Altered Th1/Th2 commitment in human CD4+ T cells with ageing

The human immune system undergoes continuous remodelling with the advancement of age. Since age-associated functional alterations in the immune system could be caused by a possible change in helper T cell regulation in elderly subjects, we comparatively studied the function of CD4+ T cells in peripheral blood obtained from both young and old healthy volunteers. Upon cell activation by phorbol myristate acetate and ionomycin, the proportion of CD4+ T cells containing interferon-gamma (IFN-gamma) was found to be greater in the old subjects. Utilizing a co-culture system, which activated CD4+ T cells via the TCR/CD3 complex and CD28, we found that CD4+ T cells from the old subjects secreted more IFN-gamma and IL-2, but less IL-4, than those from the young subjects. Upon cell activation by co-culture, CD4+ T cells from the old subjects expressed more CD26, CD40L, and LFA-1, but less CD30, than those from the young. These results together suggest that the microenvironment in which CD4+ T cells develop in older people may cause production of more cells committed to Th1 than that in younger subjects.     

树突状细胞在慢性阻塞性肺疾病中的作用

树突状细胞(dendritic cells,DCs)作为机体内最重要的一种抗原提呈细胞,在慢性阻塞性疾病(chronic obstructive pulmonary disease,COPD)炎症的发生发展过程中具有重要作用.长期烟雾刺激,会导致肺部DCs亚群失衡,DCs向肺部炎症部位募集,通过与CD4+T细胞的相互作用,导致Th17/调节性T细胞免疫失衡,介导COPD细胞免疫过程.此外,COPD肺组织中肺泡弹性蛋白降解形成的具有抗原活性的弹性蛋白肽与肺部DCs的免疫作用,在COPD疾病的持续进展过程中具有十分重要的作用.     

The potential impact of CD4+ T cell activation and enhanced Th1/Th2 cytokine ratio on HIV-1 secretion in the lungs of individuals with advanced AIDS and active pulmonary infection

Bronchoalveolar lavage fluid (BALF) provides a source of mucosal CD4(+) T cells. We investigated the physiological properties of T lymphocytes from BALF and blood and their role on the dynamic of HIV-1 replication among AIDS patients with active lung infections. Pulmonary CD4(+) T cells consist mainly of effector memory cells (CD45RO(+) and CCR7(-)) with increased expression of activation markers (HLA-DR(+) and CD69(+)) when compared to the blood counterpart. We observed a high frequency of BALF cells capable of secreting HIV-1-Ags suggesting that the local lung environment may support favorable conditions for CD4(+) T lymphocytes harboring HIV-1 DNA to initiate the viral cycle. Nevertheless, the high number of IFN-γ-producing cells and the predominance of Th1 immune response in the lung could limit the secretion of HIV-1 RNA. In conclusion, the capacity of activated CD4(+) T cells to produce HIV-1 is driven by both the level and quality of cellular activation in the lung.     

Preferential T(h)2 polarization by OCH is supported by incompetent NKT cell induction of CD40L and following production of inflammatory cytokines by bystander cells in vivo

The altered glycolipid ligand OCH is a selective inducer of T(h)2 cytokines from NKT cells and a potent therapeutic reagent for T(h)1-mediated autoimmune diseases. Although we have previously shown the intrinsic molecular mechanism of preferential IL-4 production by OCH-stimulated NKT cells, little is known about the extrinsic regulatory network for IFN-gamma production. Here we demonstrate that OCH induces lower production of IFN-gamma, not only by NKT cells but also by NK cells compared with alpha-galactosylceramide. OCH induced lower IL-12 production due to ineffective primary IFN-gamma and CD40 ligand expression by NKT cells, and resulted in lower secondary IFN-gamma induction. Co-injection of a sub-optimal dose of IFN-gamma and stimulatory anti-CD40 mAb compensates for the lower induction of IL-12 by OCH administration. IL-12 converts OCH-induced cytokine expression from IL-4 predominance to IFN-gamma predominance. Furthermore, CpG oligodeoxynucleotide augmented IL-12 production when co-administrated with OCH, resulting in increased IFN-gamma production. Taken together, the lower IL-12 production and subsequent lack of secondary IFN-gamma burst support the effective T(h)2 polarization of T cells by OCH. In addition, highlighted in this study is the characteristic property of OCH that can induce the differential production of IFN-gamma or IL-4 according to the availability of IL-12.     

