Nicotinamide Riboside Augments Human Macrophage Migration via SIRT3-Mediated Prostaglandin E2 Signaling.

NAD+ boosting via nicotinamide riboside (NR) confers anti-inflammatory effects. However, its underlying mechanisms and therapeutic potential remain incompletely defined. Here, we showed that NR increased the expression of CC-chemokine receptor 7 (CCR7) in human M1 macrophages by flow cytometric analysis of cell surface receptors. Consequently, chemokine ligand 19 (CCL19, ligand for CCR7)-induced macrophage migration was enhanced following NR administration. Metabolomics analysis revealed that prostaglandin E2 (PGE2) was increased by NR in human monocytes and in human serum following in vivo NR supplementation. Furthermore, NR-mediated upregulation of macrophage migration through CCL19/CCR7 was dependent on PGE2 synthesis. We also demonstrated that NR upregulated PGE2 synthesis through SIRT3-dependent post-transcriptional regulation of cyclooxygenase 2 (COX-2). The NR/SIRT3/migration axis was further validated using the scratch-test model where NR and SIRT3 promoted more robust migration across a uniformly disrupted macrophage monolayer. Thus, NR-mediated metabolic regulation of macrophage migration and wound healing may have therapeutic potential for the topical management of chronic wound healing.

Morinda officinalis extract exhibits protective effects against atopic dermatitis by regulating the MALAT1/miR-590-5p/CCR7 axis.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease with a genetic predisposition, and the traditional Chinese medicine Morinda officinalis and its roots are characterized with anti-inflammatory effects and have been used for the treatment of various disease. However, it is still largely unknown whether Morinda officinalis extract (MOE) can be used for the treatment of AD. OBJECTIVES: In our study we aimed to determine whether MOE could ameliorate 2,4-dinitrochlorobenzene (DNCB)-induced AD and elucidate molecular mechanisms. METHODS: We established an AD mouse model by using DNCB. Skin pathological analysis and ELISA assay were used to detect the effect of MOE on the inflammation of AD model mouse skin and the expression changes of inflammatory factors, and further functional verification was performed in TNF-α/IFN-γ-induced HaCaT cells. RESULTS: Our in vivo experiments confirmed that MOE remarkably reduced DNCB-induced AD lesions and symptoms, such as epidermal and dermal thickness and mast cell infiltration and inflammatory cytokines secretion in the mice models. In addition, the underlying mechanisms by which MOE ameliorated AD had been uncovered, and we verified that MOE inhibited MALAT1 expression in AD, resulting in attenuated expression of C-C chemokine receptor type 7 (CCR7) regulated by MALAT1-sponge miR-590-5p in a competing endogenous RNA (ceRNA) mechanisms-dependent manner, thereby inhibiting TNF-α/IFN-γ-induced cellular proliferation and inflammation.

Effect of ibrutinib on CCR7 expression and functionality in chronic lymphocytic leukemia and its implication for the activity of CAP-100, a novel therapeutic anti-CCR7 antibody.

CAP-100 is a novel therapeutic antibody directed against the ligand binding site of human CCR7. This chemokine receptor is overexpressed in chronic lymphocytic leukemia (CLL) and orchestrates the homing of CLL cells into the lymph node. Previous studies, on a very limited number of samples, hypothesized that the Bruton's tyrosine kinase inhibitor (BTKi) ibrutinib might induce loss of surface CCR7 levels in CLL cells. CAP-100 will be evaluated in clinical trials as a therapy for relapse/refractory CLL patients, who have received at least two systemic therapies (NCT04704323). As nowadays many relapse/refractory CLL patients will have received ibrutinib as a prior therapy, we aimed to investigate in a large cohort of CLL patients the impact of this BTKi on CCR7 expression and functionality as well as on the therapeutic activity of CAP-100. Our data confirm that ibrutinib moderately down-regulates the very high expression of CCR7 in CLL cells but has no apparent effect on CCR7-induced chemotaxis. Moreover, CLL cells are perfectly targetable by CAP-100 which led to a complete inhibition of CCR7-mediated migration and induced strong target cell killing through antibody-dependent cell-mediated cytotoxicity, irrespective of previous or contemporary ibrutinib administration. Together, these results validate the therapeutic utility of CAP-100 as a next-line single-agent therapy for CLL patients who failed to ibrutinib and confirm that CAP-100 and ibrutinib have complementary non-overlapping mechanisms of action, potentially allowing for combination therapy.

