Cytokines in rheumatoid arthritis.
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Arthritis, Rheumatoid↗
Biomedical subjects
R M Strieter
Publications and source records attributed to R M Strieter.
Interferon gamma modulates the expression of neutrophil-derived chemokines.
Specific cell recruitment to a site of acute inflammation is a crucial event characterized by the elicitation of mainly polymorphonuclear neutrophils (PMNs). Recently, it has been reported that PMNs can express and secrete chemotactic cytokines or chemokines, including IL-8, MIP-1 alpha, and MIP-1 beta. Moreover, PMN-derived chemokines are regulated by various soluble mediators, such as dexamethasone, prostaglandin E, classic chemoattractant factors (e.g., fMLP, C5a, leukotriene B4), IL-4, and IL-10. In this article we demonstrate that PMNs treated with IFN-gamma, a Th1-derived cytokine, can inhibit early mRNA expression for MIP-1 alpha, MIP-1 beta, and IL-8 (up to 8 hours post IFN-gamma addition), while augmenting their production at 24 hours post IFN-gamma addition. Furthermore, our studies demonstrate that one of the mechanisms for the activity of IFN-gamma in this system is via the autocrine activity of TNF-alpha. These data imply that PMN-derived chemokines are regulated by not only proinflammatory cytokines, including IL-1 beta and TNF-alpha, but also Th1- and Th2-derived cytokines, including IL-4, IL-10, and IFN-gamma. The role of these cytokine networks in regulating PMN-derived chemokines may play an important role in leukocyte elicitation during the initiation and maintenance of an inflammatory response.
Cells, Cultured↗
Monocyte chemotactic protein expression during schistosome egg granuloma formation. Sequence of production, localization, contribution, and regulation.
The present study explored the role of murine monocyte chemotactic protein (MCP) in the T cell-mediated hypersensitive granulomatous response to Schistosoma mansoni eggs. The study examined the time course of local production, contribution to cellular infiltration, and the role of T cells in endogenous regulation. Synchronized pulmonary granulomas were induced under conditions of primary and secondary states of immunity. Primer-directed polymerase chain reaction analysis showed increased MCP mRNA expression in granulomatous lungs, mainly in the secondary response. Levels of MCP were measured by enzyme-linked immunosorbent assay in cultures of intact granulomas. Spontaneous MCP production was modest in primary granuloma cultures, reaching a maximum of 5.7 +/- 0.9 ng/ml by 16 days. In contrast, the secondary response showed augmented and accelerated production, achieving 13 +/- 2.0 ng/ml by 2 days. Immunohistochemical staining revealed the strongest MCP expression within microvascular adventitial cells or pericytes as well as in scattered mononuclear cells associated with granulomas. Staining was not detected in normal lungs. Passive immunization with anti-MCP-1 antibodies caused a 40% reduction in the secondary granuloma area but did not significantly affect the primary response. With adoptive cell transfer and T cell subset depletion, it was shown that Thy-1+ and CD5+ cells augmented, whereas CD8+ cells appeared to impair, MCP production. This provides direct evidence that MCP is involved in secondary Th2-mediated response to schistosome eggs and is subject to regulation by T cells.
Animals↗
Severe combined immunodeficiency mouse and human psoriatic skin chimeras. Validation of a new animal model.
Research into the cause and pathophysiological mechanisms underlying expression of psoriatric skin lesions has been hampered by lack of an appropriate animal model for this common and enigmatic cutaneous disease. These studies characterize normal skin, pre-psoriatic skin, and psoriatic plaque skin samples transplanted onto severe combined immunodeficiency mice. In this report we document that 1), normal, prepsoriatic, and psoriatic plaque keratome skin samples can be transplanted onto severe combined immunodeficiency mice reliably with high rates of graft survival (> 85%) and with reproducible changes consistently observed over prolonged periods of engraftment; 2), after transplantation, by clinical assessment and routine light microscopy, normal skin remained essentially normal whereas pre-psoriatic skin became thicker, and psoriatic plaque skin retained its characteristic plaque-type elevation and scale; 3), by using a panel of antibodies and immunohistochemical analysis, the overall phenotype of human cell types (including immunocytes) that persisted in the transplanted skin was remarkably similar to the immunophenotype of pretransplanted skin samples; 4), clearly recognized interface zones between human and murine skin within the epidermal and dermal compartments could be identified by routine microscopy and immunostaining, with focal areas of chimerism; and 5), elevated interleukin 8 cytokine levels were present in transplanted pre-psoriatic and psoriatic plaque skin samples. We conclude that there are many similarities between pre- and post-transplanted human samples of normal and psoriatic skin that are grafted onto severe combined immunodeficiency mice. Thus, we propose that this new animal model is appropriate for additional mechanistic-type studies designed to reveal the underlying genetic/etiological abnormality, as well as better illuminate the pathophysiological basis, for this important skin disease.
