Dietary nucleic acids promote a shift in Th1/Th2 balance toward Th1-dominant immunity

BACKGROUND: Dietary sources of nucleic acids and their relative components are known to affect host immune function; however, it has not yet been clarified whether such dietary nucleic acids influence the pathogenesis of allergic reaction. OBJECTIVE: The purpose of this study is to elucidate the effect of dietary nucleic acids on Th1/Th2 balance. METHODS: Both human flora-associated and specific pathogen-free BALB/c mice were maintained on either nucleic acid-free, or -supplemented diets. The effects of nucleic acids on both in vivo antibody levels and in vitro splenocyte cytokine production were compared using these mice. RESULTS: Supplementation of nucleic acids caused a reduction in the serum antibody levels of total IgM, IgG, IgG1, and IgE in the human flora-associated mice without affecting the composition of intestinal flora. In contrast, there was no significant difference of the serum IgG2a levels between nucleic acid-free and -supplemented mice. Such a phenomenon as that, the supplementation of dietary nucleic acids reduces the serum IgE or IgG1 levels, but not the IgG2a level, was also seen in the specific pathogen free mice. Moreover, when the mice were systematically challenged with ovalbumin, the supplementation of nucleic acids also suppressed the serum ovalbumin-specific IgE and IgG1 antibody levels as well as in vitro IL-4 and IL-10 secretion, while enhancing both the serum ovalbumin-specific IgG2a antibody levels and in vitro IFN gamma secretion. CONCLUSION: These results suggested that dietary nucleic acids may play an important role in promoting a shift in Th1/Th2 balance toward Th1-dominant immunity.     

Antibiotic use during infancy promotes a shift in the T(H)1/T(H)2 balance toward T(H)2-dominant immunity in mice

BACKGROUND: Recent epidemiologic studies indicate that antibiotic use in infancy may be associated with an increased risk of development of atopy; however, its precise mechanism remains to be elucidated. OBJECTIVE: The purpose of this study is to clarify whether one such antibiotic, kanamycin, affects the T(H)1/T(H)2 balance. METHODS: BALB/c mice at 3 and 52 weeks of age were orally administered 600 mg/d kanamycin sulfate for 7 consecutive days. Blood samples were collected on weeks 0, 10, 18, and 26 after the cessation of kanamycin treatment, and the effect of the kanamycin treatment on the T(H)1/T(H)2 balance was evaluated on the basis of both the in vivo antibody levels and the in vitro splenocyte cytokine secretion pattern. RESULTS: The administration of kanamycin increased the serum levels of total IgG1 and IgE while decreasing the serum IgG2a levels. Moreover, when spleen cells were stimulated with immobilized anti-CD3 antibody in vitro, such kanamycin treatment enhanced the in vitro IL-4 secretion while reducing the in vitro IFN-gamma secretion. The basal IL-12 p70 secretion levels of splenic dendritic cells in the kanamycin-treated mice were lower than those in the control mice, although no significant difference was seen in IL-12 p40 levels between either group of mice. CONCLUSION: These results suggested that antibiotic use during infancy may indeed quantitatively disturb, qualitatively disturb, or both the intestinal microflora and thereby prevent postnatal T(H)1 cell maturation, thus resulting in a T(H)2-polarized immune deviation.     

Sublingual administration of Lactobacillus paracasei KW3110 inhibits Th2-dependent allergic responses via upregulation of PD-L2 on dendritic cells

Lactic acid bacteria have potential in immunomodulation therapy, but their clinical efficacy and underlying mechanisms are unclear. We aimed to clarify the anti-allergic immune responses induced by intragastric and sublingual administration of heat-killed Lactobacillus paracasei KW3110 and Lactobacillus acidophilus L-92. The KW3110 strain (but not the L-92 strain) enhanced ovalbumin (OVA)-induced expression of CCR-7 and PD-L2 in murine dendritic cells (DCs), and strongly inhibited IL-5 and IL-13 production in vitro in co-cultures with Th2-skewed CD4(+) T cells from DO11.10 transgenic mice. Sublingual administration of low-dose KW3110 (but not L-92) to OVA-sensitized mice selectively suppressed serum IgE production and Th2 cytokine expression in cervical lymph nodes, and significantly improved symptoms after OVA provocation in vivo. KW3110 probably accelerates DC migration into the regional lymph nodes and inhibits Th2 cytokine production through enhanced CCR-7 and PD-L2 expression. Thus, sublingual KW3110 administration may be effective in reducing allergic inflammation.     