Hizikia fusiforme extract enhances dendritic cell maturation in vitro and in vivo.

Dendritic cells (DCs) are play critical roles in the priming and regulation of immune responses. DCs rapidly process and convey these antigens to prime antigen-specific T cells. Therefore, regulation of DCs functions is important for immunity and immunotherapies. Immune adjuvants for DCs activation are needed to improve the efficacy of vaccines against tumors and many infectious diseases. Therefore, we demonstrate that H. fusiformis extract can regulate DCs maturation and activation. H. fusiformis extract induced costimulatory molecules (CD 80 and CD86), antigen-presenting molecules (major histocompatibility complex (MHC) I and II), CCR7 expression, and interleukin (IL)-12 production in DCs. These effects are associated with upregulation of mitogen-activated protein kinase (MAPK) signaling pathway. In addition, H. fusiformis extract induces costimulatory molecules on splenic DCs and activated CD8+ T cells in vivo. Taken together, these findings suggest that H. fusiformis extract may be a potential efficient immune therapeutic compound in DCs-mediated immunotherapies. ABBREVIATIONS: CTL: cytotoxic T lymphocytes; DCs: dendritic cells; ERK: extracellular signal-regulated kinases; IL: interleukini; JNK: c-Jun N-terminal kinase; MAPK: mitogen-activated protein kinase; MHC: major histocompatibility complex.

MiR-let-7a/f-CCR7 signaling is involved in the anti-metastatic effects of an herbal formula comprising Sophorae Flos and Lonicerae Japonicae Flos in melanoma.

BACKGROUND: Metastasized melanoma is extremely difficult to treat. Activation of C-C chemokine receptor type 7 (CCR7) has been linked to melanoma metastasis. CCR7 can be directly regulated by miR-let-7. We have previously shown that an ethanolic extract of an herbal formula comprising Sophorae Flos and Lonicerae Japonicae Flos (SLE) inhibits melanoma cell migration and invasion. PURPOSE: In this study, we determined whether SLE suppresses melanoma metastasis, and whether regulation of miR-let-7a/f-CCR7 signaling is involved in the effect. STUDY DESIGN AND METHODS: Small RNA sequencing was conducted to compare miRNA expression profiles of B16F10 tumors dissected from SLE-treated or untreated mice. Western blot and RT-qPCR analyses were employed to examine protein and miRNA levels, respectively. A B16F10 melanoma lung metastasis mouse model was used to evaluate the effects of SLE on melanoma metastasis. MiR-let-7a/f-knockdown and CCR7-overexpression cell models were used to investigate the involvement of miR-let-7a/f-CCR7 signaling in the anti-metastatic effects of SLE. RESULTS: It was found that SLE upregulated levels of miR-let-7a/f in B16F10 melanoma tissues. SLE significantly elevated levels of miR-let-7a/f, lowered the protein level of CCR7, inhibited the phosphorylation of CCR7 downstream molecules p38 and JNK in B16F10 and A375 melanoma cells. SLE inhibited B16F10 melanoma lung metastasis in mice. SLE upregulated levels of miR-let-7a/f, and lowered protein levels of CCR7, MMP-2, MMP-9, phospho-p38 (Thr180/Tyr182) and phospho-JNK (Thr183/Tyr185) in melanoma-invaded lung tissues. Knockdown of miR-let-7a/f diminished the effects of SLE on CCR7 signaling in, and invasion of, melanoma cells. Overexpression of CCR7 lessened the effects of SLE in inhibiting the phosphorylation of p38 and JNK in, and the invasive capability of, melanoma cells. CONCLUSION: We for the first time demonstrated that SLE inhibits melanoma metastasis in mice, and that regulation of the miR-let-7a/f-CCR7 pathway contributes to the anti-metastatic mechanisms of SLE. These findings provide a pharmacological basis for developing SLE as a modern agent for treating metastatic melanoma. Additionally and importantly, this study suggests that regulating the miR-let-7a/f-CCR7 pathway is a novel strategy for controlling melanoma metastasis.