Molecular mechanisms of T-cell receptor and costimulatory molecule ligation/blockade in autoimmune disease therapy

Summary:  Pro-inflammatory CD4⁺ T-cell-mediated autoimmune diseases, such as multiple sclerosis and type 1 diabetes, are hypothesized to be initiated and maintained by activated antigen-presenting cells presenting self antigen to self-reactive interferon-γ and interleukin-17-producing CD4⁺ T-helper (Th) type 1/Th17 cells. To date, the majority of Food and Drug Administration-approved therapies for autoimmune disease primarily focus on the global inhibition of immune inflammatory activity. The goal of ongoing research in this field is to develop both therapies that inhibit/eliminate activated autoreactive cells as well as antigen-specific treatments, which allow for the directed blockade of the deleterious effects of self-reactive immune cell function. According to the two-signal hypothesis, activation of a naive antigen-specific CD4⁺ T cell requires both stimulation of the T-cell receptor (TCR) (signal 1) and stimulation of costimulatory molecules (signal 2). There also exists a balance between pro-inflammatory and anti-inflammatory immune cell activity, which is regulated by the type and strength of the activating signal as well as the local cytokine milieu in which the naive CD4⁺ T cell is activated. To this end, the majority of ongoing research is focused on the delivery of suboptimal TCR stimulation in the absence of costimulatory molecule stimulation, or potential blockade of stimulatory accessory molecules. Therefore, the signaling pathways involved in the induction of CD4⁺ T-cell anergy, as apposed to activation, are topics of intense interest.     

Common gamma chain cytokines promote regulatory T cell development and survival at the CD4+ CD8+ stage in the human thymus

Thymic commitment of human FOXP 3⁺ regulatory T cells begins at the double‐positive (DP ) CD 4⁺ CD 8⁺ stage. In the current study, we show that interleukin‐2 promotes the development of FOXP 3⁺ thymocytes and enhances their survival at the DP phase. IL ‐2 increases the frequency of FOXP 3⁺ cells and promotes the Treg phenotype after TCR ‐mediated positive selection at the most mature DP stage. However, it has no effect on FOXP 3⁺ cells at the earlier maturation steps before positive selection. DP FOXP 3⁺ thymocytes are highly susceptible to cell death but IL ‐2 promotes their survival. The anti‐apoptotic protein BCL ‐2 (B Cell Lymphoma 2) is also upregulated by IL ‐2 at the most mature DP stage. In addition to IL ‐2, we identify IL ‐15 to have a significant role in the upregulating FOXP 3 and survival of Tregs at the DP phase. IL ‐7 also increases the expression of BCL ‐2 in the DP FOXP 3⁺ thymocytes. Our results indicate that common gamma chain cytokines IL ‐2, IL ‐7 and IL ‐15 promote the development of regulatory T cells at the most mature DP stage after TCR ‐mediated positive selection through suppressing cell death.     

