InVivoMAb anti-mouse CXCL10 (IP-10)

in vivo neutralization of CXCL10

Pöysti S, Silojärvi S, Brodnicki TC, Catterall T, Liu X, Mackin L, Luster AD, Kay TWH, Christen U, Thomas HE, Hänninen A. (2023). "Gut dysbiosis promotes islet-autoimmunity by increasing T-cell attraction in islets via CXCL10 chemokine" J Autoimmun . PubMed

CXCL10 is an IFNγ-inducible chemokine implicated in the pathogenesis of type 1 diabetes. T-cells attracted to pancreatic islets produce IFNγ, but it is unclear what attracts the first IFNγ -producing T-cells in islets. Gut dysbiosis following administration of pathobionts induced CXCL10 expression in pancreatic islets of healthy non-diabetes-prone (C57BL/6) mice and depended on TLR4-signaling, and in non-obese diabetic (NOD) mice, gut dysbiosis induced also CXCR3 chemokine receptor in IGRP-reactive islet-specific T-cells in pancreatic lymph node. In amounts typical to low-grade endotoxemia, bacterial lipopolysaccharide induced CXCL10 production in isolated islets of wild type and RAG1 or IFNG-receptor-deficient but not type-I-IFN-receptor-deficient NOD mice, dissociating lipopolysaccharide-induced CXCL10 production from T-cells and IFNγ. Although mostly myeloid-cell dependent, also β-cells showed activation of innate immune signaling pathways and Cxcl10 expression in response to lipopolysaccharide indicating their independent sensitivity to dysbiosis. Thus, CXCL10 induction in response to low levels of lipopolysaccharide may allow islet-specific T-cells imprinted in pancreatic lymph node to enter in healthy islets independently of IFN-g, and thus link gut dysbiosis to early islet-autoimmunity via dysbiosis-associated low-grade endotoxemia.

in vivo neutralization of CXCL10, in vivo inhibition of T cell recruitment

Gaylo-Moynihan A, Prizant H, Popović M, Fernandes NRJ, Anderson CS, Chiou KK, Bell H, Schrock DC, Schumacher J, Capece T, Walling BL, Topham DJ, Miller J, Smrcka AV, Kim M, Hughson A, Fowell DJ. (2019). "Programming of Distinct Chemokine-Dependent and -Independent Search Strategies for Th1 and Th2 Cells Optimizes Function at Inflamed Sites" Immunity 51(2):298-309.e6. PubMed

T-helper (Th) cell differentiation drives specialized gene programs that dictate effector T cell function at sites of infection. Here, we have shown Th cell differentiation also imposes discrete motility gene programs that shape Th1 and Th2 cell navigation of the inflamed dermis. Th1 cells scanned a smaller tissue area in a G protein-coupled receptor (GPCR) and chemokine-dependent fashion, while Th2 cells scanned a larger tissue area independent of GPCR signals. Differential chemokine reliance for interstitial migration was linked to STAT6 transcription-factor-dependent programming of integrin α_Vβ₃ expression: Th2 cell differentiation led to high α_Vβ₃ expression relative to Th1 cells. Th1 and Th2 cell modes of motility could be switched simply by manipulating the amount of α_Vβ₃ on the cell surface. Deviating motility modes from those established during differentiation impaired effector function. Thus, programmed expression of α_Vβ₃ tunes effector T cell reliance on environmental cues for optimal exploration of inflamed tissues.

in vivo neutralization of CXCL10

Chow MT, Ozga AJ, Servis RL, Frederick DT, Lo JA, Fisher DE, Freeman GJ, Boland GM, Luster AD. (2019). "Intratumoral Activity of the CXCR3 Chemokine System Is Required for the Efficacy of Anti-PD-1 Therapy" Immunity 50(6):1498-1512.e5. PubMed