Animals↗
Interleukin 12: a potential link between nerve cells and the immune response in inflammatory disorders.
BACKGROUND: The nervous system has been implicated in several inflammatory skin disorders based on evidence such as the role of stress in inducing lesions, symmetry of lesions, and sparing of denervated skin. Interleukin 12 (IL-12) is a cytokine recently shown to promote cellular immune responses characterized by delayed-type hypersensitivity and production of the TH1-lymphokine, interferon-gamma. MATERIALS AND METHODS: Using immunohistochemistry, IL-12 immunoreactivity was identified in cryostat sections of normal and diseased human skin samples, and in the peripheral and central nervous system of rodents and human tissue samples. IL-12 p35 and p40 mRNAs were detected using reverse transcriptase-polymerase chain reaction in tissue samples and cultured cells. IL-12 protein levels were also examined by ELISA and quantitative bioassay utilizing an IL-12-dependent cell line. RESULTS: By immunostaining IL-12 was detected in free nerve ending in the epidermis of normal and diseased skin samples, and also in the dermal nerve fibers. Strong reactivity was detected in axonal processes and in various glial cell types. In addition, IL-12 protein and mRNA were contained within cutaneous peripheral nerves and spinal cord tissues, and functional levels of IL-12 were produced by cultured Schwann cells. CONCLUSIONS: It is likely that IL-12 is important in initiating or propagating selected inflammatory skin lesions and in determining the pattern of disease that will develop. The presence of IL-12 in neural tissue suggests a mechanism whereby the nervous system can modify or amplify cutaneous and perhaps other immune responses.
Animals↗
Production and function of murine macrophage inflammatory protein-1 alpha in bleomycin-induced lung injury.
We investigated the role of macrophage inflammatory protein-1 alpha (MIP-1 alpha) in bleomycin-induced lung injury, a model of interstitial lung disease. Bleomycin stimulates a T cell-dependent pulmonary inflammatory response characterized by an increase in leukocyte infiltration, fibroblast proliferation, and collagen synthesis. Intratracheal challenge of CBA/J mice with bleomycin resulted in a significant time-dependent increase in MIP-1 alpha protein levels both in whole-lung homogenates and bronchoalveolar lavage fluid. The kinetics of MIP-1 alpha expression were biphasic, with the first peak occurring at 2 days postinstillation and the second peak at 16 days. These levels of Ag expression temporally correlated with the accumulation of granulocytes, lymphocytes, and mononuclear phagocytes in the lung. In addition, immunohistochemical staining identified alveolar macrophages and bronchial epithelial cells as the primary cellular sources of MIP-1 alpha production. Interestingly, passive immunization of bleomycin-challenged mice with anti-MIP-1 alpha Abs significantly reduced pulmonary mononuclear phagocyte accumulation and fibrosis. These experiments establish that MIP-1 alpha protein is expressed in the lungs of bleomycin-treated mice and provide evidence that MIP-1 alpha promotes leukocyte accumulation and activation. Furthermore, these findings support the notion that leukocyte accumulation and activation are linked to fibrosis.
Animals↗
The role of interleukin-8 in the infectious process.
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Animals↗
Inflammatory granuloma formation is mediated by TNF-alpha-inducible intercellular adhesion molecule-1.
