Differential Expression Of Adhesion Molecules Research Articles

Differential expression of adhesion molecules in sickle cell anemia and gut microbiome effect

Sickle cell anemia (SCA) causes a long-standing vascular inflammation state, leading to endothelial dysfunction and chronic overexpression of several adhesion molecules, which contributes to acute and constant vaso-occlusive (VOC) episodes. It has been demonstrated that hydroxyurea (HU) can reduce VOC events, organ damage, blood transfusions, and even the adhesion properties to endothelial cells of SCA subjects. Due to VOC episodes, these patients are also more susceptible to recurrent bacterial translocation and dysbiosis. Given this, our study aimed to uncover the interplay between adhesion molecules, gut microbiome, and hydroxyurea in a population of Angolan SCA children. Serum and fecal samples were obtained before and after HU treatment in 35 children. After HU, four of these adhesion molecules were significantly reduced: sE-selectin (p = 0.002), ADAMTS13 (p = 0.023), sICAM-1 (p = 0.003), and sVCAM-1 (p = 0.018). A positive correlation was observed between the number of neutrophils and sICAM-1, platelets, and sP-selectin, and also between leukocytes, sICAM-1, and sVCAM-1. Most taxa showing a significant correlation mainly belonged to the Clostridiales order. Specifically, from the Clostridium genera, the groups g19, g21, and g34 were all negatively correlated with HbF levels; g19, g21, and g24 positively correlated with leukocytes; g19 positively with neutrophils and sVCAM-1; and g34 positively with E- and P-selectin. Serratia, an opportunistic pathogen, was positively correlated with sE-selectin and sICAM-1 levels. Additionally, a negative correlation was observed between sP-selectin and Bifidobacterium. Research studies in this area could improve our understanding and contribute to finding new prognostic biomarkers to guarantee precise SCA patient stratification and predict severe complications.

Platelets orchestrate the resolution of pulmonary inflammation in mice by T reg cell repositioning and macrophage education.

Beyond hemostasis, platelets actively participate in immune cell recruitment and host defense, yet their potential in the resolution of inflammatory processes remains unknown. Here, we demonstrate that platelets are recruited into the lung together with neutrophils during the onset of inflammation and alongside regulatory T (T reg) cells during the resolution phase. This partnering dichotomy is regulated by differential adhesion molecule expression during resolution. Mechanistically, intravascular platelets form aggregates with T reg cells, a prerequisite for their recruitment into the lung. This interaction relies on platelet activation by sCD40L and platelet P-selectin binding to PSGL-1 on T reg cells. Physical platelet-T reg cell interactions are necessary to modulate the transcriptome and instruct T reg cells to release the anti-inflammatory mediators IL-10 and TGFβ. Notably, the presence of platelet-T reg cell aggregates in the lung was also required for macrophage transcriptional reprogramming, polarization toward an anti-inflammatory phenotype, and effective resolution of pulmonary inflammation. Thus, platelets partner with successive immune cell subsets to orchestrate both the initiation and resolution of inflammation.

Vitamin D/CD46 Crosstalk in Human T Cells in Multiple Sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS), in which T-cell migration into the CNS is key for pathogenesis. Patients with MS exhibit impaired regulatory T cell populations, and both Foxp3+ Tregs and type I regulatory T cells (Tr1) are dysfunctional. MS is a multifactorial disease and vitamin D deficiency is associated with disease. Herein, we examined the impact of 1,25(OH)2D3 on CD4+ T cells coactivated by either CD28 to induce polyclonal activation or by the complement regulator CD46 to promote Tr1 differentiation. Addition of 1,25(OH)2D3 led to a differential expression of adhesion molecules on CD28- and CD46-costimulated T cells isolated from both healthy donors or from patients with MS. 1,25(OH)2D3 favored Tr1 motility though a Vitamin D-CD46 crosstalk highlighted by increased VDR expression as well as increased CYP24A1 and miR-9 in CD46-costimulated T cells. Furthermore, analysis of CD46 expression on T cells from a cohort of patients with MS supplemented by vitamin D showed a negative correlation with the levels of circulating vitamin D. Moreover, t-Distributed Stochastic Neighbor Embedding (t-SNE) analysis allowed the visualization and identification of clusters increased by vitamin D supplementation, but not by placebo, that exhibited similar adhesion phenotype to what was observed in vitro. Overall, our data show a crosstalk between vitamin D and CD46 that allows a preferential effect of Vitamin D on Tr1 cells, providing novel key insights into the role of an important modifiable environmental factor in MS.

