Immune regulation by CD4+CD25+ T cells and interleukin-10 in birch pollen-allergic patients and non-allergic controls

BACKGROUND: CD4+CD25+ regulatory T (Treg) cells and the cytokines IL-10 or TGF-beta play key roles in the maintenance of T cell homeostasis and tolerance to infectious and non-infectious antigens such as allergens. OBJECTIVE: To investigate the regulation of immune responses to birch pollen allergen compared with influenza antigen by Treg cells obtained from birch pollen-allergic patients and non-allergic controls. METHODS: Peripheral blood was collected from 10 birch pollen-allergic patients and 10 non-allergic healthy controls. CD4+CD25+ and CD4+CD25- cells isolated by magnetic-activated cell sorting were co-cultured and stimulated with birch pollen extract or influenza vaccine in the absence or presence of anti-IL-10 or soluble TGF-betaRII. RESULTS: CD4+CD25+ cells from non-allergic controls were able to suppress influenza antigen and birch pollen stimulated effector cell proliferation, whereas CD4+CD25+ cells from allergic patients suppressed influenza antigen-, but not birch pollen-stimulated proliferation. The production of Th1 cytokines, but not Th2 cytokines, was suppressed by CD4+CD25+ cells from both allergic patients and controls, upon stimulation with birch pollen extract. Neutralization of IL-10 led to significantly increased production of IFN-gamma in cultures with CD4+CD25- T effector cells. In addition, six-fold higher concentrations of TNF-alpha were detected after neutralization of IL-10 in both CD4+CD25- and CD4+CD25+ cell cultures from allergic patients and controls. CONCLUSION: We demonstrate that the allergen-specific suppressive function of CD4+CD25+ cells from allergic patients is impaired compared with non-allergic controls. Moreover, neutralization of IL-10 enhances the production of TNF-alpha, suggesting counter-acting properties of IL-10 and TNF-alpha, where IL-10 promotes tolerance and suppression by Treg cells and TNF-alpha promotes inflammatory responses.     

Regulatory activity of human CD4 CD25 T cells depends on allergen concentration, type of allergen and atopy status of the donor

Regulatory CD4+ CD25+ FoxP3-positive T cells (Treg) are functional in most atopic patients with allergic rhinitis and are able to inhibit T helper type 1 (Th1) and Th2 cytokine production of CD4+ CD25- T cells. This study was designed to analyse the following additional aspects: influence of allergen concentration, influence of the type of allergen, and influence of the atopy status of the donor on the strength of the regulatory activity. CD4+ CD25- T cells from healthy non-atopic controls or from grass-pollen-allergic or wasp-venom-allergic donors were stimulated alone or in the presence of Treg with autologous mature monocyte-derived dendritic cells which were pulsed with different concentrations of the respective allergens. Treg from grass-pollen-allergic donors failed to inhibit proliferation but not cytokine production of CD4+ CD25- T cells at high antigen doses while Treg from non-atopic donors did not fail at these allergen concentrations. Proliferative responses and cytokine production of CD4+ CD25- T cells from most of the examined wasp-venom-allergic patients were not inhibited at any concentration of wasp venom. The use of wasp venom- or phospholipase A2-pulsed dendritic cells for stimulation of CD4+ CD25- T cells from donors who were not allergic to wasp stings only resulted in an inhibited proliferation and Th2 cytokine production by Treg at 10-fold lower than the optimal concentration, while interferon-gamma production was inhibited at all concentrations investigated. These data demonstrate that in allergic diseases the function of Treg is dependent on the concentration and the type of the respective allergen with different thresholds for individual allergens and patients.     