Recent studies have demonstrated a crucial role for TNF during inflammatory granuloma formation. In addition, TNF has been shown to up-regulate adhesion molecules that participate in cellular recruitment and lymphocyte activation. In the present study, we have examined the mechanism of TNF activation during Schistosoma mansoni egg granuloma formation and its relationship to the expression of ICAM-1. Our initial studies showed that high affinity human soluble TNFR coupled to the Fc portion of an Ig (sTNFR:Fc construct) could effectively diminish granuloma formation and lymphocyte activation in vivo. We have also assessed the increased expression of ICAM-1, its contribution to granuloma development, and its relationship with TNF during lesion formation. Increased steady state ICAM-1 mRNA expression was observed in primary egg granulomas when compared with normal lung and foreign body (Sephadex bead) granulomas, which suggests a role for ICAM-1 in Ag-induced lesion formation. Subsequent studies have demonstrated that sTNFR:Fc treatment down-regulated granuloma formation and ICAM-1 expression, thus suggesting one mechanism of TNF involvement in granuloma formation was through the induction of ICAM-1. Anti-ICAM-1 decreased the soluble egg Ag-specific T cell proliferation in vitro. In addition, passive immunization of mice with anti-ICAM-1 mAb during primary granuloma formation resulted in an attenuation of lesion development as compared with lesion development in a control Ab-treated group. The proliferative response to soluble egg Ag was also significantly reduced in ex vivo experiments that used spleen cells from the anti-ICAM-1 treated mice. These data demonstrate that both TNF and ICAM-1 participate in lymphocyte activation and granuloma formation and suggest that one mechanism of TNF in granuloma development is through TNF-induced ICAM-1 expression.
Animals↗
Inhibition of interleukin 8 attenuates angiogenesis in bronchogenic carcinoma.
We investigated the role of interleukin 8 (IL-8) in mediating angiogenesis in human bronchogenic carcinoma. Increased quantities of IL-8 were detected in tumor tissue as compared with normal lung tissue. Immunohistochemical staining of tumors revealed primary localization of IL-8 to individual tumor cells and demonstrated the capacity of tumor to elaborate IL-8. Functional studies that used tissue homogenates of tumors demonstrated the induction of both in vitro endothelial cell chemotaxis and in vivo corneal neovascularization. It is important to note that the addition of neutralizing antisera to IL-8 to these assays resulted in the marked and specific attenuation of these responses. Our observations definitively establish IL-8 as a primary mediator of angiogenesis in bronchogenic carcinoma and offer a potential target for immunotherapies against solid malignancies.
Animals↗
Regulation of neutrophil-derived chemokine expression by IL-10.
In this study, we examined IL-10 regulation of polymorphonuclear leukocyte (PMN)-derived chemokine expression. Studies demonstrated that IL-10 dose dependently suppressed the expression and production of PMN-derived macrophage inflammatory protein-1 alpha (MIP-1 alpha), MIP-1 beta, IL-8 mRNA, and protein. Although inhibition of protein synthesis was found to superinduce the expression of PMN-derived chemokine steady-state mRNA, the inhibitory activity of IL-10 was completely abrogated in the presence of either cycloheximide or puromycin. These data suggest that the effect of IL-10 on PMN-derived chemokine expression was through the production of de novo repressor protein(s). Next, we examined the half-life (t1/2) of chemokine mRNA by LPS-treated PMNs in the presence or absence of IL-10. The t1/2 of MIP-1 alpha, MIP-1 beta, and IL-8 mRNA from PMNs treated for 4 h with LPS before actinomycin-D (Ac-D) addition were approximately 40 min, 1.7 h, and 2 h, respectively, whereas the t1/2 from PMNs stimulated for 8 h before Ac-D were 2, 2, and > 9 h, respectively. Interestingly, IL-10 significantly accelerated the decay of all three of the above chemokine mRNA. The t1/2 of MIP-1 alpha, MIP-1 beta, and IL-8 mRNA from PMNs treated with LPS plus IL-10 compared with LPS alone was reduced by 62, 50, and 40%, respectively, at the 4-h time point and by 50, 25, and 70%, respectively, at the 8-h time point. These findings support the notion that PMNs are an important cellular source of both C-X-C and C-C chemokines, and that IL-10 regulates both inflammatory/immune responses by not only modulating the activities of T cell, B cell, and mononuclear phagocyte function, but also by inhibiting PMN-derived chemokine expression.
Base Sequence↗
Intercellular adhesion molecule-1 mediates the expression of monocyte-derived MIP-1 alpha during monocyte-endothelial cell interactions.
