Relationship between regulatory and type 1 T cells in dogs with oral malignant melanoma

Recent data suggest a decreased prevalence of IFN‐γ‐producing T lymphocytes (Type 1 T cells) in tumor‐bearing hosts. Moreover, it has been reported that Treg have a strong impact on the activation and proliferation of CD4 (+) and CD8 (+) lymphocytes; however, no previous reports have described the relationship between Treg and the progression of tumor, or Type 1 T cell populations in dogs with malignant tumor. In this study, the percentage of Treg, Th1, and Tc1 in the peripheral blood of dogs with oral malignant melanoma and healthy dogs was measured and compared. Although the percentages of Th1 and Tc1 in dogs with oral malignant melanoma were less than those in healthy dogs (Th1: P < 0.01, Tc1: P < 0.05), the percentage of Treg was increased (P < 0.01). A significant inverse correlation between the percentage of Tc1 and the clinical tumor stage (P < 0.01), and a significant correlation between that of Treg and the clinical tumor stage (P < 0.001) was found. Moreover, there was a significant inverse correlation between the percentages of Treg and Th1 (P < 0.05) or Tc1 (P < 0.001). In conclusion, the percentage of Treg increases with the tumor stage in the peripheral blood of dogs with oral malignant melanoma. In dogs, Treg appears to suppress Type 1 immunity, which may be responsible for anti‐tumor responses.     

T-helper (Th)1/Th2 imbalance in the peripheral blood of dogs with malignant tumor

T helper type 1 cell (Th1)/Th2 imbalance has been observed in a variety of pathological conditions, including malignant diseases. We evaluated the Th1/Th2 in peripheral blood Th cells by means of intracytoplasmic cytokine analysis in 11 dogs with advanced malignant tumor; four of them showed metastatic tumor. The percentage of Th1 was significantly lower and the percentage of Th2 was significantly higher in diseased dogs compared to healthy dogs. The percentage of Th1 in three patients with metastatic tumor was significantly lower than that in the patients with non-metastatic tumor. We conclude that the Th1/Th2 balance was polarized to Th2 in dogs with cancer.     

甲状腺自身免疫状态及细胞毒性对不孕妇女反复植入失败的影响

为了探讨RIF患者的甲状腺功能、自身免疫状态、免疫细胞及其相关性,从72名RIF妇女中抽取血样,以评估TAI的患病率、甲状腺功能、免疫细胞绝对数量和百分比。TAI患者甲状腺功能异常的患病率与无TAI患者相比无显著差异(χ^2=0.484,p>0.05)。与无TAI患者比较,TAI患者的T细胞、B细胞和自然杀伤(NK)细胞的绝对数量和百分比没有显著差异(所有p>0.05)。与无TAI的患者相比,TAI患者的细胞毒性T细胞(Tc)百分比显著降低(p<0.05);同时,Th/Tc比率显著增加(p<0.05)。RIF患者的TAI可能是由于伴侣之间潜在的密切组织相容性引起,降低的Tc百分比和增加的Th/Tc比率可能是RIF女性不良妊娠结果的另一个影响因素。     

良性前列腺增生患者外周血Th17和Treg细胞比率的变化

目的:探讨良性前列腺增生患者外周血Th17和Treg细胞比率的变化。方法:选择33例良性前列腺增生患者及19例正常对照者为研究对象,采用流式细胞术检测和比较其外周血中T淋巴细胞亚群及Th17和Treg细胞占CD4~+T细胞的比率。结果:良性前列腺增生患者外周血Th17和Treg细胞占CD4~+T细胞的比率分别为1.58±0.71和1.76±0.83,Th17/Treg的比率为0.89±0.42。正常健康对照者外周血Th17和Treg细胞占CD4~+T细胞的比率分别为0.75±0.46和1.83±0.75,Th17/Treg的比率为0.41±0.32。良性前列腺增生患者外周血Th17占CD4~+T细胞的比率和Th17/Treg的比率明显高于正常健康对照者(P0.05)。结论:良性前列腺增生患者体内Th17细胞比率升高,Th17/Treg比率失衡,可能与良性前列腺增生的发生、发展有关。     

Characterization of tumor antigen peptide-specific T cells isolated from the neoplastic tissue of patients with gastric adenocarcinoma

