• Title/Summary/Keyword: CCR7 ligand

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CCR7 Ligands Induced Expansion of Memory CD4+ T Cells and Protection from Viral Infection (CCR7 Ligand의 Memory CD4+ T 세포 증가유도 및 바이러스 감염에 대한 방어효과)

  • Eo, Seong-Kug;Cho, Jeong-Gon
    • IMMUNE NETWORK
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    • v.3 no.1
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    • pp.29-37
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    • 2003
  • 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 $L^{low}$) 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.

Ets-1 enhances tumor migration through regulation of CCR7 expression

  • Fang, Li-Wen;Kao, Ying-Hsien;Chuang, Ya-Ting;Huang, Huey-Lan;Tai, Tzong-Shyuan
    • BMB Reports
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    • v.52 no.9
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    • pp.548-553
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    • 2019
  • Ets-1 is a prototype of the ETS protein family. Members of the ETS protein family contain a unique ETS domain. Ets-1 is associated with cancer progression and metastasis in many types of cancer. Many studies have shown a link between elevated expression of Ets-1 in cancer biopsies and poor survival. CCR7 is a chemokine that binds to specific ligand CCL21/CCL19. CCR7 expression is associated with tumor metastasis and infiltration into lymph nodes. The objective of this study was to test whether Ets-1 could regulate CCR7 expression and enhance tumor metastasis. Our data showed that CCR7 expression was downregulated in Ets-1-deficient T cells upon T-cell stimulation. Overexpression of Ets-1 increased CCR7 expression in breast cancer cell lines. In contrast, knockdown of Ets-1 reduced CCR7 expression. Ets-1 could directly bind to CCR7 promoter and mediate CCR7 expression in luciferase reporter assays and chromatin immunoprecipitation assays. Transactivation activity of Ets-1 was independent of the Pointed domain of Ets-1. Ets-1 could also enhance $NF-{\kappa}B$ and CBP transactivation of CCR7 promoter. Our results also showed that Ets-1 could modulate cancer cell transmigration by altering CCR7 expression in transwell assay and wound healing assay. Taken together, our data suggest that Ets-1 can enhance CCR7 expression and contribute to tumor cell migration.

DA-6034 ameliorates hepatic steatosis and inflammation in high fat diet-induced obese mice

  • Hong Min Kim;Mi-Hye Kwon;Eun Soo Lee;Kyung Bong Ha;Choon Hee Chung
    • Journal of Yeungnam Medical Science
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    • v.41 no.2
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    • pp.103-112
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    • 2024
  • Background: Nonalcoholic fatty liver disease (NAFLD) is characterized by an increase in hepatic triglyceride content and increased inflammatory macrophage infiltration through the C-C motif chemokine receptor (CCR) 5 pathway in the liver. DA-6034 (7-carboxymethyloxy-3',4',5-trimethoxy flavone), is a synthetic derivative of eupatilin that exhibits anti-inflammatory activity in inflammatory bowel disease. However, the effect of DA-6034 on the inflammatory response in NAFLD is not well elucidated. Therefore, we aimed to determine the effect of DA-6034 on hepatic steatosis and inflammation. Methods: Forty male C57BL/6J mice were divided into the following four groups: (1) regular diet (RD), (2) RD with DA-6034, (3) high fat diet (HFD), and (4) HFD with DA-6034. All mice were sacrificed 12 weeks after the start of the experiment. The effects of DA-6034 on macrophages were assessed using RAW 264.7 cells. Results: DA-6034 not only reduced hepatic triglyceride levels and lipid accumulation but also macrophage infiltration and proinflammatory cytokines in HFD-fed mice. According to fluorescence-activated cell sorter analysis, DA-6034 reduced the CD8+ T cell fraction in the liver of HFD-fed mice. DA-6034 also reduced CCR5 expression and the migration of liver macrophages in HFD-fed mice and inhibited CCR2 ligand and CCR4 ligand, which stimulated the migration of macrophages. Conclusion: Overall, DA-6034 attenuates hepatic steatosis and inflammation in obesity by regulating CCR5 expression in macrophages.

