Soluble CD30 and CD23 in cord blood are not related to atopy in early childhood

Atopic disease, including atopic dermatitis (AD), is associated with a T-helper 2 (Th2)-dependent immune response. The cytokine receptor CD30 appears to be preferentially expressed on, and its soluble form (sCD30) released by, Th2 cells. Therefore, sCD30 may be a potential marker for atopic disorders. The aim of this study was to test the hypothesis that the sCD30 level in cord blood could be used to predict the development of atopy or AD in early childhood. In a case-control study, levels of sCD30, as well as soluble low-affinity immunoglobulin E (IgE) receptor (sCD23), interleukin-4 (IL-4) and IgE, were measured in cord blood in 35 children who subsequently developed allergic sensitization and AD before the age of three, and the results were compared to those of 35 matched children without a history of atopy. There was no difference in cord blood levels of sCD30 between controls (32.5 U/ml; 19.7–80.1) and children with subsequent atopy and AD (32.2 U/ml; 22–75.9) (median; quartiles). The concentration of sCD30 showed no relation to the levels of total IgE, sCD23 or IL-4. Levels of sCD23 were similar in children with subsequent atopy (60.2 U/ml; 44.5–76.8) and controls (55.2 U/ml; 38.3–72.5), whereas IL-4 was detectable in 10 of the atopic children and in only two of the controls (p < 0.05). In conclusion, cord blood levels of sCD30 or sCD23 do not seem to be related to the subsequent development of atopy or AD at the age of three.     

Both allergen-specific CD4 and CD8 Type 2 T cells decreased in asthmatic children with immunotherapy

Allergen-specific immunotherapy (IT) has been used for the treatment of atopic diseases since the turn of this century. The precise working mechanisms, however, remain to be clarified. The aim of this study was to investigate the role of particular subsets of allergen-specific T cells in the non-atopic individuals, untreated asthmatic children and the asthmatic children receiving immunotherapy. We collected peripheral blood from 16 untreated asthmatic children and 17 asthmatic children receiving immunotherapy over one and half years. All the patients were sensitive to mite allergen. Peripheral blood mononuclear cells (PBMC) were isolated and, in vitro , stimulated with crude mite extract to enrich the mite-specific T-cell population. After 14 days, the enriched mite-specific T cells were stimulated with phorbol-12-myristate-13-acetate (PMA) and ionomycin for intracellular detection of cytokines such as IFN-γ, IL-4 in CD4⁺ and CD8⁺ T lymphocytes. The data here demonstrated that the levels of mite-specific IgG4 and IgA increased significantly in asthmatic children after immunotherapy. In addition, both IL-4 expressing CD4⁺ and CD8⁺ T cells were significantly lower in asthmatic children after immunotherapy compared with those of before treatment and the normal control (p < 0.05). In contrast, the frequency of IFN-γ expressing CD4⁺ and CD8⁺ T cells did not significantly differ between untreated and SIT-treated groups. All these data suggested that decreased Type 2 CD4⁺ and CD8⁺ T cells might be closely correlated with the regulatory mechanisms of immunotherapy.     

哮喘患儿淋巴细胞CD40/CD40L信号分子的表达

目的：CD40/CD40L是免疫应答中的一对协同刺激分子,它们在哮喘的发病中可能起到至关重要的作用,该文旨在探讨CD40/CD40L的表达与儿童哮喘的发病关系。方法：随机选择哮喘急性发作患儿32例,对照组20例。用流式细胞仪检测其外周血T、B淋巴细胞表达分化抗原CD40及其配体CD40L的百分率,并比较哮喘组与对照组之间的差异性。结果：哮喘组B淋巴细胞CD40的表达率较对照组明显增高(17.05±4.88vs13.89±3.67,P<0.05);哮喘组CD4+T淋巴细胞CD40L的表达率较对照组明显增高(8.04±3.53vs5.58±3.00,P<0.05)。结论：哮喘急性发作患儿存在的相关免疫细胞CD40/CD40L的异常表达,可能是其免疫失衡发病因素之一。     

