Innate-like CD4 T cells selected by thymocytes suppress adaptive immune responses against bacterial infections

We have reported a new innate-like CD4 T cell population that expresses cell surface makers of effector/memory cells and produce Th1 and Th2 cytokines immediately upon activation. Unlike conventional CD4 T cells that are selected by thymic epithelial cells, these CD4 T cells, named T-CD4 T cells, are selected by MHC class II expressing thymocytes. Previously, we showed that the presence of T-CD4 T cells protected mice from airway inflammation suggesting an immune regulatory role of T-CD4 T cells. To further understand the function of T-CD4 T cells, we investigated immune responses mediated by T-CD4 T cells during bacterial infection because the generation of antigen specific CD4 T cells contributes to clearance of infection and for the development of immune memory. The current study shows a suppressive effect of T-CD4 T cells on both CD8 and CD4 T cell-mediated immune responses during Listeria and Helicobacter infections. In the mouse model of Listeria monocytogenes infection, T-CD4 T cells resulted in decreasedfrequency of Listeria-specific CD8 T cells and the killing activity of them. Furthermore, mice with T-CD4 T cells developed poor immune memory, demonstrated by reduced expansion of antigen-specific T cells and high bacterial burden upon re-infection. Similarly, the presence of T-CD4 T cells suppressed the generation of antigen-specific CD4 T cells in Helicobacter pylori infected mice. Thus, our studies reveal a novel function of T-CD4 T cells in sup-pressing anti-bacterial immunity.

外周血CD4^(+)PD-1^(+)Tcells及CD4^(+)T淋巴细胞ATP含量与复发性卵巢癌疗效的相关性分析

目的 探讨外周血CD4^(+)程序性细胞死亡受体-1(PD-1)^(+)T cells及CD4^(+)T淋巴细胞三磷酸腺苷(ATP)含量与复发性卵巢癌疗效的相关性。方法 选取30例复发性卵巢癌患者为复发组,30例未复发卵巢癌患者为非复发组;另选取30名同期体检健康者作为对照组。评估外周血CD4^(+)PD-1^(+)T cells及CD4^(+)T淋巴细胞ATP含量与复发性卵巢癌疗效的相关性。结果 复发组和非复发组的CD4^(+)PD-1^(+)T cells较对照组明显升高(P<0.05)。复发组和非复发组的CD4^(+)T淋巴细胞ATP含量较对照组明显降低(P<0.05)。复发组治疗后CD4^(+)PD-1^(+)Tcells显著低于治疗前(P<0.05),治疗后CD4^(+)T淋巴细胞ATP含量显著高于治疗前(P<0.05)。CD4^(+)PD-1^(+)T cells与复发性卵巢癌疗效成负相关(r=-0.393,P=0.039),CD4^(+)T淋巴细胞ATP含量与复发性卵巢癌疗效成正相关(r=0.449,P=0.031)。结论 复发性卵巢癌患者外周血CD4^(+)PD-1^(+)T cells及CD4^(+)T淋巴细胞ATP含量与疗效密切相关。

