Reciprocal control of T helper cell and dendritic cell differentiation

It is not known whether subsets of dendritic cells provide different cytokine microenvironments that determine the differentiation of either type-1 T helper (TH1) or TH2 cells. Human monocyte (pDC1)-derived dendritic cells (DC1) were found to induce TH1 differentiation, whereas dendritic cells (DC2) derived from CD4+CD3-CD11c- plasmacytoid cells (pDC2) induced TH2 differentiation by use of a mechanism unaffected by interleukin-4 (IL-4) or IL-12. The TH2 cytokine IL-4 enhanced DC1 maturation and killed pDC2, an effect potentiated by IL-10 but blocked by CD40 ligand and interferon-gamma. Thus, a negative feedback loop from the mature T helper cells may selectively inhibit prolonged TH1 or TH2 responses by regulating survival of the appropriate dendritic cell subset.     

Role of T-bet in commitment of TH1 cells before IL-12-dependent selection

How cytokines control differentiation of helper T (TH) cells is controversial. We show that T-bet, without apparent assistance from interleukin 12 (IL-12)/STAT4, specifies TH1 effector fate by targeting chromatin remodeling to individual interferon-gamma (IFN-gamma) alleles and by inducing IL-12 receptor beta2 expression. Subsequently, it appears that IL-12/STAT4 serves two essential functions in the development of TH1 cells: as growth signal, inducing survival and cell division; and as trans-activator, prolonging IFN-gamma synthesis through a genetic interaction with the coactivator, CREB-binding protein. These results suggest that a cytokine does not simply induce TH fate choice but instead may act as an essential secondary stimulus that mediates selective survival of a lineage.     

乳酸菌对Caco-2细胞分泌APRIL和IL-10的影响

【目的】通过检测促炎细胞因子APRIL和抗炎细胞因子IL-10的分泌水平来观察屎肠球菌和乳酸乳球菌对肠上皮细胞先天性免疫应答的调节作用。【方法】Caco-2细胞分别和PBS（CT组,阴性对照组）、Escherichia coli K88（EC组,阳性对照组）,Enterococcus faecium（EF组）或Lactococcus lactis（LL组）共孵育2 h,以及先分别和Enterococcus faecium或Lactococcus lactis共孵育1 h,再和Escherichia coli K88共孵育2 h（EF-EC组和LL-EC组）。试验结束时,用ELISA方法检测细胞培养上清中APRIL和IL-10的含量。【结果】结果表明,2株乳酸菌都促进正常状态下的肠上皮细胞分泌促炎细胞因子APRIL和抗炎细胞因子IL-10,抑制Escherichia coli K88对APRIL分泌的诱导作用,促进Escherichia coli K88感染的肠上皮细胞分泌IL-10。【结论】体外试验条件下,屎肠球菌和乳酸乳球菌能够诱导肠上皮细胞产生先天免疫应答,分泌APRIL和IL-10,抑制大肠杆菌K88引起的促炎反应,表现出抗炎作用。     