Reduced IL-2-induced IL-12 responsiveness in atopic children

Atopy may be associated with a reduced T-cell function particularly regarding maturation of T helper 1 (Th1) responses. We hypothesized that atopic children may have a reduced capacity to up-regulate the β₂ subunit of the interleukin-12 (IL-12) receptor (IL-12Rβ₂, the signal-transducing component). The study included 38 children followed from birth to the age of 7 years. Twenty one had a cumulative history of atopic disease, whereas 17 had none. Sixteen out of 21 children also had atopic symptoms within the past year (current), out of whom 10 children had atopic airway symptoms. The expression of IL-12Rβ₂ mRNA was analyzed by quantitative real-time PCR and the secretion of interferon-γ (IFN-γ), IL-5 and IL-10 was assessed by enzyme-linked immunosorbent assay (ELISA). Children with current atopic airway symptoms and high levels of total IgE up-regulated IL-12Rβ₂ mRNA expression less than non-atopic children with low IgE levels after IL-2 stimulation. This was accompanied by a low IL-2- and IL-12-induced IFN-γ production, possibly reflecting the reduced capacity of atopic children to up-regulate the IL-12 receptor. As IL-2 is needed to initiate and sustain immune responses and IL-12 promotes Th1 responses, this may contribute to the Th2-skewed pattern in atopic children.     

Expression of and responses to CD2 and CD3 in 18‐month‐old children with and without atopic dermatitis

We hypothesize that atopy is associated with a reduced T‐cell function early in life and an imbalance in cytokine production. The purpose of this study was to investigate the expression of and responses to CD2 and CD3 in children who did or did not develop atopic dermatitis early in life. The expression of CD2 and CD3 was analyzed by flow cytometry, and proliferation of CD2 and CD3 was studied by ³H‐thymidine incorporation in phytohaemagglutinin (PHA)‐ and anti‐CD3‐stimulated peripheral blood mononuclear cells (PBMC) of 18‐month‐old children, 25 with and 29 without atopic dermatitis. Exogenous interleukin (IL)‐2 was added to compensate for possible functional differences in accessory cells. Anti‐CD3‐induced secretion of IL‐4, IL‐5, IL‐6, IL‐10, IL‐13, and interferon‐γ (IFN‐γ) was analyzed by enzyme‐linked immunosorbent assay (ELISA). Atopy was associated with a low proportion of CD2⁺ lymphocytes. Responsiveness to PHA, which activates lymphocytes partly via the sheep erythrocyte receptor, CD2, was reduced in the allergic children. The anti‐CD3‐induced proliferation declined more rapidly with antibody dilution in the allergic than in the non‐allergic children. Atopic dermatitis was associated with high levels of anti‐CD3‐stimulated IL‐5 secretion. The IL‐4/IL‐10 and IL‐4/IFN‐γ ratios were higher in children with elevated total immunoglobulin E (IgE) levels. Skin prick test‐negative children with eczema produced higher levels of IL‐10 than skin prick test‐positive children. In conclusion, atopic children have a reduced T‐cell function. Atopic dermatitis is associated with increased IL‐5 production, while high total IgE levels are associated with high IL‐4/IFN‐γ and IL‐4/IL‐10 ratios.     

Prediction of atopic disease in infancy by determination of immunological parameters: IgE, IgE- and IgG-antibodies to food allergens, skin prick tests and T-lymphocyte subsets

The possibility of predicting the development of atopic diseases up to 18 months of age, by using IgE, IgE- and IgG-antibodies (Ab) to food allergens, skin prick tests (SPT) and T-lymphocyte subsets, was prospectively studied in 163 infants with atopic heredity. IgE determinations in cord blood showed a positive allergy-predictive value of only 21%, using an optimal cut-off limit (≥ 0.9 kU/l). The corresponding figure for a weakly positive RAST (≥ 0.15 < 0.35 PRU/ml) to ovomucoid (OVO) or β-lactoglobulin (BLG) at 6 months of age was 25% and for a positive RAST ≥ 0.35 PRU/ml 100%. The predictive value of positive SPT to ovalbumin (OA), OVO, BLG and whole cow's milk varied between 67 and 100% and for IgG-Ab levels to the same food allergens the predictability did not exceed 30%. Total numbers of T cells (CD2, CD3) were higher (p < 0.05) at delivery among atopic infants, but neither in cord blood nor in blood samples, taken at 2 and 6 months of age, could absolute T-cell subset numbers or the CD4/CD8 ratios predict atopic diseases in more than 45% of the cases. A low sensitivity was observed in most of the parameters studied. Thus, none of the tests used in the present study seems suitable for predicting the development of atopic diseases during early infancy.     