Structural Evaluation and Binding Mode Analysis of CCL19 and CCR7 Proteins-Identification of Novel Leads for Rheumatic and Autoimmune Diseases: An Insilico study.

The Human Chemokine (C-C motif) ligand 19 (CCL19) protein plays a major role in rheumatic and autoimmune diseases. The 3D models of the CCL19 and its receptor CCR7 are generated using homology modeling and are validated using standard computational protocols. Disulfide bridges identified in 3D model of CCL19 protein give extra stability to the overall protein structure. The active site region of protein CCL19, containing N-terminal amino acid residues (Gly22 to Leu31), is predicted using in silico techniques. Protein-protein docking studies are carried out between the CCL19 and CCR7 proteins to analyse the active site binding interactions of CCL19. The binding domain of CCL19 is subjected to structure-based virtual screening of small molecule databases, and identified several bioisosteric ligand molecules having pyrrolidone and piperidone pharmacophores. The prioritized ligands with acceptable ADME properties are reported as new leads for the design of potential CCL19 antagonists for rheumatic and autoimmune disease therapies.

[Effect of low-selenium diet on expressions of CCR7, CD206 and CD163 in the liver and kidney of rats].

OBJECTIVE: To investigate the effect of low-selenium diet on the liver and kidneys of rats and explore the role of macrophage polarization into M1 and M2 phenotypes in liver and kidney injuries. METHODS: Twenty-four rats (12 female and 12 male) were randomly divided into control group and low-selenium group and fed with normal chow (dietary selenium of 0.18 mg/kg) and low-selenium diet (dietary selenium of 0.02 mg/kg) for 109 days. After the feeding, the rats were sacrificed for HE staining to observe liver and kidney pathologies, and immunohistochemistry was performed for analyzing CCR7, CD206, CD163-positive cell numbers in the liver and kidneys. RESULTS: The rats in low-selenium group showed severer fibrosis in the liver and kidney than the control group. In either male or female rats in low-selenium group, CCR7 and CD206 expressions in the liver were comparable with those in control group, but CD163 expression was lower than that in the control group (P<0.05 for both female and male rats). In the kidney, the proximal tubule showed a slightly higher while the distal tubule showed a slightly lower CCR7 expression in low selenium group than in the control group (P>0.05). In low-selenium group, a significantly lower CD163 expression in the distal tubule and a significantly higher CD206 expression in the proximal tubule were noted as compared with the control group (P<0.05 in both female and male rats). Compared with the control rats, the male rats in low-selenium group, but not the female rats, showed a significantly lower CD163 expression in the proximal tubule of the kidney (P<0.05); the female but not the male rats in low-selenium group show a higher CD206 expression in the distal tubule (P<0.05). CONCLUSION: Low-selenium diet can cause liver and kidney fibrosis in rats and may inhibit macrophage activation into the M2 phenotype.

Baicalin attenuates inflammation in mice with OVA-induced asthma by inhibiting NF-κB and suppressing CCR7/CCL19/CCL21.

