Human blood dendritic cells: binding to vascular endothelium and expression of adhesion molecules

To investigate the binding properties of dendritic cells (DC) to vascular endothelium, a comparative analysis was undertaken of DC, monocytes and lymphocytes isolated from the blood of 25 healthy subjects using monolayers of human umbilical vein endothelial cells as the adherence substrate. More blood DC (mean 24% adherence) were adherent to endothelial monolayers than monocytes (mean 18%; P < 0.001) and lymphocytes (mean 12%; P < 0.001). When the monolayers were pretreated with tumour necrosis factor-alpha (TNF-α) all leucocyte populations exhibited an increased attachment, but there was still greater binding of DC (mean 37% adherence) in comparison with monocytes (mean 23%; P < 0.001) and lymphocytes (mean 18%; P < 0.001). Flow cytometric analysis revealed that in relation to monocytes and lymphocytes the DC had a higher surface expression of the adhesion molecules CD11a (P < 0.05), CD11c (P < 0.05) and CD54 (P < 0.05) but a lower prevalence of cells bearing CD49d (mean 38%; P < 0.05) and the homing receptor CD62L (mean 14%; P < 0.001). CD1a was present on 22% of DC and virtually absent from the surface of monocytes and lymphocytes. The intensity of expression of the β₁-integrins, CD49c, CD49d and CD49e was greater on DC than lymphocytes and monocytes (P < 0.05). Antibody blocking studies demonstrated that DC binding to untreated and TNF-α-treated endothelium was dependent upon the expression of CD11a, CD18 and CD49d, and the simultaneous application of anti-CD18 and anti-CD49d antibodies produced an approximate 70% inhibition of adhesion (P < 0.001). Thus, the expression of both β₁- and β₂-integrins contributes to the adhesive interaction between DC and endothelium.     

Chemokines and soluble adhesion molecules in renal transplant recipients with cytomegalovirus infection

Cytomegalovirus (CMV) infection is associated with leucocyte infiltration in various organs, which supports a role for chemokines and adhesion molecules in the pathogenesis of CMV infection. In a prospectively conducted study of renal transplant recipients, 10 patients with CMV disease, five patients with asymptomatic CMV infection and 10 patients who did not have any CMV infection were included. During CMV infection, and in particular during CMV disease, plasma levels of the chemokines IL-8, macrophage inflammatory protein-1alpha (MIP-1alpha) and monocyte chemotactic protein-1 (MCP-1) and the soluble adhesion molecules vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and L-selectin increased and were positively correlated with the degree of CMV pp65 antigenaemia. Furthermore, a decrease in plasma levels of these chemokines and adhesion molecules was observed following ganciclovir therapy in the patients with CMV disease. This could suggest a role for these molecules in the pathogenesis of CMV infection.     

人癌胚抗原相关细胞黏附分子1介导的小鼠淋病奈瑟菌易感性

目的 研究制备淋病奈瑟菌感染人癌胚抗原相关细胞黏附分子1(hCEACAM1)转基因小鼠模型的可行性.方法 用hCEACAM1真核表达载体pCDPGICEA1,通过显微注射法制备转基因小鼠,PCR及序列分析法检测目的基因在小鼠基因组中的整合,Western blot及FACS技术检测目的基因的表达,镜检及培养法检查淋病奈瑟菌对转基因小鼠的感染.结果 产生的22只F0代小鼠中4只为转基因整合阳性,其中1只可表达hCEACAM1蛋白,且目的蛋白表达在细胞膜上.淋病奈瑟菌可在转基因小鼠中形成感染.结论 hCEACAM1转基因小鼠可作为淋病奈瑟菌感染研究的转基因动物模型.     