Despite compelling rates of durable clinical responses to programmed cell death-1 (PD-1) blockade, advances are needed to extend these benefits to resistant tumors. We found that tumor-bearing mice deficient in the chemokine receptor CXCR3 responded poorly to anti-PD-1 treatment. CXCR3 and its ligand CXCL9 were critical for a productive CD8⁺ T cell response in tumor-bearing mice treated with anti-PD-1 but were not required for the infiltration of CD8⁺ T cells into tumors. The anti-PD-1-induced anti-tumor response was facilitated by CXCL9 production from intratumoral CD103⁺ dendritic cells, suggesting that CXCR3 facilitates dendritic cell-T cell interactions within the tumor microenvironment. CXCR3 ligands in murine tumors and in plasma of melanoma patients were an indicator of clinical response to anti-PD-1, and their induction in non-responsive murine tumors promoted responsiveness to anti-PD-1. Our data suggest that the CXCR3 chemokine system is a biomarker for sensitivity to PD-1 blockade and that augmenting the intratumoral function of this chemokine system could improve clinical outcomes.

in vivo neutralization of CXCL10

Bender C, Christen S, Scholich K, Bayer M, Pfeilschifter JM, Hintermann E, Christen U. (2017). "Islet-Expressed CXCL10 Promotes Autoimmune Destruction of Islet Isografts in Mice With Type 1 Diabetes" Diabetes 66(1):113-126. PubMed

Type 1 diabetes (T1D) results from the autoimmune destruction of insulin-producing β-cells in the pancreas. Thereby, the chemokine CXC-motif ligand 10 (CXCL10) plays an important role in the recruitment of autoaggressive lymphocytes to the islets of Langerhans. Transplantation of isolated islets as a promising therapy for T1D has been hampered by early graft rejection. Here, we investigated the influence of CXCL10 on the autoimmune destruction of islet isografts using RIP-LCMV mice expressing a lymphocytic choriomeningitis virus (LCMV) protein in the β-cells. RIP-LCMV islets express CXCL10 after isolation and maintain CXCL10 production after engraftment. Thus, we isolated islets from either normal or CXCL10-deficient RIP-LCMV mice and transferred them under the kidney capsule of diabetic RIP-LCMV mice. We found that the autoimmune destruction of CXCL10-deficient islet isografts was significantly reduced. The autoimmune destruction was also diminished in mice administered with an anti-CXCL10 antibody. The persistent protection from autoimmune destruction was paralleled by an increase in FoxP3⁺ regulatory T cells within the cellular infiltrates around the islet isografts. Consequently, CXCL10 might influence the cellular composition locally in the islet graft, thereby playing a role in the autoimmune destruction. CXCL10 might therefore constitute a potential therapeutic target to prolong islet graft survival.

in vitro neutralization of CXCL10, in vivo neutralization of CXCL10, Functional Assays

Bonvin P, Gueneau F, Buatois V, Charreton-Galby M, Lasch S, Messmer M, Christen U, Luster AD, Johnson Z, Ferlin W, Kosco-Vilbois M, Proudfoot A, Fischer N. (2017). "Antibody Neutralization of CXCL10 in Vivo Is Dependent on Binding to Free and Not Endothelial-bound Chemokine: IMPLICATIONS FOR THE DESIGN OF A NEW GENERATION OF ANTI-CHEMOKINE THERAPEUTIC ANTIBODIES" J Biol Chem 292(10):4185-4197. PubMed

To improve our understanding of properties that confer successful inhibition of chemokines in vivo, we analyzed anti-murine CXCL10 monoclonal antibodies (mAb) having different characteristics. 1B6 displayed potent inhibition of cell recruitment in vitro with an IC₅₀ of 0.5 nm but demonstrated little efficacy in various animal models of human disease. On the contrary, 1F11 showed efficacy in several models of inflammation yet was less potent at inhibiting chemotaxis in vitro with an IC₅₀ of 21 nm Furthermore, we observed that 1B6 displayed a rapid dose-dependent clearance (t_½ 10-60 h) in contrast to 1F11, which presented a dose-proportional pharmacokinetic profile and a half-life of 12 days. Moreover, 1B6 recognized glycosaminoglycan (GAG)-bound CXCL10, resulting in target-mediated clearance, which was corroborated using CXCL10-deficient mice. In contrast to 1B6, 1F11 inhibited the interaction of CXCL10 with GAGs, did not recognize GAG-bound CXCL10, and did not display target-mediated drug disposition. Confirming previous animal studies, 1B6 was poor at reversing glycemia in a model of type 1 diabetes, whereas 1F11 induced early and prolonged control of diabetes. Furthermore, when using 1A4, a subsequently generated anti-mCXCL10 mAb that shares the property with 1F11 of being unable to recognize CXCL10 immobilized on GAG, we observed a similar superior control of diabetes as compared with 1B6. We therefore concluded that targeting chemokines with antibodies such as 1B6 that recognize the more abundant GAG-bound form of the chemokine may not be the optimal strategy to achieve disease control.

