CXCR3 and its ligands participate in the host response to Bordetella bronchiseptica infection of the mouse respiratory tract but are not required for clearance of bacteria from the lung

Intranasal inoculation of mice with Bordetella bronchiseptica produces a transient pneumonia that is cleared over several weeks in a process known to require both neutrophils and lymphocytes. In this study, we evaluated the roles of the chemokines MIG (CXCL9), IP-10 (CXCL10), and I-TAC (CXCL11) and their common receptor, CXCR3. Following bacterial inoculation, message expression of interleukin-1 (IL-1), IL-6, and the neutrophil-attracting chemokines KC, LIX, and MIP-2 was rapidly induced, with maximal expression found at 6 h. In contrast, message expression of gamma interferon, MIG, IP-10, and I-TAC peaked at 2 days. Expression of all of these chemokines and cytokines returned to near baseline by 5 days, despite the persistence of high levels of live bacteria at this time. Induced MIG, IP-10, and I-TAC protein expression was localized in areas of inflammation at 2 to 3 days and was temporally associated with increased levels of CXCR3(+) lymphocytes in bronchoalveolar lavage fluid. There was no increase in mortality in mice lacking CXCR3. However, the clearance of bacteria from the lung and trachea was delayed, and the recruitment of lymphocytes and NK cells was slightly decreased, for CXCR3(-/-) mice relative to CXCR3(+/+) mice. We conclude that the CXCR3 receptor-ligand system contributes to pulmonary host defense in B. bronchiseptica infection by recruiting lymphocytes and NK cells into the lung.     

Chlamydophila pneumoniae induces production of the defensin-like MIG/CXCL9, which has in vitro antichlamydial activity

CXC chemokines that lack the ELR motif, including the monokine induced by IFN-γ (MIG/CXCL9), the IFN-induced protein of 10 kDa (IP-10/CXCL10), and the IFN-inducible T-cell α-chemoattractant (I-TAC/CXCL11), have been shown to mediate the generation of type 1 immune responses and to possess defensin-like bactericidal effects. This study revealed that the infection of mice with Chlamydophila pneumoniae via the intranasal route resulted in the local expression of MIG/CXCL9, IP-10/CXCL10, and I-TAC/CXCL11. The expression of IP-10/CXCL10 and I-TAC/CXCL11 mRNA peaked on day 4. On day 7, the expression of MIG/CXCL9 mRNA in the infected lungs was increased 156-fold relative to that in the uninfected mouse lungs. MIG/CXCL9 was also detected at a protein level from day 1, with the highest concentration in the supernatants of the infected lungs on day 7. The expression of IFN-γ displayed similar kinetics. C. pneumoniae and its inactivated form also induced the production of MIG/CXCL9 in mouse fibroblasts and in the murine macrophage cell line J774A in vitro. Cotreatment of the tissue cultures with C. pneumoniae and different quantities of IFN-γ resulted in strong increases in MIG/CXCL9 production. Recombinant MIG/CXCL9 exerted dose-dependent antibacterial activity against C. pneumoniae. Significant antichlamydial activity of MIG/CXCL9 was observed after a 15-min incubation period. Chlamydial proteins at a molecular weight of 60 kDa were identified by Far-Western blot assay and liquid chromatography-tandem mass spectrometry as binding molecules of MIG/CXCL9. The results of these experiments suggest that MIG/CXCL9 might play an important role in the innate and acquired defense mechanisms against C. pneumoniae.     

Interferon-inducible protein 10, but not monokine induced by gamma interferon, promotes protective type 1 immunity in murine Klebsiella pneumoniae pneumonia

CXC chemokines that lack the ELR motif, including interferon-inducible protein 10 [IP-10 (CXCL10)] and monokine induced by gamma interferon (IFN-gamma) [MIG (CXCL9)], have been shown to mediate the generation of type 1 immune responses. In this study, we found that intrapulmonary administration of the gram-negative bacterium Klebsiella pneumoniae resulted in the local and systemic expression of IP-10, followed sequentially by MIG expression. MIG mRNA expression in the lungs of Klebsiella-infected mice required the endogenous production of IFN-gamma, whereas IP-10 was expressed in both an IFN-gamma-dependent and an IFN-gamma-independent fashion. Antibody-mediated neutralization of IP-10 resulted in reduced bacterial clearance and decreased survival, whereas bacterial clearance was unaltered in mice treated with anti-MIG antibody. Impaired bacterial clearance in anti-IP-10 antibody-treated mice was associated with significant reductions in the number and/or activational status of NK and NK-T cells, CD4+ T cells, and gammadelta T cells, as well as a reduction in the expression of IFN-gamma. Conversely, the transient transgenic expression of murine IP-10 using adenovirus-mediated gene transfer resulted in improved bacterial clearance when IP-10 adenovirus was given concomitant with intrapulmonary bacterial challenge. These results indicate that IP-10 is an important component of innate immunity against extracellular bacterial pathogens of the lung and may represent a candidate molecule for immunotherapy in the setting of severe respiratory tract infection.     