非小细胞肺癌不同胸腔积液严重程度及预后患者lncRNA MEG3表达及其与Th17/CD4^(+)T细胞的关系

目的:研究非小细胞肺癌(NSCLC)不同胸腔积液严重程度及预后患者lncRNA MEG3表达及其与Th17/CD4^(+)T细胞的关系。方法:选取2020年1月至2022年12月福建医科大学附属泉州第一医院收治的104例NSCLC恶性胸腔积液患者作为研究对象,根据胸腔积液量分为3组:少量胸腔积液组(35例)、中量胸腔积液组(42例)、大量胸腔积液组(27例)。根据患者疾病实际发展转归分为预后良好组(29例未出现复发和转移)和预后不良组(75例出现复发和转移)。另选取同期于福建医科大学附属泉州第一医院治疗的60例肺炎良性胸腔积液患者作为对照组。实时荧光定量PCR检测两组胸腔积液中MEG3表达。收集受试者外周静脉血,流式细胞术检测外周血Th17细胞、CD4^(+)T细胞比例,并计算Th17/CD4^(+)T。对比各组患者lncRNA MEG3及外周血Th17、CD4^(+)T细胞水平。Logistic回归分析NSCLC胸腔积液及预后的影响因素。结果:NSCLC组胸腔积液lncRNA MEG3表达及CD4^(+)T细胞百分比低于对照组,Th17细胞百分比、Th17/CD4^(+)T高于对照组(P<0.05)。大量胸腔积液组lncRNA MEG3表达及CD4^(+)T细胞百分比低于少量胸腔积液组、中量胸腔积液组,中量胸腔积液组lncRNA MEG3表达及CD4^(+)T细胞百分比低于少量胸腔积液组,大量胸腔积液组Th17细胞百分比、Th17/CD4^(+)T高于少量胸腔积液组、中量胸腔积液组,中量胸腔积液组Th17细胞百分比、Th17/CD4^(+)T高于少量胸腔积液组(P<0.05)。预后不良组lncRNA MEG3表达及CD4^(+)T百分比低于预后良好组,而Th17细胞百分比、Th17/CD4^(+)T高于预后良好组(P<0.05)。Logistic回归分析结果显示,lncRNA MEG3为NSCLC胸腔积液的保护因素,Th17/CD4^(+)T为危险因素(P<0.05);lncRNA MEG3为NSCLC预后的保护因素,Th17/CD4^(+)T为危险因素(P<0.05)。结论:NSCLC不同胸腔积液严重程度及预后患者lncRNA MEG3表达及Th17/CD4^(+)T不同,且lncRNA MEG3为NSCLC胸腔积液及预后的保护因素,Th17/CD4^(+)T为危险因素,可作为胸腔积液严重程度及预后诊断的有效生物标志物。

MBD2 promotes Th2 differentiation in ovalbumin-induced CD4+T cells

Introduction:Allergen-specific CD4+T cells play a central role in autoimmune disorders,allergies and asthma,with Th2-type immunity being the typical functional response of CD4+T cells.This study aimed to investigate the role of MBD2 in regulating Th2 cell differentiation.Methods:Splenic mononuclear cells were extracted from C57BL/6 mice,and CD4+T cells were isolated using magnetic beads and confirmed through flow cytometry.Lentivirus was employed to construct MBD2-silenced CD4+T cells.In vitro experiments were performed to treat splenogenic mononuclear cells and CD4+T cells with Ovalbumin(OVA),and Th2 cell ratios and IL-4 levels were assessed using flow cytometry and ELISA.Results:The purity of the isolated CD4+T cells was 95.73%,confirming successful isolation of primary CD4+T cells.Compared to the control group,the Th2 cell ratio exhibited an increase in the Th2-induced group.Treatment with 5-Aza(concentrations,1-100μM)promoted Th2 cell differentiation and increased IL-4 levels.Notably,when combined with Th2 induction and 10μM 5-Aza treatment,silencing MBD2 further amplified Th2 cell ratios and elevated IL-4 levels in cell supernatants.Furthermore,OVA(concentration,200μg/mL)induced the differentiation of CD4+T cells into Th2 cells and increased IL-4 secretion.Interestingly,silencing MBD2 significantly increased the Th2 cell ratio and IL-4 levels in OVA-treated CD4+T cells.Conclusion:In summary,OVA promoted CD4+T cell differentiation into Th2 cells and enhanced IL-4 levels.MBD2 was identified as a mediator of Th2 cell differentiation in splenic-derived CD4+T cells,influenced by OVA or 5-Aza treatment.

Peripheral CD4^(+)CD8^(+) double positive T cells:A potential marker to evaluate renal impairment susceptibility during systemic lupus erythematosus

