C-X-C and C-C chemokine expression and secretion by the human colonic epithelial cell line, HT-29: differential effect of T lymphocyte-derived cytokines

Differential chemokine production by colonic epithelial cells is thought to contribute to the characteristic increased infiltration of selected population of leukocytes cells in inflammatory bowel disease. We have previously demonstrated that IL-13 enhances IL-1alpha-induced IL-8 secretion by the colonic epithelial cell line HT-29. We have now explored the C-C chemokine expression and modulation in this system. The combination of TNF-alpha and IFN-gamma was the minimal stimulation required for regulated on activation, normal T cell expressed and secreted (RANTES) and monocyte chemoattractant protein (MCP-1) mRNA expression and secretion by HT-29 cells. The same stimulation induced a stronger IL-8 mRNA expression and secretion. Pretreatment with IL-13 or IL-4, reduced significantly the RANTES, and MCP-1, but not IL-8 mRNA expression and secretion. In contrast, IL-10 had no effect on either MCP-1, or RANTES, or IL-8 generation. Pretreatment of HT-29 cells with wortmannin suggested that the IL-13-induced inhibition of C-C chemokine expression is via activation of a wortmannin-sensitive phosphatidylinositol 3-kinase. These data demonstrate that colonic epithelial cell chemokine production can be differentially regulated by T cell-derived cytokines and suggest an interplay between epithelial cells and T lymphocytes potentially important in the intestinal inflammation.     

Suppression of human alveolar macrophage-derived cytokines by amiloride.

Various human alveolar macrophage (AM)-derived cytokines in the lungs have been shown to be present under conditions of normal homeostasis as well as during the pathogenesis of inflammation. Although extensive investigation has demonstrated the induction of cytokines from AM, relatively little is known regarding endogenous and exogenous regulation of their production. Several pharmacologic agents, including corticosteroids, cyclooxygenase inhibitors, prostaglandins, and methyl-xanthines have been examined for their role in the modulation of mononuclear phagocyte-derived cytokines. In this study, we examine the role of amiloride for the regulation of AM-derived interleukin (IL)-8, tumor necrosis factor (TNF), IL-6, and IL-1 beta. Amiloride in concentrations of 10(-4) to 10(-6) M, concentrations capable of being achieved in the distal airways via nebulization, were shown to inhibit lipopolysaccharide-stimulated, AM-derived IL-8 and TNF in both a time- and dose-dependent fashion. In addition, 5-(N,N-hexamethylene) amiloride hydrochloride, an amiloride analogue with specific sodium channel antiport inhibition, resulted in a similar dose-dependent suppression of lipopolysaccharide-stimulated, AM-derived IL-8 production. Furthermore, the suppressive effect of amiloride appeared to be at the level of mRNA for IL-8, TNF, IL-1 beta, and IL-6, whereas steady-state levels of beta-actin mRNA remained unaltered. These findings would suggest that amiloride has a potentially important modulating influence for the regulation of AM-derived cytokines.     

Differential induction of macrophage-derived cytokines by live and dead intracellular bacteria in vitro.

Marked differences in the abilities of living and heat-killed Brucella abortus and Listeria monocytogenes organisms to induce production of tumor necrosis factor alpha by in vitro-cultured macrophages were observed. Interleukin-1 and interleukin-6 appeared to be under different control. The results are discussed in relation to the induction of gamma interferon-producing Th1 cells and acquired cellular resistance to infection by living vaccines but not killed vaccines.     

C-C chemokines,but not the C-X-C chemokines interleukin-8 and interferon-γ inducible protein-10, stimulate transendothelial chemotaxis of T lymphocytes

