Adhäsionsmoleküle in der Dermatoonkologie

Zusammenfassung Adh?sionsmoleküle sind Zell-Oberfl?chen-Proteine, welche verantwortlich sind für die Zell-Zell- und Zell-Matrix-Interaktionen. Sie sind in der Lage eine gro?e Zahl von Stimuli zu erkennen und darauf entsprechend zu reagieren. Sie bilden somit eine Basis für manchen physiologischen und pathologischen Prozess insbesonders des „Homing“-Verhaltens, der Homeostase der Immunantwort, der Wundheilung, der Entzündungen und der Tumormetastasierung. In der Dermatologie wurde das Interesse vor allem durch die Entdeckung des CLA (cutaneous lymphocyte antigen) geweckt, welches der spezifische „Homing“-Rezeptor für Memory-T-Zellen darstellt. So konnte gezeigt werden, da? die Zellen in kutanen Lymphomen CLA-positive T-Zellen sind, im Gegensatz zu prim?r nodalen Non-Hodgkin Lymphomen, wo die T-Zellen CLA negativ sind. Neuere Arbeiten haben gezeigt, da? die Adh?sionsmoleküle wie CD44v6 bei kutanen Lymphomen, welche eine systemische Ausbreitung zeigen, auf den Tumorzellen exprimiert werden und somit eine entscheidende Rolle in der Metastasierung dieser Tumoren darstellen. Eingegangen am 27. November 1995 Angenommen am 22. Dezember 1995     

Differential effects of interleukin 12 and interleukin 10 on superantigen-induced expression of cutaneous lymphocyte-associated antigen (CLA) and alphaEbeta7 integrin (CD103) by CD8+ T cells

At both cutaneous and mucosal sites, interleukin (IL)-10, IL-12 and transforming growth factor (TGF)-beta are important regulators of chronic inflammatory disease, where cutaneous lymphocyte-associated antigen (CLA) and alphaE integrin (CD103) may be expressed. Stimulation with streptococcal pyrogenic exotoxin C (SpeC) increased the expression of CD103 by CD8+ but not CD4+ T cells. While adding IL-12 augmented the expression of CLA, superantigen-induced expression of CD103 was markedly suppressed by IL-12, which could be reversed by TGF-beta. Antibodies against TGF-beta inhibited, and a combination of anti-TGF-beta and IL-12 completely abrogated the induced CD103 expression. IL-10 strongly decreased the frequency of CLA+ and although not increasing the frequency of CD103+CD8+ T cells, the amount of CD103 expressed per cell was markedly increased. Thus, the expression of CLA and CD103 may be antagonistically regulated by IL-10 and IL-12 and the balance between these cytokines could influence the T cell migration of inflammatory cells into epithelial tissues.     

大鼠急性心肌梗死后骨髓干细胞归巢于缺血心肌的时间窗研究

目的：初探心肌梗死后骨髓干细胞归巢于心肌组织的时间窗。 方法： 110只大鼠随机分为4组，GM-CSF干预组(n=40)皮下注射GM-CSF (50 μg/kg/d) 5 d，对照组(n=40)皮下注射同等剂量生理盐水，GM-CSF干预假手术组(n=15)，对照假手术组(n=15)，结扎左冠状动脉前降支复制急性心肌梗塞动物模型，同时复制假手术模型。各组在心梗后1 、3 、5 、10 d免疫组化法观察心肌组织中归巢的ckit+细胞数量，28 d测定血压、室内压及±dp/dt值变化，观察两组大鼠瘢痕组织修复差异。 结果： ①心梗后28 d GM-CSF干预组心功能显著高于对照组(P<0.05)；②GM-CSF干预组瘢痕组织横径显著高于对照组(P<0.05)，梗死区平均心肌面积显著高于对照组(P<0.05)；③GM-CSF干预组与对照组1，3，5 d均有ckit+细胞归巢现象，以第5 d最为密集，第10 d未再有新归巢的ckit+细胞，GM-CSF干预组各时点ckit+细胞归巢数量显著高于对照组(P<0.05)。 结论： 骨髓干细胞归巢的时间窗为心梗后10 d以内。     

Human circulating specific antibody-forming cells after systemic and mucosal immunizations: differential homing commitments and cell surface differentiation markers

