Peroxisome proliferator‐activated receptor γ 2 mutation may cause a subset of ulcerative colitis

Aim: Previous studies suggest the homeostasis between acquisition of tolerance to the indigenous microflora and protective immune responses appears to be disrupted in inflammatory bowel disease (IBD). Some experimental studies indicate peroxisome proliferator‐activated receptor γ (PPARγ) has been implicated as a regulator of intestinal inflammatory responses. In addition, the toll‐like receptor (TLR)‐4 can regulate expression of PPARγ in colonic epithelial cells. We attempted to demonstrate whether the functional imbalance between TLRs and PPARγ could lead to the onset and some polymorphisms of those genes could contribute to susceptibility to IBD. Methods: RT‐PCR analysis were performed to detect TLR4 and PPARγ mRNA associated with those of P65 of NFκB, TNFα, MyD88, NOD2/CARD15, TLR‐2,5,9, in the diseased colonic mucosa in ulcerative colitis (UC; n = 13) and Crohn's disease (CD; n = 7) compared with normal controls (n = 18). Consequently, we genotyped UC (n = 29) and CD (n = 10) compared with normal controls (n = 134) for the prevalence of suspicious mutations. Results: In a subset of UC patients who were revealed to carry PPARγ Pro12Ala mutation later, impaired expression of normal PPARγ mRNA was noted in the diseased mucosa accompanied with upregulations of MyD88 TLR‐4, 5, 9, P65 and TNFα in mRNA levels. The prevalence of PPARγ Pro12Ala mutation was more frequently found in UC patients compared with CD patients and normal controls (P < 0.05). Conclusions: These findings suggested that imbalances between TLRs and PPARγ in response to luminal bacteria could lead to colonic inflammation in some UC patients. Alternative explanations will be needed for the onset of the rest of UC and CD.     

STAT3 基因多态性与儿童癫痫易感性的相关性

目的探讨信号转导和转录活化因子3(STAT 3)基因两个SNP位点rs1053005和rs744166多态性与儿童癫痫易感性的关系。方法采用病例对照研究,选取462例癫痫患儿,其中包括121例难治性癫痫(RE)患儿,以493例健康儿童作为对照组。利用PCR-RFLP方法进行两个SNP位点的多态性检测,比较不同基因型及等位基因与儿童癫痫患病风险的关系。结果癫痫患儿SNP位点rs1053005的基因型(AA,AG,GG)频率与对照组比较,差异有统计学意义(χ~2=9.705,P?=0.008);癫痫患儿的等位基因G频率明显低于对照组(OR=0.734,P=0.002,95%CI:0.604~0.892);SNP位点rs744166的基因型(TT,TC,CC)频率和等位基因频率与对照组比较,差异均无统计学意义(P0.05)。在癫痫患儿中,RE患儿与非RE患儿比较,SNP位点rs1053005和rs744166的基因型频率和等位基因频率的差异均无统计学意义(P0.05)。结论 STAT3基因SNP位点rs1053005与癫痫的遗传易感性相关。     

白细胞介素6/STAT3信号活化在急性免疫性血小板减少性紫癜患儿辅助性T淋巴细胞17/调节性T淋巴细胞失衡中的作用

目的探讨IL-6/STAT3信号活化在儿童急性免疫性血小板减少性紫癜(ITP)辅助性T淋巴细胞17(Th17)/调节性T淋巴细胞(Treg)失衡中的作用。方法选择急性ITP患儿30例,同年龄健康对照组30例。ELISA法检测其血浆IL-6水平;荧光定量PCR检测CD4+T淋巴细胞RORγt mRNA、FOXP3 mRNA、细胞因子信号转导抑制因子(SOCS)1 mRNA、SOCS3 mRNA表达;流式细胞术检测其外周血CD4+CD25+FOXP3+T淋巴细胞、CD4+IL-17A+T淋巴细胞比例及CD4+T淋巴细胞磷酸化STAT3(pSTAT3)蛋白平均荧光强度(MFI);甲基化特异性定量PCR检测CD4+T淋巴细胞SOCS1基因外显子2、SOCS3基因5’端非翻译区(5’-UTR)3个可能的STAT3结合位点CpG岛甲基化水平。结果 1.与健康对照组比较,ITP组患儿CD4+IL-17A+T淋巴细胞比例及RORγt mRNA表达水平显著上调(Pa<0.05),CD4+CD25+FOXP3+T淋巴细胞比例及FOXP3 mRNA表达显著降低(Pa<0.05),Th17/Treg比值明显升高(P<0.05);2.与健康对照组比较,ITP组患儿IL-6表达水平显著上调(P<0.05),且pSTAT3 MFI值亦明显增高(P<0.05);3.与健康对照组比较,ITP组患儿CD4+T淋巴细胞SOCS1和SOCS3 mRNA水平显著增加(Pa<0.05),与其Th17/Treg比值均呈负相关(r=-0.63、-0.70,Pa<0.05);健康对照组SOCS1基因外显子2、SOCS3基因5’-UTR区第3个STAT3结合位点的CpG岛完全去甲基化,急性ITP患儿呈低甲基化状态(Pa<0.05),其去甲基化水平与表达呈正相关(r=0.76、0.65,Pa<0.05)。各组SOCS3基因5’-UTR区第1、2个STAT3结合位点CpG岛均处于完全去甲基化状态(Pa>0.05)。结论 SOCS1和SOCS3基因低甲基化所致IL-6/STAT3信号异常活化可能是急性ITP患者Th17/Treg细胞失衡的因素之一。     