Induction of Th2 cell differentiation in the primary immune response: dendritic cells isolated from adherent cell culture treated with IL-10 prime naive CD4+ T cells to secrete IL-4

A number of observations indicate that exposure to IL-4 is essential for the priming of Th2-type effector T cells and that exposure to IL-12 is essential for the priming of Th1-type effector T cells. However, the initial source of IL-4 in the early immune response has not been clearly identified. Dendritic cells (DC) are the most potent antigen- presenting cells (APC) in priming naive T cells. In this report, we show that DC exposed to IL-10 may play an important role in the priming of IL-4-secreting cells in the early immune response. DC isolated from splenic adherent cell cultures treated with rIL-10 (IL-10-DC) primed naive ovalbumin (OVA)-TCR transgenic T cells to secrete IL-4 upon re- stimulation with OVA and splenic APC. By contrast, DC isolated from rIL- 12, rIL-4 or control treated cultures induced almost exclusively Th1- type effector T cells. IL-4 secretion was detected in the primary cultures of IL-10-DC plus naive CD4+ T cells and the priming of IL-4- secreting T cells by IL-10-DC was dependent on endogenous IL-4 production in the priming culture since anti-IL-4 neutralizing antibody completely abrogated the priming of IL-4-secreting cells. Anti-B7-2 but not anti-B7-1 inhibited the ability of IL-10-DC to prime T cells to secrete IL-4. Furthermore, the ability of IL-10 DC to prime for IL-4- secreting T cells was closely related to the down-regulation of CD40 ligand-mediated IL-12 p70 production by DC in the primary cultures and was markedly reduced by adding exogenous IL-12 to the priming cultures. Thus, our findings indicate that early immunologic events that drive Th2 differentiation involve the effects of IL-10 on DC.      

Th9细胞与自身免疫性疾病

Th1、Th2、Th17和调节性T细胞（Treg）亚群是CD4＋T细胞亚群中的重要成员,其参与了人类及动物自身免疫性疾病的发病过程.既往认为,IL-9是由CD4＋Th2细胞分泌的细胞因子,是机体免疫应答中重要的调节因子.最近研究表明,机体内可能存在着一群新型的具有分泌IL-9和IL-10能力的CD4＋Th细胞亚群,称之为＂Th9＂细胞.该细胞亚群与自身免疫性疾病的相关性尚不清楚.     

Th1 cells induce and Th2 inhibit antigen-dependent IL-12 secretion by dendritic cells

Dendritic cells are the most relevant antigen-presenting cells (APC) for presentation of antigens administered in adjuvant to CD4⁺ T cells. Upon interaction with antigen-specific T cells, dendritic cells (DC) expressing appropriate peptide-MHC class II complexes secrete IL-12, a cytokine that drives Th1 cell development. To analyze the T cell-mediated regulation of IL-12 secretion by DC, we have examined their capacity to secrete IL-12 in response to stimulation by antigen-specific Th1 and Th2 DO11.10 TCR-transgenic cells. These cells do not differ either in TCR clonotype or CD40 ligand (CD40L) expression. Interaction with antigen-specific Th1, but not Th2 cells, induces IL-12 p40 and p75 secretion by DC. The induction of IL-12 production by Th1 cells does not depend on their IFN-γ secretion, but requires direct cell-cell contact mediated by peptide/MHC class II-TCR and CD40-CD40L interactions. Th2 cells not only fail to induce IL-12 secretion, but they inhibit its induction by Th1 cells. Unlike stimulation by Th1, inhibition of IL-12 production by Th2 cells is mediated by soluble molecules, as demonstrated by transwell cultures. Among Th2-derived cytokines, IL-10, but not IL-4 inhibit Th1-driven IL-12 secretion. IL-10 produced by Th2 cells appears to be solely responsible for the inhibition of Th1-induced IL-12 secretion, but it does not account for the failure of Th2 cells to induce IL-12 production by DC. Collectively, these results demonstrate that Th1 cells up-regulate IL-12 production by DC via IFN-γ-independent cognate interaction, whereas this is inhibited by Th2-derived IL-10. The inhibition of Th1-induced IL-12 production by Th2 cells with the same antigen specificity represents a novel mechanism driving the polarization of CD4⁺ T cell responses.     