High Frequencies of the CCR2b-64I and SDF1-3'A Mutations with HIV Infection in Koreans

  • Choi, Byeong-Sun;Cha, Seung-Hun;Kim, Sung Soon;Park, Yong-Keun;Lee, Joo-Shil
    • IMMUNE NETWORK
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    • v.2 no.2
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    • pp.86-90
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    • 2002
  • Background: Host genetic polymorphisms in the HIV-1 co-receptor CCR5 and CCR2b and SDF-1, ligand for co-receptor CXCR4, have been known to be associated with the resistance of HIV infection and/or the delayed disease progression in HIV-infected patients. Methods: We examined the frequencies of SDF1-3'A and CCR2b-64I alleles of 354 Koreans including 100 HIV-uninfected persons, 13 discordant spouses of HIV-infected persons, and 241 HIV-infected persons. The genotyping assays of SDF1 and CCR2b genes were carried out by polymerase chain reaction-restriction fragment length polymorphism. Results: The frequencies of CCR2b-64I and SDF1-3'A alleles in Koreans were very high compared with Caucasians and blacks. Observed frequencies of CCR2b-64I and SDF1-3'A allelic variants were 25.1% and 28.7%, respectively. The frequency of the CCR2b-64I allele in Koreans was 2~4 times higher than those of other ethnic groups with the exception of Asian. The frequencies of CCR2b-64I and SDF1-3'A genotypes did not show the significant difference between HIV-infected and uninfected Koreans. However, the prevalence of CCR2b-64I genotype of the LTNP group was about two times higher than that of the remainder group (P< 0.05). Four (45%) out of 9 LTNPs (long-term nonprogressors) showed having the SDF1-3'A allele and 7 (78%) out of 9 LTNPs carried the CCR2b-64I allele. 3 (33%) out of 9 LTNPs had both SDF1-3'A and CCR2b-64I alleles. But none of 5 RPs (rapid progressors) appeared to have both SDF1-3'A and CCR2b-64I alleles. Conclusion: The different genetic backgrounds in study populations may affect the disease progression and the AIDS epidemic in each country. Further studies need to define whether high frequencies of CCR2b-64I and SDF1-3'A allelic variants may affect the HIV disease progression.

Glucocorticoids Impair the 7α-Hydroxycholesterol-Enhanced Innate Immune Response

  • Yonghae Son;Bo-Young Kim;Miran Kim;Jaesung Kim;Ryuk Jun Kwon;Koanhoi Kim
    • IMMUNE NETWORK
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    • v.23 no.5
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    • pp.40.1-40.14
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    • 2023
  • Glucocorticoids suppress the vascular inflammation that occurs under hypercholesterolemia, as demonstrated in an animal model fed a high-cholesterol diet. However, the molecular mechanisms underlying these beneficial effects remain poorly understood. Because cholesterol is oxidized to form cholesterol oxides (oxysterols) that are capable of inducing inflammation, we investigated whether glucocorticoids affect the immune responses evoked by 7α-hydroxycholesterol (7αOHChol). The treatment of human THP-1 monocytic cells with dexamethasone (Dex) and prednisolone (Pdn) downregulated the expression of pattern recognition receptors (PRRs), such as TLR6 and CD14, and diminished 7αOHChol-enhanced response to FSL-1, a TLR2/6 ligand, and lipopolysaccharide, which interacts with CD14 to initiate immune responses, as determined by the reduced secretion of IL-23 and CCL2, respectively. Glucocorticoids weakened the 7αOHChol-induced production of CCL2 and CCR5 ligands, which was accompanied by decreased migration of monocytic cells and CCR5-expressing Jurkat T cells. Treatment with Dex or Pdn also reduced the phosphorylation of the Akt-1 Src, ERK1/2, and p65 subunits. These results indicate that both Dex and Pdn impair the expression of PRRs and their downstream products, chemokine production, and phosphorylation of signaling molecules. Collectively, glucocorticoids suppress the innate immune response and activation of monocytic cells to an inflammatory phenotype enhanced or induced by 7αOHChol, which may contribute to the anti-inflammatory effects in hypercholesterolemic conditions.

