趋化因子及其受体与自身免疫性甲状腺疾病

趋化因子及其受体是免疫系统的重要组成部分,其趋化活性可以介导免疫细胞的定向移动和活化。在自身免疫性甲状腺疾病（AITD）的形成过程中,趋化因子及其受体参与淋巴细胞在甲状腺组织的浸润、定位及活化,它们的表达是导致AITD发生的一个重要因素。     

趋化因子受体在人卵巢黄素化颗粒细胞中的表达

为探讨人卵巢黄素化颗粒细胞中趋化因子受体的表达,收集生殖中心接受卵母细胞胞浆单精子注射(intracellularsperm injection ICSI)治疗的妇女卵巢黄素化颗粒细胞,于体外分离培养。免疫细胞化学检测细胞纯度,RT-PCR检测颗粒细胞中趋化因子受体的转录水平,流式细胞术检测蛋白表达水平。结果显示,经过免疫细胞化学鉴定,原代培养的颗粒细胞纯度达95%以上;趋化因子受体以CXCR4转录水平最高,另外,CXCR6、CCR2、CCR6、CCR7转录水平也较高;流式细胞术检测CXCR4及CXCR6蛋白水平高表达,CCR3表达相对较低。人卵巢黄素化颗粒细胞中表达多种趋化因子受体,它们可能在卵泡液局部免疫调节、卵泡发育和卵母细胞成熟中发挥了重要的作用。     

趋化因子及其受体在炎症中作用的研究进展

趋化因子是能够激发白细胞趋化性的小分子分泌性蛋白质,是可受化学诱导物及细胞因子调节、并能刺激细胞趋化运动的一类细胞因子.趋化因子将循环中的淋巴细胞募集到组织损伤或炎症反应部位.早期对趋化因子的研究是基于其在炎症中的功能.最近发现趋化因子及其受体和机体内单核细胞的迁移,适应性免疫应答以及多种疾病的发病机理相关.趋化因子受体作为炎症和免疫应答的调控分子而成为多种药物的靶向分子.临床上已经开始利用趋化因子的拈抗剂治疗炎症疾病,本篇旨在阐述趋化因子及其受体在炎症疾病中的作用以及这些趋化因子在临床上的应用.     

趋化性细胞因子受体在Tc1和Tc2亚群的差异表达

目的研究趋化性细胞因子受体在体外长期培养的人Te1和Tc2细胞系中的表达。方法将新鲜分离的PBMC在特定细胞因子及细胞因子抗体存在条件下，定向诱导为Ⅰ型和Ⅱ型T细胞系，用免疫荧光染色结合流式细胞术分析鉴定，并以膜表面及胞内三色流式细胞术检测趋化性细胞因子受体在不同T细胞亚群的表达。结果①在Ⅰ型和Ⅱ型T细胞整体水平上，CXCR4的表达水平接近，CXCR3和CCR5的表达在Ⅰ型T细胞明显高于Ⅱ型T细胞，CCR3在2种T细胞系的表达水平均较低，但在Ⅱ型T细胞的表达略高于Ⅰ型T细胞；②趋化性细胞因子受体在Tc1和Tc2亚群细胞的表达与上述结果类似，即CXCR的表达水平接近，CXCR3和CCR5的表达在Tc1高于Tc2，CCR3的表达水平较低，但在Tc2则略高于Tc1。结论趋化性细胞因子受体在Tc1和Tc2亚群的表达具有差异性。     

人早孕期绒毛组织和滋养细胞趋化因子受体转录水平

目的：研究早孕期绒毛组织及滋养细胞18种趋化因子受体的转录水平，以揭示趋化因子受体在母一胎界面生理性调节作用。方法：提取人早孕期绒毛组织及滋养细胞总RNA，半定量RT-PCR检测绒毛组织和滋养细胞18种趋化因子受体mRNA的表达水平。结果：CXCR4及CXCR6在绒毛组织中普遍高表达；CCR6、CCR7、XCR1及CX3CR1呈普遍中等表达；CCR1～CCR5、CCR8～CCR10、CXCR1～CXCR3在部分绒毛组织中表达，部分绒毛组织不表达或表达量很低；早孕人绒毛组织不表达CXCR5。早孕期滋养细胞表达CCR1、CCR3～CCR5、CCR8～CCR9、CXCR1～CXCR4、CXCR6、XCR1、CX3CR1；不表达CCR2、CCR6、CCR7、CCR10及CXCR5。结论：早孕期绒毛组织及滋养细胞表达多种趋化因子受体，它们在正常妊娠中具有重要的生理学意义。     