Baicalin, extracted and purified from the Chinese medicinal plant, Scutellaria baicalensis Georgi (Huang qin in Chinese), exhibits potent anti-inflammatory activity against asthma. However, it remains unknown whether baicalin inhibits the activity of CC chemokine receptor 7 (CCR7) and its ligands, which are crucial for the initiation of airway inflammation. In the present study, we investigated the effects of baicalin on CCR7 and its ligands, CCL19 and CCL21, as well as on the nuclear factor-κB (NF-κB) pathway in a mouse model of asthma. A mouse model of acute asthma was established by exposing the mice to ovalbumin (OVA) (by intraperitoneal injection and inhalational challenge). Within 24 h of the final OVA challenge, lung function was detected by direct airway resistance analysis. Lung tissues were examined for pathological changes. Inflammatory cell counts in bronchoalveolar lavage fluid (BALF) were assessed. ELISA was utilized to evaluate the OVA-IgE, CCL19 and CCL21 levels in BALF. The interleukin (IL)-6 and tumor necrosis factor (TNF)-α levels in serum were also detected by ELISA. The protein expression levels of CCR7, as well as that of phosphorylated IκBα (p-IκBα) and phosphorylated p65 (p-p65) were determined by western blot analysis and RT-qPCR was used to determine the CCR7 mRNA levels. Our data demonstrated that the oral administration of baicalin significantly improved pulmonary function and attenuated inflammatory cell infiltration into the lungs. Baicalin also decreased the levels of OVA-IgE, IL-6, TNF-α and CCR7, as well as those of its ligand, CCL19; the levels of NF-κB were also markedly suppressed by baicalin. The CCR7 mRNA level was substantially decreased. Our results thus suggest that baicalin exerts an inhibitory effect on airway inflammation, and this effect may be associated with the inhibition of CCR7 and CCL19/CCL21, which may provide new mechanistic insight into the anti­inflammatory effects of baicalin.

Ligustrazine attenuates inflammation and the associated chemokines and receptors in ovalbumine-induced mouse asthma model.

Ligustrazine which is isolated from Chinese herb ligusticum chuanxiong hort, has been widely used in traditional Chinese medicine (TCM) for asthma treatment. In this study, we aim to observe the effect of ligustrazine on inflammation and the associated chemokines and receptors in ovalbumin (OVA)-induced mouse asthma model. Our data demonstrates that ligustrazine suppresses airway hyperresponsiveness to methacholine and lung inflammation in OVA-induced mouse asthma model. Ligustrazine also induces inhibition of inflammatory cells including neutrophils, lymphocytes and eosinophils. In addition, ligustrazine significantly reduces IL-4, IL-5, IL-17A, CCL3, CCL19 and CCL21 level in BALF of asthma mice. Furthermore, ligustrazine induces down-regulation of CCL19 receptor CCR7, STAT3 and p38 MAPK protein expression. Collectively, these results suggest that ligustrazine is effective in attenuation of allergic airway inflammatory changes and related chemokines and receptors in OVA-induced asthma model, and this action might be associated with inhibition of STAT3 and p38 MAPK pathway, which indicates that ligustrazine may be used as a potential therapeutic method to treat asthma.

Role of Berberine on molecular markers involved in migration of esophageal cancer cells.

Berberine is an isoquinoline alkaloid found in several plant species like famous chinese herb, Rhizoma coptidis which has been used locally as a strong gastrointestinal remedy for thousands of years. The inhibitory effects of berberine on tumor progression properties have been reported before. In this study, we investigated the effect of berberine on an esophageal cancer cell line, KYSE-30 with emphasis on its effects on the expression of certain chemokine receptors. The cytotoxic effect of berberine on KYSE-30 cells was analyzed by MTT assay. In vitro cell migration assay was also applied to the treated cells and the expression levels of the selected chemokine receptors (CXCR4 and CCR7) was measured at mRNA level. A retarded growth, associated with increasing concentrations of berberine, was obvious. On the other hand, the migration rate of the cells was decreased when they were treated with different concentrations of berberine and the expression levels of the two chemokine receptors, involved in the migration and metastasis of esophageal cancer cells, were decreased following the same treatments. With these results, we tend to conclude that berberine might be a proper candidate for further investigations, by targeting the chemokine receptors, and possible applications as anti-metastatic agent in cancer studies.

Curcumin treatment suppresses CCR7 expression and the differentiation and migration of human circulating fibrocytes.