Commensal Gram-negative bacteria prime human dendritic cells for enhanced IL-23 and IL-27 expression and enhanced Th1 development

Dendritic cells (DC) are the main orchestrators of specific immune responses. Depending on microbial information they encounter in peripheral tissues, they promote the development of Th1, Th2 or unpolarized Th cell responses. In this study we have investigated the immunomodulatory effect of non-pathogenic intestinal Gram-negative (Escherichia coli, Bacteroides vulgatus,Veillonella parvula, Pseudomonas aeruginosa) and Gram-positive (Bifidobacterium adolescentis, Enterococcus faecalis, Lactobacillus plantarum and Staphylococcus aureus) bacteria on human monocyte-derived DC (moDC). None of the Gram-positive bacteria (GpB) primed for Th1 or Th2 development. In contrast, despite the low levels of IL-12 they induce, all Gram-negative bacteria (GnB) primed moDC for enhanced Th1 cell development, which was dependent on IL-12 and an additional unidentified cofactor. Strikingly, GnB-matured moDC expressed elevated levels of p19 and p28 mRNA, the critical subunits of IL-23 and IL-27, respectively, suggesting that the IL-12 family members may jointly be responsible for their Th1-driving capacity. Purified major cell wall components of either GnB or GpB did not yield Th cell profiles identical to those obtained with whole bacteria, and could not explain the induction of the IL-12 family members nor Th1 priming by GnB. Importantly, this study gives indications that the expression of the different IL-12 family members is dictated by different priming conditions of immature DC.     

Vaccination strategies in young children at risk for allergy

T-cell responses against foreign antigens/allergens are common findings very early in infancy and these responses are generally Th2-skewed. Normally, these responses deviate into low level Th1-type of immunity over the first years of life. In atopic children, however, the Th2-skewing persist, resulting in persistent IgE responses against allergens and the development of allergic diseases. In healthy children, tolerance induction by environmental and immunological factors seems to be related to an immune deviation towards a Th1-type of immune response. Hypothetically, immune deviation could be achieved in atopic children by vaccination with inhalant allergen and will conceivably prevent sensitization and development of respiratory allergy. This hypothesis is currently being tested in Sweden and Germany.     

Enterococcus faecalis induces inflammatory bowel disease in interleukin-10 knockout mice

Germ-free interleukin-10 knockout (IL-10 KO) mice developed inflammatory bowel disease (IBD) after they were colonized with a pure culture of Enterococcus faecalis. E. faecalis not only induced IBD (primarily in colon and rectum) but rectal dysplasia and adenocarcinoma was also found in the IL-10 KO mice. Conventional (complex-intestinal flora) IL-10 KO mice developed IBD within 10 to 15 weeks of age and showed more pathology in the cecum (typhlitis) than we observed with E. faecalis-induced IBD in gnotobiotic IL-10 KO mice. Conversely, neither germ-free IL-10 mice nor IL-10 KO mice colonized as adults, with a pure culture of Candida albicans, Escherichia coli, Lactobacillus casei, L. reuteri, L. acidophilus, a Bifidobacterium sp., Lactococcus lactis, or a Bacillus sp. developed IBD during the 25- to 30-week study. E. faecalis is a common intestinal microbe of man and animals that can trigger IBD, dysplasia, and carcinoma in a genetically susceptible murine host.     

Bisphenol A promotes IL-4 production by Th2 cells

BACKGROUND: It has been proposed that estrogen plays an important role in modulating the Th1/Th2 cytokine balance. From this viewpoint, chemicals with estrogenic responses were expected to possess similar immunoregulatory roles which have not been defined to date. To address this, we studied the effects of one of the estrogenic chemicals, bisphenol A (BPA), on the in vitro production of Th1 and Th2 cytokines. METHODS: Mesenteric lymph node cells from Trichinella spiralis (Ts)-infected mice were incubated with serialfold dilutions of BPA under stimulation with Ts antigen. The Th2 cytokine production in the supernatant was determined by ELISA. The Th2 cytokine production by mesenteric lymph node cells from Ts-infected mice inoculated orally with BPA was compared with that of uninoculated mice infected with Ts. RESULTS: The antigen-stimulated interleukin (IL)-4 production by Th2-dominant mesenteric lymph node cells from Ts-infected mice increased significantly by addition of 3 microM of BPA. The IL-5 production was not affected. The production of IL-4, but not that of IL-5, by splenocytes of Th2-skewed Leishmania major-infected BALB/c mice increased at concentrations of 3 and 10 microM of BPA. However, the interferon gamma production was not affected by BPA in Th1-skewed L. major-infected C57BL/6 mice. The production of IL-4 and IL-10, but not that of IL-13, markedly increased in Ts-infected mice inoculated orally with BPA. CONCLUSIONS: We demonstrated that the IL-4 production was increased both in vitro and in vivo by treatment with BPA. This suggests that BPA might cause allergic diseases by stimulating the IL-4 production by Th2 cells.     