在单个细胞水平上分析抗原特异性Th1/Th2细胞因子产生的关联性

目的　在单个细胞水平上 ,观察抗原特异性Th1和Th2细胞因子产生的关联性 ,为进一步阐明CD4 T细胞的分化 ,细胞因子产生的相互关系及其特征提供理论依据。方法　从OVA TCR转基因小鼠的脾和淋巴结中分离CD4 T细胞 ,在体外在抗原提呈细胞存在下 ,用卵白蛋白 (OVA)抗原多肽刺激 3d后 ,再以同样的培养条件刺激 5～ 6h ,固定细胞 ,然后进行细胞表面和细胞内细胞因子染色 ,最后利用流式细胞仪在单个细胞水平上分析Th1和Th2细胞因子产生的关联性。结果　抗原特异性CD4 T细胞经抗原再一次刺激后 ,分泌Th1(IFN γ和IL 2 )和Th2 (IL 4、IL 5和IL 10 )细胞因子。IL 12促进IFN γ的表达 ,控制Th2细胞的分化。此外 ,大多数抗原特异性CD4 T细胞只产生 1种细胞因子 ,1个细胞同时产生 2种细胞因子极少见。结论　在单个细胞水平上的研究结果表明 ,经抗原短暂刺激后 (3d) ,不同的CD4 T细胞亚群只产生 1种Th1和 或Th2细胞因子 ,同时产生两种以上者占有很低的比率     

Differential regulation of Th1 responses and CD154 expression in human CD4+ T cells by IFN-alpha

Like interleukin (IL)-12, interferon (IFN)-alpha has been shown to play an important role in inducing human Th1 responses. Recent studies have shown that human Th1 responses driven by IL-12 are associated with enhanced expression of CD154. The present study examined the effects of IFN-alpha on CD154 expression in human CD4+ T cells, with special attention to the relationship with Th1 responses. Highly purified CD4+ T cells from healthy donors were stimulated with immobilized anti-CD3 with or without IFN-alpha and IL-12 in the complete absence of accessory cells. IFN-alpha suppressed CD154 protein and mRNA expression in CD4+ T cells at the initial phase of activation with immobilized anti-CD3, but enhanced it in the subsequent maturation phase irrespective of the presence of IL-12. By contrast, IFN-alpha by itself did not enhance IFN-gamma production or mRNA expression in CD4+ T cells in the absence of IL-12 even in the presence of stimulation with anti-CD28, but enhanced it in the presence of IL-12. Accordingly, IFN-alpha enhanced IL-12Rbeta2 mRNA expression in anti-CD3-stimulated CD4+ T cells. Neither IFN-alpha nor IL-12 influenced the stability of CD154 mRNA in anti-CD3-activated CD4+ T cells. These results indicate that IFN-alpha by itself enhances CD154 expression in CD4+ T cells independently of the induction of IFN-gamma mRNA expression. The data also suggest that the optimal induction of human Th1 responses by IFN-alpha might require the presence of IL-12 and that the induction of Th1 responses and CD154 expression in human CD4+ T cells might be regulated through different mechanisms.     

灭活HIV-1颗粒对人CD4+T细胞活化和全血Th1/Th2细胞因子分泌的影响

目的：体外研究AT-2灭活的HIV-1颗粒对人CD4+T细胞活化和全血(whole blood，WB) Th1/Th2细胞因子分泌的影响。方法:AT-2灭活HIV-1ⅢB型病毒颗粒，运用ELISA法测定所制备的灭活病毒中p24抗原的含量，按照1/500、1/50和1/5 (V/V)的浓度加入到WB中，以植物血凝素(phytohemagglutinin，PHA)组为阳性对照；24 h后，收集WB培养上清，运用流式微球分析法（cytometric bead array，CBA）检测WB分泌Th1 (IL-2、IFN-γ和TNF-α)和Th2 (IL-4、IL-6和IL-10)细胞因子水平；同时运用免疫荧光抗体染色技术结合流式细胞术检测WB中CD4+T细胞早期活化标记分子CD69的表达百分率。结果:我们所制备的灭活病毒中p24抗原的含量为85.5 μg/L；24 h后，空白对照组中，CD4+T细胞CD69的表达百分率为(1.62±0.63)%，PHA组为(38.82±6.00)%，HIV-1(1/500)组为(3.83±1.07)%，HIV-1(1/50)组为(5.94±0.85)%，HIV-1(1/5)组为(9.30±1.22)%；空白对照组WB培养上清中细胞因子主要为IL-6和TNF-α，PHA组中Th1和Th2细胞因子全部升高，3个浓度的HIV-1组中Th1和Th2细胞因子也全部升高。结论:AT-2灭活的HIV-1ⅢB颗粒能够明显引起WB中CD4＋T细胞活化，并上调WB培养上清中Th1和Th2细胞因子的水平，其机制可能是除了HIV-1病毒蛋白的作用外，HIV-1出胞时，许多宿主细胞来源的免疫分子整合到病毒颗粒包膜中，而模拟抗原提呈细胞，从而产生免疫调节作用。     