in vivo neutralization of CXCL10

Tajfirouz D, West DM, Yin XT, Potter CA, Klein R, Stuart PM. (2017). "CXCL9 compensates for the absence of CXCL10 during recurrent Herpetic stromal keratitis" Virology . PubMed

Herpetic stromal keratitis (HSK) is a disease that is typically associated with reactivation of a latent HSV-1 infection. This disease is driven, in part, by chemokines that recruit leukocytes to the cornea. Surprisingly, neutralization of CXCL10 significantly reduced disease, while B6-CXCL10-/- mice exhibited worse disease compared with similarly infected wild-type controls. We hypothesized that compensatory up-regulation of CXCL9 occurs in the absence of CXCL10. Analysis of CXCL9 expression in HSV-1-infected B6 mice and B6-CXCL10-/- mice revealed significantly more CXCL9 in B6-XCL10-/- mice. Treatment of B6 and B6-CXCL10-/- mice with neutralizing antibodies to CXCL9 reduced HSK scores in B6-CXCL10-/-, but not B6 mice. We conclude that CXCL10 production worsens HSK and that CXCL9 may compensate in CXCL10-deficient animals. These studies identify the critical role that CXCL10 plays in the pathogenesis of recurrent HSK, and that CXCL9 displays its importance when CXCL10 is absent.

in vivo neutralization of CXCL10, in vivo inhibition of T cell recruitment

Lasch S, Müller P, Bayer M, Pfeilschifter JM, Luster AD, Hintermann E, Christen U. (2015). "Anti-CD3/Anti-CXCL10 Antibody Combination Therapy Induces a Persistent Remission of Type 1 Diabetes in Two Mouse Models" Diabetes 64(12):4198-211. PubMed

Anti-CD3 therapy of type 1 diabetes results in a temporary halt of its pathogenesis but does not constitute a permanent cure. One problem is the reinfiltration of islets of Langerhans with regenerated, autoaggressive lymphocytes. We aimed at blocking such a reentry by neutralizing the key chemokine CXCL10. Combination therapy of diabetic RIP-LCMV and NOD mice with anti-CD3 and anti-CXCL10 antibodies caused a substantial remission of diabetes and was superior to monotherapy with anti-CD3 or anti-CXCL10 alone. The combination therapy prevented islet-specific T cells from reentering the islets of Langerhans and thereby blocked the autodestructive process. In addition, the local immune balance in the pancreas was shifted toward a regulatory phenotype. A sequential temporal inactivation of T cells and blockade of T-cell migration might constitute a novel therapy for patients with type 1 diabetes.

in vivo neutralization of CXCL10

Homann D. (2015). "Back From the Brink: The Uses of Targeting the CXCL10:CXCR3 Axis in Type 1 Diabetes" Diabetes 64(12):3990-2. PubMed

in vivo neutralization of CXCL10

Rashighi M, Agarwal P, Richmond JM, Harris TH, Dresser K, Su MW, Zhou Y, Deng A, Hunter CA, Luster AD, Harris JE. (2014). "CXCL10 is critical for the progression and maintenance of depigmentation in a mouse model of vitiligo" Sci Transl Med 6(223):223ra23. PubMed

Vitiligo is an autoimmune disease of the skin that results in disfiguring white spots. There are no U.S. Food and Drug Administration-approved treatments for vitiligo, and most off-label treatments yield unsatisfactory results. Vitiligo patients have increased numbers of autoreactive, melanocyte-specific CD8(+) T cells in the skin and blood, which are directly responsible for melanocyte destruction. We report that gene expression in lesional skin from vitiligo patients revealed an interferon-γ (IFN-γ)-specific signature, including the chemokine CXCL10. CXCL10 was elevated in both vitiligo patient skin and serum, and CXCR3, its receptor, was expressed on pathogenic T cells. To address the function of CXCL10 in vitiligo, we used a mouse model of disease that also exhibited an IFN-γ-specific gene signature, expression of CXCL10 in the skin, and up-regulation of CXCR3 on antigen-specific T cells. Mice that received Cxcr3(-/-) T cells developed minimal depigmentation, as did mice lacking Cxcl10 or treated with CXCL10-neutralizing antibody. CXCL9 promoted autoreactive T cell global recruitment to the skin but not effector function, whereas CXCL10 was required for effector function and localization within the skin. Surprisingly, CXCL10 neutralization in mice with established, widespread depigmentation induces reversal of disease, evidenced by repigmentation. These data identify a critical role for CXCL10 in both the progression and maintenance of vitiligo and thereby support inhibiting CXCL10 as a targeted treatment strategy.