Fas (CD95) induces alveolar epithelial cell apoptosis in vivo: implications for acute pulmonary inflammation

Activation of the Fas/FasL system induces apoptosis of susceptible cells, but may also lead to nuclear factor kappaB activation. Our goal was to determine whether local Fas activation produces acute lung injury by inducing alveolar epithelial cell apoptosis and by generating local inflammatory responses. Normal mice (C57BL/6) and mice deficient in Fas (lpr) were treated by intranasal instillation of the Fas-activating monoclonal antibody (mAb) Jo2 or an irrelevant control mAb, and studied 6 or 24 hours later using bronchoalveolar lavage (BAL), histopathology, DNA nick-end-labeling assays, and electron microscopy. Normal mice treated with mAb Jo2 had significant increases in BAL protein at 6 hours, and BAL neutrophils at 24 hours, as compared to lpr mice and to mice treated with the irrelevant mAb. Neutrophil recruitment was preceded by increased mRNA expression for tumor necrosis factor-alpha, macrophage inflammatory protein-1alpha, macrophage inflammatory protein-2, macrophage chemotactic protein-1, and interleukin-6, but not interferon-gamma, transforming growth factor-ss, RANTES, eotaxin, or IP-10. Lung sections from Jo2-treated normal mice showed neutrophilic infiltrates, alveolar septal thickening, hemorrhage, and terminal dUTP nick-end-labeling-positive cells in the alveolar septae and airspaces. Type II pneumocyte apoptosis was confirmed by electron microscopy. Fas activation in vivo results in acute alveolar epithelial injury and lung inflammation, and may be important in the pathogenesis of acute lung injury.     

IP-10 and MIG Are Compartmentalized at the Site of Disease during Pleural and Meningeal Tuberculosis and Are Decreased after Antituberculosis Treatment

The diagnosis of active tuberculosis (TB) disease remains a challenge, especially in high-burden settings. Cytokines and chemokines are important in the pathogenesis of TB. Here we investigate the usefulness of circulating and compartmentalized cytokines/chemokines for diagnosis of TB. The levels of multiple cytokines/chemokines in plasma, pleural fluid (PF), and cerebrospinal fluid (CSF) were determined by Luminex liquid array-based multiplexed immunoassays. Three of 26 cytokines/chemokines in plasma were significantly different between TB and latent tuberculosis infection (LTBI). Among them, IP-10 and MIG had the highest diagnostic values, with an area under the receiver operating characteristic curve (ROC AUC) of 0.92 for IP-10 and 0.86 for MIG for distinguishing TB from LTBI. However, IP-10 and MIG levels in plasma were not different between TB and non-TB lung disease. In contrast, compartmentalized IP-10 and MIG in the PF and CSF showed promising diagnostic values in discriminating TB and non-TB pleural effusion (AUC = 0.87 for IP-10 and 0.93 for MIG), as well as TB meningitis and non-TB meningitis (AUC = 0.9 for IP-10 and 0.95 for MIG). A longitudinal study showed that the plasma levels of IP-10, MIG, granulocyte colony-stimulating factor (G-CSF), and gamma interferon (IFN-γ) decreased, while the levels of MCP-1/CCL2 and eotaxin-1/CCL11 increased, after successful treatment of TB. Our findings provide a practical methodology for discriminating active TB from LTBI by sequential IFN-γ release assays (IGRAs) and plasma IP-10 testing, while increased IP-10 and MIG at the site of infection (PF or CSF) can be used as a marker for distinguishing pleural effusion and meningitis caused by TB from those of non-TB origins.     