Adhesion Deregulation in Acute Myeloid Leukaemia.

Cell adhesion is a process through which cells interact with and attach to neighboring cells or matrix using specialized surface cell adhesion molecules (AMs). Adhesion plays an important role in normal haematopoiesis and in acute myeloid leukaemia (AML). AML blasts express many of the AMs identified on normal haematopoietic precursors. Differential expression of AMs between normal haematopoietic cells and leukaemic blasts has been documented to a variable extent, likely reflecting the heterogeneity of the disease. AMs govern a variety of processes within the bone marrow (BM), such as migration, homing, and quiescence. AML blasts home to the BM, as the AM-mediated interaction with the niche protects them from chemotherapeutic agents. On the contrary, they detach from the niches and move from the BM into the peripheral blood to colonize other sites, i.e., the spleen and liver, possibly in a process that is reminiscent of epithelial-to-mesenchymal-transition in metastatic solid cancers. The expression of AMs has a prognostic impact and there are ongoing efforts to therapeutically target adhesion in the fight against leukaemia.

YY1 Positively Regulates Transcription by Targeting Promoters and Super-Enhancers through the BAF Complex in Embryonic Stem Cells.

SummaryYin Yang 1 (YY1) regulates early embryogenesis and adult tissue formation. However, the role of YY1 in stem cell regulation remains unclear. YY1 has a Polycomb group (PcG) protein-dependent role in mammalian cells. The PcG-independent functions of YY1 are also reported, although their underlying mechanism is still undefined. This paper reports the role of YY1 and BAF complex in the OCT4-mediated pluripotency network in mouse embryonic stem cells (mESCs). The interaction between YY1 and BAF complex promotes mESC proliferation and pluripotency. Knockdown of Yy1 or Smarca4, the core component of the BAF complex, downregulates pluripotency markers and upregulates several differentiation markers. Moreover, YY1 enriches at both promoter and super-enhancer regions to stimulate transcription. Thus, this study elucidates the role of YY1 in regulating pluripotency through its interaction with OCT4 and the BAF complex and the role of BAF complex in integrating YY1 into the core pluripotency network.

Adhesion Molecules Associated with Female Genital Tract Infection.

Efforts to develop vaccines that can elicit mucosal immune responses in the female genital tract against sexually transmitted infections have been hampered by an inability to measure immune responses in these tissues. The differential expression of adhesion molecules is known to confer site-dependent homing of circulating effector T cells to mucosal tissues. Specific homing molecules have been defined that can be measured in blood as surrogate markers of local immunity (e.g. α4β7 for gut). Here we analyzed the expression pattern of adhesion molecules by circulating effector T cells following mucosal infection of the female genital tract in mice and during a symptomatic episode of vaginosis in women. While CCR2, CCR5, CXCR6 and CD11c were preferentially expressed in a mouse model of Chlamydia infection, only CCR5 and CD11c were clearly expressed by effector T cells during bacterial vaginosis in women. Other homing molecules previously suggested as required for homing to the genital mucosa such as α4β1 and α4β7 were also differentially expressed in these patients. However, CD11c expression, an integrin chain rarely analyzed in the context of T cell immunity, was the most consistently elevated in all activated effector CD8+ T cell subsets analyzed. This molecule was also induced after systemic infection in mice, suggesting that CD11c is not exclusive of genital tract infection. Still, its increase in response to genital tract disorders may represent a novel surrogate marker of mucosal immunity in women, and warrants further exploration for diagnostic and therapeutic purposes.