in vivo neutralization of CXCL10, in vivo inhibition of T cell recruitment

Harris TH, Banigan EJ, Christian DA, Konradt C, Tait Wojno ED, Norose K, Wilson EH, John B, Weninger W, Luster AD, Liu AJ, Hunter CA. (2012). "Generalized Lévy walks and the role of chemokines in migration of effector CD8+ T cells" Nature 486(7404):545-8. PubMed

Chemokines have a central role in regulating processes essential to the immune function of T cells, such as their migration within lymphoid tissues and targeting of pathogens in sites of inflammation. Here we track T cells using multi-photon microscopy to demonstrate that the chemokine CXCL10 enhances the ability of CD8+ T cells to control the pathogen Toxoplasma gondii in the brains of chronically infected mice. This chemokine boosts T-cell function in two different ways: it maintains the effector T-cell population in the brain and speeds up the average migration speed without changing the nature of the walk statistics. Notably, these statistics are not Brownian; rather, CD8+ T-cell motility in the brain is well described by a generalized Lévy walk. According to our model, this unexpected feature enables T cells to find rare targets with more than an order of magnitude more efficiency than Brownian random walkers. Thus, CD8+ T-cell behaviour is similar to Lévy strategies reported in organisms ranging from mussels to marine predators and monkeys, and CXCL10 aids T cells in shortening the average time taken to find rare targets.

in vivo neutralization of CXCL10

Norose K, Kikumura A, Luster AD, Hunter CA, Harris TH. (2011). "CXCL10 is required to maintain T-cell populations and to control parasite replication during chronic ocular toxoplasmosis" Invest Ophthalmol Vis Sci 52(1):389-98. PubMed

Purpose: Toxoplasma gondii is a major cause of ocular disease, which can lead to permanent vision loss in humans. T cells are critically involved in parasite control, but little is known about the molecules that promote T-cell trafficking and migration in the retina. Thus, the aim of this study was to image and dissect the T-cell response during chronic toxoplasmic retinochoroiditis. Methods: C57BL/6 mice were infected with the Me49 strain of T. gondii, and T cells that infiltrated the eye were analyzed by flow cytometry and imaged using multiphoton microscopy. IFN-γ, CXCL9, CXCL10, and CXCR3 mRNA levels were measured by real-time PCR. To investigate the role of CXCL10, mice were treated with anti-CXCL10 antibodies, and histopathology and immunohistochemistry were performed to monitor changes in pathology, cellular infiltration, and parasite burden in the eye. Results: Infection with T. gondii leads to the infiltration of highly activated motile T cells into the eye. These cells express CXCR3 and are capable of producing IFN-γ and TNF-α, and CD8+ T cells express granzyme B. The expression of CXCL9 and CXCL10 in the retina was significantly upregulated during chronic infection. Treatment of chronically infected mice with anti-CXCL10 antibodies led to decreases in the numbers of CD3+, CD4+, and CD8+ T cells and the amount of IFN-γ mRNA expression in the retina and an increase in replicating parasites and ocular pathology. Conclusions: The maintenance of the T-cell response and the control of T. gondii in the eye during chronic infection is dependent on CXCL10.

in vitro neutralization of CXCL10

Christen S, Holdener M, Beerli C, Thoma G, Bayer M, Pfeilschifter JM, Hintermann E, Zerwes HG, Christen U. (2011). "Small molecule CXCR3 antagonist NIBR2130 has only a limited impact on type 1 diabetes in a virus-induced mouse model" Clin Exp Immunol 165(3):318-28. PubMed