Gastric cancer is a significant cause of morbidity and mortality worldwide. Surgical resection remains the primary curative treatment for gastric adenocarcinoma, but the poor (15–35%) survival rate at 5 years has prompted many studies for new therapeutic strategies, such as specific immunotherapy. The aim of this study was to analyze the functional properties of the T cell response to different antigen peptides related to gastric cancer in patients with gastric adenocarcinoma. To this purpose, we have cloned and characterized tumor-infiltrating T cells (TILs) isolated from the neoplastic gastric tissue samples. A T cell response specific to different peptides of gastric cancer antigens tested was documented in 17 out of 20 patients, selected for their HLA-A02 and/or -A24 alleles. Most of the cancer peptide-specific TILs expressed a Th1/Tc1 profile and cytotoxic activity against target cells. The effector functions of cancer peptide-specific T cells obtained from the peripheral blood of the same patients were also studied. The majority of peripheral blood peptide-specific T cells also expressed the Th1/Tc1 functional profile. In conclusion, in most of the patients with gastric adenocarcinoma, a specific type-1 T cell response to gastric cancer antigens was detectable and would have the potential of hamper tumor cell growth. However, in order to get tumor cell killing in vivo, the activity and the number of cancer peptide-specific Th1/Tc1 cells probably need to be enhanced by vaccination with the appropriate cancer antigenic peptides or by injection of the autologus tumor peptide-specific T cells expanded in vitro.     

Characterization of the evolution of immune phenotype during the development and progression of squamous cell carcinoma of the head and neck

While studies have indicated that squamous cell carcinoma of the head and neck (HNSCC) is associated with immune suppression, these studies did not analyze the immune response at the dysplastic stage. The present study utilized a mouse model of 4-nitroquinoline 1-oxide-induced oral carcinogenesis to examine the alterations in immune phenotype at the premalignant and malignant stages of HNSCC. Cervical lymph nodes of HNSCC-bearing mice were found to contain a greater number of cells, including a greater number of conventional (Tconv) and regulatory (Treg) T cells, compared to cervical lymph nodes of control and premalignant lesion-bearing mice, though the Tconv cells appear to be less proliferative and the Treg cells appear to be less suppressive at the HNSCC stage. Premalignant lesion-bearing mouse lymph nodes consist of a greater percentage of Tconv cells expressing markers for activation, memory, and exhaustion compared to both control and HNSCC-bearing mice. Also, lymph nodes’ cells from both premalignant lesion-bearing and HNSCC-bearing mice include increased levels of Th1, Tc1, and Th17 cells, with no differences in levels of Th2 cells, compared to control mice. The data show that while there is the expected increase in immunosuppressive Tregs in lymph nodes when HNSCC is present, there is also an unexpected increase in immune populations usually associated with a beneficial antitumor response, including Tconv cells and Th1 and Tc1 cells. In addition, the results demonstrate that the premalignant stage of HNSCC development is associated with a robust immune response involving an increase in inflammatory Th1, Tc1, and Th17 cells.     

The suppressive effect of CD25+Treg cells on Th1 differentiation requires cell-cell contact partially via TGF-β production

CD25+Treg cells (CD4+CD25+Foxp3+ regulatory T cells) play a central role in the maintenance of peripheral self-tolerance and immune homoeostasis. A previous study showed that CD25+Treg cells suppressed the differentiation and function of Th1 cells in vivo and in vitro. However, the mechanism of suppressing Th1 cell differentiation mediated by CD25+Treg cells remains unclear. In the present study, we found that CD25+Treg cells could reduce the production of IFN (interferon)-γ and the percentage of IFN-γ-, IL-2 and TNF-α-producing cells by CD25-T cells under Th1 cell culture conditions and suppress the differentiation of CD25-T cells into Th1 cells in a dose-dependent manner. Moreover, these CD25+Treg cells could inhibit the activation of CD25-T cells by down-regulating the expression of activation markers CD69 and CD25 and suppress the division and proliferation of CD25-T cells using CFSE (carboxyfluorescein diacetate succinimidyl ester)-labelling and BrdU (5-bromo-20-deoxyuridine) incorporation, respectively. Further studies showed that the suppressive effects of CD25+Treg cells on Th1 cell differentiation required cell-cell contact and was partially restored by the addition of anti-TGF-β mAb (monoclonal antibody) but not anti-IL-10 mAb, indicating that the suppression mechanism of CD25+Treg cells was cell-cell contact dependent and partially via TGF-β. This finding strongly indicates a therapeutic role for CD25+Treg cells in Th1-mediated diseases.     