IL-12 suppresses the expression of ocular immunoinflammatory lesions by effects on angiogenesis

Topical application of plasmid DNA encoding IL-12 to the cornea of mice prior to ocular infection with Herpes simplex virus type 1 (HSV) results in diminished corneal immunoinflammatory lesions. Such herpetic stromal keratitis (HSK) reactions in humans represent an important cause of blindness. The effect of IL-12 pretreatment acted via inhibitory effects on corneal neovascularization rather than by inhibiting viral replication or the function of CD4(+) T cells that mediate HSK. The antiangiogenesis induced by IL-12 DNA application was mediated indirectly via the cytokine IFN-gamma and one or both of two chemokine molecules, IP-10 and MIG. Thus IL-12 DNA administration lacked modulatory effects on HSK in GKO mice, indicating the necessary involvement of IFN-gamma induction for antiangiogenesis. In contrast, exposure of GKO mice to IP-10 DNA did suppress the severity of HSK. Furthermore, treatment with specific antisera to IP-10 and MIG in HSV-infected mice abrogated the IL-12-induced inhibitory effect on lesion severity. Taken together, our data indicate that the HSV-induced ocular immunoinflammatory lesions can be modulated by IL-12 and that this effect results from chemokine inhibition of angiogenesis. The use of antiangiogenesis therapy might represent a useful control measure against HSK.     

IFN-gamma-inducible chemokines enhance adaptive immunity and colitis.

T helper type 1 (Th1) cells secreting interferon-gamma (IFN-gamma) have been closely associated with Crohn's disease (CD). Monokine-induced by IFN-gamma (MIG), IFN-gamma-inducible T cell alpha chemoattractant (I-TAC), and IFN-gamma-inducible protein-10 (IP-10), are chemokines that bind CXCR3 and mediate the chemotaxis of leukocytes. IP-10, MIG, and CXCR3 have been shown to be expressed at sites of CD. The current study stems from our recent findings that IP-10, MIG, and I-TAC significantly contribute to the development of Th1-mediated inflammatory responses. To better understand the role of CXCR3 interactions during CD, we characterized the effects of IP-10, MIG, I-TAC, and CXCR3+ T cells on mucosal immune responses. IP-10, MIG, and I-TAC significantly enhanced antigen-specific serum and mucosal antibodies through Th1-mediated events and CD28 modulation. Additionally, the adoptive transfer of naive CXCR3+ T cells and CD4+CD45RB(HI) to T cell receptor beta (TCRbeta) x delta(-/-) mice resulted in the onset of murine colitis. Taken together, these studies suggest that IP-10, MIG, I-TAC, and CXCR3 interactions are involved in mucosal immune responses required for the induction of CD.     

An interferon-gamma-related cytokine storm in SARS patients

Fourteen cytokines or chemokines were analyzed on 88 RT-PCR-confirmed severe acute respiratory syndrome (SARS) patients. IFN-gamma, IL-18, TGF-beta, IL-6, IP-10, MCP-1, MIG, and IL-8, but not of TNF-alpha, IL-2, IL-4, IL-10, IL-13, or TNFRI, were highly elevated in the acute phase sera of Taiwan SARS patients. IFN-gamma was significantly higher in the Ab(+) group than in the Ab(-) group. IFN-gamma, IL-18, MCP-1, MIG, and IP-10 were already elevated at early days post fever onset. Furthermore, levels of IL-18, IP-10, MIG, and MCP-1 were significantly higher in the death group than in the survival group. For the survival group, IFN-gamma and MCP-1 were inversely associated with circulating lymphocytes count and monocytes count, but positively associated with circulating neutrophils count. It is concluded that an interferon-gamma-related cytokine storm was induced post SARS coronavirus infection, and this cytokine storm might be involved in the immunopathological damage in SARS patients.     

IP-10 mediates selective mononuclear cell accumulation and activation in response to intrapulmonary transgenic expression and during adenovirus-induced pulmonary inflammation.

CXC chemokines that lack the glutamine-leucine-arginine (ELR) motif, including interferon (IFN)-inducible protein 10 (IP-10 or CXCL10), have been shown to mediate the generation of type 1 immune responses. In this study, we found that the intrapulmonary transient transgenic expression of murine IP-10 in mice using adenoviral gene transfer resulted in the early accumulation of neutrophils, natural killer (NK) cells, and NK T cells within the lung, followed by the delayed accumulation of CD4+ T cells. Adenovirus-mediated transgenic expression of IP-10 also resulted in selective activation of mononuclear cells, including gamma(delta)-T cells and NK cells, as manifest by CD69 expression or induction of cell-associated IFN-gamma. Importantly, the intratracheal (i.t.) administration of a control human type 5 adenovirus also caused significant accumulation of NK, NK T, and CD4+ T cells, which was maximal at 7 days post vector administration and was associated with the induction of IP-10. Neutralization of endogenous IP-10 in animals receiving control adenovirus resulted in decreases in the numbers of NK, CD4+, and CD8+ T cells. These results indicate that IP-10 can direct the accumulation and activation of neutrophils and selected mononuclear cells to the lung and that adenovirus-induced IP-10 contributes to lung inflammatory cell recruitment/activation observed in response to adenoviral vectors used for gene therapy.     