IL-10-producing type 1 regulatory T cells and allergy

As an important subset of regulatory T （Treg） cells, IL-10-producing type 1 regulatory T cells （Trl）, have some different features to thymic-derived naturally occurring CD4^＋CD25^＋Foxp3^＋ Treg cells（nTreg cells）. Similar to nTreg cells, Trl also play important roles in the control of allergic inflammation in several ways. There is a fine balance between Trl and Th2 responses in healthy subjects. Skewing of allergic-specific effctor T cells to a Trl phenotype appears to be a critical event in successful allergen-specific immunotherapy and glucocorticoids and β2-agonists treatment. Trl suppress Th2 cells and effector cells of allergic inflammation, such as eosinophils, mast cells, basophils, through producing IL-10, and perhaps TGF-β. Understanding of Trl may be helpful in developing new strategies for treatment of allergic diseases.     

Inhibition of human allergic T-cell responses by IL-10-treated dendritic cells: differences from hydrocortisone-treated dendritic cells

BACKGROUND: Dendritic cells (DCs) are able to induce human allergic T(H)1 responses as well as T(H)2 responses. OBJECTIVE: In this study, we examined the effect of antiinflammatory agents such as IL-10 and hydrocortisone (HC) on the accessory function of DCs and the resulting T-cell response, especially that of T(H)2 cells. METHODS: Naive and memory CD4(+) T cells from atopic donors were stimulated with autologous allergen-pulsed DCs generated from CD14(+) monocytes by culture with GM-CSF/IL-4 and fully matured with IL-1 beta, TNF-alpha, and PGE(2) in the presence or absence of IL-10 or HC. RESULTS: IL-10-treated DCs and, to a lesser extent, HC-treated DCs showed a decreased expression of MHC II molecules, the costimulatory molecule CD86, and the DC-specific marker CD83, as well as a strongly reduced IL-12 secretion. Consequently, T-cell proliferation was reduced after stimulation with IL-10- or HC-treated DCs alike. However, pretreatment of DCs with IL-10 inhibited the production of T(H)1 and T(H)2 cytokines by T cells, whereas HC-treated DCs inhibited production of IFN-gamma but induced an increased release of IL-4 and no change in IL-5. Both effects were long-lasting; cytokine production remained low (which was due not to enhanced apoptosis but to functional hyporesponsiveness) or even increased after restimulation with fully matured DCs. CONCLUSION: These data indicate that IL-10- or HC-treated DCs differ in their ability to influence human allergic T-cell responses. This has major implications for therapeutic strategies aiming at the downregulation of proallergic T(H)2 responses.     

Dendritic cells generated in the presence of GM-CSF plus IL-15 prime potent CD8+ Tc1 responses in vivo

Dendritic cells (DC) comprise a system of professional antigen-presenting cells, which induce the stimulation of very rare antigen-specific naive T cells. DC progenitors can be stimulated to differentiate into immature DC by various growth factors, including GM-CSF and IL-4. Here we show that IL-15, in combination with GM-CSF, is a growth factor for murine DC. Murine bone marrow cells, depleted of T cells, B cells, I-A+ cells and Gr-1+ granulocytes, and cultured in the presence of GM-CSF plus IL-15 (IL-15 DC), yielded DC expressing high levels of CD11c and MHC class II molecules, as well as CD11b. These cells expressed significant levels of CD40, CD80 and CD86, and could stimulate allogeneic CD4+ T cells efficiently. Interestingly, IL-15 DC were far superior to DC generated with GM-CSF plus IL-4 in stimulating allogeneic CD8+ T cells in vitro. Consistent with this, IL-15 DC induced much more potent antigen-specific CD8+ T cell responses with high levels of Th1 cytokines in vivo, compared to DC generated with GM-CSF plus IL-4, or with GM-CSF plus TGF-beta, or with GM-CSF alone. Together, these data suggest that IL-15 promotes the development of DC, which induce potent Th1 and Tc1 responses in vivo. This suggests potential roles for these IL-15 DC cells in the immunotherapy of tumors and infectious diseases.     