BACKGROUND/AIM: Recent studies have demonstrated that circulating fibrocytes contribute to the formation and development of fibrosis. Curcumin, a polyphenolic compound isolated from turmeric, has been shown to have anti-fibrotic effects in various organs. We and others have demonstrated that curcumin beneficially affects the development of fibrosis. However the effect of curcumin on circulating fibrocytes has not been reported. METHODS: Human circulating fibrocytes were isolated from leukocyte concentrates of healthy human donors and identified based on the expression of CD34, CD45, collagen I (COLI), and chemokine receptor CCR7 (CCR7) via flow cytometry. Cell Counting Kit-8 was used to evaluate cell viability. The effect of curcumin on the differentiation and migration of human circulating fibrocytes was evaluated by immunofluorescence staining, flow cytometry and a transwell migration assay. Transforming growth factor (TGF)-ß1 secretion was examined by ELISA. RESULTS: Curcumin treatment (72 h; 20 µM) significantly decreased the expression of COL I, α-SMA and CCR7, as well as TGF-ßl secretion, in human circulating fibrocytes. The inhibitory effect of curcumin on the differentiation and migration of human circulating fibrocytes is likely via regulating the CCR7/CCL21 signaling pathway, in particular by reducing CCR7 expression. These observed effects may be beneficial in resolving fibrosis by suppressing TGF-ß1 secretion. CONCLUSION: Our results suggest that curcumin has the potential to suppress the differentiation and migration of circulating fibrocytes, which would provide new explanation for curcumin's application in the development of fibrosis in various organs.

Effects of undenatured whey protein supplementation on CXCL12- and CCL21-mediated B and T cell chemotaxis in diabetic mice.

BACKGROUND: Long and persistent uncontrolled diabetes tends to degenerate the immune system and leads to an increased incidence of infection. Whey proteins (WPs) enhance immunity during early life and have a protective role in some immune disorders. In this study, the effects of camel WP on the chemotaxis of B and T cells to CXCL12 and CCL21 in diabetic mice were investigated. RESULTS: Flow cytometric analysis of the surface expressions of CXCR4 (CXCL12 receptor) and CCR7 (CCL21 receptor) on B and T cells revealed that the surface expressions of CXCR4 and CCR7 were not significantly altered in diabetic and WP-supplemented diabetic mice compared with control mice. Nevertheless, B and T lymphocytes from diabetic mice were found to be in a stunned state, with a marked and significant (P < 0.05) decrease in CXCL12- and CCL21-mediated actin polymerization and subsequently, a marked decrease in their chemotaxis. WP supplementation in the diabetes model was found to significantly increase CXCL12- and CCL21-mediated actin polymerization and chemotaxis in both B and T cells. CONCLUSION: Our data revealed the benefits of WP supplementation in enhancing cytoskeletal rearrangement and chemotaxis in B and T cells, and subsequently improving the immune response in diabetic mice.

Luminal CD4⁺ T cells penetrate gut epithelial monolayers and egress from lamina propria to blood circulation.

BACKGROUND & AIMS: The egress of memory T cells from peripheral tissues, such as lung and skin, into the draining lymph nodes requires their expression of CC chemokine receptor 7 (CCR7). In the intestine, resident memory T cells in the intestinal lamina propria (LP) do not express CCR7, indicating that they are tissue bound and do not exit the intestine. METHODS: We developed a cell transfer system, using rectal administration of lymphocytes to C57BL/6 mice. Lymphotoxin α-deficient mice were crossed with RAG-2(-/-) (recombination-activating gene-2) mice to generate lymphotoxin α-deficient × RAG-2(-/-) mice. RESULTS: Severe combined immunodeficient (SCID) or RAG-2(-/-) mice given rectal administration of splenic CD4(+) T cells from normal mice developed colitis; the cells proliferated not only in the LP but also in spleen. SCID or RAG-2(-/-) mice given rectal administrations of CD4(+) T cells that expressed green fluorescent protein (GFP(+)CD4(+) T cells) localized to the LP within 6 hours but were not found in the spleen until 24 hours after administration. Immunohistochemical and electron microscopic analyses detected CD4(+) T cells in the intraepithelial space just 3 hours after intrarectal administration. However, neither CCR7 deficiency nor the sphingosine-1-phosphate receptor agonist Fingolimod impaired the egress of CD4(+) T cells from LP to systemic circulation. CONCLUSIONS: CD4(+) T cells not only penetrate from the luminal side of the intestine to the LP but also actively egress from the LP into the circulation. We developed a rectal administration system that might be used to further investigate cell trafficking in intestinal mucosa and to develop enema-based therapeutics for intestinal diseases.