T helper 1 (Th1)/Th2 cytokine expression shift of peripheral blood CD4+ and CD8+ T cells in patients at the post-acute phase of stroke

Local humoral and cellular immune responses modulate the inflammatory processes involved in the development of atherosclerotic lesions, as well as in the evolution of brain infarcts in stroke patients. The role of systemic adaptive immunity on the progression of such disease manifestations is less clear. In the current study, we evaluated the percentages of T helper 1 (Th1) [interleukin (IL)-2, interferon (IFN)-gamma] and Th2 (IL-4, IL-10) cytokine-producing peripheral blood CD4+ and CD8+ T cells in 23 patients with a history of ischaemic stroke (IS) at the chronic stable phase of the disease (median post-stroke time 34.5 months). Seven stroke-free individuals matched for age and vascular risk factors (matched controls, MC) were collected for comparison. To measure cytokine values at baseline and after stimulation, we used a flow cytometry method of intracellular cytokine staining. Intrinsic Th1 and Th2 cytokine production in unstimulated T cells was negligible in all study participants. Following mitogenic stimulation with phorbol 12-myristate13-acetate/ionomycin, both the IS and the MC groups exhibited a similarly strong Th1 response; IL-2 production predominated in the CD4+ T cells and IFN-gamma in the CD8+ T cells. However, when measuring the Th2 cytokine-production capacity post-stimulation, a significant increase in the percentage of IL-4-producing T cells was observed in the IS groups, compared with the MC group, resulting in a significantly lower ratio of IFN-gamma-/IL-4-producing T cells. No such Th2 enhancement could be confirmed for the case of IL-10. We propose that in IS patients there is a systemic shift of the immune system towards Th2 responses at the late post-acute phase of stroke.     

Endogenous protein and enzyme fragments induce immunoglobulin E‐independent activation of mast cells via a G protein‐coupled receptor,MRGPRX2

Mast cells play a central role in inflammatory and allergic reactions by releasing inflammatory mediators through 2 main pathways, immunoglobulin E‐dependent and E‐independent activation. In the latter pathway, mast cells are activated by a diverse range of basic molecules (collectively known as basic secretagogues) through Mas‐related G protein‐coupled receptors (MRGPR s). In addition to the known basic secretagogues, here, we discovered several endogenous protein and enzyme fragments (such as chaperonin‐10 fragment) that act as bioactive peptides and induce immunoglobulin E‐independent mast cell activation via MRGPRX 2 (previously known as MrgX2), leading to the degranulation of mast cells. We discuss the possibility that MRGPRX 2 responds various as‐yet‐unidentified endogenous ligands that have specific characteristics, and propose that MRGPRX 2 plays an important role in regulating inflammatory responses to endogenous harmful stimuli, such as protein breakdown products released from damaged or dying cells.     