Differential Expression of Adhesion Molecules by Sinonasal Fibroblasts among Control and Chronic Rhinosinusitis Patients

Chronic rhinosinusitis (CRS) is characterized by inflammatory cell migration into sinus tissue with resultant inflammation fueled by a milieu of cytokines. Fibroblasts may contribute to inflammation through expression of leukocyte adhesion molecules such as vascular cell adhesion molecule (VCAM) and intercellular adhesion molecule (ICAM). VCAM attracts eosinophils and mast cells contributing to Th2 skewing, and ICAM attracts neutrophils and to a lesser degree, eosinophils, and contributes to mixed Th1/Th2 skewing. The purpose of this study was to compare sinus fibroblast adhesion molecule expression ex vivo among CRS subtypes and in vitro after cytokine stimulation. Sinus biopsy specimens were taken from control patients (n = 13), CRS without nasal polyposis (CRSsNP, n = 6), and CRS with nasal polyposis (CRSwNP, n = 15). ex vivo levels of VCAM and ICAM were measured by flow cytometry from single cell suspensions of tissue biopsy specimens. Changes in VCAM and ICAM expression to cytokine exposure were assessed using in vitro cultured sinonasal fibroblasts treated with tumor necrosis factor (TNF)-α, interleukin (IL)-4, or interferon (IFN)-γ. ex vivo VCAM expression was lowest in controls, higher in CRSsNP, and highest in CRSwNP. in vitro stimulation with TNF-α and IL-4, but not IFN-γ, increased VCAM among CRSsNP, while expression in CRSwNP remained elevated with all treatments except IFN-γ. ex vivo ICAM expression was elevated in both CRS subtypes. in vitro stimulation with TNF-α and IFN-γ, but not IL-4, increased ICAM expression in all patients with the largest effects among the CRSsNP subgroup. Sinonasal fibroblast expression of adhesion molecules in sinusitis varies by disease state and is selectively influenced by exposure to inflammatory cytokines.

Endothelin-1 but not endothelial nitric oxide synthase polymorphisms are implicated in sickle cell disease (P3311)

Abstract Sickle cell disease (SCD) shows marked variability in severity among individuals; this variability probably linked to differential expression of adhesion molecules. Polymorphisms of the endothelial nitric oxide synthase (eNOS) have been implicated in disease severity, potentially delineating vascular complications. There is paucity of information on endothelin-1 (ET-1) diversity and disease severity or ethnic stratification. We examined genomic diversity and estimated haplotype frequency of eNOS and ET-1 polymorphisms in children with SCD. Thirteen SCD children (HbSS) and 176 adult and pediatric controls (HbAA) from Mali were recruited. Genotypic analysis of eNOS variants (T786C, Glu298Asp and intron 4) and ET-1 (G5665T) was carried out with a PCR-RFLP assay. Our results show the frequency distribution and allelic diversity of eNOS and ET-1 variants. Endothelin-1 (G5665T) mutant form was the most frequent, and probably most significant among children with SCD, though the distribution is out of Hardy-Weinberg equilibrium (P=0.0008). eNOS variants showed no difference between SCD and controls. We show that eNOS variants are less frequent, and may have no functional significance in SCD. Additionally, eNOS allele and genotype frequencies are not significantly different in cases and controls. Association between ET-1 and eNOS variants in African versus African American SCD children will be explored and the reason(s) for the HWE deviation will be investigated.