Interferon-gamma and interleukin-4-producing T cells in peripheral blood of multiple sclerosis patients

Pro- and anti-inflammatory cytokines are thought to participate in the development and regulation of autoimmunity in multiple sclerosis (MS), a demyelinating disease of the central nervous system (CNS). We analysed the percentage of interferon (IFN)-gamma and interleukin (IL)-4-producing cells in the peripheral blood of both active and stable MS patients, and of healthy controls. After short-term stimulation, cytokine-producing cells were intracellularly stained and sorted. Significantly lower percentages of IFN-gamma and IL-4-producing T cells were found in stable MS patients than in controls, and in active than in stable patients. The diminution affected CD4(+) (Th1, Th2) and CD8(+) (Tc1) phenotypes. Tc2 cells were not detected. The Th1/Th2 ratio did not differ in active and stable MS, nor in controls. The fact that Th2 and Tc1 cell percentages were higher in stable than in active MS possibly indicates that these cells play a downmodulating role in the immune response. In contrast, a role in exacerbating the immune response is not attributable to Th1 cells, given their reduction in acute MS. Our data do not support the hypothesis that MS is a Th1/Th2 paradigmatic disease; rather, they suggest that sequestration in the CNS, or activation-induced apoptosis (whether in vivo or in vitro) may explain reduced levels of IFN-gamma and IL-4-producing subsets in the peripheral blood of clinically acute patients.     

不明原因复发性流产再次妊娠患者血清1,25(OH)2D3、sTim-3与Th17/Treg免疫失衡和妊娠结局的关系

摘要 目的：探讨不明原因复发性流产（URSA）再次妊娠患者血清1,25-二羟维生素D3[1,25（OH)）₂D₃]、可溶性T细胞免疫球蛋白黏蛋白分子3（sTim-3）与辅助性T细胞17（Th17）/调节性T细胞（Treg）免疫失衡和妊娠结局的关系。方法：选择于湖南省妇幼保健院2020年1月~2022年1月就诊的62例URSA再次妊娠患者作为研究组,另选择同期进行孕检的正常早孕妇女30例作为对照组。比较两组孕早期血清1,25(OH) ₂D₃、sTim-3及外周血Th17细胞、Treg细胞水平、Th17/Treg比值。Pearson法分析URSA再次妊娠患者血清1,25(OH) ₂D₃、sTim-3与外周血Th17细胞、Treg细胞水平、Th17/Treg比值平的相关性。根据URSA再次妊娠患者妊娠结局的不同分为妊娠成功分娩组和妊娠再次流产组,比较两组孕早期血清1,25(OH) ₂D₃、sTim-3与外周血Th17细胞、Treg细胞水平、Th17/Treg比值。受试者工作特征（ROC）曲线分析血清1,25(OH) ₂D₃、sTim-3与外周血Th17细胞、Treg细胞水平、Th17/Treg比值对妊娠结局的预测价值。结果：研究组血清sTim-3、外周血Th17细胞水平、Th17/Treg比值高于对照组,血清1,25(OH) ₂D₃、外周血Treg细胞水平低于对照组（P<0.05）。Pearson相关分析显示,URSA再次妊娠患者血清1,25(OH) ₂D₃与血清sTim-3、外周血Th17细胞水平、Th17/Treg比值呈负相关,与Treg细胞水平呈正相关（P<0.05）;血清sTim-3与外周血Treg细胞水平呈负相关,与Th17细胞水平、Th17/Treg比值呈正相关（P<0.05）。妊娠再次流产组血清sTim-3、外周血Th17细胞水平、Th17/Treg比值高于妊娠成功分娩组,血清1,25(OH) ₂D₃、外周血Treg细胞水平低于妊娠成功分娩组（P<0.05）。ROC曲线分析显示,血清1,25(OH) ₂D₃、sTim-3及外周血Th17细胞、Treg细胞水平及Th17/Treg比值均可预测URSA再次妊娠患者妊娠再次流产的发生风险,且上述指标联合检测的预测效能更高。结论：血清1,25(OH) ₂D₃水平异常降低、sTim-3水平异常升高可导致Th17/Treg免疫失衡,导致URSA再次妊娠患者再次发生流产。上述指标联合检测对URSA再次妊娠患者妊娠再次流产的预测效能更高。     