沙门氏菌和聚肌胞处理条件下鸡免疫相关候选基因mRNA表达特性

【目的】利用高密度SNP芯片完成了对北京油鸡血清免疫球蛋白Y含量等9个免疫性状的关联分析,筛选得到了与性状显著关联位点和候选基因。基于该研究结果,以集中分布在16号染色体的候选基因CD1b、 BMA1（B locus M alpha chain 1）、TRIM27（tripartite motif-containing 27）和ZNF692（zinc finger protein 692）作为研究对象,以北京油鸡为实验材料,在聚肌胞（Polyinosinic acid-polycytidylic acid, Poly I:C）和细菌的处理下进一步对候选基因表达特性进行分析和鉴定。【方法】随机选取80只12日龄北京油鸡分为3组：空白对照组、聚肌胞处理组和肠炎沙门氏菌（Salmonella enteritidis, SE）处理组,分别饲养在独立的隔离器内。两处理组分别胸肌注射聚肌胞注射液和SE菌液,对照组注射生理盐水,于处理后12 h、24 h、3 d和6 d（days post infection, DPI）检测血清炎症因子的变化水平和候选基因表达规律。【结果】经过聚肌胞和SE处理后,体重在24 h之后显著低于空白组（P＜0.05）,体温24 h以内显著升高;血清IFN-α、IL-4和IL-6水平先升高后降低,在第24小时或第3天达到峰值,TNF-α水平持续升高,3 d后极显著高于空白组（P＜0.01）。两种处理条件下CD1b的mRNA表达没有组织特异性,其他3个基因在胸腺和法氏囊中高表达。在胸腺组织中,CD1b在两处理间12和24 h的表达量存在显著差异（P＜0.01）,在聚肌胞处理组整个感染阶段没有显著性变化,在SE组是先升高后降低的趋势,感染后24 h时表达量最高（P＜0.01）;BMA1在12 h和3 d时两处理组间差异显著,聚肌胞处理组在12 h时表达量低于SE处理组,而在3 d时显著高于SE处理组（P＜0.01）;TRIM27在聚肌胞感染6 d时表达量显著高于空白组（P＜0.05）,ZNF692的表达量在3组间没有差异。在法氏囊中,CD1b表达量在两个处理组中存在差异,在SE组12 h时表达量高;BMA1和TRIM27的表达量在两组间没有差异,TRIM27在3 d时表达量最高（P＜0.01）,ZNF692在SE组感染24 h时相对表达量高于聚肌胞处理组,在两组中都在3 d时表达最高。【结论】CD1b、BMA1、TRIM27和ZNF692参与了聚肌胞和肠炎沙门氏菌引起的免疫反应过程,是与免疫相关的功能基因;CD1b主要在肠炎沙门氏菌感染的前期发挥作用;BMA1和ZNF692分别参与胸腺和法氏囊的免疫反应。     

Cytokine-induced expression of HIV-1 in a chronically infected promonocyte cell line

A model system for cytokine-induced up-regulation of human immunodeficiency virus type 1 (HIV-1) expression in chronically infected promonocyte clones was established. The parent promonocyte cell line U937 was chronically infected with HIV-1 and from this line a clone, U1, was derived. U1 showed minimal constitutive expression of HIV-1, but virus expression was markedly up-regulated by a phytohemagglutinin-induced supernatant containing multiple cytokines and by recombinant granulocyte/macrophage colony-stimulating factor alone. Recombinant interleukin-1 (IL-1), IL-2, interferon-gamma, and tumor necrosis factor-alpha did not up-regulate virus expression. Concomitant with the cytokine-induced up-regulation of HIV-1, expression of membrane-bound IL-1 beta was selectively induced in U1 in the absence of induction of other surface membrane proteins. This cytokine up-regulation of IL-1 beta was not seen in the uninfected parent U937 cell line. These studies have implications for the understanding of the mechanism of progression from a latent or low-level HIV-1 infection to a productive infection with resulting immunosuppression. In addition, this model can be used to delineate the potential mechanisms whereby HIV-1 infection regulates cellular gene expression.     

Study on the production of IL-12, IL-10 in early stage after infection with Babesia microti and Babesia rodhaini in mice

The serum levels of IL-12 and IL-10 in mice after infected with Babesia microti(B. microti) and Babesia rodhaini (B. rodhaini) were examined. Collected the mice serum and examined the concentration of IL-12 and IL-10 by using ELISA after infection with B. microti and B. rodhaini at 0, 3, 6, 9, 12, 18, 24, 36, 72, 96 h in mice. The results showed that B. microti infection resulted in IL-12 increasing, which peaked at 3 and 24 h after the infection, while same infection did not induce a significant change in IL-10 compared to uninfected mice. When mice were infected with B. rodhaini, any significant changes were not decteted both in IL-12 and IL-10 in comparison with uninfected animals during the period of 3-72 h after infection. Instead, a significant decline in IL-12 and IL-10 was found compared to uninfected mice 96 h after infection with B. rodhaini. It indicates that the mutagenetic cytokine is IL-12 in the serum of mice after infection with B. microti, and no any significant changes were detected in both IL-12 and IL-10 from 0 to 72 h after infected with B. rodhaini.     

Regulation of alloreactivity in vivo by a soluble form of the interleukin-1 receptor

In vitro studies have shown that cytokines are involved in the regulation of the immune response, but their role in vivo is less well defined. Specific cytokine antagonists enable the identification of particular cytokines involved in the response and offer a means for modifying it. Systemic administration of a soluble, extracellular portion of the receptor for interleukin-1 (sIL-1R) had profound inhibitory effects on the development of in vivo alloreactivity. Survival of heterotopic heart allografts was prolonged from 12 days in controls to 17 days in mice treated with sIL-1R. Lymph node hyperplasia in response to a localized injection of allogeneic cells was completely blocked by sIL-1R treatment. The inhibition was overcome by simultaneous administration of interleukin-1 (IL-1); thus, sIL-1R acts by neutralizing IL-1. These results implicate IL-1 as a regulator of allograft rejection and demonstrate the in vivo biological efficacy of a soluble cytokine receptor.     