趋化因子及其受体与气道疾病关系的研究进展

气道慢性炎症是哮喘和慢性阻塞性肺疾病的本质特点。炎症细胞浸润组织是炎症和宿主免疫应答的基础，这一过程受到趋化因子的控制。本文将阐述趋休因子及其受体家族的特点，特别是在慢性气道炎症病理生理过程中的作用以及作为气道慢性炎症靶向性治疗的可能性。     

T细胞相关趋化因子及受体的研究进展

T细胞在发育、成熟、活化及发挥生物学效应的各个阶段表达不同的趋化因子受体。T细胞相关趋化因子及其受体的表达在不同的细胞类群上具有时相和分布的差异,并通过趋化因子与其受体特异性结合的模式,参与T细胞的发育过程,调控细胞的定向迁移,从而影响局部甚至整个机体的免疫状态。此外,它还在炎症、感染、肿瘤、自身免疫疾病等众多病理生理的过程中发挥重要作用。在这一领域的深入研究将为相关疾病的预防和治疗提供新的思路和途径。     

Granulocyte chemotactic protein 2 acts via both IL- 8 receptors,CXCR1 and CXCR2

Interleukin-8 (IL-γ) acts on human neutrophils via two receptors, CXCR1 and CXCR2. It shares CXCR2 with all neutrophil-activating chemokines, which like IL-8 have a conserved Glu-Leu-Arg (ELR) N-terminal motif, but is generally considered to be the only relevant agonist for CXCR1. IL-8 has a basic residue at the sixth position after the second cysteine, which was suggested to contribute to CXCR1 specificity. Among the other ELR chemokines, only granulocyte chemotactic protein 2 (GCP-2) has such a basic determinant. Using Jurkat cells that stably express either CXCR1 or CXCR2, we studied receptor activation by IL-8, GCP-2 epithelial neutrophil-activating protein 2 (ENA-78) (which shares 77 % identical amino acids with GCP-2) and growth-regulated oncogene α (GROα). At 10 nM and higher concentrations, GCP-2 and IL-8 induced significant activation of CXCR1-expressing cells, but no activity was found with GROα and ENA-78. As expected, however, all four chemokines had similar activities on CXCR2-expressing cells. A variant of GCP-2 in which the basic residue, Arg20, was replaced by a glycine was synthesized. This derivative was ineffective on CXCR1, but was as active as wild-type GCP-2 in CXCR2-expressing cells. GCP-2 displaced radiolabeled IL-8 from both receptors with low affinity, and in this respect resembled ENA-78 and GROα. Our data show that GCP-2 acts via both IL-8 receptors and thus appears to be functionally more similar to IL-8 than to the other ELR chemokines. Activation of CXCR1 appears to depend significantly on the presence of a basic binding determinant close to the second cysteine.     

子宫内膜及异位灶趋化因子受体转录在子宫内膜异位症发病中的作用

目的：探讨子宫内膜异位症患者在位内膜及异位灶18种趋化因子受体的转录特征，以揭示趋化因子受体及其配体在子宫内膜异位症发生发展中的作用。方法：以正常子宫内膜为对照，半定量RT-PCR检测子宫内膜异位症患者在位内膜及异位灶18种趋化因子受体mRNA的表达水平，并比较其差异。结果：与正常子宫内膜相比，子宫内膜异位症患者在位子宫内膜CCR6、CCR8、CCR9、CX3CR1表达明显升高（P＜0．05）。与在位内膜相比，异位灶CCR4、CCR8、CCR9、CXCR1表达显著升高（P＜0．05）。结论：在位子宫内膜CCR6、CCR8、CCR9、CX3CR1高表达，可能参与子宫内膜异位症的发生；异位灶CCR4、CCR8、CCR9、CXCR1高表达，可能参与子宫内膜异位症的进一步发展。     