Eight chemokines were tested for ability to elicit transendothelial chemotaxis of unstimulated peripheral blood T lymphocytes. The C-C chemokines monocyte chemotactic protein (MCP)-2, MCP-3, RANTES, macrophage inflammatory protein (MCP)-lα, MIP-1β, and, as previously described, MCP-1 induced significant, dose-dependent transendothelial chemotaxis of CD3⁺ T lymphocytes. In contrast, the C-X-C chemokines interleukin-8 (IL-8) and interferon-γ inducible protein-10 (IP-10) failed to induce transendothelial chemotaxis of CD3⁺ T lymphocytes or T lymphocyte subsets. RANTES, MIP-1α, and MIP-1β induced significant transendothelial chemotaxis of CD4⁺, CD8⁺, and CD45RO⁺ T lymphocyte subsets. Phenotyping of mononuclear cells that underwent transendothelial migration to MCP-2, MCP-3, RANTES, or MIP-1α showed both monocytes and activated (CD26 high), memory-type (CD45RO⁺) T cells. Both CD4⁺ and CD8⁺ T lymphocytes were recruited, but not natural killer cells or significant numbers of B cells. MCP-2 was the only C-C chemokine tested that attracted a significant number of naive-type (CD45RA⁺) T lymphocytes. In the absence of endothelium, IL-8 but not IP-10 promoted modest but significant chemotoxis of CD3⁺ T lymphocytes. Our data support the hypothesis that C-C, not the C-X-C chemokines IL-8 or IP-10, promote transendothelial chemotaxis of T lymphocytes.     

The effect of X4 and R5 HIV-1 on C, C-C, and C-X-C chemokines during the early stages of infection in human PBMCs

To better define a mechanism underlying the increase in expression of certain proinflammatory chemokines during HIV-1 infection, we analyzed the effect of X4 HIV-1 infection on C, C-C, and C-X-C chemokine mRNA levels. We demonstrate that X4 HIV-1 infection augments the expression of RANTES, IP-10, MCP-1, and Ltn in peripheral blood mononuclear cells (PBMCs). R5 HIV-1 also induces an increase in both IP-10 and MCP-1 production. Binding of UV-inactivated HIV-1 elevates MCP-1, RANTES, MIP-1alpha, MIP-1beta, and IL-8 expression, but fails to alter the production of IP-10, suggesting that the induction of IP-10 is dependent on downstream events following viral internalization. Indeed, recombinant gp120 alone was able to stimulate an eightfold increase in MCP-1 expression, but was unable to induce any detectable increase in IP-10 protein. HIV-induced modulation of chemokine expression suggests a mechanism by which HIV-infected monocytes and T cells might recruit target cells to sites of active viral replication, thus potentially aiding in the spread of the virus.     

Comprehensive analysis of chemokines and cytokines secreted in the peritoneal cavity during laparotomy

We recently found that chemokine-driven peritoneal cell aggregation is the primary mechanism of postoperative adhesion in a mouse model. To investigate this in humans, paired samples of peritoneal lavage fluid were obtained from seven patients immediately after incision (preoperative) and before closure (postoperative), and were assayed for the presence of 27 cytokines and chemokines using multiplex beads assay. As a result, IL-6 and CCL5 showed the most striking increase during operation. Recombinant CCL5 or lavage fluid induced chemotaxis of human peripheral blood mononuclear cells. We propose that CCL5 is possibly involved in the mechanism of postoperative adhesion in humans.     

In vitro activation of murine peritoneal macrophages by recombinant YopJ: production of nitric oxide, proinflammatory cytokines and chemokines

Recently it was reported that 3 μg/ml of recombinant YopJ induced apoptosis in murine peritoneal macrophages in vitro. However, in this study, we report the activation of murine peritoneal macrophages in vitro on treatment with sub-apoptotic dose of recombinant YopJ protein (1 μg/ml). The activation involves enhanced production of nitric oxide (NO), tumor necrosis factor-α (TNF-α), IL-12, and IL-6. Production of NO and IL-6 was found to peak at 24 h of rYopJ treatment, whereas IL-12 and IFN-γ production peaked at 18 h of rYopJ treatment. Increased mRNAs expression of nitric oxide, IL-12, IL-6 and IFN-γ molecules, was also observed in rYopJ-treated macrophages by RT-PCR. rYopJ induced the enhanced activity of protein tyrosine kinases which was inhibited by pharmacological inhibitor genestein, wortmanin and H-7 suggesting the role of tyrosine kinases, PI3K and PKC in the above process. rYopJ also induced increased enhanced production chemokines MIP-1α, MCP-1, and RANTES in macrophages. Significantly, increased expression of TLR-2, TLR-6, MyD 88 and IRAK-1 was also observed by immunoblotting in rYopJ-treated macrophages. rYopJ induced production of NO, TNF-α and IL-6 was significantly inhibited in macrophages pretreated with pharmacological inhibitor wortmanin, genestein and H-7 demonstrating the probable involvement of protein tyrosine kinases in the above process.     