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Ligand Based CoMFA, CoMSIA and HQSAR Analysis of CCR5 Antagonists

  • Gadhe, Changdev G.;Lee, Sung-Haeng;Madhavan, Thirumurthy;Kothandan, Gugan;Choi, Du-Bok;Cho, Seung-Joo
    • Bulletin of the Korean Chemical Society
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    • v.31 no.10
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    • pp.2761-2770
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    • 2010
  • In this study, we have developed QSAR models for a series of 38 piperidine-4-carboxamide CCR5 antagonists using CoMFA, CoMSIA and HQSAR methods. Developed models showed good statistics in terms of $q^2$ and $r^2$ values. Best predictions obtained with standard CoMFA model ($r^2$ = 0.888, $q^2$ = 0.651) and combined CoMSIA model ($r^2$ = 0.892, $q^2$ = 0.665) with electrostatics and H-bond acceptor parameter. The validity of developed models was assessed by test set of 9 compounds, which showed good predictive correlation coefficient for CoMFA (0.804) and CoMSIA (0.844). Bootstrapped analysis showed statistically significant and robust CoMFA (0.968) and CoMSIA (0.936) models. Best HQSAR model was obtained with a $q^2$ of 0.662 and $r^2$ of 0.936 using atom, connection, hydrogen, donor and acceptor as parameters and fragment size (7-10) with optimum number of 6 components. Predictive power of developed HQSAR model was proved by test set and it was found to be 0.728.

Anti-inflammatory effect of sulforaphane on LPS-stimulated RAW 264.7 cells and ob/ob mice

  • Ranaweera, Sachithra S.;Dissanayake, Chanuri Y.;Natraj, Premkumar;Lee, Young Jae;Han, Chang-Hoon
    • Journal of Veterinary Science
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    • v.21 no.6
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    • pp.91.1-91.15
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    • 2020
  • Background: Sulforaphane (SFN) is an isothiocyanate compound present in cruciferous vegetables. Although the anti-inflammatory effects of SFN have been reported, the precise mechanism related to the inflammatory genes is poorly understood. Objectives: This study examined the relationship between the anti-inflammatory effects of SFN and the differential gene expression pattern in SFN treated ob/ob mice. Methods: Nitric oxide (NO) level was measured using a Griess assay. The inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression levels were analyzed by Western blot analysis. Pro-inflammatory cytokines (tumor necrosis factor [TNF]-α, interleukin [IL]-1β, and IL-6) were measured by enzyme-linked immunosorbent assay (ELISA). RNA sequencing analysis was performed to evaluate the differential gene expression in the liver of ob/ob mice. Results: The SFN treatment significantly attenuated the iNOS and COX-2 expression levels and inhibited NO, TNF-α, IL-1β, and IL-6 production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. RNA sequencing analysis showed that the expression levels of 28 genes related to inflammation were up-regulated (> 2-fold), and six genes were down-regulated (< 0.6-fold) in the control ob/ob mice compared to normal mice. In contrast, the gene expression levels were restored to the normal level by SFN. The protein-protein interaction (PPI) network showed that chemokine ligand (Cxcl14, Ccl1, Ccl3, Ccl4, Ccl17) and chemokine receptor (Ccr3, Cxcr1, Ccr10) were located in close proximity and formed a "functional cluster" in the middle of the network. Conclusions: The overall results suggest that SFN has a potent anti-inflammatory effect by normalizing the expression levels of the genes related to inflammation that were perturbed in ob/ob mice.