Increased serum levels of interferon-gamma-inducible protein 10 and monokine induced by gamma interferon in patients with haemophagocytic lymphohistiocytosis

We measured serum interferon-gamma-inducible protein 10 (IP-10) and monokine induced by gamma interferon (MIG) levels to investigate the role of these molecules in the pathophysiology of haemophagocytic lymphohistiocytosis (HLH). Serum IP-10 and MIG levels were significantly increased in patients with active HLH compared with those of healthy controls. Serum MIG levels decreased gradually during the course of disease in a patient who recovered without therapy. On the other hand, rapid reduction of MIG and IP-10 levels was observed after chemotherapy in a patient with severe HLH. IP-10 and MIG mRNA expression was enhanced in liver and spleen, and IP-10 mRNA expression was enhanced in bone marrow in the patients, suggesting activated macrophages that infiltrated in these organs as one of the main producers of these cytokines. Serum IP-10 and MIG levels showed a significant correlation with serum IFN-gamma levels. In addition, these chemokines had a significant correlation with fever and serum LDH levels, which are clinical indicators of disease activity of HLH. These results suggest that IP-10 and MIG which are produced by activated macrophages by the stimulation of IFN-gamma, play an important role in the pathophysiology of HLH, by recruitment of activated Th1 cells into the tissues or organs.     

Effect of insulin-like growth factor blockade on hyperoxia-induced lung injury

Insulin-like growth factor (IGF)-1 is increased in different models of acute lung injury, and is an important determinant of survival and proliferation in many cells. We previously demonstrated that treatment of mice with IGF-1 receptor-blocking antibody (A12) improved early survival in bleomycin-induced lung injury. We have now examined whether administration of A12 improved markers of lung injury in hyperoxia model of lung injury. C57BL/6 mice underwent intraperitoneal administration of A12 or control antibody (keyhole limpet hemocyanin [KLH]), then were exposed to 95% hyperoxia for 88-90 hours. Mice were killed and bronchoalveolar lavage (BAL) and lung tissue were obtained for analysis. Hyperoxia caused a significant increase in IGF levels in BAL and lung lysates. Peripheral blood neutrophils expressed IGF-1R at baseline and after hyperoxia. BAL neutrophils from hyperoxia-treated mice and patients with acute lung injury also expressed cell surface IGF-1R. A12-treated mice had significantly decreased polymorphonuclear cell (PMN) count in BAL compared with KLH control mice (P = 0.02). BAL from A12-treated mice demonstrated decreased PMN chemotactic activity compared with BAL from KLH-treated mice. Pretreatment of PMNs with A12 decreased their chemotactic response to BAL from hyperoxia-exposed mice. Furthermore, IGF-1 induced a dose-dependent chemotaxis of PMNs. There were no differences in other chemotactic cytokines in BAL, including CXCL1 and CXCL2. In summary, IGF blockade decreased PMN recruitment to the alveolar space in a mouse model of hyperoxia. Furthermore, the decrease in BAL PMNs was at least partially due to a direct effect of A12 on PMN chemotaxis.     

Increased levels of chemokine receptor CXCR3 and chemokines IP-10 and MIG in patients with primary biliary cirrhosis and their first degree relatives

Infiltrating memory T cells play an important role in the destruction of the biliary tract in primary biliary cirrhosis (PBC) and inflammatory chemokines control lymphocyte traffic through their interactions with T cell chemokine receptors. In the present study, we measured plasma levels of chemokines interferon-gamma-inducible protein-10 (IP-10) and monokine induced by gamma interferon (MIG), and also studied the expression of CXCR3 chemokine receptors in 105 subjects, including 53 patients with PBC, 26 first degree relatives and 26 healthy controls. Interestingly, plasma IP-10 and MIG levels in PBC were increased significantly compared to controls and appeared to increase with disease progression. By immunohistochemistry, IP-10 and MIG expressions were evident in the portal areas in PBC. Further, the frequency of CXCR3-expressing cells in peripheral blood was also significantly higher in PBC, and CXCR3-positive cells were also found in the portal areas of diseased livers, primarily on CD4+ cells. Finally, the daughters and sisters of PBC patients also demonstrated increased plasma levels of IP-10 and MIG, but, in contrast, displayed normal frequency of CXCR3+ expressing peripheral blood lymphocytes. Our data imply a role for specific chemokine-chemokine receptor interactions in the pathogenesis of PBC and also highlight the familial risk factor.     