Monocyte/macrophage-derived CC chemokines and their modulation by HIV-1 and cytokines: a complex network of interactions influencing viral replication and AIDS pathogenesis

Monocytes/macrophages are cells of the innate arm of the immune system and exert important regulatory effects on adaptive immune response. These cells also represent major targets of HIV infection and one of the main reservoirs. Notably, macrophage-tropic viruses are responsible for the initial infection, predominate in the asymptomatic phase, and persist throughout infection, even after the emergence of dual-tropic and T-tropic variants. Functional impairment of HIV-infected macrophages plays an important role in the immune dysregulation typical of AIDS. Recent studies have underlined the pivotal role of chemokines, cytokines, and their receptors in HIV pathogenesis. It is becoming increasingly apparent that the expression level of chemokine receptors, serving as HIV coreceptors, influences the susceptibility of a CD4+ cell to viral infection and to certain HIV envelope-induced alterations in cellular functions. Numerous pathogens, including HIV, can stimulate the production of chemokines and cytokines, which in turn can modulate coreceptor availability, resulting in differential replication potential for R5 and X4 strains, depending on the microenvironment milieu. Thus, a complex network of interactions involving immune mediators produced by monocytes/macrophages and other cell types as a direct/indirect consequence of HIV infection is operative at all stages of the disease and may profoundly influence the extent of viral replication, dissemination, and pathogenesis.     

CXC and CC chemokines induced in human renal epithelial cells by inflammatory cytokines

Human renal epithelial cells might play an important role during the allograft rejection by producing chemokines in response to proinflammatory cytokines such as tumor necrosis factor (TNF)‐α and interleukin (IL)‐1β produced by endothelial and epithelial cells early after transplantation. The production of chemokines allows inflammatory cells to be drawn into the kidney graft and therefore plays a critical role in the pathophysiologic processes that lead to the rejection of renal transplant. In this process, two chemokine superfamilies, the CC and the CXC chemokines, are the most important. The CC chemokines target mainly monocytes and T lymphocytes, while most of the CXC chemokines attract neutrophils. We showed in our study that in vitro, in unstimulated cells, basal mRNA expression of CXC chemokines (Groα, Groβ, Groγ, ENA‐78 and GCP‐2, IL‐8) that attract neutrophils was detectable and expression of these genes and chemokine release were increased in TNF‐α‐ and IL‐1β‐induced renal epithelial cells. Most of the CC chemokines [monocyte chemotactic protein‐1 (MCP‐1), macrophage Inflammatory protein 1 beta (MIP‐1β), regulated upon activation, normal T cell expressed and secreted (RANTES) and macrophage inflammatory protein (MIP‐3α)] showed detectable mRNA expression only after stimulation with proinflammatory cytokines and not in control cells. TNF‐α seems to induce preferably the expression of RANTES, MCP‐1, interferon‐inducible protein (IP‐10) and Interferon‐Inducible T‐cell Alpha Chemoattractant (I‐TAC), while IL‐1β induces mainly IL‐8 and epithelial neutrophil‐activating peptide 78 (ENA‐78).     

T cell-mediated signaling to vascular endothelium: induction of cytokines, chemokines, and tissue factor

Adhesion of leukocytes to the vascular endothelium is an early event in inflammation. Since cell-cell signaling may be an important stimulus for endothelial activation, we focused in this study on the role of contact-mediated activation by T lymphocytes of endothelial cells (EC). T lymphocytes were cultured with anti-CD3 monoclonal antibody or in the presence of a combination of TNF-alpha, interleukin (IL)-6, and IL-2, prior to fixation and coculture with human umbilical vein EC. Fixed, activated (anti-CD3- or cytokine-stimulated), but not unstimulated T cells, induced release of monocyte chemotactic protein-1, IL-8, and IL-6 by EC in a contact-dependent manner. Moreover, expression of tissue-factor antigen and activity was also significantly increased. Addition of anti-CD40 ligand antibody abolished T cell-induced activation of EC. Our data suggest that contact-mediated activation of EC by T cells, involving ligand:counter ligand interactions such as CD40:CD40 ligand, may represent a novel pathogenic mechanism of progression in inflammatory diseases such as atherosclerosis or rheumatoid arthritis.     