The extravasation of leukocytes from the lumen of the vessel to a site of inflammation initially requires a specific binding event followed by migration of the cells through the endothelial cell layer into the inflammatory foci. The interaction of leukocytes with the endothelium via specific receptors may provide intracellular signals that activate the cells. In the present study we have investigated the production of MIP-1 alpha, a mononuclear cell chemotactic protein, during monocyte:endothelial cell interactions. Neither unstimulated nor interferon (IFN)-stimulated human umbilical vein endothelial cells (HUVECs) produced substantial MIP-1 alpha protein. However, the addition of enriched monocyte populations with unstimulated HUVECs resulted in the production of MIP-1 alpha. Monocytes cultured with IFN-gamma-activated HUVECs showed an additional increase in MIP-1 alpha production. Immunohistochemical analysis demonstrated that the monocyte was the cellular source of MIP-1 alpha production in this coculture system. The mechanism of MIP-1 alpha expression was further assessed by determining the role of adhesion molecules in the regulation of MIP-1 alpha production during monocyte:HUVEC interactions. To attenuate the increased production of MIP-1 alpha by the monocyte:HUVEC interaction, anti-adhesion molecule monoclonal antibodies (MoAbs) were added to the cultures. Addition of anti-ICAM-1 neutralizing MoAbs significantly inhibited the production of MIP-1 alpha, whereas neutralizing anti-VCAM-1 MoAbs failed to block MIP-1 alpha production. Furthermore, MIP-1 alpha production was induced in monocytes cultured on ICAM-1-coated plates. These results indicate an intimate relationship between leukocyte-endothelial cells, adhesion molecule, and the expression of the monocyte-derived chemokine MIP-1 alpha during cellular adhesion. This mechanism may serve an important role in cell activation and recruitment of leukocytes during the initiation of an inflammatory response.
Antibodies, Monoclonal↗
Production of IL-8 and monocyte chemotactic peptide-1 by peripheral blood monocytes. Disparate responses to phytohemagglutinin and lipopolysaccharide.
The temporal recruitment of leukocytes to a site of inflammation is dependent on a complex interplay of a number of soluble mediators. Recently, two families of chemotactic cytokines have been discovered. The -C-X-C-family, which includes IL-8, appears to recruit neutrophils and lymphocytes. In contrast, the -C-C-family, which includes monocyte chemotactic peptide-1 (MCP-1), appears to recruit predominantly monocytes. Monocytes, after their arrival at a site of inflammation, could further amplify the immune response by secreting IL-8 and MCP-1. We sought to define conditions under which human peripheral blood monocytes produce IL-8 and MCP-1. Using serum-free media, we found that PHA-stimulated monocytes expressed MCP-1 and IL-8 protein and mRNA in a dose-dependent manner. However, the onset of mRNA expression for MCP-1 occurred at least 3 h later than did the onset of IL-8 mRNA expression. IL-8 and MCP-1 gene expression by monocytes appeared to require de novo protein synthesis, in that cycloheximide blocked the expression of mRNA for both IL-8 and MCP-1 in PHA-stimulated cells. However, treatment of monocytes with cycloheximide resulted in the superinduction of IL-8 compared with control monocytes. Monocytes costimulated with PHA and LPS demonstrated enhanced amounts of IL-8 mRNA and protein, but sharply decreased amounts of MCP-1 mRNA and protein. The addition of serum to culture media increased both the constitutive and PHA-induced production of monocyte-derived MCP-1 and IL-8, but had no effect on the inhibition of PHA-stimulated MCP-1 production by LPS. These findings suggest that distinct pathways of activation exist for the production of monocyte-derived IL-8 and MCP-1. The differential expression of these different but related polypeptides may offer a means of control of the type of immune cells that are recruited to a site of inflammation.
Base Sequence↗
VCAM-1 influences lymphocyte proliferation and cytokine production during mixed lymphocyte responses.