Lupus nephritis(LN) has a high incidence in systemic lupus erythematosus(SLE) patients, but there is a lack of sensitive predictive markers. The purpose of the study was to investigate the association between the CD4^(+)CD8^(+)double positive T(DPT) lymphocytes and LN. The study included patients with SLE without renal impairment(SLE-NRI), LN, nephritic syndrome(NS), or nephritis. Peripheral blood lymphocyte subsets were analyzed by flow cytometry. Biochemical measurements were performed with peripheral blood in accordance with the recommendations proposed by the National Center for Clinical Laboratories. The proportions of DPT cells in the LN group were significantly higher than that in the SLE-NRI group(t=4.012, P<0.001), NS group(t=3.240,P=0.001), and nephritis group(t=2.57, P=0.011). In the LN group, the risk of renal impairment increased significantly in a DPT cells proportion-dependent manner. The risk of LN was 5.136 times(95% confidence interval, 2.115–12.473) higher in cases with a high proportion of DPT cells than those whose proportion of DPT cells within the normal range. These findings indicated that the proportion of DPT cells could be a potential marker to evaluate LN susceptibility, and the interference of NS and nephritis could be effectively excluded when assessing the risk of renal impairment during SLE with DPT cell proportion.

Combined TIM-3 and PD-1 blockade restrains hepatocellular carcinoma development by facilitating CD4+ and CD8+T cellmediated antitumor immune responses

BACKGROUND Immune checkpoint inhibitors(ICIs)targeting programmed cell death protein 1(PD-1)and T cell immunoglobulin and mucin domain-containing protein 3(TIM-3)are beneficial to the resumption of anti-tumor immunity response and hold extreme potential as efficient therapies for certain malignancies.However,ICIs with a single target exhibit poor overall response rate in hepatocellular carcinoma(HCC)patients due to the complex pathological mechanisms of HCC.AIM To investigate the effects of combined TIM-3 and PD-1 blockade on tumor development in an HCC mouse model,aiming to identify more effective immunotherapies and provide more treatment options for HCC patients.METHODS The levels of PD-1 and TIM-3 on CD4+and CD8+T cells from tumor tissues,ascites,and matched adjacent tissues from HCC patients were determined with flow cytometry.An HCC xenograft mouse model was established and treated with anti-TIM-3 monoclonal antibody(mAb)and/or anti-PD-1 mAb.Tumor growth in each group was measured.Hematoxylin and eosin staining and immunohistochemical staining were used to evaluate T cell infiltration in tumors.The percentage of CD4+and CD8+T cells in tissue samples from mice was tested with flow cytometry.The percentages of PD-1+CD8+,TIM-3+CD8+,and PD-1+TIM-3+CD8+T cells was accessed by flow cytometry.The levels of the cytokines including tumor necrosis factor alpha(TNF-α),interferon-γ(IFN-γ),interleukin(IL)-6,and IL-10 in tumor tissues were gauged with enzyme-linked immunosorbent assay kits.RESULTS We confirmed that PD-1 and TIM-3 expression was substantially upregulated in CD4+and CD8+T cells isolated from tumor tissues and ascites of HCC patients.TIM-3 mAb and PD-1 mAb treatment both reduced tumor volume and weight,while combined blockade had more substantial anti-tumor effects than individual treatment.Then we showed that combined therapy increased T cell infiltration into tumor tissues,and downregulated PD-1 and TIM-3 expression on CD8+T cells in tumor tissues.Moreover,combined treatment facilitated the production of T cell effector cytokines TNF-α and IFN-γ,and reduced the production of immunosuppressive cytokines IL-10 and IL-6 in tumor tissues.Thus,we implicated that combined blockade could ameliorate T cell exhaustion in HCC mouse model.CONCLUSION Combined TIM-3 and PD-1 blockade restrains HCC development by facilitating CD4+ and CD8+T cell-mediated antitumor immune responses.

中药调控CD^(+)_(4)T细胞干预湿疹炎症应答的研究进展

湿疹是一种变态反应性炎症性皮肤病,近期研究表明以CD^(+)_(4)T细胞亚群如Th1/Th2、Th17/调节性T细胞(regulatory T cells,Treg)细胞分化失衡导致湿疹发病中出现过度炎症应答,而中药以改善CD^(+)_(4)T细胞亚群分化平衡干预湿疹免疫微环境具有较好的调节作用。以湿疹炎症应答前沿研究动态,探讨中药在改善调控CD^(+)_(4)T细胞亚群分化干预湿疹致病的作用优势,为中药在改善湿疹临床症状及机制研究提供一定的理论指导。

Study on the effect and mechanism of the dysfunction of CD4^+ T cells in the disease process of chronic cardiac failure