Serum Proteins of Gnotobiotic Rats

Cellulose-acetate and agar gel immunoelectrophoresis were used to study the serum protein patterns of germfree rats before and after monoassociation with a pure culture of Staphylococcus aureus (phage type 80/81), Streptococcus faecalis, Lactobacillus acidophilus, Bacteroides fragilis, Pseudomonas aeruginosa, or Proteus vulgaris. All six bacteria quickly established themselves in the gastrointestinal tract of the germfree rat, and all six increased the animals' total serum proteins. Only S. aureus and P. aeruginosa caused a noticeable rise in gamma globulins. L. acidophilus, S. faecalis, and B. fragilis multiplied readily in the gastrointestinal tract but caused only minimal alterations in the serum proteins. P. vulgaris caused a marked increase in the alpha and beta, but not the gamma globulins.     

卵清蛋白雾化吸入诱导肠道菌群失调小鼠肺部过敏反应的发生

目的:在抗生素所致肠道菌群失调小鼠模型上采用卵清蛋白(OVA)雾化吸入激发,探讨气道变应性反应与肠道菌群失调的关系.方法:112只BALB/c小鼠分为6组:菌群失调Ⅰ组、对照Ⅰ组、菌群失调Ⅱ组、菌群失调加激发组、激发组、对照Ⅱ组.前2组和后4组分别于第6天和第14天时取盲肠内容物做细菌培养计数,后4组同时行支气管肺泡灌洗液(BALF)细胞分类计数、BALF和血清中OVA特异性IgE(OVA-sIgE)检测以及肺部病理观察;采用流式细胞术检测肺组织中Th1以及Th2细胞水平.结果:应用抗生素的小鼠出现肠道菌群失调,菌群失调加激发组小鼠肺部出现以嗜酸粒细胞和淋巴细胞为主的炎症细胞浸润,肺部黏液分泌明显增高,BALF中细胞总数、淋巴细胞、嗜酸粒细胞和中性粒细胞增加,OVA-sIgE水平显著增高,肺部Th2细胞水平增高,Th1细胞与对照组无差异.结论:抗生素致肠道菌群失调小鼠经过OVA雾化吸入后,可产生Th2细胞优势的变应性气道反应,提示抗生素所致肠道菌群失调是诱发哮喘等变应性疾病的危险因素之一.     

Dietary nucleic acid and intestinal microbiota synergistically promote a shift in the Th1/Th2 balance toward Th1-skewed immunity

BACKGROUND: Intestinal microbiota are known to play an important role in the establishment of oral tolerance, thereby protecting the organism from food allergies. Dietary intake of nucleic acid (NA) is also reported to have such an anti-allergic effect; however, one unsolved question is whether or not dietary NA would act through a process of toll-like receptor 9 signaling activated by DNA containing a CpG motif, a well-known sequence leading to immunostimulatory activity. In this study, we focused on the question of whether the addition of dietary NA lacking CpG motifs would allow continued modulation of the Th1/Th2 balance. METHODS: Germ free (GF) and Bifidobacterium-infantis-monoassociated BALB/c mice were maintained on either an NA-free casein diet or on an NA-supplemented casein diet for 4 weeks. Thereafter, both the in vivo anti-casein antibody levels and in vitro splenocyte cytokine secretion pattern were evaluated. RESULTS: Feeding with a casein diet elicited a substantial increase in the serum anti-casein-specific IgG1, IgG2a, and IgE levels of GF mice fed the NA free-diet. The in vitro cytokine production profile showed that enhanced IL-4 production in the GF mice fed the NA free-diet was markedly reduced by the supplementation with dietary NA in both the GF and B.-infantis-monoassociated mice. In addition, IFN-gamma secretion increased in the B.-infantis-reconstituted mice fed the diet containing NA. CONCLUSIONS: These results suggest that dietary intake of NA devoid of CpG motifs may prevent the development of allergies via acceleration of Th1-dominant immunity.     

