The red cell LW blood group protein is an intercellular adhesion molecule which binds to CD11/CD18 leukocyte integrins

Leukocyte adhesion involves the leukocyte-specific integrins CD11a/CD18, CD11b/CD18 and CD11c/CD18, which bind to intercellular adhesion molecules (ICAM). Three ICAM have been described, and are expressed on leukocytes and various other cells, but are absent from red cells. Here, we show that the red cell Landsteiner-Wiener (LW) blood group glycoprotein is an ICAM which binds to the leukocyte-specific integrins. This finding has important implications in red cell physiology.     

Triamcinolone acetonide modulates permeability and intercellular adhesion molecule-1 (ICAM-1) expression of the ECV304 cell line: implications for macular degeneration

Whilst animal studies and a pilot clinical trial suggest that intravitreal triamcinolone acetonide (TA) may be useful in the treatment of age-related macular degeneration (AMD), its mode of action remains to be fully elucidated. The present study has investigated the capacity of TA to modulate the expression of adhesion molecules and permeability using a human epithelial cell line (ECV304) as a model of the outer blood-retinal barrier (BRB). The influence of TA on the expression of ICAM-1 and MHC-I was studied on resting and phorbol myristate acetate (PMA)- or interferon-gamma (IFN-gamma)- and/or tumour necrosis factor-alpha (TNF-alpha)-activated cells using flow cytometry and immunocytochemistry. Additionally, ECV304 cells were grown to confluence in uncoated Transwell chambers; transepithelial resistance (TER) across resting and PMA-activated cells was monitored. TA significantly decreased the paracellular permeability of ECV304 cells and down-regulated ICAM-1 expression, consistent with immunocytochemical observations. PMA-induced permeability changes were dose-dependent and TA decreased permeability of both resting and PMA-activated monolayers. MHC-I expression by ECV304 cells however, was not significantly affected by TA treatment. The modulation of TER and ICAM-1 expression in vitro correlate with clinical observations, suggesting re-establishment of the BRB and down-regulation of inflammatory markers are the principal effects of intravitreal TA in vivo. The results further indicate that TA has the potential to influence cellular permeability, including the barrier function of the retinal pigment epithelium (RPE) in AMD-affected retinae.     

ICAM‐1 and β3 integrin immunoexpression in malignant melanoma cells: can they be used as additional predictors?

Malignant melanoma usually progresses from the intraepidermal microenvironment through a distinct radial growth phase, in which malignant potential cannot always be accurately evaluated, to invasion of the dermis (vertical growth phase) and metastasis. During these stages malignant cells interact with each other and with the extracellular matrix. This interaction is mediated by cell surface adhesion molecules such as the beta(3) integrin subunit and ICAM-1. Our aim was to investigate whether the expression of these two molecules is associated with the various histopathologic prognosticators commonly evaluated in malignant melanoma. Using a standard three-step immunoperoxidase technique we evaluated the above molecules' expression in a documented series of 66 cutaneous malignant melanomas. Forty-five were superficial spreading melanomas, including 18 in mixed growth phase. Positive immunoreaction was estimated by image analysis. ICAM-1 immunopositivity status was significantly more frequent among malignant melanomas of the nodular type (p=0.0001), and was associated with the vertical growth phase, Breslow thickness of >0.77 mm, and with evident lymphocytic infiltration. beta(3) integrin immunopositivity showed similar results in certain respects; it was more frequently detected in superficial spreading melanomas in which vertical growth had developed (p=0.002) and in cases with regression. There appears to be an association of these molecules with histopathologic features that predict increased tumorigenicity of malignant melanocytes.     

银杏叶提取物(GBE)对大鼠局灶性脑缺血后细胞间黏附分子-1及其mRNA表达的影响

目的　探讨银杏叶提取物对鼠脑缺血后细胞间黏附分子 1(ICAM 1)及其mRNA表达的影响。方法　建立大鼠大脑中动脉闭塞 /再灌注模型 ,应用RT PCR及免疫组织化学的方法 ,观察各实验组鼠脑缺血后细胞间黏附分子 1及其mRNA的表达。结果　ICAM 1及其mRNA在假手术组鼠脑组织呈低表达 ;缺血 90min再灌 2 4h脑组织ICAM 1及其mRNA表达较前显著增高 (P 0 .0 1) ;银杏叶提取物治疗组于相同时限ICAM 1及其mRNA的表达与缺血再灌注组相比较显著下调 (P 0 .0 1)。结论　银杏叶提取物能显著下调ICAM 1及其mRNA的表达 ,减轻脑缺血后炎性病理损害 ,具有明显的缺血脑保护作用。     