Objective: To study the effect and mechanism of the dysfunction of CD4+ T cells in the disease process of chronic cardiac failure (CHF).Methods:According to different group technologies, 100 CHF patients were divided into the following groups: ischemia group and non-ischemia group, heart function Ⅰ-Ⅱ group and heart function Ⅲ-Ⅳ group, event group and non-event group, and 50 healthy volunteers were included in the control group. Realtime PCR was used to detect transcription factors T-bet and GATA-3 of Th1 and Th2; flow cytometry was applied to determine the ratio of Th17 and Treg cells; ELISA was employed to test cytokines IFN-γ, IL-4, IL-17 and IL-10 of peripheral blood Th1, Th2, Th17 and Treg cells, respectively; ultrasonic cardiogram was used to exploit to LVEF and LVEDd; and electrochemilu minescene immunoassay was used to examine plasma BNP. The differences of all indexes of all groups were analyzed and the correlation between CD4 T cells and clinical indexes was analyzed by Pearson correlation analysis. Results: As compared to the control group, the transcription factors T-bet and GATA-3 of Th1 and Th2, the ratio of cytokines Th17 and IFN-γ, cytokines IL-17, T-bet/GATA-3, IFN-γ/IL-4, Th17 cells/Treg cells, IL-17/IL-10 of the ischemia group and non-ischemia group, heart functionⅠ-Ⅱgroup and heart function Ⅲ-Ⅳ group, event group and non-event group were all increased significantly, while their transcription factor GATA-3 of Th2, cytokines IL4, Treg cells ratio, cytokines IL10 were decreased obviously. The differences showed statistical significance (P < 0.05). The increase or decrease of the partial CD4+ T cells of the ischemia group, heart function Ⅲ-Ⅳ group and event group was more distinctly. The results of Pearson correlation analysis showed that IFN-γ and IL-17 were significantly positively correlated with LVEDd and BNP, IL-4 and IL-10 were also significantly positively correlated with LVEF, but correlated negatively with BNP, and IL-17 was negatively correlative with LVEF. Conclusions: There was a correlation between CHF and the dysfunction of CD4+ T cells showing immune activation phenomenons of deviations from the Th1/Th2 balance towards Th1 and from the Th17/Treg balance towards Th17, which was also related to the types, severity and prognosis of the disease.

An Association between Immunosenescence and CD4^+CD25^+ Regulatory T Cells: A Systematic Review

Objective Age-related increment of the prevalence of CD4^＋CD25^＋ regulatory T （Treg） cells were described controversially, and whether such changes explain immune dysfunction in the elderly is still unclear. The aim of this systematic review is to evaluate the role of the Tregs in immunosenescence. Methods Medline and manual searches were performed to identify all published epidemiological and animal studies investigating the efficacy of the association between immunosenescence and Treg cells. Results It was founded that the frequency, phenotypic characteristics, and number/function of Tregs were altered significantly with aging. Medical conditions in individuals with advanced ageas well as apoptosis intensity of Treg cells had an impact on the accumulation of Tregs which in turn could deteriorate cytotoxic activity of CD8＋ T and NK cells and production of IL-2. The range of immune cells that could be suppressed by Treg cells was quite wide and covered CD4^＋CD25^＋ T cells, NK cells, dendritic cells and even monocytes. These changes were observed both in humans and experimental animals. Besides, it was believed that frequency of Tregs increased with age and was accompanied by intensified suppressive activity for Tregs in patients, for example, with Alzheimer disease （AD） and Parkinson disease （PD）. The impaired condition of CD4＋ T cells, so-called immunosenescence, rendered transplant recipients less responsive to an allogeneic kidney graft, an effect that was limited to transplant recipients who were aged over 60 years. Conclusions Treg cells are associated with immunosenescence. All these changes contribute to the aging-related decline of immune responses and lead to the higher risk of immune-mediated diseases, cancer or infections in aged individuals.