Expression of cell interaction molecules by immature rat thymocytes during passage through the CD4+8+ compartment: developmental regulation and induction by T cell receptor engagement of CD2, CD5, CD28, CD11a,CD44 and CD53

Rat thymocytes of the T cell receptor^low (TcR^low) CD4⁺8⁺ subset which is the target of repertoire selection are heterogeneous with respect to expression of the cell interaction (CI) molecules CD2, CD5, CD11a/CD18 (LFA-1), CD28 and CD44. We show that this heterogeneity is due to the developmental regulation of these CI molecules during passage through the CD4⁺8⁺ compartment, and to up-regulation by TcR engagement. Thus, cohorts of CD4⁺8⁺ cells differentiating synchronously in vitro from their direct precursors, the immature CD4^?8⁺ cells, were homogeneous with regard to CI molecule expression. Upon entry into the CD4⁺8⁺ compartment, they expressed relatively high levels of CD2 and CD44, and moderate levels of CDS, CD28 and CD11a. CD2, CD28 and CD44 were slightly down-regulated during the following 2 days, whereas CD5 slightly increased and CD11a remained constant. TcR stimulation using immobilized monoclonal antibodies resulted in rapid and dramatic up-regulation of CD2, CD5 and CD28 and, to a lesser extent, of CD11a and CD44. Finally CD53, a triggering structure absent from unstimulated CD4⁺8⁺ thymocytes was also rapidly induced by TcR stimulation. Inclusion of interleukin (IL)-2, IL-4, or IL-7 in this in vitro differentiation system did not affect the levels of CI molecules studied. Since the high levels of CI molecules induced by TcR-stimulation correspond to those found in vivo on TcR^intermediate thymocytes known to be undergoing repertoire selection, these results suggest that upregulation of CI molecules by TcR engagement provides a mechanism by which thymocytes that have entered the selection process gain preferential access to further interactions with stromal and lymphoid cells in the thymus.     

Defective suppression of Th2 cytokines by CD4+CD25+ regulatory T cells in birch allergics during birch pollen season

BACKGROUND: CD4(+)CD25+ regulatory T cells suppress proliferation and cytokine production by human T cells both to self-antigens and exogenous antigens. Absence of these cells in human newborns leads to multiple autoimmune and inflammatory disorders together with elevated IgE levels. However, their role in human allergic disease is still unclear. OBJECTIVE: This study aimed to evaluate the capacity of CD4(+)CD25+ regulatory T cells to suppress proliferation and cytokine production outside and during birch-pollen season in birch-allergic patients relative to non-allergic controls. METHODS: CD4+ cells were obtained from blood of 13 birch-allergic patients and six non-allergic controls outside pollen season and from 10 birch-allergic patients and 10 non-allergic controls during birch-pollen season. CD25+ and CD25- fractions were purified with magnetic beads and cell fractions, alone or together in various ratios, were cultured with antigen-presenting cells and birch-pollen extract or anti-CD3 antibody. Proliferation and levels of IFN-gamma, IL-13, IL-5 and IL-10 were measured by thymidin incorporation and ELISA, respectively. Numbers of CD25+ cells were analysed by flow cytometry. RESULTS: CD4(+)CD25+ regulatory T cells from both allergics and non-allergics potently suppressed T cell proliferation to birch allergen both outside and during birch-pollen season. However, during season CD4(+)CD25+ regulatory T cells from allergic patients but not from non-allergic controls were defective in down-regulating birch pollen induced IL-13 and IL-5 production, while their capacity to suppress IFN-gamma production was retained. In contrast, outside pollen season the regulatory cells of both allergics and non-allergic controls were able to inhibit T-helper 2 cytokine production. CONCLUSION: This is the first study to show differential suppression of Th1 and Th2 cytokines, with CD4(+)CD25+ regulatory T cells from birch-pollen-allergic patients being unable to down-regulate Th2, but not Th1 responses during birch-pollen season.     