Induction of cytokines and chemokines in human monocytes by Mycoplasma fermentans-derived lipoprotein MALP-2

Bacterial infections are characterized by strong inflammatory reactions. The responsible mediators are often bacterially derived cell wall molecules, such as lipopolysaccharide or lipoteichoic acids, which typically stimulate monocytes and macrophages to release a wide variety of inflammatory cytokines and chemokines. Mycoplasmas, which lack a cell wall, may also stimulate monocytes very efficiently. This study was performed to identify mycoplasma-induced mediators. We investigated the induction of cytokines and chemokines in human monocytes exposed to the Mycoplasma fermentans-derived membrane component MALP-2 (macrophage-activating lipopeptide 2) by dose response and kinetic analysis. We found a rapid and strong MALP-2-inducible chemokine and cytokine gene expression which was followed by the release of chemokines and cytokines with peak levels after 12 to 20 h. MALP-2 induced the neutrophil-attracting CXC chemokines interleukin-8 (IL-8) and GRO-alpha as well as the mononuclear leukocyte-attracting CC chemokines MCP-1, MIP-1alpha, and MIP-1beta. Production of the proinflammatory cytokines tumor necrosis factor alpha and IL-6 started at the same time as chemokine release but required 10- to 100-fold-higher MALP-2 doses. The data show that the mycoplasma-derived lipopeptide MALP-2 represents a potent inducer of chemokines and cytokines which may, by the attraction and activation of neutrophils and mononuclear leukocytes, significantly contribute to the inflammatory response during mycoplasma infection.     

Expression patterns of cytokines and chemokines genes in human hepatoma cells

Various cytokines and chemokines play a role in carcinogenesis. However, no study has previously been undertaken to investigate comprehensively the expressions of cytokines and chemokines in hepatoma cells. In this study, we determined which cytokines and chemokines are expressed in hepatoma cells. Recently, it was reported that the expressions of several chemokines could be increased by Fas stimulus in many normal and cancer cells. Therefore, we also investigated whether chemokines expression is regulated by Fas ligation. To address this issue, we performed RNase protection assays upon 13 cytokines and 8 chemokines genes in 10 human hepatoma cell lines, comprising 8 hepatitis B virus (HBV)-associated hepatoma cell lines. Transforming growth factor-beta2 (TGF-beta2) was found to be expressed in 8 HBV-associated hepatoma cell lines, and to be potently expressed in 5 cell lines; however, the mRNA expressions of interleukin-10 (IL-10), IL-12, interferon-gamma(IFN-gamma) and tumor necrosis factor-alpha(TNF-alpha) were not detected in any cell lines examined. Among the chemokines investigated in this study, IL-8 was expressed by 8 HBV- associated hepatoma cell lines, and monocyte chemoattractant protein-1 (MCP-1) by 7 HBV-associated hepatoma cell lines. However, the mRNA expressions of macrophage inflammatory protein-1alpha(MIP-1alpha), MIP-1beta, interferon-inducible protein-10 (IP-10), RANTES, lymphotactin and I-309 were either very weak or undetectable. Fas ligation did not increase chemokines expression in hepatoma cells. Conclusively, TGF-beta2, IL-8 and MCP-1 were overexpressed in HBV-associated hepatoma cells, and the expressions of chemokines were not increased by Fas ligation in human hepatoma cells.     

NK细胞趋化因子和细胞因子的分泌与调节

Natural killer (NK) cells are the important members involved in innate immunity, which can kill virus-, intracellular bacteria-, and parasite-infected target ceils or tumor cells. NK cells can secrete cytokines/ chemokines as well, in order to mediate immune response and inflammation. However, its cytokine-secretion ability is related with the maturation of NK cells and is regulated by some factors, for example, P110δ. There-fore, more work should be done to elucidate the function and regulation of these factors, which have a signifi-cant influence on inflammation and tissue impairment in some diseases involving NK cells.     