Analysis of CD4^+CD25^+ Regulatory T Cells and Foxp3 mRNA in the Peripheral Blood of Patients with Asthma

The changes of CD4^＋CD25^＋ regulatory T cells （CD4^＋CD25^＋ Treg） and Foxp3 mRNA in peripheral blood mononuclear cells （PBMCs） from patients with asthma were investigated in order to elucidate the possible roles of CD4^＋CD25^＋ Treg in the development of asthma. The peripheral blood samples were collected from 29 healthy controls （normal control group） and 78 patients with asthma which included 30 patients in exacerbation group, 25 patients in persistent group, and 23 patients in remission group. By using flow cytometry and RT-PCR, the CD4^＋CD25^＋ Treg ratio and Foxp3 mRNA in PBMCs were detected. The CD4^＋CD25^＋ Treg ratio and Foxp3 mRNA in PBMCs of exacerbation and persistent groups were lower than that of remission and normal control groups （P〈0.05）. Although the CD4^＋CD25^＋ Treg ratio and Foxp3 mRNA of remission group were also lower than that of normal control group, there was no significant difference between them （P〉0.05）. As compared with persistent group, exacerbation group had lower CD4^＋CD25^＋ Treg ratio and Foxp3 mRNA （P〈0.05）. It was indicated that the decrease of CD4^＋CD25^＋ Treg ratio and its function in PBMCs may be responsible for pathogenesis of asthma.

Depletion of CD4^+CD25^+ regulatory T cells can promote local immunity to suppress tumor growth in benzo[a]pyrene-induced forestomach carcinoma

AIM： To elucidate the distribution of CD4^＋CD25^＋ regulatory T cells （Tregs） in different lymphoid tissues and its local enhancement on tumor growth before and after depletion of CD4^＋CD25^＋ Tregs. METHODS： Female ICR mice were garaged with benzo[a]pyrene （BaP） to induce forestomach carcinoma. CD4^＋CD25^＋ Tregs were intraperitoneally depleted with monoclonal antibody PC61. These mice were divided into BaP-only, BaP ＋ IgG, BaP ＋ PC61, and control groups. The forestomach of mice was dissected for histological analysis, and tunnel test was performed for apoptosis of tumor cells. CD4^＋CD25^＋ Tregs were sorted from different lymphoid tissues and expression of Foxp3, IL-10, and chemokine receptors was analyzed by flow cytometry, semi-quantitative and veal-time polymerase chain reaction. RESULTS： The mice gavaged with only BaP showed increased forestomach papilloma and carcinoma at wk 16 and 32. The proportion of CD4^＋CD25^＋ Tregs was significantly higher in peri-stomach regional lymph nodes than in other lymphoid tissues. These CD4^＋CD25^＋ Tregs in regional lymph nodes expressed higher levels of Foxp3 and IL-10, enriched in the CD62L-subset, and CCR1 and CCR5 chemokine receptors. In mice gavaged with BaP ＋ PC61, the number of tumor nodules and tumor volume decreased significantly with massive infiltrating cells and apoptosis of tumor cells. In the draining regional lymph nodes, the number of CD4^＋CD25^＋ Tregs also decreased significantly. CONCLUSION： Inducible and activated CD4^＋CD25^＋ Tregs in the draining regional lymph nodes suppress host local immunity during tumor growth. Depletion of CD4^＋CD25^＋ Tregs can promote host local immunity to suppress tumor growth.

All-transRetinoic Acid Regulates Th1/Th2 Balance in CD4+T cells When GATA-3 is Deficient

The essential effect of vitamin A on immune function occurs through various mechanisms including direct effect on ThloTh2 balance modulation. However, it is unclear whether or not vitamin A can regulate Thl-Th2 balance under a strong Thl-polarizing condition. Therefore, the purpose of our study was to examine the effect of vitamin A metabolite allotrans retinoic acid （ATRA） on ThloTh2 differentiation in CD4~ T cells under GATA-3 deficiency, which can induce Thl-polarizing condition. In the present study, GATA-3 deficiency T cells were induced by siRNA and checked by real-time quantitative PCR and western blot. GATA-3 deficiency CD4＋ T cells and normal CD4＋ T were treated for 48 h with or without ATRA.

