CD4+CD25+调节性T细胞、Foxp3与多发性硬化的关联

调节性T细胞(regulatoryT cell.Treg)是一类具有免疫调节功能的T细胞哑群,它们在维持外周免疫耐受、预防自身免疫性疾病的发牛过程中起着重要作用.     

The role of regulatory T cells in nervous system pathologies

Regulatory T (Treg) cells are a special subpopulation of immunosuppressive T cells that are essential for sustaining immune homeostasis. They maintain self‐tolerance, inhibit autoimmunity, and act as critical negative regulators of inflammation in various pathological states including autoimmunity, injury, and degeneration of the nervous system. Treg cells are known to convey both beneficial and detrimental influences in certain disease contexts, and accumulating research suggests that their action may be altered in a range of peripheral and central nervous system pathologies. In this review, we discuss emerging evidence for the dichotomous role of Treg cells in various neurological pathologies including multiple sclerosis, Guillain‐Barré syndrome, neuropathic pain, traumatic central nervous system injury, stroke, and neurodegenerative diseases such as amyotrophic lateral sclerosis, Alzheimer's disease, and Parkinson's disease. We are in the early stages of uncovering the role of Treg cells in these conditions, and a better understanding of the ways in which these cells operate in the nervous system will enable us to develop novel therapeutic interventions.     

Interferon-beta-1a treatment increases CD56 natural killer cells and CD4+CD25+ Foxp3 expression in subjects with multiple sclerosis

Disease modifying effects of interferon (IFN)-β therapy in patients with multiple sclerosis (MS) may be mediated in part through enhanced immunoregulation by the CD56^bright subpopulation of natural killer (NK) cells and by Foxp3+ (not italicized) CD4+CD25+ regulatory T cells (Treg). We found that IFN-β-1a(IM) treatment of relapsing–remitting (RR)MS subjects over 12 months significantly increased both percentage of CD56^bright NK cells and Foxp3 mRNA expression compared to baseline values, untreated RRMS subjects and healthy controls (HC). This striking enhancement of two prominent immunoregulatory pathways lends support to the idea that beneficial effects of IFN-β-1a in MS include control of pernicious autoimmunity.     

EAE大鼠胸腺CD4~+ CD25~+ Foxp3~+ Treg细胞的动态变化及α-硫辛酸的干预作用

目的探讨实验性变态反应性脑脊髓炎(EAE)大鼠不同病程中胸腺CD4+CD25+Foxp3+Treg细胞变化情况及α-硫辛酸对EAE大鼠胸腺的干预作用。方法取不同时期对照组、自然病程EAE组及α-硫辛酸EAE组大鼠的胸腺组织做流式细胞学,动态检测CD4+CD25+Foxp3+Treg细胞的变化情况。结果 EAE组大鼠急性期、复发期CD4+CD25+Foxp3+Treg细胞较同时期对照组明显减少(P<0.05),缓解期有所上升;α-硫辛酸组与同期EAE组相比CD4+CD25+Foxp3+Treg细胞无明显变化;半年期三组大鼠胸腺CD4+CD25+Foxp3+Treg细胞都明显下降,各组间无统计学差异。结论 CD4+CD25+Foxp3+Treg细胞参与了EAE的发病,与病程的发展密切相关;α-硫辛酸对EAE大鼠的干预作用并非通过CD4+CD25+Foxp3+Treg细胞发挥其治疗作用;随着年龄的增长,胸腺不再是机体的主要免疫器官。     

Direct demonstration of the infiltration of murine central nervous system by Pgp-1/CD44 CD45RB CD4 T cells that induce experimental allergic encephalomyelitis