Role of increased CD8/CD28(null) T cells and alternative co-stimulatory molecules in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease; it is a leading cause of death and existing treatments have no proven disease-modifying effect. The mechanisms underlying this resistance are largely unknown, but suggest the presence of some self-maintaining pathogenic process, possibly initiated by cigarette smoking, that prevents the normal resolution of inflammation. We have previously reported increased production of proinflammatory cytokines and granzyme b by CD8(+) T cells in COPD; costimulatory receptor/ligand interactions required include CD80:86/CD28, B7-1/CTLA4, 4-1BB/1BBL and OX40/OX40L. We hypothesized that a dysregulated expression/function of these molecules may play a role in inflammatory/autoimmune components of COPD. We analysed T cell co-stimulatory molecules in blood from 34 controls, 15 smokers and 48 COPD subjects. We assessed the potential functional relevance of CD8/CD28(null) cells in COPD by measuring their production of proinflammatory cytokines, co-stimulatory molecules, granzyme and perforin. A smoke-exposed murine model was applied to investigate the relative expression of CD8/CD28(null) T cells in blood, lung tissue and airway. CD8/CD28(null) cells were increased in both current- and ex-smoker COPD groups; these cells expressed significantly more interferon (IFN)-γ, OX40, 4-1BB, CTLA4, granzyme and perforin when stimulated than CD8/CD28(+) T cells. There were no changes in CD4/CD28(null) T cells. In mice exposed to cigarette smoke for 12 weeks, CD8/CD28(null) T cells were significantly increased in the airway with a trend for an increase in lung tissue and blood. Increased production of proinflammatory cytokines and expression of alternative co-stimulatory molecules by CD8/CD28(null) T cells may play a role in inflammatory or autoimmune responses in COPD and identify therapeutic targets.     

High-frequency activation of single CD4+ and CD8+ T cells to proliferate and secrete cytokines using anti-receptor antibodies and IL-2(1).

A high cloning efficiency single-cell culture system was developed to define the activation requirements of isolated CD4+ and CD8+ T cells to proliferate and secrete cytokines. T cells were triggered using solid-phase anti-CD3 and anti-CD4 or anti-CD8 antibodies plus rIL-2. Activation was measured by microscopic scoring of proliferation and by measurement of cytokine production using the cytokine-responsive cell lines FDC-P1, which responds to GM-CSF, IL-3, IFN-gamma and IL-4, and 32D clone 3 which responds to IL-3 only. Whilst anti-CD3 plus rIL-2 triggered only 4% of peripheral T cells to proliferate, anti-CD3 plus anti-CD8 mAb triggered about 40% of CD8+ T cells; 80% of the resultant clones secreted cytokine and 90% of these were IL-3+. Anti-CD3 plus anti-CD4 mAb triggered proliferation in about 20% of CD4+ T cells, of which 34% formed cytokine-producing clones with 47% of these secreting IL-3. In addition to responding at higher frequency, CD8+ T cells formed larger clones which produced higher levels of cytokines than CD4+ cells. Cell separation on the basis of Pgp-1 expression suggested that this culture system did not select for previously activated cells. Whereas Pgp-1+ T cells from keyhole limpet haemocyanin (KLH)-primed mice were enriched in KLH-specific cells, no significant differences were observed in the clonogenicity or cytokine-secreting capacity of Pgp-1+ and Pgp-1- T cells from normal mice.     

A role for CD4+CD25+ T cells in regulation of the immune response during human tuberculosis

Active tuberculosis (TB) is associated with prolonged suppression of Mycobacterium tuberculosis (MTB)-specific immune responses, but mechanisms involved are understood incompletely. We investigated a potential role for CD4+CD25+ regulatory T cells in depressed anti-MTB immunity by evaluating serially CD4 cell phenotype and interferon (IFN)-gamma production by mononuclear cells from patients with TB. At diagnosis, frequencies of CD4+CD25+ T cells were increased in blood from TB patients compared to healthy purified protein derivative (PPD)-positive controls (with a history of prior TB exposure), and remained elevated at completion of therapy (6 months). By contrast, expression of another activation marker, CD69, by CD4 T cells was increased at diagnosis, but declined rapidly to control levels with treatment. Among CD4+CD25+ T cells from TB patients at diagnosis those expressing high levels of CD25, probably representing regulatory T cells, were increased 2.9-fold when compared to control subjects, while MTB-stimulated IFN-gamma levels in whole blood supernatants were depressed. A role for CD4+CD25+ T cells in depressed IFN-gamma production during TB was substantiated in depletion experiments, where CD25+-depleted CD4 T cells produced increased amounts of IFN-gamma upon MTB stimulation compared to unseparated T cells. At follow-up, IFN-gamma production improved most significantly in blood from TB patients with high baseline frequencies of CD4+CD25+ T cells (more than threefold higher than controls for both total and CD25hi+ CD4 T cells), who also had a significant drop in frequencies of both total and 'regulatory' CD4+CD25+ T cells in response to treatment. Expansion of CD4+CD25+ regulatory T cells during active TB may play a role in depressed T cell IFN-gamma production.     