Super-resolution immunohistochemistry study on CD4 and CD8 cells and the relation to macrophages in human cochlea

Recently, the human cochlea has been shown to contain numerous resident macrophages under steady-state. The macrophages accumulate in the stria vascularis, among the auditory nerves, and are also spotted in the human organ of Corti. These macrophages may process antigens reaching the cochlea by invasion of pathogens and insertion of CI electrode. Thus, macrophages execute an innate, and possibly an adaptive immunity. Here, we describe the molecular markers CD4 and CD8 of T cells, macrophage markers MHCⅡ and CD11b, as well as the microglial markers TEME119 and P2Y12, in the human cochlea. Immunohistochemistry and the advantageous super-resolution structured illumination microscopy(SR-SIM) were used in the study. CD4^+ and CD8^+ cells were found in the human cochleae. They were seen in the modiolus in a substantial number adjacent to the vessels, in the peripheral region of the Rosenthal's canal, and occasionally in the spiral ligament. While there are a surprisingly large number of macrophages in the stria vascularis as well as between the auditory neurons,CD4^+ and CD8^+ cells are hardly seen in these areas, and neither are seen in the organ of Corti. In the modiolus,macrophages, CD4^+ and CD8^+ cells appeared often in clusters. Interaction between these different cells was easily observed with SR-SIM, showing closely placed cell bodies, and the processes from macrophages reaching out and touching the lymphocytes. Otherwise the CD4^+ and CD8^+ cells in human cochlear tissue are discretely scattered. The possible roles of these immune cells are speculated.

Advanced Glycation End Products Promote Differentiation of CD4^+ T Helper Cells toward Pro-inflammatory Response

This study investigated the effect of advanced glycation end products（AGEs） on differentiation of na ve CD4＋T cells and the role of the receptor of AGEs（RAGE） and peroxisome proliferator-activated receptors（PPARs） activity in the process in order to gain insight into the mechanism of immunological disorders in diabetes. AGEs were prepared by the reaction of bovine serum albumin（BSA） with glucose. Human na ve CD4＋T cells, enriched from blood of healthy adult volunteers with negative selection assay, were cultured in vitro and treated with various agents including AGEs, BSA, high glucose, PGJ2 and PD68235 for indicated time. In short hairpin（sh） RNA knock-down experiment, na ve CD4＋T cells were transduced with media containing shRNA-lentivirus generated from lentiviral packaging cell line, Lent-XTM293 T cells. Surface and intracellular cytokine stainings were used for examination of CD4＋T cell phenotypes, and real-time PCR and Western blotting for detection of transcription factor mRNA and protein expression, respectively. The suppressive function of regulatory T（Treg） cells was determined by a [3H]-thymidine incorporation assay. The results showed that AGEs induced higher pro-inflammatory Th1/Th17 cells differentiated from na ve CD4＋T cells than the controls, whereas did not affect anti-inflammatory Treg cells. However, AGEs eliminated suppressive function of Treg cells. In addition, AGEs increased RAGE mRNA expression in na ve CD4＋T cells, and RAGE knock-down by shRNA eliminated the effect of AGEs on the differentiation of CD4＋T cells and the reduction of suppressive function of Treg cells. Furthermore, AGEs inhibited the mRNA expression of PPARγ, not PPARα; PPARγ agonist, PGJ2, inhibited the effect of AGEs on na ve CD4＋T cell differentiation and reversed the AGE-reduced suppressive function of Treg cells; on the other hand, PPARγ antagonist, PD68235, attenuated the blocking effect of RAGE shRNA on the role of AGEs. It was concluded that AGEs may promote CD4＋T cells development toward pro-inflammatory state, which is associated with increased RAGE mRNA expression and reduced PPARγ activity. ＋

Downregulation of CD4+CD25+ regulatory T cells may underlie enhanced Th1 immunity caused by immunization with activated autologous T cells