Enhanced production of IL4 but not of IFNλ and IL10 by peripheral blood mononuclear cells from atopic children in response to CD2 plus CD28 stimulation

Peripheral blood mononuclear cells from 16 children with atopic disease (range of IgE levels: 33 - 2892 kU/l) and 12 age matched controls were stimulated either with mAbs specific for CD3, CD2, CD3 plus CD28, CD2 plus CD28, with Tetanus Toxoid, SEA, or PHA plus PMA and their cell proliferation was determined. In addition, their cytokine production (IL2, IL4, ILIO, IFNλ) following selected stimuli was measured. We found that the cells from atopies proliferated significantly better in response to CD2 stimulation than control cells, with no difference in response to CD3 or SEA stimulation. Furthermore, cells from atopies produced significantly higher amounts of IL4 than cells from controls, a difference most pronounced following CD2 plus CD28 stimulation. No differential production was found for IL 10 and IFNλ. We conclude that in atopic children with moderately elevated IgE a hyperreactivity of the CD2 pathway of stimulation and a clear elevation of IL4 but not of IL 10 or IENλ production can be demonstrated.     

Low-dose cyclosporin A microemulsion in children with severe atopic dermatitis: Clinical and immunological effects

Cyclosporin A (CsA) is an effective and well-tolerated treatment for severe childhood atopic dermatitis (AD). By starting at a low dose, the therapeutic safety should be further increased. The aim of this study was to evaluate low-dose CsA in childhood AD with respect to clinical outcome and modulation of T-cell dysregulation. In an open prospective study, 10 children (age: 22–106 months) with severe AD (mean objective SCORAD score > 40 on two baseline measurements at a minimum interval of 2 weeks) were treated with CsA solution for 8 weeks. All patients received a starting dose of 2.5 mg/kg/day, which was increased stepwise in non-responders to a maximum of dose of 5 mg/kg/day. Disease activity was monitored using the SCORAD index. The frequency of cytokine-producing peripheral blood T lymphocytes was analyzed by intracellular cytokine staining, and T-cell numbers were measured by fluorescence-activated cell sorter (FACS) analysis. Twenty healthy age-matched children were included as controls for the immunological data. Nine of the 10 patients had a SCORAD reduction of at least 35%. In seven patients this was achieved with low-dose CsA at 2.5 mg/kg/day (n = 4) and 3.5 mg kg/day (n = 3). Seven of the nine responders experienced no relapse within the 4-week follow-up period. At baseline the percentage of interleukin-4 (IL-4), IL-13, and human leucocyte antigen (HLA)-DR-positive CD3⁺ cells was higher in the patient group than in the controls. After CsA treatment there was a significant reduction in interferon-γ (IFN-γ), IL-2, IL-4, IL-13, and HLA-DR-positive CD3⁺ cells. Hence, in severe pediatric AD, CsA microemulsion, when started at a low dose (2.5 mg/kg/day), improves clinical measures of disease, reduces T-lymphocyte cytokine production, and regulates T-cell activation.     

Correlation between early neonatal diet and atopic symptoms up to 5-7 years of age in very low birth weight infants: follow-up of randomized, double-blind study

The influence of early feeding on the risk of atopic diseases has been studied in full-term newborns, not in very low birth weight infants (VLBW). The study evaluated effect of early feeding of VLBW infants with either cow's milk-based formula (CMF) or extensively hydrolyzed milk formula (HF) on incidence of atopic diseases and markers of atopy at 5-7 years of age. This was a follow-up of the randomized, double-blind study evaluating the influence of different enteral feeding protocols on the early morbidity of VLBW infants. In the original study 80 children were randomly allocated into 2 groups receiving during first month of life HF (experimental group) or CMF (control group). At the age of 5-7 years, 62 children among 74 available (84%) with mean birthweight 1124g were evaluated according to standardized ISAAC (International Study of Asthma and Allergies in Childhood) protocol. Total IgE level, specific IgE, lymphocyte CD4+CCR4+/CD4+CXCR3+ ratio and skin prick tests (SPT) were done. Prevalence of obvious allergic diseases was not significantly different between the studied groups (HF: 12/33; CMF: 6/29; RR [relative risk] HF vs CMF: 1.76; 95%CI [confidence interval]: 0.76–4.09). Comparison of atopic status across groups revealed similar rate of positive markers of atopy: IgE (RR: 2.57 95%CI: 0.91–8,08), SPT (RR: 5.13; 95%CI: 0.93–31.6), lymphocyte CD4+CCR4+/CD4+CXCR3+ ratio (OR: 2.32; 95%CI: 0.78–7.53) in the both studied groups. Based on the carried out follow-up study we were unable to confirm the usefulness of hydrolyzed formula in prevention of allergy in an unselected cohort of very low birth weight infants.     