白细胞介素18和鸡白细胞介素18

白细胞介素 18是一种新发现的细胞因子 ,主要由单核巨噬细胞系统的细胞分泌。目前在分子水平上已经证明 ,人、哺乳动物和某些鸟类中都有 IL- 18存在。IL- 18在结构上属于 IL- 1家族 ,在功能上它与 IL- 12相似 ,且二者有协同效应。 IL- 18具有多种生物学功能 ,它不仅可以增强 Th1型免疫反应 ,而且在 Th2型免疫反应中也发挥一定的作用。人类医学研究证明 IL- 18在抗微生物感染、抗肿瘤免疫中具有应用潜力。在集约化畜禽养殖业中 ,包括白细胞介素 18在内的细胞因子作为天然的免疫调节剂 ,目前已被公认为是一种可以替代传统疗法的新型治疗剂。鸡 IL- 18基因是最近才被发现的 ,由于它具有与人和哺乳动物相似的生物学功能 ,因而鸡 IL- 18在比较免疫学研究和禽病治疗中具有重要意义。     

鼠李糖乳杆菌对巨噬细胞先天性免疫应答的调节作用

【目的】通过测定先天性免疫效应因子分泌水平的变化,研究鼠李糖乳杆菌（Lactobacillus rhamnosus）体外对巨噬细胞先天性免疫应答调节的影响。【方法】将培养好的鼠巨噬细胞系RAW264.7细胞分为4组,分别用PBS（CT组,对照组）、Escherichia coli K88（EC组）和Lactobacillus rhamnosus（LR组）处理12 h,以及先用Lactobacillus rhamnosus预处理1 h,再用Escherichia coli K88处理12 h（LR-EC组）。试验结束时,收集各组的细胞培养液,用ELISA检测TNF-α、IFN-γ、IL-1β、IL-6、IL-12、IL-8、IL-10,以及PGE2和 的含量。【结果】结果表明,CT组（对照组）可产生TNF-α、IFN-γ、IL-8和IL-10,几乎不产生IL-1β、IL-6和IL-12。与对照组相比,EC组TNF-α、IFN-γ、IL-8、IL-10及PGE2和 含量均极显著提高（P＜0.01）,且可大量产生IL-1β、IL-6和IL-12;LR组TNF-α、IFN-γ、IL-10及PGE2和 也极显著提高（P＜0.01）,IL-8显著增加（P＜0.05）,同样不产生IL-1β和IL-6,但可产生微量的IL-12（P＜0.01）;LR-EC组所有的促炎细胞因子（TNF-α、IFN-γ、IL-1β、IL-6、IL-12）、趋化因子IL-8和PGE2均极显著高于EC组（P＜0.01）,但IL-10和 含量都显著低于EC组（P＜0.01）。【结论】在体外试验条件下,鼠李糖乳杆菌作为益生菌对生理状态下巨噬细胞先天性免疫应答的刺激作用远低于病原菌,不会产生炎症反应,但可极大增强受感染巨噬细胞的促炎免疫应答水平,且可能具有避免过度炎症反应的作用。     

鲤鱼白细胞介素10(IL-10)基因cDNA克隆及序列分析

[目的]获取鲤鱼全长IL-10(interleukin 10)cDNA,并对其序列进行分析。[方法]利用DD-RTPCR(differential display RT-PCR)方法获得差异表达IL-10 cDNA片段,以地高辛标记做为探针,对有丝分裂原刺激的鲤鱼外周血白细胞cDNA文库进行核酸杂交筛选,克隆鲤鱼IL-10全长cDNA,并对该序列进行序列分析和同源性比较。[结果]鲤鱼全长IL-10 cDNA共1 117 bp,包含55 bp的5'端非编码区,一个540 bp的编码179个氨基酸的开放阅读框及522 bp的3'端非编码区,其中,3'非编码区包含3个mRNA不稳定基序"ATTTA";该蛋白序列具有IL-10家族的典型序列特征;序列同源性比较表明,所获得的序列与GenBank上登录的鲤鱼IL-10基因同源性为89.1%。[结论]该试验为进一步研究IL-10在体内的表达方式、功能特点、调控机理及其在炎症反应和免疫应答中的作用机制奠定了基础。     