妊娠梅毒患者外周血中Th17和Treg细胞水平及其临床意义分析

目的:探讨妊娠梅毒患者外周血中Th17和Treg细胞水平及其临床意义。方法:选择2015年4月至2016年5月我院收治的35例妊娠梅毒患者作为观察组,并选择同期进行孕检的健康孕妇30例作为对照组。分析和比较其外周血Th17和Treg细胞水平及其诊断妊娠梅毒的临床价值。结果:观察组患者外周血Th17水平显著高于对照组,而外周血Treg水平显著低于对照组(P0.05)。多因素logistic回归分析结果显示外周血Th17和Treg水平与妊娠梅毒发病具有明显相关性。外周血Th17诊断妊娠梅毒的AUC为0.776,95%CI为0.656～0.896,外周血Treg诊断妊娠梅的ROC曲线下的面积(area under curve,AUC)为0.947,95%CI为0.897～997,Th17+Treg诊断妊娠梅毒的AUC为0.960,95%CI为0.913～1.000;Th17和Treg单独检测分别和联合检测曲线下面积比较均具有显著差异(Z=-2.807、-0.375,P0.05);Th17+Treg联合检测的特异度、准确度分别为91.73%、93.28%,显著高于各指标单独检测(P0.05)。结论:妊娠梅毒患者外周血Th17细胞增多,Treg细胞减少,联合检测外周血Th17和Treg细胞水平诊断妊娠梅毒具有较高的准确度,可作为诊断妊娠梅毒的重要参考指标。     

The immunologic aspects in advanced ovarian cancer patients treated with paclitaxel and carboplatin chemotherapy

Till now, little is known about the effects of chemotherapy on the immunity of cancer patients and the ideal timing (“window” period) for immunotherapy combined with chemotherapy. In this study, we addressed the immunogenicity of apoptotic ovarian cancer cells induced by paclitaxel and carboplatin, the immunologic aspects in ovarian cancer patients under chemotherapy, and the CTL response when CD8⁺ T cells were stimulated with tumor antigen in the “window” period. The immunogenicity of apoptotic ovarian cancer cells was detected first. Then, blood samples from each ovarian cancer patient were obtained before (S₀) and at days 5–7 (S₁), days 12–14 (S₂) and days 25–28 (S₃) after chemotherapy. The proportions of immunocyte subsets and the function of NK cells were studied. We found that apoptotic ovarian cancer cells elicited a powerful CTL response with antitumor activity in vitro. The proportions of CD3⁺ T cells, CD4⁺ T cells and the ratio of CD4⁺ to CD8⁺ cells did not change significantly on S₁, S₂ and S₃, compared to S₀, whereas the percentage of Treg cells decreased remarkably on S₂. The proportions of Th1, Tc1, CD45RO memory T, NKT cells and the ratio of Tc1 to Tc2 cells increased significantly on S₂. IFN-γ secreting CD8⁺ T cells also increased remarkably on S₂, especially when CD8⁺ T cells were stimulated with autologous tumor antigen. From our point of view, chemotherapy induces temporary immune reconstitution and augments anti-tumor immune response. It is probable that the “window” period of days 12–14 after chemotherapy provides the best opportunity for immunotherapy.     

Metastatic tumour cells favour the generation of a tolerogenic milieu in tumour draining lymph node in patients with early cervical cancer