Bromelain treatment leads to maturation of monocyte-derived dendritic cells but cannot replace PGE2 in a cocktail of IL-1ß, IL-6, TNF-α and PGE2.

Immunotherapy using dendritic cells (DC) has shown promising results. However, the use of an appropriate DC population is critical for the outcome of this treatment, and the search for an optimal DC subset is still ongoing. The DC used in immunotherapy today are usually matured with a cytokine cocktail consisting of TNF-α, IL-1ß, IL-6 and PGE(2). These cells have deficits in their cytokine production, particularly IL-12p70, mainly because of the presence of PGE(2). Bromelain is a pineapple stem extract containing a mixture of proteases that has been used clinically in adjuvant cancer treatment. In this study, we analysed the effect of bromelain on human monocyte-derived DC. We added bromelain to the cytokine cocktail and modified cytokine cocktails with either no PGE(2) or reduced amounts of PGE(2), respectively. Combining bromelain with the cytokine cocktails containing PGE(2) resulted in an increased surface expression of CD83, CD80 and CD86. The chemokine receptor CCR7 was also considerably upregulated in these DC populations compared with DC treated with the cytokine cocktail alone. Removal or reduction of PGE(2) from the cytokine cocktail did not increase the IL-12p70 secretion from stimulated DC, and addition of bromelain to the different cytokine cocktails resulted in only a minor increase in IL-12p70 production. Moreover, combining bromelain with the cytokine cocktails did not improve the T cell stimulatory capacity of the generated DC populations. In conclusion, bromelain treatment of monocyte-derived DC does not improve the functional quality compared with the standard cytokine cocktail.

CCL19-induced chemokine receptor 7 activates the phosphoinositide-3 kinase-mediated invasive pathway through Cdc42 in metastatic squamous cell carcinoma of the head and neck.

Metastatic squamous cell carcinoma of the head and neck (SCCHN) has been shown to express chemokine receptor 7 (CCR7), which activates phosphoinositide-3 kinase (PI3K) to promote invasion and survival of SCCHN cells. We hypothesized that Cdc42 might be involved in the CCR7-PI3K pathway. Adhesion assays, migration assays, immunofluorescence staining, Western blotting and immunohistochemical analysis were used to find whether Cdc42 can be activated by CCL19 (the CCR7 ligand) and its role in SCCHN. Results showed that CCL19 induced polarized localization of Cdc42 and actin polymerization in the leading edge of migrating cells. The level of activated membrane-bound Cdc42 was elevated, as measured by the GTPase activity pull-down assay. The increased membrane localization and membrane-bound activity of Cdc42 were abolished by CCR7 and PI3K inhibition, indicating the involvement of Cdc42 in the CCR7-PI3K cascade. Knockdown of Cdc42 by small interfering RNA (siRNA) led to significant reduction in the activation of Rac, filamentous actin (F-actin) accumulation as well as in the migration and invasion induced by CCL19. Taken together, our data indicate the important role played by Cdc42 in CCL19-induced migration and invasion of SCCHN cells.

[Impact of secondary lymphoid tissue chemokine on lymphocyte migration and the significance thereof in pathogenesis of ulcerative colitis: experiment with rats].