扁蒴藤素对支气管哮喘患儿Th17 / Treg 失衡的影响及意义

目的:探讨扁蒴藤素对支气管哮喘患儿Th17/ Treg 体外培养细胞的影响及意义,从而探讨免疫因素在支气管哮喘治疗中的机理。方法:提取支气管哮喘患儿外周血单个核细胞,并在体外给予扁蒴藤素干预,流式细胞术检测Th17 及Treg 比例,ELISA 方法检测细胞培养上清液中IL-17 及TGF-β含量变化,实时定量PCR 检测ROR-T 及Foxp3 含量。结果:扁蒴藤素干预组与对照组相比,CD4+ IL-17+ T 细胞(即Th17 细胞)表达量显著降低,CD4+ CD25+ Foxp3+ T 细胞(即Treg 细胞)表达量显著升高,各组均存在统计学意义(P<0.05);与对照组相比,IL-17 含量显著降低,TGF-β含量显著升高,各组均存在统计学意义(P<0.05);与对照组相比,ROR T 含量显著降低,Foxp3 含量显著升高,各组均存在统计学意义(P<0.05)。结论:扁蒴藤素干预可较大程度缓解体外培养Th17/ Treg 细胞失衡,提示该药物可能通过影响免疫平衡来调节哮喘的发生发展,为扁蒴藤素在临床治疗哮喘的应用提供了理论支持。     

IL-10-treated dendritic cells decrease airway hyperresponsiveness and airway inflammation in mice

BACKGROUND: IL-10 affects dendritic cell (DC) function, but the effects on airway hyperresponsiveness (AHR) and inflammation are not defined. OBJECTIVE: We sought to determine the importance of IL-10 in regulating DC function in allergen-induced AHR and airway inflammation. METHODS: DCs were generated from bone marrow in the presence or absence of IL-10. In vivo IL-10-treated DCs from IL-10(+/+) and IL-10(-/-) donors pulsed with ovalbumin (OVA) were transferred to naive or sensitized mice before challenge. In recipient mice AHR, cytokine levels, cell composition of bronchoalveolar lavage (BAL) fluid, and lung histology were monitored. RESULTS: In vitro, IL-10-treated DCs expressed lower levels of CD11c, CD80, and CD86; expressed lower levels of IL-12; and suppressed T(H)2 cytokine production. In vivo, after transfer of OVA-pulsed IL-10-treated DCs, naive mice did not have AHR, airway eosinophilia, T(H)2 cytokine increase in BAL fluid, or goblet cell metaplasia when challenged, and in sensitized and challenged mice IL-10-treated DCs suppressed these responses. Levels of IL-10 in BAL fluid and numbers of lung CD4(+)IL-10(+) T cells were increased in mice that received OVA-pulsed IL-10-treated DCs. Transfer of IL-10-treated DCs from IL-10-deficient mice were ineffective in suppressing the responses in sensitized and challenged mice. CONCLUSIONS: These data demonstrate that IL-10-treated DCs are potent suppressors of the development of AHR, inflammation, and T(H)2 cytokine production; these regulatory functions are at least in part through the induction of endogenous (DC) production of IL-10. CLINICAL IMPLICATIONS: Modification of DC function by IL-10 can attenuate lung allergic responses, including the development of AHR.     

Human CD4+CD25+ T cells derived from the majority of atopic donors are able to suppress TH1 and TH2 cytokine production

BACKGROUND: Recently, it has been established that CD4(+)CD25(+) T cells with regulatory capacity are present in human peripheral blood, inhibiting allogeneic proliferation and cytokine production of preactivated CD4(+)CD25(-) respond-er T cells. OBJECTIVE: The aim of this study was to analyze in an allergen-specific setting whether such regulatory CD4(+)CD25(+) T cells also exist and function normally in atopic individuals, especially concerning the inhibition of T(H)2 cytokines. METHODS: For this purpose, CD4(+)CD25(-) or CD4(+)CD25(+) T cells from donors allergic to grass or birch pollen (mainly with rhinitis) or from healthy nonatopic donors were stimulated in the presence of autologous, mature, monocyte-derived, allergen-pulsed dendritic cells, and the preactivated CD4(+)CD25(+) T cells were added to CD4(+)CD25(-) T cells during restimulation. RESULTS: CD4(+)CD25(+) T cells from the nonatopic donors and from the majority of the patients investigated proliferated poorly, produced fewer cytokines, and inhibited the proliferation and T(H)1 (IFN-gamma) and T(H)2 (IL-4 and IL-5) cytokine production of CD4(+)CD25(-) T cells but not IL-10 production. The suppression of CD4(+)CD25(-) T cells by CD4(+)CD25(+) T cells was at least partially antigen unspecific and not reversible with anti-IL-10, anti-transforming growth factor beta, or anti-cytotoxic T lymphocyte-associated antigen 4 mAb but was reversible with IL-2. In some atopic patients preactivated CD4(+)CD25(+) T cells reproducibly showed strong proliferative responses, produced higher amounts of IL-4 and IL-10 than CD4(+)CD25(-) T cells, and suppressed only the IFN-gamma production of CD4(+)CD25(-) T cells. CONCLUSION: These data indicate that regulatory CD4(+)CD25(+) T cells are present and functional in most atopic patients with allergic rhinitis and are able to inhibit T(H)1, as well as T(H)2, cytokine production.     