毛细支气管炎CD4+CD25+调节性T细胞和Foxp3 mRNA表达及与IgE关系

目的：通过对呼吸道合胞病毒(RSV)毛细支气管炎患儿CD4+CD25+调节性T细胞（CD4+CD25+Treg）、Foxp3 mRNA的表达、IgE合成的检测,以探讨其在RSV毛细支气管炎发病机制中的作用。方法：在RSV检测阳性的57例毛细支气管炎患儿中,运用流式细胞仪检测外周血CD4+CD25+Treg的比例,RT-PCR检测Foxp3 mRNA的表达量、ELISA法检测血清总IgE含量。25例健康儿童作为对照组。结果：毛细支气管炎患儿外周血CD4+CD25+Treg细胞数量减少,特应性体质（7.7±1.6%）和非特应性体质组（8.8±2.1%）均低于对照组（10.5±1.6%）（P均<0.01）。毛细支气管炎特应性体质和非特应性体质组外周血Foxp3 mRNA表达亦均低于对照组（P<0.01）。而血清总IgE含量毛细支气管炎特应性体质（241.2±102.5 IU/mL）和非特应性体质组(125.5±63.2 IU/mL)均高于对照组(27.2±10.5 IU/mL)（P<0.01）。外周血CD4+CD25+Treg细胞数量、Foxp3 mRNA表达及血清总IgE含量在毛细支气管炎特应性体质和非特应性体质组之间差异有显著性意义。CD4+CD25+Treg、Foxp3 mRNA与血清IgE水平之间相关密切,r=-0.70,-0.79(均P<0.01)。结论：毛细支气管炎外周血淋巴细胞CD4+CD25+Treg和Foxp3 mRNA表达降低,二者低水平表达使IgE合成增多,共同参与了RSV毛细支气管炎的发病。［中国当代儿科杂志,2009,11（5）：349-353］     

������������ѪTh17ϸ�� CD4+CD25+������ϸ���仯�����벡����ط���?

目的探讨支气管哮喘患儿外周血中辅助T细胞(Th)17细胞和CD4+CD25+调节性T细胞(Treg)的变化与儿童哮喘病情的相关性。方法收集2009年月5月至2010年4月于郑州大学第一附属医院就诊的患儿,均为首次确诊哮喘或规范吸入激素停用>3个月后复发及近1个月内无明显感染者。采用流式细胞仪测定患儿外周血中Th17细胞及CD4+CD25+Treg比例的变化。结果 Th17细胞在哮喘急性期组(2.24%±1.02%)较哮喘缓解期组(1.65%±0.38%)及健康儿童组(1.02%±0.28%)均显著增高(P<0.05),哮喘缓解期组(1.65%±0.38%)和健康儿童组(1.02%±0.28%)无明显差别,CD4+CD25+Treg细胞比例在3组儿童间差异均有统计学意义(F=45.604,P<0.05),与健康儿童组(7.11%±0.89%)相比,哮喘缓解期组(6.05%±0.87%)和哮喘急性期组(5.37%±0.80%)的比例明显下降,而哮喘急性期组较健康儿童组下降。哮喘急性期组轻、中、重度3组之间差异同样有统计学意义。Th17细胞与哮喘患儿病情呈正相关(r=0.649,P<0.05),而CD4+CD25+...     