Platelets guide lymphocytes to vascular injury sites

Insight on Spectre et al. Thromb Haemost 2012; 108: 328-337. In this issue of Thrombosis and Haemo stasis, Spectre et al. (1) demonstrate that (activated) platelets promote lymphocyte adhesion to extracellular matrix components under arterial flow conditions, thereby further connecting thrombotic processes to inflammation and immunity. At sites of vascular injury, platelets adhere and aggregate on exposed subendothelial extracellular matrix (ECM) components and thereby form a plug that seals the wound or eventually occludes a diseased vessel, e.g. at sites of atherosclerotic plaque rupture (2). Besides this essential role in haemostasis and thrombosis, platelets are increasingly recognised to also orchestrate inflammatory processes, a combination of events best described by the term “thrombo-inflammation” (3). Several studies have shown that platelets can directly interact with lymphocytes and that this interaction is important for the modulation of adaptive immunity (3). However, lymphocytes are also abundantly found in atherosclerotic plaques and it is not clear whether they are recruited there by direct interactions with exposed plaque ECM components or through a plateletdependent mechanism. Spectre and coworkers now show in a series of elegant experiments that platelets are essentially required to support lymphocyte adhesion to different ECM components under arterial flow conditions ex vivo (500 s-1). Interestingly, the nature of the adhesive substrate largely determined the ability of the attached platelets to recruit specific lymphocyte subsets. For example, while platelets attached to collagen or fibrinogen, but not von Willebrand factor (vWF) efficiently recruited CD4+ and CD8+ T cells, all three substrates primed platelets to recruit NK cells in this system. The authors further provide evidence that the differential expression of adhesion molecules, most notably PSGL1 (CD162) and Mac-1, on different lymphocyte subpopulations, which interact with P-selectin and GPIb on platelets, respectively, may contribute to this selectivity, but further studies will be required to address this in more detail. Together, these observations provide a possible mechanism how platelets promote chronic inflammatory diseases such as atherogenesis, and may also serve as a basis for a better understanding of acute “thrombo-inflammatory“ disease states, such as ischaemic stroke where platelets and T cells have been identified as essential pathogenic factors but their mechanistic link has not been identified (3).

Differential Expression of Adhesion Molecules and Chemokine Receptors Confers Increased Migrative Capacity to ZAP-70-Positive Subclones in CLL Primary Cells,

Abstract 3889Chronic Lymphocytic Leukemia (CLL) is a lymphoproliferative disease characterized by the accumulation and proliferation of mature B-lymphocytes. CLL clinical course is extremely heterogeneous; patients with worse prognosis can be identified by the presence of high ZAP-70 expression. Increasing evidence indicates that the microenvironment plays a critical role providing survival and proliferative signals to CLL cells. In this sense, ZAP-70 protein expression has been related to increased capability of the cells to respond to several survival and migration signals provided by the cellular microenvironment through chemokines and cell-to-cell direct contact.We aimed to analyze the expression levels of several adhesion molecules and chemokine receptors potentially involved in CLL pathogenesis and progression in subclones of CLL cells with high or low ZAP-70 expression within the same patient. For this we obtained peripheral blood mononuclear cells from 40 patients diagnosed with CLL at our institution after informed consent. We then performed a flow cytometry analysis with 7 parameters that allowed for the measurement of the expression of different molecules in CD19+/CD5+ CLL cells with high or low ZAP-70 expression. The expression level of ZAP-70 protein in CD3+ T lymphocytes was used to set the threshold between CLL cells with low or high ZAP-70 expression (Figure 1). Using this approach we analyzed the differential expression of CCR7, CXCR4, CXCR5, CD44, CD49d and CD62L. Interestingly, we found that the expression levels of all the adhesion molecules and cytokine receptors analyzed were significantly higher in those CLL subclones with high ZAP-70 expression compared to CLL cells with low ZAP-70 expression within the same patient (Table 1), suggesting that the relationship with the microenvironment is not uniform across the CLL clone, but those CLL cells with higher expression of ZAP-70 have increased potential to receive signals from other cells. In order to analyze if this could translate into an increased capacity of the CLL cells with high ZAP-70 expression to migrate towards chemokines, we performed an in vitro transmigration assay across bare polycarbonate filters using primary CLL cells from 7 of the patients. We allowed the cells to migrate for 6 hours towards a media containing 1 μg/ml of CCL21 (the ligand of CCR7) and proceed to measure the percentage of CD19+/CD5+ CLL cells with ZAP-70 expression among those cells that had transmigrated and to compare it with the percentage of ZAP-70-positive cells within the ones that did not migrate. Of note, for all the cases analyzed, we observed that the percentage of ZAP-70-positive cells was significantly higher in the cells that had migrated compared to the cells present in the upper chamber (p=0.018) indicating that ZAP-70-positive CLL cells have an enhanced ability to respond to and to migrate towards CCL21. In conclusion, the differential expression of adhesion molecules and chemokine receptors in primary CLL cells with higher expression of ZAP-70 can influence their relationship with the microenvironment and confers them a higher migratory potential towards CCL21. [Display omitted] Table 1:MFI: mean fluorescence intensity SEM: standard error of the meanMean MFI ± SEM Low ZAP-70 CLL cellsMean MFI ± SEM High ZAP-70 CLL cellsPaired samples t-test p valueCCR7163.56 ± 11.3178.20 ± 13.40.007CXCR4263.01 ± 36308.95 ± 45.30.004CXCR5604.02 ± 62.6652.89 ± 67.50.001CD441081.11 ± 76.91210.8 ± 82.5>0.001CD49d58.43 ± 16.169.6 ± 17.6>0.001CD62L33.81 ± 8.947.63 ± 12.1>0.001 Disclosures:No relevant conflicts of interest to declare.

