Association of serum chemokine ligand 21 levels with asthma control in adults

OBJECTIVES: The chemokine ligand (CCL) 21 regulates the maturation, migration, and function of dendritic cells, and has been implicated in the pathogenesis of asthma. This study aimed to investigate the association between serum CCL21 levels and asthma control. METHODS: The serum levels of CCL21 and other inflammatory cytokines were analyzed in patients with asthma (n=44) and healthy controls (n=35) by enzyme-linked immunosorbent assay. IgE levels and eosinophil counts were determined by turbidimetric inhibition immunoassay and fully automatic blood analysis, respectively. The Asthma Control Test (ACT) questionnaire was used, and spirometry and fractional exhaled nitric oxide (FENO) measurements were performed. A multiple unpaired Student's t-test was performed to analyze the differences in CCL21 and interleukin levels between patients with asthma and healthy controls. The correlation of CCL21 levels with disease severity was evaluated using the Pearson's rank correlation test. RESULTS: Serum CCL21 levels were lower in patients with asthma (254.78±95.66 pg/mL) than in healthy controls (382.95±87.77 pg/mL) (p<0.001). Patients with asthma had significantly higher levels of IL-1β (19.74±16.77 vs. 2.63±5.22 pg/mL), IL-6 (7.55±8.65 vs. 2.37±2.47 pg/mL), and tumor necrosis factor-α (12.70±12.03 vs. 4.82±3.97 pg/mL) compared with the controls. CCL21 levels were positively correlated with the ACT score (rs=0.1653, p=0.0062), forced expiratory volume in 1s (FEV1)/forced vital capacity (rs=0.3607, p<0.0001), and FEV1 (rs=0.2753, p=0.0003), and negatively correlated with FENO (rs=0.1060, p=0.0310). CCL21 levels were negatively correlated with serum IgE levels (rs=0.1114, p=0.0268) and eosinophil counts (rs=0.3476, p<0.0001). CONCLUSIONS: Serum CCL21 levels may be a new biomarker for assessing asthma control.

Progress in targeting therapy of cancer metastasis by CCL21/CCR7 axis / 生物工程学报

Metastasis is the leading cause of mortality for cancer patients, and lymphatic metastasis is one of the main ways of tumor metastasis. The role of CCL21 and its receptor CCR7 in lymphatic metastasis has been increasingly concerned in recent years. CCR7 is mainly expressed by both dendritic cells and T cells for immune responses. CCL21, the chemokine ligand for CCR7, secreted from lymphatic endothelial cells binds CCR7 and recruits immune cells toward lymphatic vessels and lymphatic nodes. CCR7 expressed tumor cells can also metastasize to lymphatic system by the similar way as immune cells. Targeting CCL21/CCR7 axis to inhibit lymphatic metastasis but remain potent anti-tumor immune response has increasingly become a spot light of tumor immunotherapy. In this review, we summarize the role of CCL21/CCR7 axis in lymphatic metastasis, as well as preclinical trials and clinical trials in targeting CCL21/CCR7 axis for tumor metastasis therapy, hoping to accelerate the progress on tumor metastasis therapy by targeting CCL21/CCR7 axis.

Sarcoplasmic reticulum Ca²⁺ ATPase 2 (SERCA2) reduces the migratory capacity of CCL21-treated monocyte-derived dendritic cells

The migration of dendritic cells (DCs) to secondary lymphoid organs depends on chemoattraction through the interaction of the chemokine receptors with chemokines. However, the mechanism of how lymphoid chemokines attract DCs to lymphoid organs remains unclear. Here, we demonstrate the mechanism of DC migration in response to the lymphoid chemokine CCL21. CCL21-mediated DC migration is controlled by the regulation of sarcoplasmic reticulum Ca²⁺ ATPase 2 (SERCA2) expression rather than through the activation of mitogen-activated protein kinases CCL21-exposed mature DCs (mDCs) exhibited decreased SERCA2 expression but not decreased phospholamban (PLB) or Hax-1 expression, which are known to be SERCA2-interacting proteins. In addition, CCL21 did not affect the mRNA levels of SERCA2 or its interacting protein Hax-1. Interestingly, SERCA2 expression was inversely related to DC migration in response to chemokine stimulation. The migratory capacity of CCL21-treated mDCs was decreased by the phospholipase C inhibitor U73122 and by the protein kinase C inhibitor BAPTA-AM. The migratory capacities of mDCs were increased in response to SERCA2 siRNA expression but were decreased by SERCA2 overexpression. In addition, DCs treated with a SERCA2-specific inhibitor (cyclopiazonic acid) had significantly increased migratory capacities as mDCs regardless of SERCA2 expression. Moreover, SERCA2 expression was dependent on DC maturation induced by cytokines or Toll-like receptor agonists. Therefore, the migratory capacities differed in differentially matured DCs. Taken together, these results suggest that SERCA2 contributes to the migration of CCL21-activated DCs as an important feature of the adaptive immune response and provide novel insights regarding the role of SERCA2 in DC functions.