Circulating spontaneous antibody-secreting cells (ASC) induced by mucosal and systemic immunizations in human volunteers have been characterized with respect to differentiation stage and homing commitments. Irrespective of the immunization route, the large majority of ASC co-expressed CD19 and HLA-DR, which are normally lost during the transition of plasmablasts to plasmocytes, as well as CD38, a marker of activated B cell blasts, expressed also by plasmocytes. However, these cells expressed neither CD28, a molecule acquired by plasmocytes, nor CD22 and CD37, which are lost during the transition of plasmablasts to plasmocytes. Therefore, the large majority of ASC found in peripheral blood after oral and parenteral immunizations are terminally differentiated B cells, but not fully differentiated plasmocytes. As a whole, the mucosally derived ASC population seemed to be more homogenously differentiated. CD25 was detected on few ASC, whereas ASC expressing CD71 were more numerous, especially among systemically derived ASC. Almost all ASC expressed the adhesion molecules CD44 and α4-integrins, irrespective of immunization route. However, virtually all systemically derived ASC expressed L-selectin, recognizing the peripheral lymph node addressin, whereas only a minority of mucosally induced blood ASC expressed L-selectin. These studies are the first to demonstrate in humans that circulating precursors of mucosal B cell immunoblasts utilize organ-specific recognition mechanisms distinct from those of corresponding systemic B cells and appear to be more advanced in the B lineage maturation pathway. Specialization of receptor expression could explain both the unification of immune responses in diverse mucosal sites and the physiologic segregation of mucosal from non-mucosal immune mechanisms in humans.     

Expression of the monoclonal antibody HECA-452 defined E-selectin ligands in Langerhans cell histiocytosis

The cutaneous lymphocyte associated antigen (CLA) recognized by the monoclonal antibody (moAb) HECA-452 plays a major role in the homing of lymphocyte subpopulations to the skin by binding to E-selectin on dermal microvessels. The factors responsible for the immigration of Langerhans cells (LC) and their precursors into the skin are still unknown, but because normal resting LC are also capable of expressing CLA, the antigen was proposed as a candidate LC-homing structure. To gain insight into these mechanisms, the expression of HECA-452 on neoplastic LC within and outside the skin was investigated in paraffin-embedded sections from 44 patients with localized and disseminated forms of Langerhans cell histiocytosis (LCH) presenting with proliferating cells positive for CD45, CD1a, S100 and HLADR. Irrespective of the clinical presentation or the type of organ involved, HECA-452-positive LC were detected in all biopsies tested (range 5->90%). The most prominent HECA-452 reactivity was observed in skin lesions and in areas with accumulations of eosinophilic granulocytes. Our data provide evidence for a heterogeneous expression of sLe^x/sLe^a structures in various stages of activated and/or differentiated LCH cells. Remarkably, CLA-antigen expression on LCH-cells was not restricted to cutaneous sites. In view of recent findings on the expression of HECA-452 on resting epidermal LC, our data are compatible with the view that local cytokine production by keratinocytes or cells from the surrounding infiltrate induce and/or modulate CLA expression on LC in both cutaneous and extra-cutaneous sites.This work is dedicated to Professor Dr. Thaddäus Radaszkiewicz, who died in September 1995     

红细胞生成素对慢性肾衰竭大鼠残肾组织归巢因子表达的影响

目的 观察红细胞生成素(EPO)对慢性肾衰竭(CRF)大鼠肾组织归巢因子表达的影响.方法 采用分阶段5/6肾切除制备大鼠CRF模型.实验动物随机分为3组:假手术组、CRF模型组和EPO治疗组.从第3周开始,治疗组大鼠每次皮下注射重组人EPO 50 IU/kg,每周3次,共6周.8周后检测各组大鼠血肌酐(Scr)、血尿素氮(BUN)、尿蛋白、血红蛋白(Hb)；采用实时荧光定量PCR、Western印迹和免疫组化方法检测残肾组织EPO及其受体(EPOR)、归巢因子及其受体(SDF-1、CXCR4、Ang-1、Tie2、SCF、c-Kit)的表达.结果 与模型组比较,EPO治疗可上调残肾组织归巢因子及其受体(SDF-1、CXCR4、Ang-1、Tie2、SCF、c-Kit)mRNA和蛋白的表达(均P＜0.05)；同时,EPO治疗还可上调残肾组织EPO及EPOR的mRNA和蛋白的表达(均P＜ 0.05).此外,EPO治疗还能下调大鼠Scr、BUN和尿蛋白水平(均P＜0.05),上调Hb水平(P＜0.05).结论 EPO能改善慢性肾衰竭大鼠的肾功能,这种作用可能与其激活残肾组织归巢因子而参与损伤肾脏的修复有关.     