Relation between serum IL‐4, IL‐13 and IFN‐γ levels and recurrence of wheezing episodes in infants with acute bronchiolitis

Lower respiratory tract infections are the most important factors among various causes which trigger wheezing in the first year of life. The factors associated with episodic wheezing in children with acute bronchiolitis are still subjects of research. Infections, environmental factors, immunologic mechanisms are sorted as etiologic risk factors of episodic wheezing. We aimed to investigate the relationship between serum interleukin (IL)‐4, IL‐13 and γ‐interferon (IFN‐γ) levels and recurrence of wheezing episodes in infants with acute bronchiolitis. One hundred twenty infants between 3 and 36 months with acute bronchiolitis enrolled in the study. Personal histories, clinical and laboratory data of infants were recorded. The patients were followed for a year. Venous blood samples were obtained to determine serum IL‐4, IL‐13, and IFN‐γ levels during acute bronchiolitis episode. The number of wheezing episodes was significantly higher in infants with a positive family history of allergy. A statistically significant correlation was determined between serum IL‐13 levels of infants and number of wheezing episodes. High serum IL‐13 levels and a positive history of allergy may have important roles in the recurrence of acute bronchiolitis.     

Determination of T‐cell subpopulations and intracellular cytokine production (interleukin‐2, interleukin‐4, and interferon‐γ) by cord blood T‐lymphocytes of neonates from atopic and non‐atopic parents

This report describes the results of a prospective study on immunological markers in cord blood for the prediction of allergic diseases in children. First we evaluated methodological aspects of the flow cytometric technique on cord blood cytokine measurements. Subsequently, the T‐cell subsets and percentage of cytokine‐producing cord blood T‐helper (Th) and T‐suppressor/cytotoxic lymphocytes of neonates from atopic and non‐atopic parents were compared. A group of 33 healthy, full‐term newborn infants of whom 23/33 were at risk for atopy (i.e. having at least one parent with one or more atopic symptoms and positive specific immunoglobulin E [IgE] to at least one common inhalant allergen) was studied. A flow cytometric technique was used to analyze cord blood T‐cell subsets and to determine the percentage of interleukin (IL)‐2‐, IL‐4‐, and interferon‐γ (IFN‐γ)‐producing cord blood Th and T‐suppressor/cytotoxic lymphocytes following stimulation with phorbol 12‐myristate 13‐acetate (PMA) and ionomycin. The percentage of CD3 (T lymphocytes), CD3⁺ CD4⁺ (Th lymphocytes), CD3⁺ CD8⁺ (T‐suppressor/cytotoxic lymphocytes), CD19⁺ (B lymphocytes), CD3⁺ CD4⁺ CD45RO⁺ (memory Th lymphocytes), and CD3⁺ CD4⁺ CD45RA⁺ (naive Th lymphocytes) cells was unrelated to parental atopic status. PMA stimulation augmented the percentage of IL‐2‐ and IFN‐γ‐producing Th and T‐suppressor/cytotoxic lymphocytes, whereas the number of IL‐4‐producing T lymphocytes remained very low or undetectable. No differences in the percentage of IL‐2‐, IL‐4‐ and IFN‐γ‐producing Th and T‐suppressor/cytotoxic lymphocytes were found between neonates from atopic and non‐atopic parents. These results will be re‐evaluated when the atopic status of the children at the age of 1 and 2 years can be assessed.     

Attenuation of rat chronic small bowel allograft rejection by n‐3 polyunsaturated fatty acids is associated with reduced expression of graft IL‐15

Interleukin‐15 was found to play key roles in various immunological processes including chronic rejection after renal and cardiac transplantation. n‐3 polyunsaturated fatty acids (n‐3 PUFA) have shown beneficial effects to chronic allograft rejection. The objective of this study is to search the possible mechanism of this inhibitory effect in chronic small bowel allograft rejection. Animals were divided into three groups: isograft (CsA + corn oil‐supplemented diet); allograft (CsA + corn oil‐supplemented diet); and allograft (CsA + fish oil‐supplemented diet). Donor intestines from F344 rats were transplanted orthotopically into Lewis rat recipients. CsA was administered at 5 mg/kg/day for 2 wk post‐operatively. Post‐transplant weight was recorded. Histopathological changes and graft IL‐15 expression were measured on POD 90. Chronic small bowel allograft rejection developed on POD 90. n‐3 PUFA significantly decreased the score of chronic rejection and increased the post‐operative weight gain rate. This attenuation is associated with reduced graft IL‐15 expression. n‐3 PUFA contributed to improved pathological and clinical outcome during chronic small bowel allograft rejection, and this improvement was associated with reduced graft IL‐15 expression.     