CCL21-CD40L fusion gene induce augmented antitumor activity in colon cancer / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the anti-tumor activity of CCL21-exCD40L eukaryotic expression vector.</p><p><b>METHODS</b>CCL21-exCD40L fusion gene were constructed by overlap PCR connecting CCL21 and exCD40L through a flexible linker (Gly3Ser)4, and then was cloned into expression vector pcDNA3.1(+). pcDNA3.1(+)/CCL21 and pcDNA3.1(+)/exCD were constructed as negative control. Wsestern blot was used to identify the fusion protein. CHO cells was transfected with pcDNA3.1(+)/CCL21-exCD, pcDNA3.1(+)/CCL21 and pcDNA3.1(+), respectively. The chemotatic function of the expressed product was detected by Transwell method and its anti-tumor activity was tested with vivo transfection.</p><p><b>RESULTS</b>Gene sequencing and restrictive digestion proved the successful construction of pcDNA3.1(+)/CCL21-exCD40L,and its expression was conformed by western blot. The transfectant supernantes of pcDNA3.1(+)/CCL21-exCD40 group had a significant chmotactic function to DCs, of which the cell numbers passing through the film was 14.95 times of blank control every high power microscope visual field. After tumor orthotoic injection of plasmid carrying fusion gene in Balb/c mouse, the tumor mass reduced remarkablely, and all the mouse in fusion gene group survived after 4 weeks.</p><p><b>CONCLUSION</b>CCL21-exCD40L fusion protein had a remarkable function to DCs and it can inhibit tumor growth and prolong the mouse survival time, which is more effective than all control group.</p>

Intratumoral Administration of Secondary Lymphoid Chemokine and Unmethylated Cytosine-phosphorothioate-guanine Oligodeoxynucleotide Synergistically Inhibits Tumor Growth in Vivo

Secondary lymphoid tissue chemokine (SLC), which is expressed in T cell zones of secondary lymphoid organs, including the spleen and lymph nodes, strongly recruits both T lymphocytes and mature dendritic cells. As appropriate interaction of tumor-specific T cells and mature dendritic cells, equipped with tumor antigens, is a prerequisite for effective T cell immunity against established tumors, we mobilized lymphocytes and dendritic cells to tumor sites by intratumoral injection of secondary lymphoid tissue chemokine-Fc (SLC-Fc) fusion protein using the B16F10 murine melanoma model. Activation of dendritic cells, another prerequisite for the effective activation of naive tumor-specific T cells, was achieved by the addition of immunostimulatory cytosine-phosphorothioate-guanine oligodeoxynucleotide (CpG-ODN) into the tumor site. Intratumoral administration of SLC-Fc or CpG-ODN revealed antitumor effects against B16F10 murine melanoma grown in the subcutaneous space. Co-treatment of SLC-Fc and CpG-ODN displayed synergistic effects in reducing the tumor size. The synergistic antitumor effect in co-treatment group was correlated with the synergistic/additive increase in the infiltration of CD4+ T cells and CD11c+ dendritic cells in the tumor mass compared to the single treatment groups. These results suggest that the combined use of chemokines and adjuvant molecules may be a possible strategy in clinical tumor immunotherapy.

Expression of CCR6 and CCR7 in laryngeal squamous cell carcinoma / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To evaluate the expressions of chemokine receptor 6 (CCR6), chemokine receptor 7 (CCR7) and their ligands (CCL20, CCL19/CCL21) in laryngeal squamous cell carcinoma (LSCC), and then explore their correlation with the clinicopathological features of LSCC.@*METHOD@#Blood samples, fresh specimens of LSCC and paired adjacent tissues were collected. The expressions of CCR6, CCR7 and their ligands CCL20, CCL19/ CCL21 mRNA as well as the protein CCR6, CCR7 were detected by real-time qRT-PCR and IHC respectively. Flow cytometry was also used to investigate CCR6, CCR7 expressed on PBMC.@*RESULT@#The relative expression levels of CCR6, CCR7, CCL19 and CCL21 mRNA in tumor tissue was significantly higher than that of adjacent tissues (P < 0.05), while the relative expression level of CCL20 mRNA in tumor tissue were significantly lower than that of adjacent tissues (P < 0.05). IHC confirmed the expression of protein CCR6 and CCR7 in both tumor tissue and metastatic ILN and the expression levels of protein CCR6, CCR7 were higher in the cases with lymphatic metastasis than that of those without lymphatic metastasis (P < 0.05). FCM showed the percentage of CD4+ CCR6+ T cells of LSCC was significantly higher than that of normal control (P < 0.05), while that of CD4+ CCR7+ T cells was significantly lower (P < 0.05).@*CONCLUSION@#CCR6 and CCR7 are expressed in tumor situ, metastatic LN and PBMC,and might exert a potential role in LSCC development.