NK细胞趋化因子和细胞因子的分泌与调节

Natural killer (NK) cells are the important members involved in innate immunity, which can kill virus-, intracellular bacteria-, and parasite-infected target ceils or tumor cells. NK cells can secrete cytokines/ chemokines as well, in order to mediate immune response and inflammation. However, its cytokine-secretion ability is related with the maturation of NK cells and is regulated by some factors, for example, P110δ. There-fore, more work should be done to elucidate the function and regulation of these factors, which have a signifi-cant influence on inflammation and tissue impairment in some diseases involving NK cells.     

Secretion of cytokines and chemokines by polarized human epithelial cells from the female reproductive tract

BACKGROUND: Pro-inflammatory chemokines that attract and cytokines that activate immune cells contribute to normal physiological homeostasis in the female reproductive tract, and are needed to deal effectively with potential pathogenic microbes. Mucosal epithelial cells are capable of producing these factors that communicate with cells of the innate and adaptive immune systems. METHODS: Epithelial cells from Fallopian tube, endometrium and endocervix were isolated and grown to high transepithelial resistance in cell inserts from seven patients who had hysterectomies. Interleukin (IL)-8, IL-6, granulocyte colony-stimulating factor (G-CSF), monocyte chemoattractant protein-1 (MCP-1), granulocyte-macrophage colony-stimulating factor (GM-CSF), tumour necrosis factor-alpha (TNF-alpha) and macrophage inflammatory peptide-1beta (MIP-1beta) were assessed by Luminex bead analysis or enzyme-linked immunosorbent assay (ELISA) in epithelial cell conditioned media from the apical and basolateral compartments. RESULTS: With the exception of MCP-1, the seven chemokines/cytokines constitutively produced by the polarized epithelial cells were preferentially secreted apically. A concentration pattern was found in all cases, with IL-8 and IL-6 produced in the greatest quantity. CONCLUSIONS: The concentrations of IL-8, IL-6, G-CSF and MCP-1 are similar to the levels found in reproductive tract fluids of patients with infection. The constitutive secretion and compartmentalization of large quantities of bioactive chemokines and cytokines provide additional evidence for the role of epithelial cells as gatekeepers of innate immune protection in the female reproductive tract.     

NK细胞趋化因子和细胞因子的分泌与调节

Natural killer (NK) cells are the important members involved in innate immunity, which can kill virus-, intracellular bacteria-, and parasite-infected target ceils or tumor cells. NK cells can secrete cytokines/ chemokines as well, in order to mediate immune response and inflammation. However, its cytokine-secretion ability is related with the maturation of NK cells and is regulated by some factors, for example, P110δ. There-fore, more work should be done to elucidate the function and regulation of these factors, which have a signifi-cant influence on inflammation and tissue impairment in some diseases involving NK cells.     

NK细胞趋化因子和细胞因子的分泌与调节

Natural killer (NK) cells are the important members involved in innate immunity, which can kill virus-, intracellular bacteria-, and parasite-infected target ceils or tumor cells. NK cells can secrete cytokines/ chemokines as well, in order to mediate immune response and inflammation. However, its cytokine-secretion ability is related with the maturation of NK cells and is regulated by some factors, for example, P110δ. There-fore, more work should be done to elucidate the function and regulation of these factors, which have a signifi-cant influence on inflammation and tissue impairment in some diseases involving NK cells.     

NK细胞趋化因子和细胞因子的分泌与调节

Natural killer (NK) cells are the important members involved in innate immunity, which can kill virus-, intracellular bacteria-, and parasite-infected target ceils or tumor cells. NK cells can secrete cytokines/ chemokines as well, in order to mediate immune response and inflammation. However, its cytokine-secretion ability is related with the maturation of NK cells and is regulated by some factors, for example, P110δ. There-fore, more work should be done to elucidate the function and regulation of these factors, which have a signifi-cant influence on inflammation and tissue impairment in some diseases involving NK cells.