The allogeneic mixed lymphocyte reaction (MLR) is regarded as an effective model for examining the events which occur during an allospecific immune response. Numerous studies have delineated the role of adherence molecule interactions during the MLR response. In the present study we have identified VCAM-1 as having a contribution to the generation of an allogeneic MLR response. These findings may have broad implications in vivo during antigen-specific and allograft rejection events. RT-PCR analysis was initially used to examine whether VCAM-1 mRNA expression was observed during MLR responses and demonstrated peak expression between 12 and 48 hr of culture. Immunolocalization of VCAM-1 on adherent mononuclear phagocytes, but not nonadherent lymphocytes, from MLR cultures verified its expression during this response. Addition of anti-VCAM-1 mAbs to MLR assays inhibited the proliferative response by over 70%, while addition of anti-VCAM-1 as late as Day 2 of the assay allowed significant inhibition of the proliferative response. This correlated with peak expression of VCAM-1 mRNA observed as late as 48 hr in RT-PCR analyses. In further studies, anti-VCAM-1 significantly inhibited peak expression of IL-2 on Days 3 and 4, while TNF-alpha production was diminished at 30 min and 1, 96, and 120 hr of culture, compared to control cultures. The production of macrophage inflammatory protein-1 alpha (MIP-1 alpha), a chemotactic cytokine which has an important role in vivo for the recruitment of leukocytes to a site of inflammation, was also significantly inhibited during peak production on Days 4 and 5 of the MLR assay. This study demonstrates novel findings of VCAM-1 expression during an allogeneic MLR response. The expression of VCAM-1 may have important implications during allospecific immune responses for the activation and proliferation of T lymphocytes as well as cytokine production.
Antibodies, Monoclonal↗
Regulation of chemokine production by the oxidative metabolism of L-arginine in a human mixed lymphocyte reaction.
Previous studies have shown that during the development of a mixed lymphocyte reaction (MLR) levels of the chemotactic cytokines IL-8 and MCP-1 (members of the C-X-C and C-C supergene families, respectively) increase in a time-dependent fashion, and that the production of these chemokines correlates with the magnitude of responsiveness to alloantigen. Furthermore, the responsiveness to alloantigen in the context of a MLR has been shown to be regulated by the oxidative metabolism of L-arginine. We postulated that competitive antagonism of the L-arginine metabolic pathway in a human MLR may alter the production of members of the C-C and C-X-C chemokine families. To test this hypothesis, mononuclear cells were isolated from healthy individuals and subjected to a one-way MLR in the presence or absence of varying concentrations of an L-arginine competitive inhibitor, NG-methyl-L-arginine (NMA: 50 to 500 microM). When the MLR was performed in the presence of NMA (500 microM), the production of IL-8 increased twofold (P < 0.05) and ENA-78 increased fivefold (P < 0.05), while MCP-1 and MIP-1 alpha were not significantly altered. These findings suggest that NMA, an inhibitor of the L-arginine metabolic pathway, may regulate the production of specific C-X-C chemokines, IL-8 and ENA-78, during a MLR. In contrast, the production of MCP-1 and MIP-1 alpha, members of the C-C chemokine family, does not appear to be regulated by this inhibitor of the oxidative metabolism of L-arginine in the context of a MLR.
Arginine↗
Keratinocyte interleukin-10 expression is upregulated in tape-stripped skin, poison ivy dermatitis, and Sezary syndrome, but not in psoriatic plaques.
Despite the highly diverse reaction patterns of benign and malignant skin diseases involving T lymphocytes, polymerase chain reaction analysis of cytokine mRNAs present in biopsy samples has revealed that many cutaneous responses can be categorized into essentially two discrete groups. One group exemplified by psoriasis is characterized by consistently detectable mRNAs for IL-2, IFN-gamma, and TNF-alpha, but not IL-4, IL-5, IL-10, thereby closely resembling the murine Th1-type cell-mediated response. The second group exemplified by tape-stripped skin, poison ivy dermatitis, and Sezary syndrome contains predominantly IL-4, IL-5, and IL-10 mRNAs resembling the Th2-type cytokine profile. Because of the growing interest in the immunoregulatory role of IL-10, which can suppress IFN-gamma production and inhibit cell-mediated reactions, we produced a rabbit antiserum that was used to immunohistochemically localize IL-10 in a total of 27 biopsies. The results revealed that in Th2-type skin diseases, IL-10 was predominantly identified throughout all levels of epidermis in the cytoplasm of keratinocytes (KCs), with accentuation of their membranes in upper level cells. In Sezary syndrome, T cells were also immunoreactive for IL-10, which was confirmed using the HUT 78 T cell line derived from a Sezary syndrome patient. While normal skin was devoid of IL-10 expression, KCs began expressing it as early as 6 hr following tape stripping or application of poison ivy antigen and became strongly and diffusely positive by 18-24 hr. In contrast, psoriatic plaques contained no IL-10 immunoreactivity in either the parakeratotic scale or the epidermal KCs. These results confirm the earlier IL-10 mRNA analysis using whole skin samples and immunolocalize IL-10 to epidermal KCs in the Th2 diseases.