In vivo administration of interleukin 1 elicits increased Ia antigen expression on B cells through the induction of interleukin 4

The effects of the in vivo administration of interleukin 1 (IL 1) on lymphocytes from lymph node and spleen were analyzed. Mice received five daily subcutaneous (s.c.) injections of various doses of human recombinant IL 1 beta. Either 1 or 7 days after IL 1 treatment, spleens, popliteal and inguinal lymph nodes were collected. Lymphadenosis and splenomegaly were observed in the IL 1-treated animals. Lymph nodes from IL 1-treated mice contained a higher percentage of B cells than controls, and B cells from IL 1-treated mice expressed dramatically increased levels of Ia antigen. Lymphadenosis and splenomegaly, as well as the changes in subset distributions and Ia expression were transient. Concomitant treatment of mice with IL 1 and anti-IL 4 monoclonal antibody suppressed IL 1 effects on B cell Ia expression, but not on the B/T cell ratio. In situ hybridization analyses revealed that IL 1 treatment induced the expression of mRNA for IL 4, interferon-gamma, and IL 2 in lymph node and spleen cells. The distribution of cells expressing the various cytokine mRNA was markedly different between the spleens and lymph nodes.     

ELR-negative CXC chemokine CXCL11 (IP-9/I-TAC) facilitates dermal and epidermal maturation during wound repair

In skin wounds, the chemokine CXCR3 receptor appears to play a key role in coordinating the switch from regeneration of the ontogenically distinct mesenchymal and epithelial compartments toward maturation. However, because CXCR3 equivalently binds four different ELR-devoid CXC chemokines (ie, PF4/CXCL4, IP-10/CXCL10, MIG/CXCL9, and IP-9/CXCL11), we sought to identify the ligand that coordinates epidermal coverage with the maturation of the underlying superficial dermis. Because CXCL11 (IP-9 or I-TAC) is produced by redifferentiating keratinocytes late in the regenerative phase when re-epithelialization is completed and matrix maturation ensues, we generated mice in which an antisense construct (IP-9AS) eliminated IP-9 expression during the wound-healing process. Both full and partial thickness excisional wounds were created and analyzed histologically throughout a 2-month period. Wound healing was impaired in the IP-9AS mice, with a hypercellular and immature dermis noted even after 60 days. Re-epithelialization was delayed with a deficient delineating basement membrane persisting in mice expressing the IP-9AS construct. Provisional matrix components persisted in the dermis, and the mature basement membrane components laminin V and collagen IV were severely diminished. Interestingly, the inflammatory response was not diminished despite IP-9/I-TAC being chemotactic for such cells. We conclude that IP-9 is a key ligand in the CXCR3 signaling system for wound repair, promoting re-epithelialization and modulating the maturation of the superficial dermis.     

MIG (CXCL9), IP-10 (CXCL10) and I-TAC (CXCL11) concentrations after nasal allergen challenge in patients with allergic rhinitis

Introduction

The role of monokine induced by interferon-γ (IFN-γ, MIG/CXCL9), IFN-γ-inducible protein (IP-10/CXCL10), and IFN-inducible T cell α chemoattractant (I-TAC/CXCL11) in allergic inflammation has not been explored in detail in vivo. The aim of the study was to examine the changes in concentrations of MIG/CXCL9, IP-10/CXCL10 and I-TAC/CXCL11 in nasal lavages collected from healthy and allergic subjects during nasal allergen challenge.

Material and methods

Subjects allergic to grass pollen and healthy controls were included. Nasal allergen challenge preceded by placebo administration was performed outside the pollen season. Nasal lavages were collected before and 30 min after application of the placebo and 30 min after allergen administration. Concentrations of chemokines were determined using ELISA.