Differential Adhesion Molecule Expression during Murine Embryonic Stem Cell Commitment to the Hematopoietic and Endothelial Lineages

Mouse embryonic stem cells (ESC) make cell fate decisions based on intrinsic and extrinsic factors. The decision of ESC to differentiate to multiple lineages in vitro occurs during the formation of embryoid bodies (EB) and is influenced by cell-environment interactions. However, molecular mechanisms underlying cell-environmental modulation of ESC fate decisions are incompletely understood. Since adhesion molecules (AM) influence proliferation and differentiation in developing and adult tissues, we hypothesized that specific AM interactions influence ESC commitment toward hematopoietic and endothelial lineages. Expression of AM in the adherens, tight and gap junction pathways in ESC subpopulations were quantified. E-cadherin (E-cad), Claudin-4 (Cldn4), Connexin-43 (Cx43), Zona Occludens-1 (ZO-1) and Zona Occludens-2 (ZO-2) transcript levels were differentially expressed during early stages of hematopoietic/endothelial commitment. Stable ESC lines were generated with reduced expression of E-cad, Cldn4, Cx43, ZO-1 and ZO-2 using shRNA technology. Functional and phenotypic consequences of modulating AM expression were assessed using hematopoietic colony forming assays, endothelial sprouting assays and surface protein expression. A decrease in E-cad, Cldn4, Cx43 and ZO-1 expression was associated with less commitment to the hematopoietic lineage and increased endothelial differentiation as evidenced by functional and phenotypic analysis. A reduction in ZO-2 expression did not influence endothelial differentiation, but decreased hematopoietic commitment two-fold. These data indicate that a subset of AM influence ESC decisions to commit to endothelial and hematopoietic lineages. Furthermore, differentially expressed AM may provide novel markers to delineate early stages of ESC commitment to hematopoietic/endothelial lineages.

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 homozygotes = 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.

Unique Modulation of Cadherin Expression Pattern during Posterior Frontal Cranial Suture Development and Closure

Cranial suture development involves coordinated expression of multiple genes and tissue contribution from neural crest cells and paraxial mesoderm for timely sutural morphogenesis. Transcription factors, growth factors, and neural crest determinant genes play critical roles in calvarial growth ensuring normal development of the underlying brain. In vitro studies have implicated cell-cell adhesion molecules as a driving force behind suture closure. We performed cDNA microarray to study differential expression of adhesion molecules during the timing of suture closure in a mouse model where only the posterior frontal (PF) suture closes. Our results indicate increased expression of E-cadherin during the period of PF suture closure. Quantitative RT-PCR analysis of E- and N-cadherin in PF closing suture revealed a biphasic expression of N-cadherin, the first phase coinciding with cellular condensation preceding chondrogenesis followed by a second phase coinciding with E-cadherin co-expression and suture closure. Furthermore, expression analysis of the N-cadherin and E-cadherin transcriptional repressors Wnt7a and Snail indicate a specific temporal regulation of these genes, suggesting their potential role as regulators of both E- and N-cadherin during the PF suture development and closure. Finally, given the in vitro evidence of fibroblast growth factor (FGF)-2 as a potential regulator of E- and N-cadherin we investigated the expression of E-cadherin during PF suture closure in Fgf-2 deficient mice. In contrast to in vitrodata previously reported, E-cadherin expression is normal in these animals, and PF suture closure occurs properly, probably due to potential redundancy of FGF ligands ensuring normal temporal expression of E-cadherin and PF suture closure.

Differential binding of hyaluronan on the surface of tissue-specific endothelial cell lines.