Differential expression of chemokine receptors on human IgA+ and IgG+ B cells

Organ-specific lymphocyte homing is dependent on the expression of tissue-specific homing receptors and selected chemokine receptors. During the effector phase of an immune response, IgA and IgG antibody-secreting cells (ASC) are differently distributed in the body. Still, B cell expression of L-selectin and the mucosal homing receptor integrin alpha4beta7 is not related to the isotype produced, but only to the site of antigen encounter. In this study, we examined if differences in chemokine responsiveness between IgA+ and IgG+ B cells could explain their different tissue localization. Circulating CD19+ B cells were isolated and their expression of IgA, IgG, and selected chemokine receptors was determined by flow cytometry. Few Ig+ cells expressed CCR2, CCR3, or CCR9, and there was no difference in the expression of these receptors between IgA+ and IgG+ cells. In contrast, CCR4, CCR5, and CXCR3 was expressed on significantly more IgG+ than IgA+ cells. The function of chemokine receptors on memory B cells and ASC was then tested in the transwell system. IgG+ memory cells migrated to a higher extent than IgA+ cells towards the CXCR3 ligand CXCL11/I-TAC, while there was only a small migration towards the CCR4 ligand CCL17/TARC and the CCR9 ligand CCL25/TECK. ASC migrated poorly to all chemokines tested. In conclusion, this study shows that IgG+ and IgA+ memory B cells have a differential expression of the Th1 associated chemokine receptor CXCR3, as well as of CCR4 and CCR5. In contrast, none of the studied chemokine receptors was preferentially expressed by IgA+ cells.     

Sphingosine kinase inhibitor suppresses dendritic cell migration by regulating chemokine receptor expression and impairing p38 mitogen-activated protein kinase

The migration of dendritic cells (DCs) to secondary lymphoid organs plays a crucial role in the initiation of adaptive immune responses. Although lipopolysaccharide enhances chemokine receptor 7 (CCR7) expression on DCs, the second signal for the migration of DCs toward the chemokine CCL19 remains unknown. In this study, we show that sphingosine kinase inhibitor (SKI) inhibits the migration of DCs toward CCL19 through the down-regulation of CCR7. Inhibition of p38 mitogen-activated protein kinase (MAPK) activation by SKI may be responsible for the SKI-mediated effects on the regulation of chemokine receptor expression. Impairment of DC migration by the inhibition of p38 MAPK and down-regulation of CCR7 expression may contribute to the protective effects of SKI in DC-related disorders. These results suggest that sphingosine kinase-mediated signalling plays a role in the innate and adaptive immune responses by altering DC migration.     

Rapid and coordinated switch in chemokine receptor expression during dendritic cell maturation

Dendritic cells (DC) migrate into inflamed peripheral tissues where they capture antigens and, following maturation, to lymph nodes where they stimulate T cells. To gain insight into this process we compared chemokine receptor expression in immature and mature DC. Immature DC expressed CCR1, CCR2, CCR5 and CXCR1 and responded to their respective ligands, which are chemokines produced at inflammatory sites. Following stimulation with LPS or TNF-α maturing DC expressed high levels of CCR7 mRNA and acquired responsiveness to the CCR7 ligand EBI1 ligand chemokine (ELC), a chemokine produced in lymphoid organs. Maturation also resulted in up-regulation of CXCR4 and down-regulation of CXCR1 mRNA, while CCR1 and CCR5 mRNA were only marginally affected for up to 40 h. However, CCR1 and CCR5 were lost from the cell surface within 3 h, due to receptor down-regulation mediated by chemokines produced by maturing DC. A complete down-regulation of CCR1 and CCR5 mRNA was observed only after stimulation with CD40 ligand of DC induced to mature by LPS treatment. These different patterns of chemokine receptors are consistent with “inflammatory” and “primary response” phases of DC function.     