Effects of TNCB sensitization in DS-Nh mice, serving as a model of atopic dermatitis, in comparison with NC/Nga mice

BACKGROUND: It has been predicted that a type-1 and type-2 helper T cell (Th1/Th2) imbalance exists in atopic dermatitis (AD). In DS-Nh mice, an AD mouse model, Staphylococcus aureus increases on the skin surface. OBJECTIVE: To investigate whether the Th1-dominant response has an influence on the development of AD, we induced chronic allergic hypersensitivity with 2,4,6-trinitrochlorobenzene (TNCB ) in two AD mouse models: NC/Nga mice and DS-Nh mice. Th1 and Th2 cytokine production of splenocytes was assessed under stimulation with staphylococcal enterotoxin B (SEB) which induces a Th1 response in DS-Nh mice with or without TNCB sensitization. METHODS: We examined clinical skin changes, transepidermal water loss (TEWL), the number of S. aureus on the skin and the serum IgE levels in these mice treated repeatedly with TNCB under conventional conditions (free of fur mites). The splenocytes of DS-Nh mice were cultured with SEB and the cytokine levels in the supernatants were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Significant skin changes were observed on the skin even where TNCB was not applied in both mice treated with TNCB. Increases in S. aureus on the skin and serum IgE levels were detected in DS-Nh mice, but not in NC/Nga mice. In DS-Nh mice, IFN-gamma and IL-13 production of splenocytes increased in the mice treated with TNCB. CONCLUSION: These results suggest that there might be a different mechanism of dermatitis induction between NC/Nga and DS-Nh mice. Th1 responses might play an important role in the development of dermatitis and increase in serum IgE levels in DS-Nh mice through an increase in IL-13 production.     

Safety evaluation of Lactobacillus delbrueckii subsp. lactis UO 004, a probiotic bacterium

Lactobacillus delbrueckii subsp. lactis UO 004 was evaluated for its use as a potential probiotic from a safety point of view. The strain did not exhibit mucinolytic or other enzymatic activities that might be detrimental, such as those involving glycosidases (beta-D-glucosaminidase or alpha-D-galactosidase) or arylamidases (factor Xa and quimotrypsin-like activities), frequently present in Lactobacillus strains isolated from patients with endocarditis, although it was able to express protein Ca and kallikrein-like activities. On the other hand, the presence of the strain did not interfere with the growth of certain species of normal intestinal microbiota, such as Enterococcus fecalis, Escherichia coli, Bifidobacterium bifidum or Bacteroides fragilis. Moreover, the potential probiotic strain UO 004 is sensitive to antibiotics with transmissible resistance mechanisms in Lactobacillus such as chloramphenicol, erythromycin, tetracycline and vancomycin. In addition, strain L. delbrueckii UO 004 was not able to translocate towards the intestinal barrier of mice or produce changes in their activity or general health status.     

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。     

Maternal and postnatal dietary probiotic supplementation enhances splenic regulatory T helper cell population and reduces ovalbumin allergen-induced hypersensitivity responses in mice

Neonatal to early childhood is the critical period for establishing a balance of T helper 1 (Th1) versus T helper 2 (Th2) cellular immunity within the gut, which is strongly influenced by the source and establishment of gut microflora. Probiotic administration has been shown to attenuate Th2-biased cellular immunity and predisposition to food allergies. To test this hypothesis we provided ad libitum a probiotic-supplemented (Primalac 454 Feed Grade Microbials) or control diet to lactating dams with suckling pups and weaned pups until 10 weeks of age. Weaned mice were sensitized/challenged with egg allergen ovalbumin, saline or adjuvant at 6, 8 and 10 weeks of age. At 3, 6, 8 and 10 weeks, fecal samples were collected for microbial analysis, while blood samples were analyzed for ovalbumin-IgE and total plasma IgE levels. At termination, splenic T helper cell lymphocyte population subtypes were determined using FACS analysis and Th1/Th2/Th17 gene expression by PCR array. At 21 days of age, pups suckled by lactating dams fed the probiotic supplemented diet had significantly enhanced Lactobacillus acidophilus fecal counts compared to controls. Moreover, mice fed the probiotic supplemented diet had enhanced splenic naturally occurring and induced regulatory T cell populations, enhanced TGFβ gene expression and reduced expression of allergic mediator IL13 compared to controls. These results provide evidence that early probiotic supplementation may provide host protection from hypersensitivity reactions to food allergens by attenuating food allergen inflammatory responses.     