Biopsy↗
The role of chemokines in Schistosoma mansoni granuloma formation.
The eradication of parasitic diseases, such as schistosomiasis, has been the focus of investigations worldwide for many decades. However, attempts to control their continual spread have, at best, been met with limited success. In the face of these results, it is important to attempt to understand and thus to control the pathology of these widespread diseases. In this review, Nicholas Lukacs, Steven Kunkel, Robert Strieter and Stephen Chensue focus on a family of cytokines that play a pertinent role for leukocyte recruitment in chronic inflammation.
Journal Article↗
Interleukin-10 inhibition of HLA-DR expression in human herpes stromal keratitis.
PURPOSE: Human herpes stromal keratitis (HSK) is an important cause of visual loss and morbidity. The presentation of corneal and/or viral antigens is thought to activate T lymphocytes, resulting in aberrant cell-mediated immune responses that are central to the pathogenesis of HSK. Aberrant cellular expression of HLA-DR and intercellular adhesion molecule-1 (ICAM-1), both of which are necessary for optimal antigen-induced T-lymphocyte responses, is present in lesions of HSK, but little is known concerning endogenous cytokines that may inhibit HLA-DR or ICAM-I expression in human disease. In this study, the authors investigated the effects of interleukin-10 (IL-10) on HLA-DR and ICAM-1 expression in human HSK. METHODS: Penetrating keratoplasty specimens removed from 5 patients with HSK were divided to provide adjacent sections that were incubated with control medium or the same medium containing IL-10 (100 U/ml) for 48 hours. Immunoperoxidase staining was performed on each control and IL-10-treated corneal specimen to determine HLA-DR and ICAM-1 antigen expression. RESULTS: Interleukin-10 treatment resulted in profound reduction in immunoreactive HLA-DR, but not ICAM-1, in corneal cells and infiltrating leukocytes of all five HSK specimens. CONCLUSIONS: This study suggests that HLA-DR antigens may be selectively inhibited by cytokines released during inflammation in HSK. These results are the first to demonstrate cytokine suppression of HLA-DR in a human disease. Pharmacologic doses of IL-10 may inhibit HLA-DR-dependent immune responses that underlie a variety of destructive ocular inflammatory diseases.
Adult↗
Monocyte chemoattractant protein production in red cell incompatibility.
BACKGROUND: Mononuclear phagocytes play a central role in hemolytic transfusion reactions by erythrophagocytosis and production of inflammatory mediators. Factors that affect the number or function of monocyters would be expected to alter the clinical course of hemolytic transfusion reactions, and thus the production of monocyte chemoattractant protein-1 (MCP-1), a recently described chemotactic and activating cytokine specific for monocytes, was investigated in two distinct settings of red cell (RBC) incompatibility. STUDY DESIGN AND METHODS: Fresh heparinized whole blood was incubated with ABO-compatible or -incompatible RBCs. Isolated peripheral blood mononuclear cells were incubated with anti-D-coated or uncoated RBCs. MCP-1 was measured in the plasma or culture medium by enzyme-linked immunosorbent assay. MCP-1 gene expression was detected by Northern blot analysis of buffy coat or mononuclear cell total RNA. RESULTS: Significant levels of MCP-1 protein in plasma or medium were detected 24 hours after the addition of incompatible RBCs, but not in the first 6 hours. Nonimmune hemolysis of added RBCs did not stimulate MCP-1 production. The inactivation of complement by heat treatment of plasma prior to the addition of RBCs to whole blood did not prevent MCP-1 production. Nor did neutralizing antibodies to tumor necrosis factor prevent MCP-1 production in ABO incompatibility. MCP-1 production was associated with increased steady-state levels of white cell MCP-1 mRNA, which occurred more rapidly in ABO than Rh incompatibility. CONCLUSION: The monocyte-specific chemotactic cytokine MCP-1 is produced by peripheral blood leukocytes in response to RBC incompatibility. MCP-1 may act in a positive feedback loop to recruit and activate monocytes during hemolytic transfusion reactions, thus contributing to the maintenance of these reactions.
ABO Blood-Group System↗