CTLA-4 expression in T cells of patients with atopic dermatitis

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4; CD152) is a surface molecule of activated T cells with sequence homologous to CD28, and may act as a negative regulator of T-cell activation. In murine animal models, cross-linkage of CTLA-4 molecules on the cell surface results in decreased T-cell proliferation, accompanied by increased interleukin (IL)-2 production and apoptosis. To clarify the activation of peripheral blood T cells, we studied the CTLA-4 expression in 32 patients with atopic dermatitis who visited our institution, and 19 normal children who visited for pre-operative laboratory examination were used as normal controls. Whole blood was obtained from all subjects and stained with anti-CD3, anti-CD4, anti-CD8 monoclonal antibodies (mAb). After erythrocyte lysis with lysing solution, the cells were stained with anti-CTLA-4 mAb, and stained cells were analysed by fluorescence-activated cell sorter (FACScan) flow cytometer. Intracellular expression of CTLA-4 was significantly upregulated in peripheral blood CD3+ T cells (36.8%), CD4+ T cells (21.7%) and CD8+ T cells (18.7%) of patients with atopic dermatitis, compared with normal control (18.3%, 9.7%, 9.8%; respectively). Furthermore, CTLA-4-positive CD3+ T cells in patients with severe atopic dermatitis were significantly higher compared with milder group (42.8% vs. 32.2%). However, no significant difference was obtained in CD4+ and CD8+ T cells. Mean percentage of T cells expressing CTLA-4 in patients with atopic dermatitis was higher than the control group. These observations suggest the possibility that the disease activity can be correlated with the CTLA-4 level.     

Predictive features for persistence of atopic dermatitis in children

Allergen exposure plays an important role in atopic dermatitis (AD). Because immunological mechanisms underlying asthma and AD have great similarities, we evaluated whether features such as allergen sensitization, immune response, disease severity and duration or allergen exposure could be considered predictive for AD persistence. Seventy-one AD children (age range 14–158 months) were enrolled and followed for 3 consecutive years for AD severity using the SCORAD index (SI). At enrollment, reactivity to inhalant and food allergens using the skin prick test (SPT) and house dust mite (HDM) atopy patch test (APT), and HDM allergens in house dust were evaluated. After 3 years, 38 children outgrew their AD (AD^– group), while in 33 AD persisted (AD⁺ group). At enrollment, AD⁺ children had a higher SI, higher rate of positivity to SPT and APT for mites (p = 0.001), and higher environmental exposure to HDM allergens (p = 0.035). The AD⁺ children developed more respiratory symptoms in comparison to AD^– children (p < 0.001). None of the AD^– children presented APT positivity. In our study population, positivity of SPT and APT for HDM, environmental allergen exposure levels and severity of the disease at enrollment presented a significant predictive power towards AD persistence. Subjects with positive skin reactivity to HDM should be considered at risk of AD persistence and of possible development of allergic respiratory disorders.     

High levels of urinary eosinophil protein X in young asthmatic children predict persistent atopic asthma

Levels of urinary eosinophil protein X (U-EPX) and eosinophil counts were measured in 32 children (12–36 months of age) who were hospitalized for acute asthma, and the U-EPX levels were measured in 20 healthy children of the same age. The ability of these parameters to predict persistent asthma (at least one wheezing episode during the last 6 months) and atopic asthma (a positive skin-prick test [SPT]), was evaluated at a follow-up 2 years later. On admission, levels of U-EPX were higher in children with asthma (median: 120 µg/mmol of creatinine; quartiles: 67–123 µg/mmol of creatinine) than in controls (60 µg/mmol of creatinine, 38–74 µg/mmol of creatinine; p< 0.001). The U-EPX level was higher in those with persistent atopic asthma at follow-up (173 µg/mmol of creatinine, 123–196 µg/mmol of creatinine, n = 16), than in those with persistent non-atopic asthma (73 µg/mmol creatinine, 46–105 µg/mmol of creatinine, n = 8; p< 0.05), and higher than in those with transient asthma (no symptoms at follow-up) (106 µg/mmol creatinine; 42–167 µg/mmol of creatinine, n = 8; p< 0.05). By multiple logistic regression analysis, U-EPX was the only parameter able to predict persistent atopic asthma; eosinophil counts, parental atopy, age or gender could not. Parental atopy was the only parameter predictive for persistent asthma, regardless of atopic status. In conclusion, levels of U-EPX, but not eosinophil counts, measured in young children hospitalized with acute asthma can predict the persistence of atopic asthma 2 years later.     