In experimental allergic encephalomyelitis (EAE), autoimmune T cells infiltrate the central nervous system (CNS) and initiate demyelinating pathology. We have used flow cytometry to directly analyse the migration to the CNS of MBP-reactive CD4⁺ T cells labelled with a lipophilic fluorescent dye (PKH2), in SJL/J mice with passively transferred EAE. Labelled cells constituted about 45% of the CNS CD4⁺ population at the time of EAE onset. Almost all (>90%) of the PKH2-labelled CD4⁺ T cells from EAE CNS were blasts and were α/β T cell receptor (TCR)⁺, CD44(Pgp-1)^high, and the majority were CD45RB^low. By contrast, most PKH2-labelled CD4⁺ T cells in lymph nodes, although CD44^high, were CD45RB^high cells. The cells that were transferred to induce EAE were essentially similar to antigen-primed lymph node cell populations, containing less than 15% CD44^high cells, and most of them were CD45RB^high. The CD44^high CD45RB^low phenotype is characteristic of memory/effector T cells that have been activated by antigen recognition. The difference in CD45RB expression between CNS and LN could therefore reflect differential exposure and/or response to antigen. Consistent with this, PKH2-labelled CD4⁺ cells isolated from the CNS were responsive to MBP in vitro, whereas PKH2⁺ CD4⁺ cells from lymph nodes showed almost undetectable responses. In control experiments in which ovalbumin (OVA)-reactive T cells were transferred, a small number of fluorescent-labelled CD4⁺ T cells were also detected in CNS, but there were very few blasts, and these remained CD45RB^high. These results argue for induction of the memory/effector phenotype of CD4⁺ cells, their selective retention in the CNS, as a consequence of antigen recognition.     

帕金森病大鼠CD4+CD25highFoxP3+调节性T细胞的变化

目的 研究帕金森病(Parkinson's disease,PD)大鼠外周血中调节性T细胞(regulatory T cells,Treg)的改变,并探讨其与脑内免疫炎症反应的相关性.方法 SD大鼠随机分为对照组、假手术组、PD 4周组、PD 2周组.PD 4周组和2周组定向注射6-羟多巴建立PD大鼠模型,假手术组注射PBS缓冲液,PD 2周组于术后第2 周,其他组于术后第4 周时,应用免疫荧光染色法观察各组大鼠黑质处酪氨酸羟化酶(Tyrosine hydroxylase,TH)阳性神经元、离子钙接头蛋白分子-1(Ionized calcium bindingadaptor molecule-1,iba-1)和胶原纤维酸性蛋白(Glial fibrillary acid protein,GFAP)阳性细胞数量及形态的改变,并通过流式细胞术(Flow cytometry,FCM)检测其外周血中CD4+CD25highFoxP3+ Treg 占T 淋巴细胞比例的变化.结果 PD4 周组TH 阳性神经元偏侧毁损率(91.33%±8.53%)较对照组和假手术组增加(P<0.01),且较PD2周组(64.56%±17.94%)毁损更为严重(P<0.05).PD4周组iba-1阳性细胞增加率(82.60%±11.52%)和GFAP阳性细胞增加率(86.62%±6.80%)较对照组及假手术组均增加(P<0.01),但PD 4 周组较2 周组iba-1 阳性细胞增加率(104.89%±13.39%)和GFAP 阳性细胞增加率(117.92%±15.34%)均减少(P<0.05).FCM示PD4周组大鼠外周血中CD4+CD25highFoxP3+ Treg占T淋巴细胞的比例(0.64%±0.08%)较对照组、假手术组及PD2周组均降低(P<0.01).另外,外周血T淋巴细胞中Treg比例变化与TH 阳性神经元毁损率(r=-0.59,P<0.01)、iba-1 阳性细胞增加率(r=-0.87,P<0.01)和GFAP 阳性细胞增加率(r=-0.89,P<0.01)均呈负相关.结论 PD大鼠外周血中Treg比例减少且可能与脑内免疫炎症反应相关.     

The involvement of the sympathetic nervous system in the centrogenic pressor and tachycardiac effects of prostaglandins E2 and F2α in anaesthetised cats

The intracerebroventricular (i.c.v.) administration of prostaglandin E₂ (PGE₂, 1 μg) and prostaglandin F_2α (PGF_2α, 10 μg) produced prolonged pressor and tachycardiac responses in chloralose-anaesthetised cats. Phenoxybenzamine-pretreatment completely prevented the pressor response without altering the tachycardiac response, whereas propranolol intervention completely inhibited the tachycardiac response and also attenuated the pressor response. The pretreatment with pentolinium completely antagonised both the pressor and tachycardiac responses to i.c.v. PGE₂ and PGF_2α. The results suggest that the centrally administered PGE₂ and PGF_2α augment sympathetic outflow to the heart and vascular system and thereby cause excitatory cardiovascular responses in anaesthetised cats.     