OBJECTIVE: To explore the impact of secondary lymphoid tissue chemokine (SLC) on lymphocyte migration and the significance thereof in the pathogenesis of ulcerative colitis (UC). METHODS: Sixty SD rats were randomly divided into 3 equal groups: model group undergoing dripping of 40% acetone solution of dinitro-chlorobenzene (DNCB) on the back for 2 weeks and then enema of 6% DNCB acetone solution so as to establish models of UC, and then intravenous injection of normal saline (NS) for 5 days; SLC antibody intervention group undergoing intravenous injection of SLC antibody 15 microg x ml(-1) x kg(-1) immediately after the establishing of model; and control group undergoing enema of NS nly and then intravenous injection of NS for 5 days. Six days after the establishing of model venous blood samples were collected from the portal veins of the 3 groups. Lymphocytes were isolated and cultured. RT-PCR was used to detect the mRNA expression of the SLC receptor CCR7. Boyden chamber system was used to examine the migration ability of the lymphocytes exposed to SLC of 20, 40, 60, 80, and 100 ng/ml respectively. ELISA was used to detect the expression of interleukin (IL)-10 and interferon (IFN)-gamma in the supernatants of the lymphocytes of different groups. RESULTS: RT-PCR showed that the CCR7 mRNA expression level of the model group was (0.792 +/- 0.108), significantly higher than that of the intervention group (0.386 +/- 0.115, P = 0.0429), and the CCR7 mRNA expression levels of these 2 groups were both significantly higher than that of the control group (0.106 +/- 0.029, both P < 0.01). SLC dose-dependently promoted the migration ability of the lymphocytes, but there existed a saturation phenomenon. Exposed to 80 ng/ml SLC the migration level of the lymphocytes of the model group peaked to (85.9 +/- 16.0), 3.7 times as high as that of the control group (20.5 +/- 1.8, P < 0.01), and the migration level of the lymphocytes of the intervention group was 38.2 +/- 6.3, significantly higher than that of the control group too (P < 0.05). SLC enhanced the expression of IFN-gamma of the lymphocytes of the model group, while reduced the IL-10 level, and both effects peaked at the concentration of 80 ng/ml (P = 0.042, P = 0.036). CONCLUSION: SLC promotes the lymphocyte migration and boosts the differentiation of lymphocytes, thus participating in the pathogenesis of UC.

[Abnormal lymphocyte homing and colon lesions in ulcerative colitis: experiment with rats].

OBJECTIVE: To investigate the relationship between abnormal lymphocyte homing and colon lesions in ulcerative colitis. METHODS: 60 Sprague-Dawley rats were randomly divided into 3 equal groups: model group [undergoing enema of dinitrochlorobenzene to establish models of ulcerative colitis and then venous injection of normal saline (NS) once a day for 5 days], lymphocyte homing intervention group [undergoing venous injection of secondary lymphoid-tissue chemokine (SLC) antibody, and then venous injection of NS for 5 days], and control group [undergoing venous injection of NS for 5 days]. On the 6th day blood samples were collected from the portal vein to isolated lymphocytes. Distant colon was dissected to undergo pathological examination of submucosal aggregated lymphatic follicles, ulceration, and inflammation, thus observing the lymphocyte homing situation. Specimens of colon mucosa underwent detection cytokine of interleukin (IL)-2 and IL-6. RT-PCR was used to detect the mRNA expression of SLC gene and the chemokine receptor CCR7. The proportion of CCR7 positive lymphocytes which drainage from colonic vein were measured by flow cytometry (FC). RESULTS: Abnormal lymphocyte homing phenomenon under colonic mucosa was found in the model and intervention groups. The relative grey degree of SLC gene mRNA expression of the model and intervention groups were 0.85 +/- 0.05 and 0.77 +/- 0.14 respectively, both significantly higher than that of the control group (0.31 +/- 0.11, both P < 0.01), however, without significant difference between the 2 former groups. The relative grey degree of CCR7 mRNA expression of the model group was 0.79 +/- 0.11, significantly higher than that of the intervention groups (0.39 +/- 0.12, P = 0.0429), and both were significantly higher than that of the control group (0.11 +/- 0.03, both P < 0.01). FC showed that the proportion of CCR7(+) lymphocytes drainage from colonic vein of the model and the intervention groups were 69% +/- 5% and 77% +/- 10% respectively, both significantly higher than that of the control group (17% +/- 84%, both P < 0.01), however, without significant difference between these 2 former groups (P = 0.0837). CONCLUSION: Abnormal lymphocyte homing is associated with inflammation of the colonic mucosa. Blocking of the lymphocyte homing is effective in reducing the inflammation of colonic mucosa.