Cytokine, chemokine and secretory IgA levels in human milk in relation to atopic disease and IgA production in infants

The relationship between breast-feeding, IgA production and development of atopic disease in children is a matter of controversy. Some of this controversy might be due to individual differences in the composition of breast milk. The aim of this study was to relate the levels of cytokines, chemokines and secretory (S)-IgA antibodies in breast milk to the development of atopic manifestation and salivary IgA production in infants. Cytokine, chemokine and SIgA levels, as measured with enzyme-linked immunosorbent assay (ELISA), in colostrum and mature milk were analyzed in relation to the development of positive skin-prick tests (SPT), allergic symptoms and salivary IgA antibody production during the first 2 years of life in 53 infants. There was no association between levels of IL-4, -5, -6, -8, -10, -13, -16, IFN-γ, TGF-β1, -β2, RANTES, eotaxin or SIgA levels in the breast milk with either SPT-positivity, development of allergic symptoms or salivary IgA levels during the first 2 years of life in the infants. Thus, differences in the composition of cytokines, chemokines and SIgA in breast milk did not, to any major degree, affect the development of a positive SPT, atopic symptoms, nor salivary IgA antibody production during the first 2 years of life.     

Functional assessment of CD2, CD3 and CD28 on the surface of peripheral blood T-cells from infants at low versus high genetic risk for atopy

Recent studies from several laboratories suggest that the rate of postnatal maturation of T-cell function(s) associated with in vitro activation may be slower in children at high genetic risk for atopy (HR), compared to their normal (low risk; LR) counterparts. The present study compared the in vitro activity of the function-associated surface molecules CD2, CD3 and CD28 in panels of 27 HR and 13 LR infants, with a reference panel of 10 adults, employing assay systems involving T-cell stimulation with MoAbs against these molecules. The response maxima induced by saturating levels of the MoAbs were equivalent in all 3 groups, but T-cells from the HR infants required 10–50 fold higher levels of anti-CD3 stimulation to attain their maximum response, relative to adults (p = 0.02); T-cells from LR infants were also less responsive to anti-CD3 than adults, but these differences were smaller and did not attain statistical significance. It is suggested that these differences are attributable to varying proportions of competent T-memory cells (which respond to low levels of anti-CD3) in PBL from these populations, the postnatal accumulation of which proceeds slowest in the HR group.     

Expression of CD69 on T-cells from HIV-1-infected children and adolescents increases with increasing viral load

We evaluated the use of a whole-blood assay that measures spontaneous and activation-induced CD69 expression on peripheral blood T-cells in vitro for assessment of T-cell function in HIV-1-infected paediatric patients. Heparinized venous blood from 28 HIV-1 positive children and adolescents and 23 healthy controls was incubated for 4 h with or without 5 μg/ml phytohaemagglutinin (PHA). Thereafter, analysis of CD69 expression on CD4⁺ and CD8⁺ T-cells was done by flow cytometry; simultaneously we determined CD4⁺ T-cell counts and plasma HIV-1 viral load. Neither spontaneous nor PHA-induced CD69 expression differed significantly between HIV-1 positive patients and healthy controls. However, T-cells from HIV-1 positive patients with plasma HIV-1 viral load levels above 70 × 10³ copies/ml showed a higher spontaneous CD69 expression than T-cells from patients with lower plasma viral load levels in different stages of the disease. Antiretroviral treatment in four patients reduced spontaneous CD69 expression in CD4⁺ T-cells and PHA-induced CD69 expression in CD4⁺ and CD8⁺ T-cells significantly after 8 weeks of therapy. Conclusion Spontaneous and activation-induced expression of the early (activation) antigen CD69 on peripheral blood T-cells does not distinguish HIV-1 positive patients from HIV-1 negative healthy controls and is not correlated with peripheral blood CD4⁺ T-cell counts. This test may not be a reliable marker for functional T-cell deficiency during early stages of HIV disease. Increased spontaneous as well as PHA-induced CD69 expression on T-cells from HIV-1-infected children and adolescents in vitro may rather reflect HIV-induced pre-activation of T-cells in vivo. Received: 11 February 1998 / Accepted in revised form: 9 July 1998     