Colitogenic and non-colitogenic commensal bacteria differentially trigger DC maturation and Th cell polarization: an important role for IL-6

We investigated whether commensal bacteria modulate activation and maturation of bone marrow-derived DC and their ability to prime CD4(+) T cells. We used Escherichia coli mpk, which induces colitis in gnotobiotic IL-2-deficient (IL-2(-/-)) mice, and Bacteroides vulgatus mpk, which prevents E. coli-induced colitis. Stimulation of DC with E. coli induced TNF-alpha, IL-12 and IL-6 secretion and expression of activation markers. Moreover, stimulation of DC with E. coli increased T cell activation and led to Th1 polarization. Stimulation with B. vulgatus led only to secretion of IL-6, and DC were driven into a semi-mature state with low expression of activation markers and did not promote Th1 responses. B. vulgatus-induced semi-mature DC were non-responsive to stimulation by E. coli in terms of maturation, T cell priming and TNF-alpha but not IL-6 production. The non-responsiveness of B. vulgatus-stimulated DC was abrogated by addition of anti-IL-6 mAb or mimicked with rIL-6. These data suggest that B. vulgatus-induced IL-6 drives DC into a semi-mature state in which they are non-responsive to proinflammatory activation by E. coli. This in vitro mechanism might contribute to the prevention of E. coli-triggered colitis development by B. vulgatus in vivo; high IL-6 mRNA expression was consistently found in B. vulgatus-colonized or B. vulgatus/E. coli co-colonized IL-2(-/-) mice and was associated with absence of colitis.     

T helper cell IL-4 drives intestinal Th2 priming to oral peanut antigen,under the control of OX40L and independent of innate-like lymphocytes

Intestinal T helper type 2 (Th2) immunity in food allergy results in IgG1 and IgE production, and antigen re-exposure elicits responses such as anaphylaxis and eosinophilic inflammation. Although interleukin-4 (IL-4) is critically required for allergic sensitization, the source and control of IL-4 during the initiation of Th2 immunity in vivo remains unclear. Non-intestinal and non-food allergy systems have suggested that natural killer-like T (NKT) or γδ T-cell innate lymphocytes can supply the IL-4 required to induce Th2 polarization. Group 2 innate lymphoid cells (ILCs) are a novel IL-4-competent population, but their contribution to initiating adaptive Th2 immunity is unclear. There are also reports of IL-4-independent Th2 responses. Here, we show that IL-4-dependent peanut allergic Th2 responses are completely intact in NKT-deficient, γδ T-deficient or ILC-deficient mice, including antigen-specific IgG1/IgE production, anaphylaxis, and cytokine production. Instead, IL-4 solely from CD4⁺ Th cells induces full Th2 immunity. Further, CD4⁺ Th cell production of IL-4 in vivo is dependent on OX40L, a costimulatory molecule on dendritic cells (DCs) required for intestinal allergic priming. However, both Th2 cells and ILCs orchestrated IL-13-dependent eosinophilic inflammation. Thus, intestinal Th2 priming is initiated by an autocrine/paracrine acting CD4⁺ Th cell-intrinsic IL-4 program that is controlled by DC OX40L, and not by NKT, γδ T, or ILC cells.     

Differential inflammatory mediator response in vitro from murine macrophages to lactobacilli and pathogenic intestinal bacteria

Chronic active colitis (including inflammatory bowel disease - IBD) is maintained by a variety of pro-inflammatory mediators. Certain intestinal bacterial strains may induce colitis, whereas some strains (e.g. Lactobacillus spp.) show a protective effect in colitis owing to their anti-inflammatory activity. In this study, we have examined the production of selected inflammatory cytokines, reactive oxygen species (ROS), nitric oxide (NO) and the expression of haeme oxygenase-1 (HO-1) by murine peritoneal macrophages stimulated in vitro by the intestinal bacterial strains, isolated from mice with colitis. Lactobacillus strains (Lactobacillus reuteri, L. johnsonii, L. animalis/murinus) and two potentially pathogenic bacteria (Escherichia coli and Enterococcus faecalis) induced the production of substantial amounts of cytokines with a strain specific profile. Despite some interstrain differences, all lactobacilli induced production of anti-inflammatory cytokines (IL-10(high), IL-6(low), IL-12p70(low)). Conversely, E. faecalis and E. coli induced the production of proinflammatory cytokines (TNF-alpha, IL-12p70), the cytokines essential for chronic IBD. Macrophages released comparably substantial amounts of ROS in response to all Lactobacillus strains tested, while E. coli and E. faecalis ability to induce generation of ROS was negligible. In contrast to ROS, the production of NO/NO(2) (-) by macrophages activated with all bacterial strains tested was similar. Moreover, for the first time, it has been shown that intestinal bacteria differed in their ability to induce expression of HO-1, a stress-inducible enzyme with antioxidant and anti-inflammatory properties. The beneficial immunoregulatory properties of candidate probiotic bacteria for the treatment of IBD are discussed.     