Tissue-specific heterogeneity of endothelial cells, both structural and functional, plays a crucial role in physiologic as well as pathologic processes, including inflammation, autoimmune diseases and tumor metastasis. This heterogeneity primarily results from the differential expression of adhesion molecules that are involved in the interactions between endothelium and circulating immune cells or disseminating tumor cells. Among these molecules present on endothelial cells is hyaluronan (HA), a glycosaminoglycan that contributes to primary (rolling) interactions through binding to its main receptor CD44 expressed on leukocytes and tumor cells. While the regulation of CD44 expression and function on either leukocytes or tumor cells has been well characterized, much less is known about the ability of endothelial cells to express HA on their surface. Therefore, in these studies we analyzed HA levels on tissue-specific endothelium. We used endothelial cell lines of different origin, including lung, skin, gut and lymph nodes that had been established previously as model lines to study interactions between the endothelium and leukocytes/tumor cells. Our results indicate that HA is accumulated on the surface of all endothelial cells examined. Moreover, retention of endogenous HA differs between the lines and may depend on their tissue origin. Analysis of binding of exogenous HA reveals the presence of specific HA binding sites on all endothelial cell lines tested. However, the retention of endogenous HA and the binding of exogenous HA is mediated through a CD44-independent mechanism.

Adhesion Molecules and Kinases Involved in γ δ T Cells Migratory Pathways:Implications for Viral and Autoimmune Diseases

gammadelta T lymphocytes are involved in the defence from viral and mycobacterial infections; however they are also responsible for autoimmune reactions. Herein, we discuss the characteristics of these cells, focusing on the mechanism(s) underlying extravasation and tissue localization. We show that Vdelta1 and Vdelta2 gammadeltaT cells display differential expression of adhesion molecules and chemokine receptors, the former being preferentially PECAM-1(+)CXCR4(+), the latter expressing NKRP1A and CXCR3. The two cell populations transmigrate across endothelial cells by activation of distinct kinase pathways and in response to interferon-gamma-inducing protein-10 (IP-10/CXCL10) or stromal-derived factor-1 (SDF-1/CXCL12) according to the expression of the specific receptors CXCR3 and CXCR4. IP-10/CXCL10 and SDF-1/CXCL12-induced transmigration are phosphoinositide-3 kinase (PI-3K) and Akt/PKB-dependent. In addition, occupancy of CXCR3, but not of CXCR4, leads to CAMKII activation; blocking of CAMKII decreases IP-10/CXCL10 and 6Ckine/SLC/CCL21-driven transmigration. We report that HIV-1-infected patients have an increased number of circulating Vdelta1 T cells possibly due to the interference of Tat protein on the function of chemokine receptors. In turn, patients with relapsing-remitting multiple sclerosis (MS), display an increase in peripheral Vdelta2 gammadelta T cells and this is related to interleukin-12-mediated upregulation of NKRP1A. Finally, the possible role of gammadelta T lymphocytes in post-transplantation immune reconstitution is discussed.

Differential expression of adhesion molecules and chemokines between nasal and small intestinal mucosae: implications for T‐ and sIgA+ B‐lymphocyte recruitment

Nasal and small intestinal mucosae are the first sites of contact with infectious agents and the sites of T-cell-mediated and secreted immunoglobulin A (IgA)-mediated defences against pathogens. We investigated the factors controlling the infiltration of CD3(+) T lymphocytes and surface IgA(+) (sIgA(+)) B lymphocytes into swine epithelium and lamina propria (LP) within and between these two mucosal effector sites. Vascular addressins, vascular cell adhesion molecule 1 and mucosal addressin cell adhesion molecule-1 were reciprocally expressed in both mucosae. Strong expression of alpha(4)beta(1) relative to alpha(4)beta(7) was characteristic of CD3(+) T cells in nasal mucosa LP and epithelium and of sIgA(+) cells in nasal mucosa epithelium. The same profile was observed on corresponding blood cells. Conversely, higher levels of integrins beta(7) and alpha(4)beta(7) than alpha(4)beta(1) were characteristic of CD3(+) T cells and sIgA(+) cells in the small intestine. However, about 40% of the LP-activated sIgA(+) cells displayed sIgA(high), integrin alpha(4) and integrin alpha(4) expression. Whereas CCL19, CXCL12, CCL21 and CCL28 messenger RNAs were similarly expressed in both mucosae, CCL25 messenger RNA was only expressed in the small intestine. Thus, the nasal and small intestine mucosae represent separate compartments for infiltration by CD3(+) T cells and sIgA(+) effector cells, with the exception of a population of small intestine activated sIgA(+) cells, which may gain access to both mucosae.