Highly sensitivity adhesion molecules detection in hereditary haemochromatosis patients reveals altered expression

Several abnormalities in the immune status of patients with hereditary haemochromatosis (HH) have been reported, suggesting an imbalance in their immune function. This may include persistent production of, or exposure to, altered immune signalling contributing to the pathogenesis of this disorder. Adhesion molecules L-, E- and P-Selectin, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) are some of the major regulators of the immune processes and altered levels of these proteins have been found in pathological states including cardiovascular diseases, arthritis and liver cancer. The aim of this study was to assess L-, E- and P-Selectin, ICAM-1 and VCAM-1 expression in patients with HH and correlate these results with HFE mutation status and iron indexes. A total of 139 subjects were diagnosed with HH (C282Y homozygotes = 87, C282Y/H63D = 26 heterozygotes, H63D homozygoyes = 26), 27 healthy control subjects with no HFE mutation (N/N), 18 normal subjects heterozygous for the H63D mutation served as age-sex-matched controls. We observed a significant decrease in L-selectin (P = 0.0002) and increased E-selectin and ICAM-1 (P = 0.0006 and P = 0.0059) expression in HH patients compared with healthy controls. This study observes for the first time that an altered adhesion molecules profile occurs in patients with HH that is associated with specific HFE genetic component for iron overload, suggesting that differential expression of adhesion molecules may play a role in the pathogenesis of HH.     

Effect of human cytomegalovirus and glucose on adhesion molecules expression in cultured human endothelial cells

The aim this study was to investigate the effect of glucose on the induction of adhesion molecules by Human cytomegalovirus (HCMV) in endothelial cells in vitro. Primary cultures of human umbilical vein endothelial cells (HUVECs) pretreated with 16.5 mmol/l glucose for 24 hrs were infected with a HCMV strain with tropism for endothelial cells. Expression of adhesion nmolecules (ICAM-1, VCAM-1 and ELAM-1) was measured by flow cytometry. While high concentrations of glucoseperse activated the expression of all three adhesion molecules tested, HCMV induced the expression of ICAM-1 only. Moreover, it potentiated the expression of ICAM-1 in glucose-pretreated HUVECs, while it did not affect at all or slightly suppressed the glucose-activated expression of VCAM-1 and ELAM-1. The modulatory effect of glucose and HCMV on the expression of adhesion molecules in endothelial cells may be applied in increased vulnerability to patients with diabetes mellitus or atherosclerosis.     

Differential effects of monoclonal antibody blockade of adhesion molecules on in vivo susceptibility to soft tissue infection.

Leukocyte adherence to endothelial cells has been implicated in the pathogenesis of microvascular injury as well as in host defense against various infectious microorganisms. Administration of monoclonal antibodies directed against the beta chain of the leukocyte integrins inhibits leukocyte-endothelial-cell adherence and has been reported to modulate ischemia-reperfusion and inflammatory injury. However, such inhibition of adhesion molecule function adversely affects resistance to infection. The following studies were carried out to determine whether monoclonal antibodies to other adhesion molecules, including L-selectin (CD62L), and CD11a (the alpha chain of LFA-1), also increase susceptibility to infection. New Zealand White rabbits were shaved and given subcutaneous injections on their dorsa with 10(9) CFU of Staphylococcus aureus ATCC 25923 at two sites and with 10(8) CFU at two sites. A second set of rabbits were given subcutaneous injections with 10(8) CFU of P. aeruginosa ATCC 27853 at two sites and with 10(7) CFUs at two sites. The animals were monitored for 1 week. There were three blinded experimental groups: controls given saline and two groups given blocking monoclonal antibodies to either L-selectin (Dreg-200) or CD11a (R7.1). In contrast to monoclonal antibodies to CD18, none of the monoclonal antibodies significantly increased the risk of abscess formation by S. aureus, although inhibition of CD11a increased the rate of abscess formation by P. aeruginosa.     

I-E expression and susceptibility to parasite infection

In most inbred strains of mice, antigen-presenting cells express I-A and I-E antigens (class II major histocompatibility complex antigens), and these antigens are involved in antigen-recognition by T cells. In some strains I-E products are not expressed or aberrantly expressed, yet these mice seem to be immunologically normal. In this article, Don Wassom and his colleagues discuss reports that antigen presented in the context of I-E produces a response which suppresses I-A restricted T-cell proliferation, in relation to their own findings that mice which do express I-E molecules are more susceptible to certain nematode infections than mice which do not express I-E.     