Results

We observed significantly higher concentrations of IP-10/CXCL10 in allergic patients compared to the healthy subjects before (354.49 ±329.24 vs. 164.62 ±175.94 pg/ml; p = 0.036), 30 min after placebo (420.3 ±421.28 vs. 246.88 ±353.24 pg/ml; p = 0.021) and 30 min after allergen administration (403.28 ±359.29 vs. 162.68 ±148.69 pg/ml; p = 0.025). IP-10/CXCL10 levels did not change 30 min after allergen provocation. In contrast, MIG/CXCL9 levels were similar in both groups before and after placebo. However, a significant rise in MIG/CXCL9 concentration was noted in allergic patients 30 min after the allergen (138.88 ±109.59 vs. 395.8 ±301.2 pg/ml; p = 0.00026). I-TAC/CXCL11 concentrations increased after placebo as well as the allergen in both groups.

Conclusions

IP-10/CXCL10 concentrations are elevated in nasal lavages from allergic patients and this chemokine may play a role in chronic allergic inflammation. MIG/CXCL9 levels increase rapidly after allergen application, which may suggest its role in the early allergic response. Results on I-TAC/CXCL11 concentrations remain inconclusive.     

IL-10-treated dendritic cells decrease airway hyperresponsiveness and airway inflammation in mice

BACKGROUND: IL-10 affects dendritic cell (DC) function, but the effects on airway hyperresponsiveness (AHR) and inflammation are not defined. OBJECTIVE: We sought to determine the importance of IL-10 in regulating DC function in allergen-induced AHR and airway inflammation. METHODS: DCs were generated from bone marrow in the presence or absence of IL-10. In vivo IL-10-treated DCs from IL-10(+/+) and IL-10(-/-) donors pulsed with ovalbumin (OVA) were transferred to naive or sensitized mice before challenge. In recipient mice AHR, cytokine levels, cell composition of bronchoalveolar lavage (BAL) fluid, and lung histology were monitored. RESULTS: In vitro, IL-10-treated DCs expressed lower levels of CD11c, CD80, and CD86; expressed lower levels of IL-12; and suppressed T(H)2 cytokine production. In vivo, after transfer of OVA-pulsed IL-10-treated DCs, naive mice did not have AHR, airway eosinophilia, T(H)2 cytokine increase in BAL fluid, or goblet cell metaplasia when challenged, and in sensitized and challenged mice IL-10-treated DCs suppressed these responses. Levels of IL-10 in BAL fluid and numbers of lung CD4(+)IL-10(+) T cells were increased in mice that received OVA-pulsed IL-10-treated DCs. Transfer of IL-10-treated DCs from IL-10-deficient mice were ineffective in suppressing the responses in sensitized and challenged mice. CONCLUSIONS: These data demonstrate that IL-10-treated DCs are potent suppressors of the development of AHR, inflammation, and T(H)2 cytokine production; these regulatory functions are at least in part through the induction of endogenous (DC) production of IL-10. CLINICAL IMPLICATIONS: Modification of DC function by IL-10 can attenuate lung allergic responses, including the development of AHR.     

CXC chemokines Gro(alpha)/IL-8 and IP-10/MIG in Helicobacter pylori gastritis

Infection with Helicobacter pylori causes chronic active gastritis, which is characterized by neutrophils infiltrating the gastric epithelial layer and the underlying lamina propria as well as by T, B lymphocytes and macrophages accumulating in the lamina propria. In this study, the chemokine profile responsible for the recruitment of these inflammatory cells is investigated. Using both RNA/RNA in situ hybridization and immunohistochemistry, the expression of the neutrophil and/or lymphocyte-attractant CXC chemokines growth-related oncogene alpha (Gro(alpha)), IL-8, interferon-gamma (IFN-gamma)-inducible protein-10 (IP-10), monokine induced by IFN-gamma (MIG) and the CC chemokines macrophage inflammatory protein-1alpha (MIP-1alpha), -1beta, regulated on activation normal T cell expressed and secreted (RANTES) and monocyte chemoattractant protein-1 (MCP-1) is studied and microanatomically localized in the gastric mucosa. Macrophages in the lamina propria at sites with neutrophil infiltration and gastric epithelium infiltrated by neutrophils highly expressed the neutrophil-attractant chemokines Gro(alpha) and IL-8. Additionally, Gro(alpha) and IL-8 were expressed by neutrophils themselves localized within gastric epithelium, in the foveolar lumen and in the cellular debris overlying mucosal erosion. IP-10 and to a lower extent MIG, both selectively chemotactic for inflammatory T cells, were expressed by endothelial cells of gastric mucosal vessels and by mononuclear cells at sites with T cell infiltration. Expression of all other CC chemokines tested was significantly lower. These in vivo data indicate that a set of predominantly CXC chemokines modulates the inflammation in H. pylori gastritis. Gro(alpha) and IL-8 may play an important role in neutrophil trafficking from the mucosal vessel into the gastric epithelium, whereas IP-10 and MIG contribute to the recruitment of inflammatory T cells into the mucosa.     