Dendritic cells from Chlamydia-infected mice show altered Toll-like receptor expression and play a crucial role in inhibition of allergic responses to ovalbumin

Our previous study has shown that Chlamydia lung infection can inhibit local eosinophilic inflammation induced by allergen sensitization and challenge, which is correlated with altered cytokine production. In the present study, we examined the role played by dendritic cells (DC) in chlamydial infection-mediated modulation of allergic responses. The results showed that DC freshly isolated from Chlamydia-infected mice (iIDC), unlike those from naive control mice (iNDC), could efficiently modulate immune responses to ovalbumin in vitro and in vivo. Co-culture of freshly isolated DC with naive CD4 cells from T cell receptor transgenic mice (DO11.10) showed that iIDC directed Th1-dominant, while iNDC directed Th2-dominant, allergen-specific CD4 T cell responses. Moreover, adoptive transfer of iIDC, but not iNDC, could inhibit systemic and local eosinophilia induced by allergen exposure. The reduction of eosinophilia was associated with a decrease in IL-5 receptor expression on bone marrow cells and the production of IL-5 and IL-13 by T lymphocytes. Analysis of the DC showed that iIDC expressed significantly higher levels of mRNA for Toll-like receptor 9 and produced more IL-12 compared to iNDC. The data demonstrate a critical role played by DC in infection-mediated inhibition of allergic responses.     

佐剂性关节炎大鼠肺功能变化与Th1/Th2细胞、调节性T细胞的相关性研究

目的:探讨细胞因子、Th1/Th2细胞及调节性T细胞(Treg)、转录因子Foxp3在佐剂性关节炎(AA)大鼠肺功能损害中的作用机制。方法:将24只Wistar大鼠随机分为正常对照(NC)组和模型(Model)组,每组12只,向Model组大鼠右后足跖皮内注射弗氏完全佐剂0.1mL致炎,复制成AA模型。致炎48d后,观察两组大鼠足跖肿胀度(E)及关节炎指数(AI),HE染色观察肺组织病理学改变,计算两组大鼠肺系数(LI)、肺泡炎积分,免疫组化染色法检测Foxp3、TGF-β1蛋白表达情况。通过小动物肺功能仪检测肺功能,ELISA法测定细胞因子的变化,流式细胞术(FCM)测定Treg的表达。结果:与NC组相比,Model组大鼠E、AI、LI、1s内平均呼气流量(FEV1/FVC%)、肺泡炎积分、血清TNF-α、Th1/Th2、肺组织TGF-β1、CD4+ CD25- T细胞的表达水平明显升高,且两者差异有统计学意义(P<0.05或P<0.01);用力肺活量(FVC)、25%肺活量的最大呼气流量(FEF25)、50%肺活量的最大呼气流量(FEF50)、75%肺活量的最大呼气流量(FEF75)、最大呼气中期流量(MMF)、用力最大呼气流量(PEF)、肺动态顺应性(Cldyn)、血清IL-10、CD4+ Treg、CD4+ CD25- Treg、肺组织Foxp3蛋白表达水平显著降低(P<0.01)。Spearman相关分析结果显示,AA大鼠肺功能参数分别与E、AI、TNF-α、IL-10、Th1/Th2及CD4+ Treg、CD4+CD25+Treg、CD4+ CD25- T细胞、Foxp3、TGF-β1表达呈相关性,且相关有统计学意义(P<0.05或P<0.01)。结论:大鼠在致炎后对抗原刺激呈高敏反应状态,Th1/Th2状态失衡、CD4+ CD25- T细胞转化成CD4+ CD25+ Treg受阻,免疫调节功能紊乱,释放大量细胞因子和炎症介质,导致局部关节的病变和肺组织损害,从而发生AA肺功能降低。     

