the most complicated cases of multiple food intolerance.