小檗碱对淋巴细胞与血管内皮细胞粘附及粘附分子的影响

目的：通过研究小檗碱对淋巴细胞与血管内皮细胞粘附及粘附分子的影响,探讨小檗碱免疫抑制作用机制。方法：以小檗碱处理人淋巴细胞或人脐静脉内皮细胞（ＨＵＶＥＣ）后,用蛋白染料染色法研究对淋巴细胞与内皮细胞粘附的作用,用细胞ＥＬＩＳＡ,免疫细胞化学染色法研究对细胞表面粘附分子表达的影响。结果：小檗碱能抑制静息的及ＩＬ－１,ＴＮＦ激活的内皮细胞与淋巴细胞间的粘附,其主要分子机制为下调内皮细胞表面粘附分子ＩＣ     

Aberrant expression of alpha-Gal on primary human endothelium does not confer susceptibility to NK cell cytotoxicity or increased NK cell adhesion

The contribution of Gal alpha 1,3Gal (alpha-Gal) to cell-mediated organ xenograft rejection is controversial. We have used recombinant lentiviruses encoding a porcine alpha 1,3 galactosyltransferase (alpha 1,3GalT) to obtain alpha-Gal-expressing primary human aortic endothelial cells (HAEC) at a frequency of 70-90%. These cells were compared to non-transduced and mock-transduced HAEC with regard to their susceptibility to human NK cell-mediated lysis, ability to stimulate IFN-gamma production by NK cells, and support of NK cell adhesion under static and dynamic conditions. Using green fluorescent protein (GFP) as a reporter gene, it was shown that the frequency of green fluorescent HAEC increased until day 5 post-transduction, and at a multiplicity of infection of 2.5, it reached 98%. Lentiviral transduction did not result in activation of HAEC, and transduced HAEC responded as expected to TNF-alpha and IFN-gamma stimulation. No differences were detected between non-alpha-Gal- and alpha-Gal-expressing HAEC in terms of their susceptibility to NK cell-mediated lysis, ability to stimulate IFN-gamma production by NK cells, or ability to support NK cell adhesion under static and dynamic conditions. In conclusion, these data argue against an important role for the alpha-Gal epitope in the direct interaction between endothelium and NK cells and prove that recombinant lentiviruses are efficient gene carriers for primary human endothelial cells.     

Acute cytomegalovirus infection modulates the intestinal microbiota and targets intestinal epithelial cells

Primary and recurrent cytomegalovirus (CMV) infections frequently cause CMV colitis in immunocompromised as well as inflammatory bowel disease (IBD) patients. Additionally, colitis occasionally occurs upon primary CMV infection in patients who are apparently immunocompetent. In both cases, the underlying pathophysiologic mechanisms are largely elusive - in part due to the lack of adequate access to specimens. We employed the mouse cytomegalovirus (MCMV) model to assess the association between CMV and colitis. During acute primary MCMV infection of immunocompetent mice, the gut microbial composition was affected as manifested by an altered ratio of the Firmicutes to Bacteroidetes phyla. Interestingly, these microbial changes coincided with high-titer MCMV replication in the colon, crypt hyperplasia, increased colonic pro-inflammatory cytokine levels, and a transient increase in the expression of the antimicrobial protein Regenerating islet-derived protein 3 gamma (Reg3γ). Further analyses revealed that murine and human intestinal epithelial cell lines, as well as primary intestinal crypt cells and organoids represent direct targets of CMV infection causing increased cell death. Accordingly, in vivo MCMV infection disrupted the intestinal epithelial barrier and increased apoptosis of intestinal epithelial cells. In summary, our data show that CMV transiently induces colitis in immunocompetent hosts by altering the intestinal homeostasis.     

外周血干细胞动员调节CD34+细胞β整合素及L-选择素的表达

目的观察造血干细胞表面粘附分子的变化在外周血干细胞动员中的作用。方法用双色免疫荧光法研究15例恶性血液病患者经化疗+G-CSF动员外周血干细胞前后、骨髓和外周血CD34+细胞表面β1整合素(CD49d)、β2整合素(CD11a、CD11b)及L-选择素(CD62L)的表达。结果①动员后第7天CD34+细胞表面较动员前CD49d、CD11a、CD62L表达下降(P＜0.01),而CD11b无变化(P＞0.05)。②外周血CD34+细胞表达CD49d、CD11a、CD11b、CD62L较骨髓低(P＜0.05)。③外周血CD34+细胞绝大多数处于GO/G1期,该期的干细胞CD49d的密度低于S+G2/M期。结论化疗+G-CSF通过粘附分子的变化而使造血干细胞从骨髓进入外周血中。     

Human cytomegalovirus infection up-regulates interleukin-8 gene expression and stimulates neutrophil transendothelial migration.

