CD4^＋CD25^＋调节性T细胞及其分子标记物与支气管哮喘

CD4^＋CD25^＋调节性T细胞是一类以免疫抑制和免疫无能为特征的淋巴细胞群,FOXP3是CD4^＋CD25^＋调节性T细胞一个特征性的分子标志物,并且对CD4^＋CD25^＋调节性T细胞的发育、外周表达和功能维持有着关键性的作用。近年来,多项研究显示CD4^＋CD25^＋调节性T细胞参与并影响了支气管哮喘的发生、发展过程,对调节性T细胞或其相关基因的干预也许会成为支气管哮喘治疗的新方向。     

急性ITP患儿外周血中CD4^＋CD25^＋Foxp3^＋Tr细胞、IL-7水平变化及意义

目的探讨急性特发性血小板减少性紫癜（AITP）的发病机制。方法选择35例AITP患儿（AITP组）和30例健康查体者（对照组）,用流式细胞仪检测外周血CD4^＋CD25^＋Foxp3^＋调节性T（Tr）细胞数量及占CD4^＋细胞比例,ELISA法检测血浆中IL-7水平。结果AITP组和对照组外周血CD4^＋CD25^＋Foxp3^＋Tr细胞／CD;细胞分别为0．11±0．04、0．15±0．02,IL-7分别为（2．32±0．53）、（0．44±0．80）pg／ml,P均〈0．05;AITP组外周血IL-7水平与CD4^＋CD25^＋Foxp3^＋Tr细胞／CD;细胞呈负相关（r=0．71,P〈0．05）。结论CD4^＋CD25^＋Foxp3^＋Tr细胞数量减少、IL-7水平升高可能在AITP发病中具有重要作用,机制为降低有效免疫抑制作用,导致自身反应性T细胞激活增多、凋亡减少,促进血小板破坏。     

CD4^＋CD25^＋调节性T细胞在食管癌中的表达及意义

目的探讨CD4^＋CD25^＋调节性T细胞在食管癌患者免疫失效机制中的作用。方法应用流式细胞仪检测97例食管癌患者外周血和肿瘤组织的CD4^＋CD25^＋调节性T细胞比例,比较不同病理类型、不同分期、有无淋巴结转移患者外周血CD4^＋CD25^＋调节性T细胞的分布变化。结果食管癌患者外周血中CD4^＋CD25^＋调节性T细胞占CD4^＋T淋巴细胞的比例为（17．57±3．99）％,肿瘤组织CD4^＋CD25^＋调节性T细胞比例为（18．97±2．38）％,均高于健康对照组（P均〈0．01）。CD4^＋CD25^＋调节性T细胞比例在不同临床分期、有无淋巴结转移患者间差异有统计学意义（P均〈0．01）。结论食管癌患者全身及肿瘤局部均存在免疫异常,CD4^＋CD25^＋调节性T细胞可能参与了食管癌的发生与发展。     

调节性T细胞在系统性红斑狼疮中的研究进展

系统性红斑狼疮（SEE）是一种以产生大量自身抗体为特征的自身免疫病，其自身抗体的产生呈T细胞依赖性。SLE自身耐受的破坏主要表现为T细胞免疫失调、B细胞高反应性和细胞因子产生异常。近来发现调节性T细胞（regulatory Tcells，Treg）在维持自身免疫耐受中起重要作用，Treg缺陷可引起SLE等多种自身免疫病。Treg是一类具有主动免疫调节功能的T细胞群，根据产生和表型不同分为不同亚群。目前研究最多的是天然CD4^＋CD25^＋调节性T细胞（naturally occurring CD4^＋CD25^＋ regulatory T cells，nTreg），该类细胞数量或功能缺陷将影响自身免疫环境的稳定。此外，诱导型调节性T细胞（induced regulatory T cells，iTreg）也具有免疫抑制功能，包括Ⅰ型调节性T细胞（type 1 regulatory T cells，Tr1）和辅助性T细胞3（T helper cells 3，Th3）等。本文将对Treg的产生、分类、特性及其在SLE中的作用作一综述。     