The establishment of regional identity in the Xenopus blastula.

The molecules involved in the commitment of Xenopus cells to particular germ layers are unknown. The question has been investigated for the cells of the blastula in in vivo cell transplantation assays and in vitro aggregation assays. Using the former technique, we have shown that vegetal cells become committed before gastrulation, even when placed in inappropriate sites. We could find no evidence of regional determination within the endoderm germ layer at the early gastrula stage. In aggregation assays, animal and vegetal cells sorted incompletely at the mid-blastula stage and more efficiently at the gastrula stage. Their behaviour may be mediated by differential expression of adhesion molecules, which so far remain unidentified.

Gastric cancer cells in collagen gel matrix: Three‐dimensional growth and differential expression of adhesion molecules (CD44s, CD54, E‐cadherin)

To characterize the growth of human gastric cancer cells in collagen gel matrix and adhesive status of the cells in comparison with conventional monolayer cells. Three kinds of human gastric cancer cell lines (BGC823, SGC7901, and MKN28) were cultured alone or co-cultured with normal human fibroblasts in collagen gel matrix, and their cell cycle, metabolic function, and the expression of adhesive molecules (CD44s, CD54, and E-cadherin) were analyzed by flow cytometry or other methods. Two of three cell lines (BGC823 and SGC7901) and their co-cultures showed multilayer growth in collagen gel matrix, and their growth and metabolism rate became slow and the cell adhesion molecules (CAMs) expression was down regulated. Gastric cancer cell alone or with fibroblasts in collagen gel matrix showed distinct growth feature when compared with monolayer cells, which represent two kinds of different experimental models. BGC823 and SGC7901 cells growing in three-dimension may recur some characteristics of their original solid tumor in vivo with the invasive or metastatic ability. According to different aims, it should pay great care in choice of experimental model to get more reasonable results.

Differential expression of adhesion molecules in lung tumours

Differential expression of adhesion molecules in lung tumours

T and IgA B lymphocytes of the pharyngeal and palatine tonsils: differential expression of adhesion molecules and chemokines.

The pharyngeal (Ph) and palatine (Pa) tonsils, although located in different regions of the upper aero-digestive tract (UADT), are thought to protect the respiratory tract similarly against infections by inducing and disseminating T and surface IgA(+) (sIgA(+)) B cells. We investigated the factors controlling the migratory properties of T and sIgA(+) B lymphocytes in the UADT of pigs by comparing the expression of vascular addressins, homing receptors and chemokine transcripts in Ph/Pa tonsils, Peyer's patches (PP) and their draining lymph nodes (LN). The vascular addressin PNAd was detected on high endothelial venules in both tonsils, whereas mucosal addressin cell adhesion molecule-1, otherwise present in PP and mesenteric LN, was not detected. More importantly, the vascular cell adhesion molecule-1 (VCAM-1) addressin was present in Ph tonsil and LN but neither in Pa tonsil nor in PP vascular cells, whereas both T and sIgA(+) B lymphocytes displayed similar levels of alpha4beta1(high) integrin, the ligand of VCAM-1. Analysis of transcript levels for several lymphoid (CCL19, CXCL12 and CCL21) and epithelial chemokines also demonstrated opposite chemokine mRNA ratios for Ph tonsil (CCL28 > CCL25) and PP, with Pa tonsil expressing very low levels of CCL28. Collectively, these data indicate that the differential compartmentalization of sIgA(+) lymphocytes between Pa and Ph tonsils may partly result from the differential expression of VCAM-1 and CCL28. They also suggest that tonsillar addressins and epithelial chemokines, rather than the cells intravasating it, control the regionalization of sIgA(+) lymphocytes in the UADT.