B7/CD28和ICAM-1/LFA-1共刺激信号对T及B细胞功能影响的研究

目的　研究共刺激途径Ｂ７／ＣＤ２８ 和ＩＣＡＭ１／ＬＦＡ１ 对Ｔ 细胞活化以及Ｂ 细胞效应的作用。方法　在体外建立ＡＰＣＴＢ 细胞反应系统, 用Ｂ７１ 单抗和ＩＣＡＭ１ 单抗分别阻断Ｂ７／ＣＤ２８ 和ＩＣＡＭ１／ＬＦＡ１ 共刺激途径, 利用３ ＨＴｄＲ 法检测Ｔ 细胞增殖,ＥＬＩＳＡ 法测定Ｂ 细胞分泌的抗体, 用ＲＴＰＣＲ 法检测细胞因子基因的表达。结果　Ｂ７１ 单抗和ＩＣＡＭ１ 单抗均可抑制Ｔ 细胞增殖及ＩＬ２ 的产生。Ｂ７１ 单抗可下调Ｂ 细胞抗体的产生（ Ｐ＜ ０ ．０５） , 而ＩＣＡＭ１ 单抗未见明显的抑制（ Ｐ＞ ０ ．０５） 。Ｂ７１ 单抗和ＣｓＡ 联用能阻断Ｔ 细胞增殖活性及Ｂ 细胞的效应, 而ＩＣＡＭ１ 单抗和ＣｓＡ联用则无此作用。Ｂ７１ 单抗能下调ＩＬ２ 和ＩＦＮγｍ ＲＮＡ 表达,Ｂ７１ 单抗和ＣｓＡ 联用则阻断ＩＬ２ 和ＩＦＮγｍ ＲＮＡ 表达,ＩＬ４ 和ＩＬ１０ ｍ ＲＮＡ 仍可表达。结论　Ｂ７／ＣＤ２８ 和ＩＣＡＭ１／ＬＦＡ１ 共刺激途径在Ｔ 细胞活化中具有不同的作用,Ｂ７１ 单抗和ＣｓＡ 联用可导致Ｔ 细胞功能失活即无能。     

血管紧张素II对单核细胞趋化因子及粘附分子表达的影响

为了观察血管紧张素II (AII)对人单核细胞株THP 1分泌单核细胞趋化因子 (MCP 1)、人类脐静脉内皮细胞(HUVEC )分泌细胞间粘附分子 (ICAM 1)的影响及AII对HUVEC与THP 1的粘附功能的影响 ,我们利用ELISA法检测AII作用后THP 1分泌MCP 1及HUVEC分泌ICAM 1的表达 ,利用计数法观察经AII作用的HUVEC与THP 1的粘附率。结果发现四种不同浓度的AII(10 6、 10 7、 10 8、 10 9mol/L )刺激THP 1及HUVEC 2 4h后 ,MCP 1及ICAM 1的分泌明显增加 ,AII(10 6mol/L )作用HUVEC 6h后 ,其对THP 1细胞粘附率明显增加 ,表明AII具有调节THP 1分泌MCP 1及HUVEC分泌ICAM 1的作用 ,AII可通过致炎症作用参与动脉粥样硬化的发病过程。     

A CD44 monoclonal antibody differentially regulates CD11a/CD18 binding to intercellular adhesion molecules CD54, CD102 and CD50

We have made a monoclonal anti-CD44 antibody which is able to activate the leukocyte integrin CD11a/CD18. Activated T cells strongly aggregated, and the aggregation was shown to be intercellular adhesion molecule (ICAM)-1 (CD54) and ICAM-2 (CD102) dependent. Using purified ICAM coated on plastic, only binding to ICAM-1 was increased by the CD44 antibody, whereas activation by phorbol ester increased binding to both ICAM-1 and ICAM-3. The binding to ICAM-2 was not affected by either treatment. These findings show that the CD11a/CD18 integrin can be activated in a ligand-specific manner by engagement of CD44.     

慢性充血性心力衰竭患者血清可溶性细胞间粘附分子-1的变化及与C-反应蛋白的相关性分析

目的了解慢性充血性心力衰竭(心衰)患者血清可溶性细胞间粘附分子-1(sICAM-1)的变化及与C-反应蛋白(CRP)的相关性.方法测定60例心衰患者和20例健康人的血清sICAM-1及CRP水平.比较分析心衰患者及不同程度心衰患者之间sICAM-1、CRP水平的变化,以及sICAM-1与CRP的相关性.结果心衰患者血清sICAM-1及CRP水平明显高于健康对照组(P＜0.01),二者均随心衰程度加重而增高,呈高度正相关(r=0.68,P＜0.01).不同程度心衰患者之间血清sICAM-1及CRP水平差异有显著性(P＜0.05).结论心衰患者存在着免疫激活和心肌炎症反应,心衰程度愈重,炎症反应愈明显.