Virus-induced alterations in the cellular expression of chemokines may be important in directing the migration of specific leucocyte subsets to sites of infection, thereby playing a pivotal role in viral pathogenesis. We show here that cytomegalovirus (CMV) infection of human fibroblasts resulted in significantly increased expression of the C-X-C or alpha-chemokine interleukin-8 (IL-8), at both the mRNA and protein levels. Increased IL-8 production was seen following infection with the high passage laboratory CMV strains AD169, Towne, or Davis, as well as the low passage clinical CMV isolates Toledo or C1F. The increase in IL-8 production had functional consequences, as demonstrated by the ability of supernatants from CMV-infected fibroblasts to significantly enhance neutrophil transendothelial migration. The latter was independent of alterations in adhesion molecule expression on the endothelial cells, and was abrogated by neutralizing antibodies specific for IL-8. Direct infection of endothelium with the endothelial cell-tropic CMV strain C1FE, also resulted in enhanced neutrophil transendothelial migration. Neutrophils play an important role in the dissemination of CMV throughout the body, and thus CMV-induced neutrophil recruitment would be expected to enhance CMV dissemination. Increased production of chemokines in response to CMV infection could also disrupt the fine balance between a beneficial and a destructive immune response, thereby potentially contributing to pathology.     

Expression of adhesion molecules in human intestinal graft-versus-host disease.

The distribution of three cellular adhesion molecules, ICAM-1, ELAM-1 and VCAM-1, was studied in normal rectal mucosa and in graft-versus-host disease (GvHD) using immunohistological and morphometric techniques. In normal controls, ICAM-1 was demonstrable on endothelial cells and leucocytes within the lamina propria, ELAM-1 on endothelial cells only and VCAM-1 on lamina propria leucocytes, many of which exhibited long dendritic processes surrounding the glands. In GvHD, the enterocytes became positive for ICAM-1 and this was often associated with the presence of intra-epithelial LFA-1+ lymphocytes and macrophages, the latter containing debris of apoptotic cells. The staining was, however, restricted to the luminal membrane of the epithelial cells, raising doubts about the role of ICAM-1 as a ligand for LFA-1 on mucosal leucocytes in rectal GvHD. ELAM-1 expression was increased in GvHD both in terms of the length of positive endothelium and staining intensity. VACM-1 was increased on endothelial cells but not leucocytes in the lamina propria in contrast to our previous findings in cutaneous GvHD where VCAM-1+ dendritic cells were increased and endothelial cells remained negative. Normal patterns of adhesion molecule staining were seen in two biopsies exhibiting no morphological evidence of GvHD, from patients who had strong clinical evidence of the disease, indicating that immunostaining for these molecules is unlikely to be of help in improving the sensitivity of histological diagnosis. However, the possibility that adhesion molecule staining may be useful in improving diagnostic specificity by helping to distinguish GvHD from identical histological changes produced by irradiation and cytotoxic drugs is worthy of further investigation.     

Substance P and adrenocorticotropic hormone do not affect T-lymphocyte adhesion to vascular endothelium or surface expression of adhesion receptors

Substance P (SP) and adrenocorticotropic hormone (ACTH) are peptides that have been shown to have both neurological and immunological effects. Because of the demonstrated effects upon immune function, we examined the effects of these peptides on T-lymphocyte adhesion to vascular endothelium and surface adhesion receptor expression. Neither the adhesion assays nor the expression assays showed any statistically significant effect of SP (10 μM) or ACTH (1 μM) for any incubation period used. We conclude that, while SP and ACTH have a variety of immunomodulatory effects, direct modulation of T-lymphocyte adhesion to vascular endothelium is probably not one of them.     

Altered expression of nectin-like adhesion molecules in the peripheral nerve after sciatic nerve transection

Following axotomy several processes involving cell-cell interaction occur, such as loss of synapses, axon guidance, and remyelination. Two recently discovered families of cell-cell adhesion molecules, nectins and nectin-like molecules (necls) are involved in such processes in vitro and during development, but their roles in nerve injury have been largely unknown until recently. We have previously shown that axotomized motoneurons increase their expression of nectin-1 and nectin-3 and maintain a high expression of necl-1. We here investigate the expression of potential binding partners for motoneuron nectins and necls in the injured peripheral nerve. In situ hybridization (ISH) revealed a decreased signal for necl-1 mRNA in the injured nerve, whereas no signal for necl-2 was detected before or after injury. The signals for necl-4 and necl-5 mRNA both increased in the injured nerve and necl immunoreactivity displayed a close relation to axon and Schwann cell markers. Finally, signal for mRNA encoding necl-5 increased in axotomized spinal motoneurons. We conclude that peripheral axotomy results in altered expression of several necls in motoneurons and Schwann cells, suggesting involvement of the molecules in regeneration.     