鲤鱼白细胞介素10(IL-10)基因cDNA克隆及序列分析(英文)

[目的]获取鲤鱼全长IL-10(interleukin 10)cDNA,并对其序列进行分析。[方法]利用DD-RTPCR(differential display RT-PCR)方法获得差异表达IL-10cDNA片段,以地高辛标记做为探针,对有丝分裂原刺激的鲤鱼外周血白细胞cDNA文库进行核酸杂交筛选,克隆鲤鱼IL-10全长cDNA,并对该序列进行序列分析和同源性比较。[结果]鲤鱼全长IL-10cDNA共1117bp,包含55bp的5’端非编码区,一个540bp的编码179个氨基酸的开放阅读框及522bp的3’端非编码区。其中,3’非编码区包含3个mRNA不稳定基序"ATTTA";该蛋白序列具有IL-10家族的典型序列特征;序列同源性比较表明,所获得的序列与GenBank上登录的鲤鱼IL-10基因同源性为89.1%。[结论]该试验为进一步研究IL-10在体内的表达方式、功能特点、调控机理及其在炎症反应和免疫应答中的作用机制奠定了基础。     

胡黄连单体ScrocaffesideA对小鼠细胞因子分泌影响的体外研究

[目的]研究ScrocaffesideA（SA）免疫调节活性,为新型免疫增强剂的开发提供试验依据。[方法]从西藏胡黄连的根茎中分离鉴定得到的单体E-咖啡酰基-6-（4-O-β—D一吡喃葡萄糖基）-E一咖啡酰基-O-β—D一吡喃葡萄糖苷,命名为ScrocaffesideA（SA）。通过用不同浓度的SA协同ConA体外刺激小鼠脾淋巴细胞,采用双抗夹心ELISA法,检测细胞上清中细胞因子的分泌量。[结果]不同浓度SA协同ConA（5mg／L）与细胞作用24及48h后,在25和125mg／L浓度组显著上调了Th1细胞分泌的主要细胞因子IL-2、IL一12和IFN一1的分泌量;Th2细胞分泌的主要细胞因子IL-4和IL—10分泌量也显著升高,仅IL一10的分泌量在48h,SA浓度为125ms／L剂量时有所下降。[结论]SA能上调相关细胞因子的表达,具有免疫增强作用。     

白细胞介素-10分子佐剂增强口蹄疫DNA疫苗黏膜免疫效果研究

 【目的】研究白细胞介素-10作为黏膜分子佐剂是否可以增强口蹄疫DNA疫苗（pcD-VP1）的黏膜免疫应答。【方法】利用RT-PCR技术以Balb/c小鼠脾脏组织总RNA为模板,扩增出小鼠的IL-10基因,并构建真核表达质粒proVAX-IL-10, 通过鼻腔接种方式,将口蹄疫DNA疫苗（pcD-VP1）和真核表达质粒（proVAX-IL-10）共同免疫小鼠,用ELISA法检测免疫小鼠黏膜部位（肺脏、生殖道）sIgA滴度,免疫组织化学法检测气管、生殖道和小肠中sIgA 的表达情况,CSFE染色法检测小鼠扁桃体淋巴细胞增殖反应水平,用胞内细胞因子染色法通过流式细胞仪检测扁桃体部位CD4+阳性T细胞内IFN-γ和IL-4的表达量。【结果】成功构建了proVAX-IL-10真核重组质粒,且重组质粒可以在BHK细胞中有效表达;将proVAX-IL-10与口蹄疫DNA疫苗pcD-VP1共同免疫小鼠后发现,与单独接种pcD-VP1相比,加入IL-10分子佐剂后,可以诱导更高水平的黏膜sIgA的表达及分泌,极大的提高了黏膜部位抗原特异性T细胞增殖反应水平以及CD4+ T细胞中IL-4的表达量。【结论】IL-10作为分子佐剂,通过鼻腔黏膜免疫后,可以有效增强机体对口蹄疫DNA疫苗的黏膜免疫应答,对于预防口蹄疫病毒的感染和清除体内病毒起到重要的作用。     