不同来源的CD34^＋细胞归巢相关分子的表达

目的 研究不同来源CD34^＋细胞归巢相关分子（HRM）的表达情况。方法采用免疫磁珠法（MACS）分选不同来源的CD34^＋细胞，免疫荧光标记流式细胞仪测定HRM的表达。结果骨髓（BM）、动员后的外周血（mPB）及脐血（UCB）来源的CD34^＋细胞均高表达细胞黏附分子CD49d、CD49e、CD54、CD11a、CD62L、CD44、CD31。UCB来源的CD34^＋细胞表面表达的细胞黏附分子中，CD49e表达显著低于BM和mPB来源的CD34^＋细胞（P〈0．05），CD54表达显著低于mPB来源者（P〈0．05），CXCR4表达显著低于BM来源者（P〈0．05）。结论UCB来源的造血干／祖细胞归巢能力低可能是UCB移植造血重建延迟的原因之一。     

造血干细胞在心脏中的归巢与分化

利用造血干细胞治疗心脏损伤尤其是由退化、缺血和炎症引起的损伤已被认为是新近发展的重要治疗心脏病变的手段之一。造血干细胞在生理及病理条件下均能归巢于心肌,并能被动员至外周血且参与心脏的自稳态和组织维持。现就造血干细胞在心脏中归巢与分化的机制以及造血干细胞在治疗心脏病变中的应用进行简要综述。     

Phenotypes and distribution of mucosal memory B-cell populations in the SIV/SHIV rhesus macaque model

As vaccine-elicited antibodies have now been associated with HIV protective efficacy, a thorough understanding of mucosal and systemic B-cell development and maturation is needed. We phenotyped mucosal memory B-cells, investigated isotype expression and homing patterns, and defined plasmablasts and plasma cells at three mucosal sites (duodenum, jejunum and rectum) in rhesus macaques, the commonly used animal model for pre-clinical vaccine studies. Unlike humans, macaque mucosal memory B-cells lacked CD27 expression; only two sub-populations were present: naïve (CD21⁺CD27⁻) and tissue-like (CD21⁻CD27⁻) memory. Similar to humans, IgA was the dominant isotype expressed. The homing markers CXCR4, CCR6, CCR9 and α4β7 were differentially expressed between naïve and tissue-like memory B-cells. Mucosal plasmablasts were identified as CD19⁺CD20^+/−HLA-DR⁺Ki-67⁺IRF4⁺CD138^+/− and mucosal plasma cells as CD19⁺CD20⁻HLA-DR⁻Ki-67⁻IRF4⁺CD138⁺. Both populations were CD39^+/−CD27⁻. Plasma cell phenotype was confirmed by spontaneous IgA secretion by ELISpot of positively-selected cells and J-chain expression by real-time PCR. Duodenal, jejunal and rectal samples were similar in B-cell memory phenotype, isotype expression, homing receptors and plasmablast/plasma cell distribution among the three tissues. Thus rectal biopsies adequately monitor B-cell dynamics in the gut mucosa, and provide a critical view of mucosal B-cell events associated with development of vaccine-elicited protective immune responses and SIV/SHIV pathogenesis and disease control.     

骨髓干细胞动员后归巢梗死心肌的实验研究

目的初步探讨骨髓干细胞动员后归巢梗死心肌的可能机制。方法结扎Wistar大鼠左冠状动脉制作急性心肌梗死(acutemyocardialinfarction,AMI)模型,用干细胞因子(SCF)动员骨髓干细胞,部分大鼠予激素干预治疗,另设AMI组为对照组(A组)。制模后24h杀死大鼠,取出心脏,免疫组化法了解归巢于梗死心肌的CD34细胞数量,心肌组织中炎症趋化因子基质细胞衍生因子(SDF-1)表达量,以及HE染色观察心肌组织学变化。结果应用SCF动员治疗后,AMI 动员组(A1组)大鼠梗死灶内SDF-1表达量明显大于AMI组和AMI 激素 动员组(A2组),同时AMI 动员组(A1组)大鼠梗死灶内CD34阳性细胞数量也明显大于另2组。而AMI 激素 动员组(A2组)的SDF-1表达量最少,其梗死灶内CD34阳性细胞数量也最少。AMI 动员组(A1组)大鼠心肌梗死程度轻,可见CD34阳性的幼稚心肌细胞样细胞。结论应用SCF动员AMI大鼠的骨髓干细胞后,其向梗死灶归巢的能力增强,较多CD34细胞迁移到缺血灶内,并向心肌细胞等分化。骨髓干细胞动员后,心肌梗死灶内SDF-1表达量上调是吸引骨髓干细胞归巢的可能机制之一。