Human cytomegalovirus infection induces mRNA expression and secretion of plasminogen inhibitor type-1 in endothelial cells

The aim of the study was to investigate whether infection of endothelial cells with human cytomegalovirus (HCMV) perturbs expression and production of plasminogen activator inhibitor type-1 (PAI-1). mRNA expression of PAI-1 was investigated by isolating total RNA from HCMV-infected and control cells, followed by Northern blotting and probing with ³²P-labelled PAI-1 probe. Sandwich ELISA was used to investigate PAI-1 production. HCMV induced the expression of PAI-1-mRNA at 2–5 days postinfection (maximum expression was at 3 days postinfection which was 40% higher than control). HCMV also induced secretion of PAI-1 at 2–5 days postinfection. These results indicate that infection of endothelial cells with HCMV disturbs PAI-1 expression and production in these cells. J. Med. Virol. 55:268–271, 1998. © 1998 Wiley-Liss, Inc.     

Antibiotic-induced perturbations of the intestinal microbiota alter host susceptibility to enteric infection

Intestinal microbiota comprises microbial communities that reside in the gastrointestinal tract and are critical to normal host physiology. Understanding the microbiota's role in host response to invading pathogens will further advance our knowledge of host-microbe interactions. Salmonella enterica serovar Typhimurium was used as a model enteric pathogen to investigate the effect of intestinal microbiota perturbation on host susceptibility to infection. Antibiotics were used to perturb the intestinal microbiota. C57BL/6 mice were treated with clinically relevant doses of streptomycin and vancomycin in drinking water for 2 days, followed by oral infection with Salmonella enterica serovar Typhimurium. Alterations in microbiota composition and numbers were evaluated by fluorescent in situ hybridization, differential plating, and Sybr green staining. Antibiotics had a dose-dependent effect on intestinal microbiota composition. The chosen antibiotic regimen did not significantly alter the total numbers of intestinal bacteria but altered the microbiota composition. Greater preinfection perturbations in the microbiota resulted in increased mouse susceptibility to Salmonella serovar Typhimurium intestinal colonization, greater postinfection alterations in the microbiota, and more severe intestinal pathology. These results suggest that antibiotic treatment alters the balance of the microbial community, which predisposes the host to Salmonella serovar Typhimurium infection, demonstrating the importance of a healthy microbiota in host response to enteric pathogens.     

肾移植后巨细胞病毒感染的检测

背景：肾移植后因患者细胞免疫、体液免疫均明显下降,易发生各种类型感染,其中以巨细胞病毒感染多见,且有较高的发病率和病死率,早期准确的检测有利于指导临床治疗。 目的：对肾移植后巨细胞病毒感染检测研究的文献资料进行多层次的探讨分析。 方法：以电子检索的方式对CNKI数据库2002-01/2011-12 有关肾移植后巨细胞病毒感染检测研究的文献进行分析,采用检索词为“肾移植(renal transplantation);巨细胞病毒(cytomegalovirus);BK病毒(BK virus);疱疹病毒(herpes virus)”。巨细胞病毒是肾移植后感染的主要病原体,与肾移植后肺炎、肝炎、视网膜炎及肾移植后急、慢性排斥反应的发生有着密切的联系。 结果与结论：肾移植后巨细胞病毒感染的检测方法不断改进,检测方法较多,目前尚无一种理想的方法可以早期及时准确检测出活动性巨细胞病毒感染,主要是将血清学检测、荧光免疫标记检测、抗原抗体检测以及基因检测进行相结合来检测诊断肾移植后巨细胞病毒感染,尤其是巨细胞病毒晚期抗原(pp65)检测迅速发展,提高了巨细胞病毒感染检测的特异性及敏感性,为临床诊断及预防治疗提供了重要的参考依据。