Type I strain of Toxoplasma gondii from chicken induced different immune responses with that from human,cat and swine in chicken

In this study,four strains of Toxoplasma gondii with the same genetic type(Type I) originated from chicken,human,cat and swine were used to compare the immune responses in resistant chicken host to investigate the relationships between the parasite origins and the pathogenicity in certain host.A total of 300,10-day-old chickens were allocated randomly into five groups which named JS(from chicken),CAT(from cat),CN(from swine),RH(from human) and a negative control group(—Ve) with 60 birds in each group.Tachyzoites of four different T.gondii strains(JS,CAT,CN and RH) were inoculated intraperitoneally with the dose of 1×10~7 in the four designed groups,respectively.The negative control(-Ve) group was mockly inoculated with phosphate-buffered saline(PBS) alone.Blood and spleen samples were obtained on the day of inoculation(day 0) and at days 4,11,25,39 and 53 post-infection to screen the immunopathological changes.The results demonstrated some different immune characters of T.gondii infected chickens with that of mice or swine previous reported.These differences included up-regulation of major histocompatibility complex class Ⅱ(MHC Ⅱ) molecules in the early stage of infection,early peak expressions of interleukin(IL)-12(IL-12) and-10(IL-10) and long keep of IL-17.These might partially contribute to the resistance of chicken to T.gondii infection.Comparisons to chickens infected with strains from human,cat and swine,chickens infected with strain from chicken showed significant high levels of CD4~+ and CD8~+ T cells,interferon gamma(IFN-γ),IL-12 and IL-10.It suggested that the strain from chicken had different ability to stimulate cellular immunity in chicken.     

Release of multiple hormones by a direct action of interleukin-1 on pituitary cells

Exposure to bacterial endotoxins has long been known to stimulate the release of anterior pituitary hormones; administration of endotoxin was at one time a common clinical test of anterior pituitary function. Endotoxin is a potent stimulus for production of the endogenous pyrogenic protein, interleukin-1 (IL-1), by macrophages and monocytes. The possibility that IL-1 has a direct effect on the secretion of hormones by rat pituitary cells in a monolayer culture was investigated. Recombinant human IL-1 beta stimulated the secretion of adrenocorticotropic hormone, luteinizing hormone, growth hormone, and thyroid-stimulating hormone. Increased hormone secretion into culture supernatants was found with IL-1 concentrations ranging from 10(-9) M to 10(-12) M. Prolactin secretion by the monolayers was inhibited by similar doses. These concentrations of IL-1 are within the range reported for IL-1 in serum, suggesting that IL-1 generated peripherally by mononuclear immune cells may act directly on anterior pituitary cells to modulate hormone secretion in vivo. Incubation of IL-1 solutions with antibody to IL-1 neutralized these actions. These pituitary effects of IL-1 suggest that this monokine may be an important regulator of the metabolic adaptations to infectious stressors.     

Two new IncRNAs regulate the key immune factor NOD1 and TRAF5 in chicken lymphocyte

Reticuloendotheliosis virus (REV) causes the atrophy of immune organs and immuno-suppression in chickens, but the underlying molecular mechanism of the immune response after infection by REV is not well understood. Presently, the RNA-seq was used to analyze the regulation of immune response to REV in chicken lymphocytes from peripheral blood. Overall, 134 differentially expressed long non-coding RNAs (lncRNAs) between cells with REV infection or without in vitro were screened. Based on the differentially expressed protein-coding genes, the nucleotide-binding oligomerization domain (NOD)-like receptor pathway related to immune regulation was enriched. Two lncRNAs (L11530 and L09863) were predicted to target the NOD1 and tumor necrosis factor receptor-associated factor 5 (TRAF5) gene, respectively, which are involved in the NOD-like receptor pathway with cis-regulation way. The in vitro results revealed the significantly up-regulated (P<0.01) levels of lncRNA-L11530 and its target gene, NOD1, and the significantly down-regulated (P<0.05) levels of lncRNA-L09863 and its target gene, TRAF5, in lymphocytes after REV infection. These changes also occurred in vivo in blood lymphocytes of chickens infected with REV. Further, L09863 and L11530 were respectively interfered, the expression levels of their target genes NOD1 or TRAF5 were significantly down-regulated, accompanied by the change of IL-8 and IL-18 secretions in lymphocytes. The NOD-like receptor pathway appears to be important in the immune response to REV, LncRNA-11530 and IncRNA-09863 might involve in the immune regulation on REV infection by targeting NOD1 or TRAF5 in blood lymphocytes of chickens. Our findings reveal a new regulation of lncRNAs (L11530 and L09863) on immunity in chicken peripheral blood lymphocytes for REV infection by changing the expression of the target genes via the NOD-like receptor pathway.     