Stroma-rich variant of hyaline-vascular Castleman's disease: a clinicopathologic and histogenetic study / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the histologic features and immunohistochemical findings of interfollicular stromal cells in hyaline-vascular Castleman's disease (HVCD), and to explore the role of these stromal cells in the pathogenesis of this disease.</p><p><b>METHODS</b>The clinical findings and microscopic features of 23 cases of HVCD cases were reviewed. Immunohistochemical study for CCL21, MSA, CD21, CD35, S-100 and CD34 was carried out.</p><p><b>RESULTS</b>According to the criteria proposed by Danon et al., stroma-rich variant of HVCD contained prominent interfollicular zone which occupied at least 50% of the lymph node area. In the current study, there were 14 cases of stroma-rich HVCD and 9 cases of conventional HVCD. Eleven of the stroma-rich HVCD had paraneoplastic pemphigus and contrastly, no pemphigus lesion obtained in all the 9 cases of conventional HVCD. The association between stromal cell hyperplasia and paraneoplastic pemphigus was statistically significant (P < 0.01).In all the conventional HVCD cases studied, CCL21 and MSA were positive in the stromal cells.The stromal cells in 13 of the 14 cases of the stroma-rich HVCD were also positive for CCL21 and MSA, however, staining for CD21, CD35, S-100 and CD34 was negative in both groups. There was no statistical significance obtained (P > 0.05) between the differences of the staining results.</p><p><b>CONCLUSIONS</b>Stroma-rich HVCD and conventional HVCD represent two distinctive histologic variants and have a different association with paraneoplastic pemphigus. Most of the stromal cells locating in the interfollicular areas are fibroblastic reticular cells in origin, with the immunophenotype as CCL21(+)/MSA(+)/CD34⁻/CD21⁻/S-100⁻. The stromal cells proliferation correlate with the occurrence of paraneoplastic pemphigus, nevertheless, more cases are expected for a further study of the underlying pathogenesis.</p>

Construction of murine CCL21 eukaryotic expression plasmid and chemotactic function of its products / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To construct the murine CCL21 eukaryotic expression plasmid, and to investigate the chemotactic function of its products.</p><p><b>METHODS</b>Murine CCL21 cDNA was amplified by RT-PCR from murine total RNA, and was inserted into eukaryotic expression plasmid pcDNA3.1 after confirmation of sequencing. The recombinant CCL21 plasmid was transferred into mouse forestomach carcinoma (MFC) cells and the chemotactic function of expressed products was detected by chemotaxis assay.</p><p><b>RESULT</b>Gene sequencing, gel electrophoresis of PCR products and restrictive digestion proved the successful construction of CCL21, and its expression was confirmed by Western Blot. The transfected tumor cells had a significant chemotactic function to DC.</p><p><b>CONCLUSION</b>The recombinant murine CCL21 eukaryotic expression plasmid has been successfully constructed, and its expression products in tumor cells have a marked chemotactic function to DC.</p>

Role of secondary lymphoid tissue chemokine in the pathogenesis of rat ulcerative colitis / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the effect of secondary lymphoid tissue chemokine (SLC) on experimental colon lesions in rats with ulcerative colitis.</p><p><b>METHODS</b>Sixty Sprague-Dawley rats were randomly divided into control group, model group and SLC intervention group. Colonic mucosal lesions of different groups were observed with HE staining for inflammation and lymphocyte homing situation. Cytokine IL-2 and IL-6 levels were measured by ABC-ELISA. Semi-quantitative RT-PCR was used to examine the colonic SLC expression.</p><p><b>RESULTS</b>Intestinal inflammation score and colonic cytokine levels were significantly different among three groups (P<0.05, P<0.01). Abnormal lymphocyte homing phenomenon under colonic mucosa was found in the model group and the intervention group. SLC mRNA expression of the model and intervention groups increased significantly compared with the control group (0.846+/-0.047, 0.768+/-0.135 vs 0.312+/-0.112, P<0.01). However, there was no significant difference between model group and intervention group.</p><p><b>CONCLUSIONS</b>SLC may play an important role in experimental colonic mucosal inflammation in rats with ulcerative colitis. Blockade of SLC may be one of effective ways in reducing colonic mucosal inflammation.</p>

Implications of lung interstitial dendritic cells of mice in multiple organ dysfunction syndrome / 中华病理学杂志