Effective induction of therapeutic antitumor immunity by dendritic cells coexpressing interleukin-18 and tumor antigen

Dendritic cell (DC) based cancer vaccine can induce potent antitumor immunity in murine models; however, objective clinical responses have been observed only in a minority of cancer patients. To improve the antitumor effect of DC vaccine, Th1-biasing cytokine interleukin (IL) 18 and melanoma-associated antigen gp100 were cotransfected into bone marrow-derived DC (IL-18/gp100-DC), which were used as vaccine to induce the protective and therapeutic immunity in a B16 melanoma model. Immunization with IL-18/gp100-DC resulted in tumor resistance in 87.5% of the mice challenged with B16 cells; however, 12.5% and 25% of mice immunized with gp100 gene-modified DC (gp100-DC) or IL-18 gene-modified DC (IL-18-DC) were tumor free, respectively. Most importantly, IL-18/gp100-DC immunization led to the generation of potent therapeutic immunity that significantly inhibited the tumor growth and improved the survival period of mice bearing established melanoma. Immune cell depletion experiments identified that CD4(+) T cells also played an important role in the priming phase of antitumor immunity and CD8(+) T lymphocytes were the primary effectors. gp100-specific CTL response were induced most markedly in the tumor-bearing mice immunized with IL-18/gp100-DC. Administration with such vaccine also significantly increased the production of Th1 cytokine (IL-2 and interferon-gamma) and induced infiltration of inflammatory cells inside and around the tumors. In addition, natural killer cell activity was also augmented. These results indicate that immunization with DC vaccine coexpressing Th1 cytokine IL-18 and tumor antigen gene may be an effective strategy for a successful therapeutic vaccination.     

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.     

慢性乙肝患者树突状细胞对Th1/Th2分化的影响

探讨慢性乙肝患者树突状细胞(dendritic cells,DC)对CD4+Th细胞亚群分化的影响。分离慢性乙肝患者外周血单个核细胞(PBMC),以rhIL-4(50 ng/ml)、rhGM-CSF(10 ng/ml)和rhTNF-α(100 u/ml)诱导培养DC。以流式细胞仪检测DC表面CD1a、CD83、CD80、CD86、HLA-DR分子表达情况。MTT法检测DC刺激同种异体淋巴细胞增殖能力。免疫磁珠分离外周血CD4+T细胞亚群,PMA+Ionomycin刺激后胞内荧光染色,流式细胞仪检测辅助性T细胞(helper T cell,Th)内特征性细胞因子IFN-γ/IL-4以判断Th1/Th2分化。ELISA法检测DC或Th细胞培养上清中IL-6、IL-12、IFN-γ和IL-4的含量。结果:慢性乙肝患者的DC表达CD1a、CD83、CD80、CD86、HLA-DR分子水平明显低于正常人(P<0.01);培养至第7天,慢性乙肝患者DC分泌的IL-12水平低于正常人(P<0.01),而分泌的IL-6水平增高(P<0.05)。与正常人相比,慢性乙肝患者外周血中Th1细胞占CD4+T细胞的百分比较低(P<0.01),其Th细胞培养上清中IFN-γ的量也较低(P<0.01)。患者DC与同种异体的健康人Th细胞共培养,刺激Th1型细胞因子IFN-γ产生的能力低于正常人(P<0.01)。慢性乙肝患者体内DC功能的异常可能导致了外周血Th1细胞分化不足。