The chemokine SDF-1, stromal cell-derived factor 1, attracts early stage B cell precursors via the chemokine receptor CXCR4

In the bone marrow, progenitor (pro-) and precursor (pre-) B cells depend on close contact with stromal cells for growth and maturation. Stromal cell-derived factor 1 (SDF-1), also known as pre-B cell growth-stimulating factor, is produced by bone marrow stromal cells and was reported to act together with interleukin-7 as co-mitogen for pre-B cells. SDF-1 was recently shown to be a chemokine which is chemotactic for different types of leukocytes and acts via the chemokine receptor CXCR4. Using sorted B220⁺ bone marrow cells and several B cell lines characteristic for different stages of B lymphopoiesis, we now show that SDF-1 is a potent attractant for pro- and pre-B cells, but is inactive on B cells at later stages of development. In early B cell precursors, SDF-1 induced intracellular Ca²⁺ mobilization and in vitro migration with a potency and efficacy similar to that observed for chemokines acting on blood leukocytes. These responses were mediated via CXCR4 as they could be inhibited by an anti-receptor antibody. SDF-1 is the first chemokine shown to act on early-stage B cell precursors. Mice lacking SDF-1 die perinatally and show a severe deficiency in B lymphopoiesis. We propose that SDF-1 released from the stromal cells exerts its critical hematopoietic function by selectively attracting and confining early B cell precursors within the bone marrow microenvironment that provides the necessary factors for growth and differentiation.     

Mechanisms of leukocyte trafficking in allergic diseases: insights into new therapies targeting chemokines and chemokine receptors

Marked inflammatory infiltration by activated leukocytes is a characteristic feature of allergic diseases. Elucidation of the mechanisms of leukocyte trafficking in allergic diseases would identify targets to establish novel anti-inflammatory strategies for treatment of these diseases. Leukocyte trafficking is controlled by tissue-specific expression of chemokines and chemokine receptor expression on the leukocyte surface. Here, we review the role of chemokines and their receptors in leukocyte trafficking to inflammatory sites in allergic diseases and discuss therapeutic strategies targeting chemokine networks for treatment of these diseases.     

Down‐regulated expression of monocyte/macrophage major histocompatibility complex receptors in human and mouse monocytes by expression of their ligands

Mouse monocyte/macrophage major histocompatibility complex (MHC) receptor 1 (MMR1; or MMR2) specific for H-2D^d (or H-2K^d) molecules is expressed on monocytes from non-H-2D^d (or non-H-2K^d), but not those from H-2D^d (or H-2K^d), inbred mice. The MMR1 and/or MMR2 is essential for the rejection of H-2D^d- and/or H-2K^d-transgenic mouse skin onto C57BL/6 (H-2D^bK^b) mice. Recently, we found that human leucocyte antigen (HLA)-B44 was the sole ligand of human MMR1 using microbeads that had been conjugated with 80 types of HLA class I molecules covering 94·2% (or 99·4%) and 92·4% (or 96·2%) of HLA-A and B molecules of Native Americans (or Japanese), respectively. In the present study, we also explored the ligand specificity of human MMR2 using microbeads. Microbeads coated with HLA-A32, HLA-B13 or HLA-B62 antigens bound specifically to human embryonic kidney (HEK)293T or EL-4 cells expressing human MMR2 and to the solubilized MMR2-green fluorescent protein (GFP) fusion protein; and MMR2⁺ monocytes from a volunteer bound HLA-B62 molecules with a K_d of 8·7 × 10⁻⁹ M, implying a three times down-regulation of MMR2 expression by the ligand expression. H-2K^d (or H-2D^d) transgene into C57BL/6 mice down-regulated not only MMR2 (or MMR1) but also MMR1 (or MMR2) expression, leading to further down-regulation of MMR expression. In fact, monocytes from two (i.e. MMR1⁺/MMR2⁺ and MMR1^–/MMR2^–) volunteers bound seven to nine types of microbeads among 80, indicating ≤ 10 types of MMR expression on monocytes.The physiological role of constitutive MMRs on monocytes possibly towards allogeneic (e.g. fetal) cells in the blood appears to be distinct from that of inducible MMRs on macrophages toward allografts in tissue.     

Chemokines and chemokine receptors in susceptibility to HIV-1 infection and progression to AIDS

A multitude of host genetic factors plays a crucial role in susceptibility to HIV-1 infection and progression to AIDS, which is highly variable among individuals and populations. This review focuses on the chemokine-receptor and chemokine genes, which were extensively studied because of their role as HIV co-receptor or co-receptor competitor and influences the susceptibility to HIV-1 infection and progression to AIDS in HIV-1 infected individuals.