Objective  We compared the immune system state in metastatic tumour draining lymph nodes (mTDLN) and metastasis free TDLN (mfTDLN) in 53 early stage cervical cancer patients to assess whether the presence of metastatic tumour cells worsen the balance between an efficacious anti-tumour and a tolerogenic microenvironment. Methods  The immune system state was measured by immunophenotypic and functional assessment of suppressor and effector immune cell subsets. Results  Compared to mfTDLN, mTDLN were significantly enriched in CD4⁺Foxp3⁺ regulatory T cells (Treg), which, in addition, exhibited an activated phenotype (HLA-DR⁺ and CD69⁺). Treg in mTDLN were also significantly enriched in neuropilin-1 (Nrp1) expressing cells, a subset particularly potent in dampening T cell responses. mTDLN tended to be enriched in a population of CD8⁺Foxp3⁺T cells (operationally defined as CD8⁺Treg) that showed a suppressor potency similar to Treg under the same experimental conditions. Plasmacytoid dendritic cells (pDC) and myeloid DC (mDC) generally show distinct roles in inducing T cell tolerance and activation, respectively. In line with the excess of suppressor T cells, the ratio pDC to mDC was significantly increased in mTDLN. Immunohistochemical testing showed that metastatic tumour cells produced the vascular endothelial growth factor, a natural ligand for Nrp1 expressed on the cell surface of Nrp1⁺Treg and pDC, and therefore a potential mediator by which tumour cells foster immune privilege in mTDLN. Consistent with the overall tolerogenic profile, mTDLN showed a significant Tc2 polarisation and tended to contain lower numbers of CD45RA⁺CD27⁻ effector memory CD8⁺T cells. Conclusions  The increased recruitment of suppressor type cells concomitant with the scarcity of cytotoxic type cells suggests that in mTDLN the presence of tumour cells could tip the balance against anti-tumour immune response facilitating the survival of metastatic tumour cells and possibly contributing to systemic tolerance.     

CD4+ T Cells Disarm or Delete Cytotoxic T Lymphocytes under IL-17-Polarizing Conditions

Previous studies have shown that TGF-β acts cooperatively with IL-6 to elicit a high frequency of IL-17-secreting CD4(+) T cells (termed Th17) and an elevated CD8(+)IL-17(+) T cell population (termed Tc17). These CD8(+) cells fail to behave like most cytotoxic T lymphocytes that express IFN-γ and granzyme B, but they exhibit a noncytotoxic phenotype. Although a significant increase in the number of these Tc17 cells was found in tumors, their role and interaction with other cell types remain unclear. In this study, we demonstrate that the presence of CD4(+)CD25(-) T cells, but not the CD4(+)CD25(+) (regulatory T [Treg]) cell population, significantly reduced the elicitation of Tc17 cells, possibly as a result of the induction of apoptotic signals. Importantly, these signals may be derived from soluble mediators, and the addition of anti-IL-2 restored the reduction of Tc17 cells in the presence of CD4(+)CD25(-) T cells. Finally, the elicited Tc17 and Treg cells exhibited a close association in patients with head and neck cancer, indicating that the surrounding Treg cells might maintain the survival of the Tc17 cells. Taken together, these results reveal an intriguing mechanism in which Tc17 cells are controlled by a finely tuned collaboration between the different types of CD4(+) T cells in distinct tumor microenvironments.     

Circulating FoxP3+ Regulatory T and Interleukin17-Producing Th17 Cells Actively Influence HBV Clearance in De Novo Hepatitis B Virus Infected Patients after Orthotopic Liver Transplantation

Objective

To longitudinally investigate the role of FoxP3+ Regulatory T cells (Treg) and interleukin17-producing T helper 17 cells (Th17) in De Novo Hepatitis B Virus infection after orthotopic Liver Transplantation (DNHB-OLT), and analyze the possible correlation between these cells and HBV clearance of the disease.

Methods

We enrolled 12 control cases after orthotopic Liver Transplantation (OLT) and 24 patients, including 12 diagnosed with DNHB-OLT and 12 diagnosed with Acute Hepatitis B Virus infection (AHB), into the study from the liver transplantation and research center at Beijing 302 Hospital. Flow cytometry was used to detect the frequencies of Treg and Th17, and ELISA was applied to detect the concentration of IL6, IL22, TGF-β and IL2 in peripheral blood. We also measured the gene expression level by real time-quantitative PCR and protein expression using immunohistochemistry and western-blot. Furthermore, we divided DNHB-OLT patients into the clearance and non-clearance groups and examined longitudinally Th17, Treg cells at different times.