Commensal intestinal bacterial strains trigger ankylosing enthesopathy of the ankle in inbred B10.BR (H-2(k)) male mice

Joint disease ankylosing enthesopathy (ANKENT) naturally occurs in inbred mice with C57Bl/10 genetic background. ANKENT has many parallels to human ankylosing spondylitis (AS) and represents an animal model for AS. Environmental conditions (i.e., microbial load of the organism) are among the risk factors for ANKENT, similar to AS. The role of microflora in the development of ANKENT was investigated. ANKENT was tested in four experimental groups of germ-free mice associated with different numbers of various intestinal microbes and three control groups: germ-free, specific pathogen-free, and conventional (CV) mice. Mice were colonized either with anaerobic bacteria isolated from the intestine of a CV mouse or with bacterial strains obtained from the collection of microorganisms. Microbes were characterized and checked by microbiological cultivation methods and with the use of polymerase chain reaction amplification and rDNA sequence analysis. Joint disease developed in GF mice colonized with a mixture containing Bacteroides spp. and Enterococcus sp., and/or Veillonella sp. and Staphylococcus sp. No ANKENT appeared in males colonized with probiotic bacterium Lactobacillus sp. In control groups ANKENT occurred in SPF and CV animals; the GF animals remained healthy. The results confirmed that the germ-free conditions protect from joint inflammation, and thus microbes are necessary for ANKENT development. In colonized mice the ANKENT was triggered by luminal anaerobic bacteria, which are common components of intestinal microflora.     

Enhanced expression of B7.2 (CD86) by percutaneous sensitization with house dust mite antigen

House dust mite antigen is a well-known allergen in the pathogenesis of atopic dermatitis (AD), a chronic relapsing inflammatory skin disease. We evaluated the AD model mice sensitized with house dust mite antigen and observed a Th2-dominant immune response. In this experiment, BALB/c mice were sensitized percutaneously with house dust mite antigen three times with 7 days interval after skin barrier disruption. A remarkable infiltration of polymorphonuclear granulocytes and monocytes in the cutis was observed in mice treated with this antigen, high serum IgE levels and IL-4 mRNA expression in local lymph node cells was also observed. CD19(+) B cell numbers overturned to CD4(+) helper T cells. In these mice, there was significant increase of B7.2 (CD86) expression on CD19(+) B cells. These results indicate that house dust mite antigen sensitizes BALB/c mice and skews their Th1/Th2 balance toward Th2.     

The anti-allergic effects of lactic acid bacteria are strain dependent and mediated by effects on both Th1/Th2 cytokine expression and balance

BACKGROUND: There is growing interest in the immune-stimulating effect and in particular, the anti-allergic effect, of lactic acid bacteria (LAB). However, no comprehensive studies have been done that compare the immune-stimulating potential of LAB strains. METHODS: The in vitro immune-stimulating effects on Th1/Th2 balance of more than 100 LAB strains were compared in splenocytes from ovalbumin-sensitized Th2-polarized mice. The in vivo anti-allergic ability of strain KW3110 was studied in the Th2-polarized model by detecting serum IgE concentration, Th1/Th2 cytokine secretion from splenocytes, and the expression of co-stimulatory molecules on macrophages. RESULTS: In vitro studies from Th2-polarized splenocytes, using IL-12 as a Th1 parameter and IL-4 secretion as a Th2 parameter revealed a wide variety of IL-12-inducing and IL-4-repressing activities, depending on the strain of LAB, not depending on the species. However, evaluation of individual strains in vivo revealed that after exposure to Lactobacillus paracasei KW3110 strain, the serum IgE elevation elicited by repeated OVA injection of mice was strongly inhibited. Cytokine secretion from splenocytes 20 weeks after KW3110 administration showed increased IL-12 and decreased IL-4 expression. Both CD40 and B7-1 expression on macrophages was upregulated by administration of KW3110. CONCLUSIONS: Improving the consequences of the Th1/Th2 imbalance by administration of LAB was dependent upon the LAB strain rather than the LAB species. Oral KW3110 administration in the mouse allergy model directed the Th1/Th2 balance toward Th1 through the maturation of APCs and inhibition of serum IgE elevation.