几种免疫细胞在感染HIV-1过程中的作用

随着免疫学的发展，人们发现艾滋病病毒Ⅰ型（HIV-1）感染及其疾病进展与机体内一些细胞的免疫功能有关。CD4^＋CD25^＋调节性T细胞（Tr）在机体感染免疫中具有重要作用，在人类HIV-1感染中CD4^＋CD25^＋T细胞能控制机体CD4^＋和CD8^＋T细胞的特异性抗HIV-1免疫应答，并且与HIV-1感染状态有关。在多种疾病中都发现Th1／Th2的异常转化。目前多数研究结果表明：HIV-1感染也会造成Th2的极化，并最终造成CD4^＋T细胞功能的缺失。在机体抗HIV-1感染中，树突状细胞（DC）具有双重作用，DC在HIV-1感染中的这种双重作用导致机体内DC数量减少及功能削弱。NK细胞是对抗病毒感染的第一道防线，慢性HIV-1感染会引起NK细胞群的异常。有学者报道CD56^＋CD16^＋CD3^-CD4^＋CCR5^＋／CXCR4^＋的NK细胞可被HIV-1感染，使感染者天然免疫功能低下。虽然上述这些细胞在HIV-1感染中都有各自的功能，但是作为免疫系统网络整体而言，它们功能变化导致的HIV-1感染性疾病的进展是这些细胞相互作用、相互调节、共同作用的结果。     

CD4+CD25+FOXP3+调节性T细胞在肺癌患者外周血中的表达及意义

选择同期收治的60例肺癌患者（肺癌组）和34例健康查体者（对照组），利用流式细胞仪检测其外周血CD4^＋CD25^＋FOXP3^＋调节性T细胞表达情况。结果肺癌组外周血CD4^＋CD25^＋FOXP3^＋调节性T细胞表达水平显著高于对照组。认为CD4^＋CD25^＋FOXP3^＋调节性T淋巴细胞可能通过调节机体免疫力参与肺癌的发生、发展，临床可通过抑制或阻断FOXP3表达抑制调节性T细胞的功能，提高机体对肿瘤抗原的免疫应答。     

Toll样受体、CD4+CD25+调节性T细胞与支气管哮喘的关系

Toll样受体（TLR）是机体识别环境中各种微生物的主要受体，是介导天然免疫和获得性免疫的桥梁。支气管哮喘（哮喘）的发病是环境和基因相互作用的结果，TLR与哮喘有着十分密切的关系。近年来，人们逐渐认识到Th1／Th2理论并不能充分阐明哮喘的发病机制。随着对哮喘的深入研究，CD4^＋CD25^＋调节性T细胞凸现其冰山一角。本文就近年来对TLR、CD4^＋CD25^＋调节性T细胞和哮喘关系的研究进展作一综述。     

CD4+CD25+调节性T细胞在哮喘发生发展中的作用研究进展

支气管哮喘被普遍认为是因Th1／Th2失衡，由过度激活的Th2细胞介导的气道炎症性疾病。然而，Th1／Th2理论并不能充分阐明哮喘的发病机制。近几年来，越来越多的证据显示调节性T细胞在哮喘的发生发展中起到很重要的作用，CD4^＋CD25^＋调节性T细胞作为调节性T细胞的一种亚型成为目前研究的热点。本文就近来对CD4^＋CD25^＋调节性T细胞研究的进展及其与哮喘的关系作一综述。     

Foxp3仍然是人调节性T细胞的标志？

CD4＋CD25＋调节性T细胞是维持机体免疫稳态和免疫耐受的一个重要机制。缺乏这群细胞与许多自身免疫性疾病的发生和发展密切相关。目前积累的证据表明，在啮齿类动物中，一个叉头样转录因子Foxp3基因及其编码产物（scurfin）是CD4^＋CD25^＋调节性T细胞的特异性标志物。Foxp3基因控制着CD4^＋CD25^＋调节性T细胞的发育,并且直接影响它的功能。虽然早期研究认为Foxp3也在人CD4^＋CD25^＋调节性T细胞上特异性表达，但是越来越多的研究发现Foxp3在人类激活的CD4^＋效应T细胞中也有表达。Foxp3是否也是人的调节性T细胞的特异性分子标志？本文对当前国际免疫调节领域相关方面的工作进展进行总结，以供同行参考。     

调节性T细胞在慢性乙型肝炎病毒感染免疫发病机制中的作用

CD4^＋CD25^＋调节性T细胞（CD4^＋CD25^＋ Treg）是一个具有独特免疫调节功能的T细胞亚群,它不仅能抑制自身免疫性疾病的发生,而且参与诱导移植耐受、肿瘤和感染免疫的调节,在维持机体免疫内环境的稳定中起重要作用。本文综述了CD4^＋CD25^＋调节性T细胞的特点和调节机制,以及在慢性乙型肝炎病毒感染免疫发病机制中可能起的作用。最新研究提示其对自身抗原和非己抗原均有较强的免疫抑制作用。这些研究成果,尤其是对在慢性乙型肝炎病毒感染发病机制中的作用研究,将有助于对乙型肝炎病毒慢性感染免疫应答机制的了解以及对慢性肝炎发生机制和免疫耐受的认识,并最终为慢性乙型肝炎病毒感染开辟新的免疫治疗途径。     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.