Results

The percentage of Treg cells, expression of FoxP3 mRNA and related anti-inflammatory cytokines such as IL2 and TGF-β1 in the DNHB-OLT group were significantly higher than that in the AHB and OLT groups. The percentage of Th17 cells, expression of RORγt mRNA and related pro-inflammatory cytokines such as IL17 and IL22 in the DNHB-OLT group were significantly lower than that in the AHB group, but the levels of these cytokines are very similar to the OLT group. The ratios of Treg to Th17 in the DNHB-OLT group were significantly higher than that in the OLT and AHB groups. Treg frequencies significantly correlated with HBV DNA, whereas IL17 frequencies didn’t significantly correlate with ALT. In DNHB-OLT patients, the clearance group was accompanied by a rapid increase in the Th17 cells during the first 4^th week and afterwards continuously decrease to the control group, together with a continuously decrease in Treg cells from the onset time point, which lead to a significant reduction in the ratios of Treg to Th17. The non-clearance group was accompanied by an increase in the Treg cells during the first 4^th week and afterwards sharply decrease, together with a relatively stable and unchanged Th17 cells, which lead to a significant change in the ratios. In addition, compared to clearance group, the ratios of Treg to Th17 in non-clearance group were significantly higher at the onset point, 4^th and 12^th week, but no difference at 24^th week.

Conclusion

DNHB-OLT patients possessed a favorable Treg differentiation environment, accompanied by a sustained higher preferentially Treg frequencies and up-regulation of related anti-inflammatory cytokines. The immune imbalance of the ratios between Treg and Th17 existed in DNHB-OLT patients. The changes of the ratios during the DNHB-OLT events were associated with HBV clearance, which suppressed immune inflammation reaction as well as inhibited ability of specific HBV clearance and led to immune escape and chronicity.     

Administration of a CD25-directed immunotoxin, LMB-2, to patients with metastatic melanoma induces a selective partial reduction in regulatory T cells in vivo

CD25+ CD4+ T regulatory (Treg) cells regulate peripheral self tolerance and possess the ability to suppress antitumor responses, which may in part explain the poor clinical response of cancer patients undergoing active immunization protocols. We have previously shown that in vitro incubation of human PBMC with LMB-2, a CD25-directed immunotoxin, significantly reduced CD25+ FOXP3+ CD4+ Treg cells without impairing the function of the remaining lymphocytes. In the current study, eight patients with metastatic melanoma were treated with LMB-2 followed by MART-1 and gp100-specific peptide vaccination. LMB-2 administration resulted in a preferential, transient reduction in mean circulating CD25+ CD4+ T cell number, from 83 +/- 16 cells/microl to a nadir of 17 +/- 5 cells/microl, a 79.1% reduction. FOXP3 analysis revealed a less robust depletion with mean FOXP3+ CD4+ Treg cell number decreasing from 74 +/- 15 cells/microl to 36 +/- 8 cells/microl, a 51.4% reduction. FOXP3+ CD4+ Treg cells that survived LMB-2-mediated cytotoxicity expressed little or no CD25. Similar to the peripheral blood, immunohistochemical analysis showed a 68.9% mean reduction in FOXP3+ CD4+ Treg cell frequency in evaluable lesions. Despite inducing a reduction in Treg cell numbers in vivo, LMB-2 therapy did not augment the immune response to cancer vaccination and no patient experienced an objective response or autoimmunity. These data demonstrate the capacity of a CD25-directed immunotoxin to selectively mediate a transient partial reduction in circulating and tumor-infiltrating Treg cells in vivo, and suggest that more comprehensive Treg cell elimination may be required to bolster antitumor responses in patients with metastatic melanoma.     

Strenuous exercise decreases the percentage of type 1 T cells in the circulation.