尘螨变应性哮喘患儿外周血T淋巴细胞中协同刺激分子和细胞因子的异常表达及其意义

目的分析变应原刺激前后变应性哮喘患儿外周血T淋巴细胞表面协同刺激分子及胞内细胞因子表达的变化,探讨CD28家族不同协同刺激信号在变应性哮喘免疫病理机制中的作用。方法选取尘螨变应性哮喘患儿(哮喘组)和健康儿童(健康对照组)各30例,密度梯度离心法分离其外周血单个核细胞,应用免疫荧光标记和流式细胞术检测尘螨刺激前后体外培养的CD4+T淋巴细胞表面协同刺激分子CD28、可诱导共刺激分子(ICOS)和细胞毒T淋巴细胞相关抗原4(CTLA-4)的表达,运用细胞内染色技术检测CD4+T淋巴细胞内细胞因子γ干扰素(IFN-γ)、IL-4和IL-13的表达。并运用统计学方法比较哮喘组和健康对照组之间的差异。结果哮喘组患儿外周血CD4+T淋巴细胞表面CD28和ICOS的表达与健康对照组比较差异均无统计学意义(Pa>0.05),而CTLA-4的表达显著降低(P<0.01);细胞内IFN-γ表达水平显著升高(P<0.000 1),而IL-4和IL-13表达水平无明显变化(Pa>0.05)。经尘螨刺激后,体外培养的哮喘患儿外周血CD4+T淋巴细胞表面ICOS的表达较健康对照组儿童显著上调(P<0.000 1),CD28和CTLA-4的表达则无明显变化(Pa>0.05);细胞内细胞因子IL-4和IL-13的表达显著上调(Pa<0.000 1),而IFN-γ的表达则无明显差异(P>0.05)。结论变应性哮喘患儿外周血存在组成性的CTLA-4的表达下调和细胞因子IFN-γ的表达上调,介导Th1型细胞的异常活化;而变应原尘螨的刺激又介导了ICOS依赖的Th2型细胞的分化,导致Th1/Th2失衡。     

CD4+ cells from patients with Common Variable Immunodeficiency have a reduced ability of CD40 ligand membrane expression after in vitro stimulation

Background: Common Variable Immunodeficiency (CVID) is characterized by defective antibody production. This has been variably attributed to intrinsic B-cell defects or to T-cell disfunctions. Recently, it has been reported that the expression of the CD40 Ligand (CD40L), a T-cell surface molecule that plays a critical role in the cell-contact-mediated helper signals provided to B-cells, is defective in a subset of patients with CVID.
Methods: To demonstrate that the defective expression is due to intrinsic functional abnormalities of CD4+ lymphocytes, CD4+ cells were purified from eight patients with CVID and eight age-paired controls, stimulated with PMA+Ionomycin. and studied for CD40L expression by flow cytome-try using specific monoclonal antibodies.
Results and conclusions: The percentage of CD4+ cells expressing CD40L after optimal stimulation was correlated with age both in patients with CVID (r: 0. 74: p: 0.04) and in healthy controls (r: 0. 73; p: 0.04). The percentage of CD40L+ cells was reduced in patients with CVID compared to that of controls (p: 0.02 when data are paired for age) with a reduced density of expression (p: < 0.01). The defect was variable in different patients and in some cases it was marginal.     

急性白血病患儿CD4~+CD25~+调节性T细胞和NK细胞免疫作用探讨

目的观察外周血CD4+CD25+调节性T细胞(CD4+CD25+Treg)及自然杀伤细胞(na-ture killer cell,NK)在白血病患儿及非白血病患儿的不同,了解白血病患儿的免疫状态,探讨CD4+CD25+Treg细胞及NK细胞在小儿急性白血病肿瘤免疫中的意义。方法以流式细胞术检测急性白血病初诊患儿及非白血病患儿各30例的外周血CD4+CD25+Treg细胞、NK细胞的数量及比例。结果外周血CD4+CD25+CD127-细胞占CD4+T细胞的比例白血病组为(11.45±1.41)%,显著高于对照组为(6.98±1.09)%(P<0.05)。而NK细胞数量白血病组为(5.13±2.97)%,显著低于对照组为(15.06±3.91)%(P<0.05)。结论 (1)急性白血病患儿外周血CD4+CD25+Treg细胞数量升高,NK细胞数量降低,表明急性白血病患儿NK细胞免疫功能处于抑制状态。CD4+CD25+Treg细胞可能在白血病的发生、发展中起一定作用。(2)通过检测CD4+CD25+CD127-T细胞可较好的反映CD4+CD25+Treg细胞的比例,简便可行、重复性好、检测结果准确、可靠。