Polysaccharide Nucleic Acid of Bacillus Calmette Guerin Modulates Th1/Th2 Cytokine Gene Expression in Lipopolysaccharide-Induced Mastitis in Rats

The aim of this study was to evaluate, in rats, the changes in the T helper type 1 (Th 1)/Th2 radio in mammary glands after an intramammary infusion of lipopolysaccharide (LPS) and to characterize the moderating effects of the polysaecharide nucleic acid of Bacillus Calraette Guerin (BCG-PSN) on the mammary gland. In the control group, the levels of IL-2 and INF-γ, mRNA expression increased, whereas IL-4 mRNA expression decreased after LPS challenge. As a consequence, the INF-γ/IL-4 mRNA ratio was significantly higher at 3, 6, and 9 h post-infusion (PI) compared to the control value (O h; P<0.01).BCG-PSN increased mRNA expression of both INF-γ' and IL-4 before infusion of LPS. LPS challenge significantly the reduced Th1/Th2 eytokine ratio due to Th1 cytokine IFN-γ suppression and Th2 cytokine IL-4 upregulation compared with the control group. A significant reduction ofN-acety1-β-D-glucosaminidase (NAGase) was observed at 24 h PI in the BCG-PSN treatment group compared to the control group (P<0.05). Thus, it was demonstrated that level of BCG-PSN might change the Th1/Th2 ratio mainly by enhancing the Th2 immune response. This is the first report of a Th1/Th2 change induced by coliform mastitis and characterization of the effect of BCG-PSN on mammary gland inflammation. This study makes a better understanding of the mechanisms of coliform mastitis and provides a putative novel strategy for the prevention and/or treatment of mastitis.     

Cytokine profile of albino rats’ changes under the impact of Salmonella against the background of subacute T-2 toxicosis

The results of the study demonstrated the immunosuppression in albino rats under a complex impact of T-2 toxin and Salmonella, manifested by the significant increase of anti-inflammatory cytokine IL-1β content in the blood and a slight increase of IL-4, stimulating the humoral immunity, the decrease of concentration of other anti-inflammatory mediators (TNF-α, IL-8), immunoregulatory interleukins IL-2, interferon-γ and anti-inflammatory cytokine IL-10, and interferon–γ/IL-4 ratio, indicating an evident T-deficit and a more significant suppression of Th-1 lymphocyte function.     

Polysaccharide Nucleic Acid of Bacillus Calmette Guerin Modulates Th1/ Th2 Cytokine Gene Expression in Lipopolysaccharide-lnduced Mastitis in Rats

The aim of this study was to evaluate, in rats, the changes in the T helper type 1（Th1）/Th2 radio in mammary glands after an intramammary infusion of lipopolysaccharide （LPS） and to characterize the moderating effects of the polysaccharide nucleic acid of Bacillus Calmette Guerin （BCG-PSN） on the mammary gland. In the control group, the levels of IL-2 and INF-7 mRNA expression increased, whereas IL-4 mRNA expression decreased after LPS challenge. As a consequence, the INF-γ/IL-4 mRNA ratio was significantly higher at 3, 6, and 9 h post-infusion （PI） compared to the control value （0 h; P〈0.01）. BCG-PSN increased mRNA expression of both INF-γ and IL-4 before infusion of LPS. LPS challenge significantly the reduced Th1/Th2 cytokine ratio due to Thl cytokine IFN-γ suppression and Th2 cytokine IL-4 upregulation compared with the control group. A significant reduction of N-acetyl-β-D-glucosaminidase （NAGase） was observed at 24 h PI in the BCG-PSN treatment group compared to the control group （P〈 0.05）. Thus, it was demonstrated that level of BCG-PSN might change the Th1/Th2 ratio mainly by enhancing the Th2 immune response. This is the first report of a Th1/Th2 change induced by coliform mastitis and characterization of the effect of BCG-PSN on mammary gland inflammation. This study makes a better understanding of the mechanisms of coliform mastitis and provides a putative novel strategy for the prevention and/or treatment of mastitis.