Prolonged strenuous exercise is followed by a temporary functional immune impairment. Low numbers of CD4+ T helper (Th) and CD8+ T cytotoxic (Tc) cells are found in the circulation. These cells can be divided according to their cytokine profile into type 1 (Th1 and Tc1), which produce interferon-gamma and interleukin (IL)-2, and type 2 (Th2 and Tc2) cells, which produce IL-4. The question addressed in the present study was whether exercise affected the relative balance between the circulating levels of these cytokine-producing T cells. Nine male runners performed treadmill running for 2.5 h at 75% of maximal oxygen consumption. The intracellular expression of cytokines was detected following stimulation with ionomycin and phorbol 12-myristate 13-acetate in blood obtained before, during, and after exercise. The percentage of type 1 T cells in the circulation was suppressed at the end of exercise and 2 h after exercise, whereas no changes were found in the percentage of type 2 T cells. Plasma epinephrine correlated negatively with the percentage of circulating CD8+ T cells producing IL-2, whereas peak IL-6 correlated with the percentage of CD8+ IL-4-producing T cells in the circulation. Peak plasma IL-6 correlated with plasma cortisol postrunning. In conclusion, the postexercise decrease in T lymphocyte number is accompanied by a more pronounced decrease in type 1 T cells, which may be linked to high plasma epinephrine. Furthermore, IL-6 may stimulate type 2 T cells, thereby maintaining a relatively unaltered percentage of these cells in the circulation compared with total circulating lymphocyte number.     

The Ratio of Treg/Th17 Cells Correlates with the Disease Activity of Primary Immune Thrombocytopenia

Background

Primary immune thrombocytopenia (ITP) is an autoimmune heterogeneous disorder that is characterized by decreased platelet count. Regulatory T (Treg) cells and T helper type 17 (Th17) cells are two subtypes of CD4⁺ T helper (Th) cells. They play opposite roles in immune tolerance and autoimmune diseases, while they share a common differentiation pathway. The imbalance of Treg/Th17 has been demonstrated in several autoimmune diseases. In this study, we aimed to investigate the ratio of the number of Treg cells to the number of Th17 cells in ITP patients and evaluate the clinical implications of the alterations in this ratio.

Methods

Thirty adult patients with newly diagnosed ITP enrolled in this study. Twelve patients had been clinically followed up for 12 months. The percentages of CD4⁺CD25^hiFoxp3⁺ Treg cells and CD3⁺CD4⁺IL-17-producing Th17 cells in these patients and healthy controls (n = 17) were longitudinally analyzed by flow cytometry.

Results

The percentage of Treg cells in ITP patients was significantly lower than that of healthy controls, and the percentage of Th17 cells increased significantly at disease onset. The ratio of Treg/Th17 correlated with the disease activity.

Conclusion

The ratio of Treg/Th17 might be relevant to the clinical diversity of ITP patients, and this Treg/Th17 ratio might have prognostic role in ITP patients.     

An Increase in CD3+CD4+CD25+ Regulatory T Cells after Administration of Umbilical Cord-Derived Mesenchymal Stem Cells during Sepsis

Sepsis remains an important cause of death worldwide, and vigorous immune responses during sepsis could be beneficial for bacterial clearance but at the price of collateral damage to self tissues. Mesenchymal stem cells (MSCs) have been found to modulate the immune system and attenuate sepsis. In the present study, MSCs derived from bone marrow and umbilical cord were used and compared. With a cecal ligation and puncture (CLP) model, the mechanisms of MSC-mediated immunoregulation during sepsis were studied by determining the changes of circulating inflammation-associated cytokine profiles and peripheral blood mononuclear cells 18 hours after CLP-induced sepsis. In vitro, bone marrow-derived MSCs (BMMSCs) and umbilical cord-derived MSCs (UCMSCs) showed a similar morphology and surface marker expression. UCMSCs had stronger potential for osteogenesis but lower for adipogenesis than BMMSCs. Compared with rats receiving PBS only after CLP, the percentage of circulating CD3+CD4+CD25+ regulatory T (Treg) cells and the ratio of Treg cells/T cells were elevated significantly in rats receiving MSCs. Further experiment regarding Treg cell function demonstrated that the immunosuppressive capacity of Treg cells from rats with CLP-induced sepsis was decreased, but could be restored by administration of MSCs. Compared with rats receiving PBS only after CLP, serum levels of interleukin-6 and tumor necrosis factor-α were significantly lower in rats receiving MSCs after CLP. There were no differences between BMMSCs and UCMSCs. In summary, this work provides the first in vivo evidence that administering BMMSCs or UCMSCs to rats with CLP-induced sepsis could increase circulating CD3+CD4+CD25+ Treg cells and Treg cells/T cells ratio, enhance Treg cell suppressive function, and decrease serum levels of interleukin-6 and tumor necrosis factor-α, suggesting the immunomodulatory association of Treg cells and MSCs during sepsis.