尼古丁对卵蛋白致敏大鼠CD4+T细胞Th1/Th2细胞因子和T-bet/GATA-3表达的影响

目的 研究尼古丁对卵白蛋白致敏大鼠CD4+T淋巴细胞Th1/Th2平衡的影响.方法 卵清白蛋白(OVA)腹腔注射致敏Wistar大鼠,CD4+T淋巴细胞纯化柱分离大鼠脾脏CD4+T细胞,体外培养,将细胞随机分为4组:对照组、1 μg/ml尼古丁组、10 μg/ml尼古丁组、100μg/ml尼古丁组(各组加等浓度的OVA),不同浓度尼古丁刺激24 h,酶联免疫吸附试验(ELISA)检测细胞培养上清液IFN-γ和IL-4含量,实时荧光定量PCR检测培养细胞T-bet和GATA-3 mRNA的表达.结果 (1)不同尼古丁干预组IFN-γ的表达分别为(113.78±6.06) ng/L、(70.31±7.26) ng/L、( 20.00±2.14)ng/L,均较对照组[(142.30±5.89) ng/L]明显减少,差异有统计学意义(F=265.52,P＜0.01);不同尼古丁干预组IL-4的表达分别为(50.97±3.07) ng/L、(69.49±3.91) ng/L、( 93.63±4.56)ng/L,均较对照组[ (36.91±3.24) ng/L]明显增加,差异有统计学意义(F=128.67,P＜0.01).(2)不同尼古丁干预组T-bet mRNA分别为0.73±0.03、0.57±0.04、0.31 ±0.00,均较对照组(0.98±0.09)明显减少,差异有统计学意义(F=75.76,P＜0.01);不同尼古丁干预组GATA-3 mRNA的表达分别为4.31±0.26、5.16±0.23、1.56±0.14,均较对照组(1.00±0.07)明显增加,差异有统计学意义(F=348.41,P＜0.01).结论 尼古丁可能通过促进转录因子GATA-3 mRNA的表达同时抑制T-bet mRNA的表达,在哮喘Th2过敏性气道炎症中具有一定的作用.     

Activating and inhibitory receptors on synovial fluid natural killer cells of arthritis patients: role of CD94/NKG2A in control of cytokine secretion

Natural killer (NK) cells are activated early during inflammatory events and contribute to the shaping of the ensuing adaptive immune response. To further understand the role for NK cells in inflammation, we investigated the phenotype and function of synovial fluid (SF) NK cells from patients with chronic joint inflammation, as well as from patients with transient inflammation of the knee following trauma. We confirm that synovial NK cells are similar to the well-characterized CD56(bright) peripheral blood (PB) NK-cell subset present in healthy individuals. However, compared to this PB subset the synovial NK cells express a higher degree of activation markers including CD69 and NKp44, the latter being up-regulated also on CD56(bright) NK cells in the PB of patients. Activated synovial NK cells produced interferon-gamma and tumour necrosis factor, and the production was further up-regulated by antibody masking of CD94/NKG2A, and down-regulated by target cells expressing human leucocyte antigen-E in complex with peptides known to engage CD94/NKG2A. We conclude that synovial NK cells have an activated phenotype and that CD94/NKG2A is a key regulator of synovial NK-cell cytokine synthesis.