Regulatory T cells （Treg） play important roles in immune system homeostasis, and may also be involved in tumor immunotolerance by suppressing Th1 immune response which is involved in anti-tumor immunity. We have previously reported that immunization with attenuated activated autologous T cells leads to enhanced anti-tumor immunity and upregulated Thl responses in vivo. However, the underlying molecular mechanisms are not well understood. Here we show that Treg function was significantly downregulated in mice that received immunization of attenuated activated autologous T cells. We found that Foxp3 expression decreased in CD4＋CD25＋ T cells from the immunized mice. Moreover, CD4＋CD25＋Foxp3＋ Treg obtained from immunized mice exhibited diminished immunosuppression ability compared to those from naive mice. Further analysis showed that the serum of immunized mice contains a high level ofanti-CD25 antibody （about 30 ng/ml, p〈0.01 vs controls）. Consistent with a role ofanti-CD25 response in the downregulation of Treg, adoptive transfer of serum from immunized mice to naive mice led to a significant decrease in Treg population and function in recipient mice. The triggering of anti-CD25 response in immunized mice can be explained by the fact that CD25 was induced to a high level in the ConA activated autologous T cells used for immunization. Our results demonstrate for the first time that immunization with attenuated activated autologous T cells evokes anti-CD25 antibody production, which leads to impeded CD4＋CD25＋Foxp3＋ Treg expansion and function in vivo. We suggest that dampened Treg function likely contributes to enhanced Thl response in immunized mice and is at least part of the mechanism underlying the boosted anti-tumor immunity.

Proliferation and Apoptosis of Bone Marrow CD4^+ T Cells in Patients with Aplastic Anemia and Impacts of the Secreted Cytokines on Hematopoietic Stem Cells from Umbilical Cord Blood

Recent studies indicate that immune-associated aplastic anemia(AA)resembles such autoimmune diseases as insulin-dependent diabetes and chronic autoimmune thyroiditis that belong to organ-specific autoimmune diseases.Many independent investigation groups have successfully isolated the pathopoiesis-associated T cell clone causing hematopoiesis failure with a CD4 phenotype from peripheral blood and bone marrow(BM)in AA patients.In the current study,BM CD4+ T cells were isolated from AA patients and healthy con...

CD4^+CXCR5^+ T cells activate CD27^+IgG^+ B cells via IL-21 in patients with hepatitis C virus infection

BACKGROUND： Chronic hepatitis C virus （HCV） infection causes the skewing and activation of B cell subsets, but the characteristics of IgG＋ B cells in patients with chronic hepa- titis C （CHC） infection have not been thoroughly elucidated. CD4＋CXCR5＋ follicular helper T （Tfh） cells, via interleukin （IL）-21 secretion, activate B cells. However, the role of CD4＋CXCR5＋ T cells in the activation ofIgG＋ B cells in CHC patients is not clear. METHODS： The frequency of IgG＋ B cells, including CD27-IgG＋ B and CD27＋IgG＋ B cells, the expression of the activation markers （CD86 and CD95） in IgG＋ B cells, and the percentage of circu- lating CD4＋CXCR5＋ T cells were detected by flow cytometry in CHC patients （n=70） and healthy controls （n=25）. The con- centrations of serum IL-21 were analyzed using ELISA. The role of CD4＋CXCR5＋ T cells in the activation of IgG＋ B cells was investigated using a co-culture system. RESULTS： A significantly lower proportion of CD27＋IgG＋ B cells with increased expression of CD86 and CD95 was observed in CHC patients. The expression of CD95 was negatively correlated with the percentage of CD27＋IgG＋ B cells, and it contributed to CD27＋IgG＋ B cell apoptosis. Circulating CD4＋CXCR5＋ T cells and serum IL-21 were significantly increased in CHC patients. Moreover, circulating CD4＋CXCR5＋ T cells from CHC patients induced higher expressions of CD86 and CD95 in CD27＋IgG＋ B cells in a co-culture system; the blockade of the IL-21 decreased the expression levels of CD86 and CD95 in CD27＋IgG＋ B cells.CONCLUSIONS： HCV infection increased the frequency of CD4＋CXCR5＋ T cells and decreased the frequency of CD27＋IgG＋ B cells. CD4＋CXCR5＋ T cells activated CD27＋IgG＋ B cells via the secretion of IL-21.