Dopamine receptor D2 on CD4+ T cells is protective against neuroinflammation and neurodegeneration in a mouse model of Parkinson's disease

Parkinson's disease (PD) is a chronic neurodegenerative disease. Recently, neuroinflammation driven by CD4⁺ T cells has been involved in PD pathophysiology. Human and murine lymphocytes express all the five subtypes of dopamine receptors (DRs), DRD1 to DRD5. However, roles of DRs particularly DRD2 expressed on CD4⁺ T cells in PD remain elucidated. Global Drd1- or Drd2-knockout (Drd1^−/− or Drd2^−/−) mice or CD4⁺ T cell-specific Drd2-knockout (Drd2^fl/fl/CD4^Cre) mice were intraperitoneally injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to induce PD with the different mutants. On the 7th day following MPTP injection, mice were assessed for dopaminergic neurodegeneration, locomotor impairments, microglial activation, as well as CD4⁺ T-cell differentiation and function. Furthermore, in vitro CD4⁺ T cells were exposed to DRD2 agonist and antagonist and then differentiation and function of the cells were determined. MPTP induced dopaminergic neuronal loss in the nigrostriatal system, motor coordinative and behavioral impairments, microglial activation, and CD4⁺ T-cell polarization to pro-inflammatory T-helper (Th)1 and Th17 phenotypes. Importantly, either Drd2^−/− or Drd2^fl/fl/CD4^Cre mice manifested more severe dopaminergic neurodegeneration, motor deficits, microglial activation, and CD4⁺ T-cell bias towards Th1 and Th17 phenotypes in response to MPTP, but Drd1^−/− did not further alter MPTP intoxication. DRD2 agonist sumanirole inhibited shift of CD4⁺ T cells obtained from MPTP-intoxicated mice to Th1 and Th17 phenotypes and DRD2 antagonist L-741,626 reversed sumanirole effects. These findings suggest that DRD2 expressed on CD4⁺ T cells is protective against neuroinflammation and neurodegeneration in PD. Thus, developing a therapeutic strategy of stimulating DRD2 may be promising for mitigation of PD.     

β-Endorphin alters the course of central nervous system disease induced by a temperature-sensitive vesicular stomatitis virus in reconstitued nude mice

A 100 plaque forming unit (pfu) dose of a temperature-sensitive (ts) mutant of vesicular stomatitis virus (VSV), tsG31 KS5, engendered a slowly progressive paralytic central nervous system (CNS) disease that killed all BALB/c nude mice within 28 days. Reconstitution of nude mice with 10⁷ syngeneic splenocytes 24 h before intracerebral inoculation with tsG31 KS5 VSV, however, protected 92% of the animals from death. When these reconstituted animals were injected intracerebroventricularly with 14 pmol of β-endorphin 24 h after reconstitution with splenocytes and 24 h befor inoculation with tsG31 KS5 VSV, only 72% of the animals survived. Furthermore, whereas 40% of the afflicted reconstituted nude mice given intracerebroventricular injections of sterile water were able to recover from the symptoms of disease, those surviving animals which received β-endorphin were unable to do so. A single intravenous injection of 14 pmol β-endorphin, or repeated postinfection administration of 28 pmol of β-endorphin intravenously into nude mice reconstituted with syngeneic splenocytes, which were pretreated with β-endorphin, did not alter the course of CNS disease induced by tsG31 KS5 VSV. The effect induced by intracerebroventricular injection of β-endorphin as antagonized by naloxone, but not by the neuropeptide fragment β-endorphin-(1–27). A simultaneous intracerebroventricular injection of reconstituted nude mice with 1220 pmol of naloxone and 14 pmol of β-endorphin resulted in a 89% survival rate, and 33% of the afflicted animals were able to overcome the symptoms of the disease induced by tsG31 KS5 VSV. Intracerebroventricular injection of reconstituted nude mice with 330 pmol of β-endorphin-(1–27) and 14 pmol of β-endorphin resulted in a 72% survival rate and the surviving animals were unable to improved appreciably the clinical status of their disease. Injection of reconstituted nude mice with either 1220 pmol of naloxone or 330 pmol of β-endorphin-(1–27) alone did not alter the course of the CNS disease in any way. A single intracerebroventricular injection of 29 pmol of another psychoactive peptide, [Des-Tyr]-endorphin, 24 h after reconstitution of nude mic with splenocytes and 24 h prior to infection with virus, resulted in 74% survival; and 39% of the afflicted animals were able to recover from the clinical symptoms.