高体积分数氧致慢性肺疾病新生鼠信号转导转录活化因子3表达及其对表面活性蛋白-B的影响

目的 探讨高体积分数氧(高氧)损伤状态下,肺组织内信号转导转录活化因子3(STAT3)的动态变化规律,及其对表面活性蛋白-B(SP-B)的影响.方法 新生鼠160只,依据吸氧体积分数(FiO2)分为4组:实验1组(FiO2=800 mL·L-1)、实验2组(FiO2=600 mL·L-1)、实验3组(FiO2=400 mL·L-1)、空气对照组(FiO2=210 mL·L-1).每组分别于实验1 d、3 d、5 d、7 d、14 d,免疫组织化学检测STAT3水平,反转录-PCR检测SP-B水平.结果 高氧暴露使SP-B mRNA表达异常,实验1组1 d、3 d SP-B mRNA 水平与空气对照组比较差异均无统计学意义(Pa>0.05),实验1组5 d、7 d、14 d SP-B mRNA水平与空气对照组比较差异均有统计学意义(Pa<0.05),实验2组5 d时SP-B mRNA水平与空气对照组比较差异有统计学意义(P<0.05),实验3组与空气对照组差异无统计学意义(P>0.05).实验各组肺组织STAT3蛋白的表达高氧刺激3 d明显增加,5 d、7 d差异更为显著(Pa<0.05).实验组SP-B mRNA表达与STAT3呈明显正相关(r=0.892,P<0.001).结论 高氧肺损伤的早期伴随有信号转导酪氨酸蛋白激酶STAT3通路的激活发挥其对肺组织的保护作用,SP-B合成、分泌信号可能是STAT3途径转导的.     

Markers of operational immune tolerance after pediatric liver transplantation in patients under immunosuppression

A prospective identification of the estimated 20–50% of pediatric LTX recipients developing operational tolerance would be of great clinical advantage. So far markers of immune tolerance – T‐cell subpopulations or gene expression profiles – have been investigated only retrospectively in successfully weaned patients. Fifty children aged 8–265 months (median 89) were investigated 1–180 months (median 44) after LTX under ongoing immunosuppression. T‐cell subpopulations were measured during regular post‐transplant visits using FACS (Vδ1‐ vs. Vδ2‐γδ‐T cells and Tregs). A Vδ1/Vδ2‐γδ‐T‐cell ratio ≥1.42 previously reported in operational tolerance was found in 12 of 50 (24%) patients. In analogy, a Treg count ≥44 per μL was found in 35 of 50 (70%) patients and a Treg proportion ≥2.23% of CD3⁺‐T cells in 39 of 50 (78%) patients. Only 9 of 50 patients (18%) fulfilled both criteria. The parameters Vδ1/Vδ2‐γδ‐T‐cell ratio and Tregs were not significantly correlated to each other or with donor type or immunosuppression. Vδ1/Vδ2‐γδ‐T‐cell ratio was more stable in serial examinations compared with Treg analyses. The observed proportion of 18% pediatric LTX patients with potential operational tolerance is in accordance with previous reports. However, clinical experience shows that rejections may happen even after long‐time weaning of immunosuppression. This suggests that operational tolerance is a dynamic process, with uncertain prediction by Vδ1/Vδ2‐γδ‐T‐cell ratio and/or Tregs under immunosuppression.     

Peripheral expansion of Vδ1-Jδ1/Jδ2+γδT cells and large granular lymphocytes in a patient with Wiskott-Aldrich syndrome

A 7 month old Japanese boy was diagnosed to have Wiskott-Aldrich syndrome (WAS) because of eczema, thrombocytopenia, progressive immune defect and CD43 (sialophorin) abnormality. He had developed repeated infections since 16 months of age. γδT cell-receptor positive T cells in the peripheral blood were gradually increased from 3.1% (7 months of age) to 5.6% (12 months), 19.6% (18 months) and 56.7% (25 months). The phenotypes of expanded γδT cells were δTCS1-positive (Vδ1-Jδ1/Jδ2) and CD8 dim-positive. The proportion of increased granular lymphocytes correlated well with that of γδT cells. The significance of peripheral expansion of γδT cells and granular lymphocytes in WAS is discussed.     

High production of interleukin‐10 and interferon‐γ in influenza‐associated MERS in the early phase

Mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) occurs in various diseases and pathologies, and the clinical symptoms are not consistent with the impaired region. The mechanism of the region specificity is unclear. We investigated the cytokine profiling in cerebrospinal fluid (CSF) and serum obtained from a child with MERS during influenza infection, and compared them with those of serious another serious type of influenza‐associated encephalopathy. There was no elevation of Interleukin (IL)‐1β, which induces convulsion. The inhibitory cytokines of IL‐10 and IFN‐γ were elevated in the early phase in CSF. Comparing them with other patients, the elevation of the cytokine levels were generally mild. Considering that the prognosis of this MERS case was favorable and high levels of inhibitory cytokines including IL‐10 and IFN‐γ might work to localize the lesion and to prevent sequelae.