Increase of CD4^+CD25^+ T cells in Smad3^(-/-) mice

AIM： To investigate the changes of lymphocyte subpopulations, especially CD4^＋CD25^ T regulatory cells in Smad3^-/- mice. METHODS： Hematological changes and changes of lymphocyte subpopulations were detected in Smad3＂/- mice using cell counter and flow cytometry, respectively, and compared to their littermate controls. RESULTS： The numbers of neutrophils and lymphocytes in peripheral blood were significantly increased in Smad3^-/- mice compared to littermate controls. CD19^＋ expressing cells in blood and spleen, and CD8^＋ T cells in thymus were all markedly decreased in Smad3^-/- mice. More important, Smad3^-/- mice had an increased population of CD4^＋CD25^＋ T cells in peripheral lymphoid tissues, including thymus, spleen, and lymph nodes. CONCLUSION： These observations suggest that the changes of lymphocyte subpopulations might play a role in susceptibility to inflammation of Smad3^-/- mice.

Influence of Danshen Injection on airway inflammation and CD4^+ CD25^+ regulatory T cells of asthmatic rats

Objective： To investigate the influence of Danshen Injection on airway inflammation and CD4^＋CD25^＋ regulatory T cells（CD4^＋CD25^＋ Tr） of asthmatic rats, and elucidate the possible mechanism of Danshen Injection in treatment of asthma. Methods： 30 Wister rats were randomly divided into control group, asthma group and Danshen Injection treated group. Bronchoalveolar lavage fluids （BALF） were collected, and cytology studies were conducted. Lung tissues were obtained and pathologic analyses were done with hematoxylin and eosin stain （HE）. Flow cytometry was used to detect the CD4^＋CD25^＋ Tr ratio in peripheral blood mononuclear cells （PBMCs）. Results： Total cell, the percentage of lymphocytes, neutrophils and eosinophils （Eos） in BALF of Danshen Injection-treated group were lower than that in asthma group （P〈0.05, P〈0.01）. Compared with asthma group, less infiltration of inflammatory cells in lung tissues was observed in Danshen Injection-treated group. CD4^＋CD25^＋ Tr of asthma group was lower than that of control and Danshen Injection treated group （P〈0.05）. Conclusion： Danshen Injection can suppress airway inflammation of asthmatic rats, probably by increasing the number of CD4^＋CD25^＋ Tr.

Role of LAP^+CD4^+ T cells in the tumor microenvironment of colorectal cancer

AIM To investigate the abundance and potential functions of LAP^+CD4^+ T cells in colorectal cancer(CRC). METHODS Proportions of LAP^+CD4^+ T cells were examined in peripheral blood and tumor/paratumor tissues of CRC patients and healthy controls using flow cytometry. Expression of phenotypic markers such as forkhead box(Fox)p3, cytotoxic T-lymphocyte-associated protein(CTLA)-4, chemokine CC receptor (CCR)4 and CCR5 was measured using flow cytometry. LAP^-CD4^+ and LAP^+CD4^+ T cells were isolated using a magnetic cellsorting system and cell purity was analyzed by flow cytometry. Real-time quantitative polymerase chain reaction was used to measure expression of cytokines interleukin (IL)-10 and transforming growth factor(TGF)-β.RESULTS The proportion of LAP^+CD4^+ T cells was significantly higher in peripheral blood from patients (9.44% ± 3.18%) than healthy controls (1.49% ± 1.00%, P < 0.001). Among patients, the proportion of LAP^+CD4^+ T cells was significantly higher in tumor tissues(11.76% ± 3.74%) compared with paratumor tissues (3.87% ± 1.64%, P < 0.001). We also observed positive correlations between the proportion of LAP^+CD4^+ T cells and TNM stage(P < 0.001), distant metastasis(P < 0.001) and serum level of carcinoembryonic antigen(P < 0.05). Magnetic-activated cell sorting gave an overall enrichment of LAP^+CD4^+ T cells (95.02% ± 2.87%), which was similar for LAP^-CD4^+ T cells(94.75% ± 2.76%). In contrast to LAP^-CD4^+ T cells, LAP^+CD4^+ T cells showed lower Foxp3 expression but significantly higher levels of CTLA-4, CCR4 and CCR5(P < 0.01). LAP^+CD4^+ T cells expressed significantly larger amounts of IL-10 and TGF-β but lower levels of IL-2, IL-4, IL-17 and interferon-γ, compared with LAPCD4+ T cells.CONCLUSION LAP^+CD4^+ T cells accumulated in the tumor microenvironment of CRC patients and were involved in immune evasion mediated by IL-10 and TGF-β.