<p><b>OBJECTIVE</b>To explore the role of lung interstitial dendritic cells in immunodissonance and organ injury in multiple organ dysfunction syndrome (MODS).</p><p><b>METHODS</b>Animal model of MODS was established by injecting zymosan into the peritoneal cavity of C57BL/6 mice. The mice were randomly divided into groups of normal, 3 - 6 hours, 12 - 48 hours, 5 - 7 days, 10 - 12 days post injection. Pathological changes of lung and interstitial dendritic cells were studied by light and transmission electron microscope. Immunohistochemistry, RT-PCR and flow cytometry analyses were used to document status of biomarkers, including specific surface markers (CD205 and CD11c), costimulatory molecules (CD80 and CD86), SLC and its receptor CCR7 in lung, CD4+ and CD8+ T lymphocyte subtypes in peripheral blood.</p><p><b>RESULTS</b>At early stage of injury, interstitial dendritic cells showed an increase in proliferation with expression of low level of CD80 and CD86. In contrast, the expression of SLC and its receptor CCR7 in lung were increased. The ratio of CD4+/CD8+ declined in peripheral blood. At the stage of SIRS, interstitial dendritic cells continued to proliferate with high expressions of CD80 and CD86. SLC and CCR7 in lung also increased. The ratio of CD4+/CD8+ declined markedly in peripheral blood. At the MODS stage, interstitial dendritic cells further proliferated, but the expression of CD80 and CD86 declined to a very low level. Although the level of SLC increased consistently, the level of CCR7 continued to decrease, along with a markedly decreased CD4+/CD8+ ratio in peripheral blood.</p><p><b>CONCLUSIONS</b>Alterations of lung interstitial dendritic cells are likely to influence the course of immunological dysfunction of MODS. The level of CCR7 may serve as an indicator of the migration activity of interstitial dendritic cells and systemic immune response.</p>

Cloning and expression in Escherichia coli of secondary lymphoid-tissue chemokine (SLC) gene / 生物工程学报

Secondary lymphoid-tissue chemokine (SLC) is a type of CC chemokine identified by searching the Expressed Sequence Tag (EST) database. The full-length SLC gene was synthesized based on human SLC sequence using SOE-PCR. The sequenced SLC gene was cloned into expression vector pTMF and pALM, which used to transform Escherichia coli. Then the E. coli was cultured and induced according to protocol. The expressed target protein was identified by Western blotting. The target protein was expressed as soluble protein as well as inclusion bodies, the ratio of these two forms target protein varied with the difference conditions of culture and induction. The target protein was purified with the methods of nickel-nitrilotriacetic acid (Ni-NTA) metal-affinity chromatography. The results of electrophoresis of the purified target protein showed that the molecular weight was larger than the predicted molecular weight.

CCR7 Ligands Induced Expansion of Memory CD4+ T Cells and Protection from Viral Infection

BACKGROUND: CC chemokine receptor (CCR) 7 and cognate CCR7 ligands, CCL21 (formerly secondary lymphoid tissue chemokine [SLC]) and CCL19 (formerly Epstein-Barr virus-induced molecule 1 ligand chemokine [ELC]), were known to establish microenvironment for the initiation of immune responses in secondary lymphoid tissue. As described previously, coadministration of DNA vaccine with CCR7 ligand-encoding plasmid DNA elicited enhanced humoral and cellular immunity via increasing the number of dendritic cells (DC) in secondary lymphoid tissue. The author hypothesized here that CCR7 ligand DNA could effectively expand memory CD4+ T cells to protect from viral infection likely via increasing DC number. METHODS: To evaluate the effect of CCR7 ligand DNA on the expansion of memory CD4+ T cells, DO11.10.BALB/c transgenic (Tg)-mice, which have highly frequent ovalbumin (OVA)(323-339) peptide-specific CD4+ T cells, were used. Tg-mice were previously injected with CCR7 ligand DNA, then immunized with OVA(323-339) peptide plus complete Freund's adjuvant. Subsequently, memory CD4+ T cells in peripheral blood lymphocytes (PBL) were analyzed by FACS analysis for memory phenotype (CD44(high) and CD62(Llow)) at memory stage. Memory CD4+ T cells recruited into inflammatory site induced with OVA-expressing virus were also analyzed. Finally, the protective efficacy against viral infection was evaluated. RESULTS: CCR7 ligand DNA-treated Tg-mice showed more expanded CD44(high) memory CD4+ T cells in PBL than control vector-treated animals. The increased number of memory CD4+ T cells recruited into inflammatory site was also observed in CCR7 ligand DNA-treated Tg-mice. Such effectively expanded memory CD4+ T cell population increased the protective immunity against virulent viral infection. CONCLUSION: These results document that CCR7 and its cognate ligands play an important role in intracellular infection through establishing optimal memory T cell. Moreover, CCR7 ligand could be useful as modulator in DNA vaccination against viral infection as well as cancer