Potential role of the chemokine receptors CXCR3, CCR4, and the integrin alphaEbeta7 in the pathogenesis of psoriasis vulgaris

Various adhesion molecules have been implicated in T lymphocyte binding to dermal vascular endothelium in psoriasis vulgaris, but the chemotactic signals that promote subsequent homing into the adjacent dermis and overlying epidermis are poorly defined. We studied chemokine receptor (CCR1-CCR5, CXCR1-CXCR3), chemokine (interferon-gamma inducible protein 10 [IP-10]), monokine induced by interferon-gamma (MIG), thymus and activation-regulated chemokine (TARC), macrophage-derived chemokine (MDC), and adhesion molecule (cutaneous lymphocyte antigen [CLA], E-selectin, lymphocyte function-associated antigen-1 [LFA-1], intercellular adhesion molecule-1 [ICAM-1], very late antigen 4 [VLA-4], vascular cell adhesion molecule-1 [VCAM-1], alphaEbeta7, and E-cadherin) expression in psoriasis by immunohistology, flow cytometry, and molecular techniques. CXCR3 and CCR4 were expressed by dermal CD3+ lymphocytes, and their chemokine ligands, IP-10, MIG, TARC, and MDC, were up-regulated in psoriatic lesions. Keratinocytes stimulated with tumor necrosis factor-alpha and interferon-gamma up-regulated expression of IP-10, MIG, and MDC mRNA, whereas dermal endothelial cells, similarly stimulated, up-regulated expression of IP-10, MDC, and TARC mRNA, suggesting that these cell types were sources of the chemokines detected in biopsies. There was enhanced expression of E-selectin, CLA, LFA-1, ICAM-1, VLA-4, VCAM-1, and alphaEbeta7 in psoriatic lesions versus nonlesional skin. Finally, intra-epidermal CLA+ and alphaEbeta7+ T lymphocytes selectively expressed the chemokine receptor CXCR3. Collectively, these data suggest that CXCR3 and CCR4 may be involved in T lymphocyte trafficking to the psoriatic dermis and that CXCR3 is selectively involved in subsequent T cell homing to the overlying epidermis.     

T cells in hypersensitivity pneumonitis: effects of in vivo depletion of T cells in a mouse model.

C57BL/6 mice were given intranasal instillation of optimal doses of the actinomycete Faeni rectivirgula 150 micrograms/mouse 3 days/wk), an important offending agent causing hypersensitivity pneumonitis. This instillation was associated with a very significant increase in the lung weight of the mice and also a large increase (10-fold) in the number of cells recovered from the bronchoalveolar lavage (BAL) of instilled mice. Also, this instillation was associated with a very significant fibrosis at 4 and 8 wk (2-fold increase in hydroxyproline levels in the lungs). We determined the effect of depleting certain T-cell subsets on the progression of this inflammatory disease. Elimination of the L3T4 subset did not significantly affect the increase in the lung index, the lung cellular influx, or its profile. Fibrosis was also unaffected by this depletion of L3T4+ cells. Similarly, depletion of Lyt2+ (CD8+) cells did not lead to significant changes in these disease parameters. Depletion of all T cells (Thyl+) was also ineffective at modifying the number of infiltrating cells and the lung index score. However, identification of cell types in BAL showed that mice depleted of Thyl+ cells had a cellular influx that was almost exclusively neutrophilic throughout the instillation period, whereas control mice developed only a transient neutrophilic response to F. rectivirgula instillation, which was replaced by a recruitment of mononuclear cells, mostly macrophages. Also, depletion of Thyl+ cells before and during F. rectivirgula challenge had no effect on tumor necrosis factor-alpha levels in the BAL of treated mice (63 +/- 13 U/ml in anti-Thy1. 2 antibodies treated versus 52 +/- 10 U/ml in the BAL of control mice given F. rectivirgula).(ABSTRACT TRUNCATED AT 250 WORDS)