CXCL10 is one of the key chemokines involved in trafficking of autoaggressive T cells to the islets of Langerhans during the autoimmune destruction of beta cells in type 1 diabetes (T1D). Blockade of CXCL10 or genetic deletion of its receptor CXCR3 results in a reduction of T1D in animal models. As an alternative to the use of neutralizing monoclonal antibodies to CXCL10 or CXCR3 we evaluated the small molecule CXCR3 antagonist NIBR2130 in a virus-induced mouse model for T1D. We found that the overall frequency of T1D was not reduced in mice administered with NIBR2130. An initial slight delay of diabetes onset was not stable over time, because the mice turned diabetic upon removal of the antagonist. Accordingly, no significant differences were found in the islet infiltration rate and the frequency and activity of islet antigen-specific T cells between protected mice administered with NIBR2130 and control mice. Our data indicate that in contrast to direct inhibition of CXCL10, blockade of CXCR3 with the small molecule antagonist NIBR2130 has no impact on trafficking and/or activation of autoaggressive T cells and is not sufficient to prevent T1D.

in vivo neutralization of CXCL10

Hintermann E, Bayer M, Pfeilschifter JM, Luster AD, Christen U. (2010). "CXCL10 promotes liver fibrosis by prevention of NK cell mediated hepatic stellate cell inactivation" J Autoimmun 35(4):424-35. PubMed

Chemokines, such as CXCL10, promote hepatic inflammation in chronic or acute liver injury through recruitment of leukocytes to the liver parenchyma. The CXCL10 receptor CXCR3, which is expressed on a subset of leukocytes, plays an important part in Th1-dependent inflammatory responses. Here, we investigated the role of CXCL10 in chemically induced liver fibrosis. We used carbon tetrachloride (CCl(4)) to trigger chronic liver damage in wildtype C57BL/6 and CXCL10-deficient mice. Fibrosis severity was assessed by Sirius Red staining and intrahepatic leukocyte subsets were investigated by immunohistochemistry. We have further analyzed hepatic stellate cell (HSC) distribution and activation and investigated the effect of CXCL10 on HSC motility and proliferation. In order to demonstrate a possible therapeutic intervention strategy, we have examined the anti-fibrotic potential of a neutralizing anti-CXCL10 antibody. Upon CCl(4) administration, CXCL10-deficient mice showed massively reduced liver fibrosis, when compared to wildtype mice. CXCL10-deficient mice had less B- and T lymphocyte and dendritic cell infiltrations within the liver and the number and activity of HSCs was reduced. In contrast, natural killer (NK) cells were more abundant in CXCL10-deficient mice and granzyme B expression was increased in areas with high numbers of NK cells. Further detailed analysis revealed that HSCs express CXCR3, respond to CXCL10 and secrete CXCL10 when stimulated with IFNγ. Blockade of CXCL10 with a neutralizing antibody exhibited a significant anti-fibrotic effect. Our data suggest that CXCL10 is a pro-fibrotic factor, which participates in a crosstalk between hepatocytes, HSCs and immune cells. NK cells seem to play an important role in controlling HSC activity and fibrosis. CXCL10 blockade may constitute a possible therapeutic intervention for hepatic fibrosis.

in vivo inhibition of T cell recruitment

Zhu X, Fallert-Junecko BA, Fujita M, Ueda R, Kohanbash G, Kastenhuber ER, McDonald HA, Liu Y, Kalinski P, Reinhart TA, Salazar AM, Okada H. (2010). "Poly-ICLC promotes the infiltration of effector T cells into intracranial gliomas via induction of CXCL10 in IFN-alpha and IFN-gamma dependent manners" Cancer Immunol Immunother 59(9):1401-9. PubMed

Stimulation of double-stranded (ds)RNA receptors can increase the effectiveness of cancer vaccines, but the underlying mechanisms are not completely elucidated. In this study, we sought to determine critical roles of host IFN-alpha and IFN-gamma pathways in the enhanced therapeutic efficacy mediated by peptide vaccines and polyinosinic-polycytidylic acid [poly(I:C)] stabilized by lysine and carboxymethylcellulose (poly-ICLC) in the murine central nervous system (CNS) GL261 glioma. C57BL/6-background wild type (WT), IFN-alpha receptor-1 (IFN-alphaR1)(-/-) or IFN-gamma(-/-) mice bearing syngeneic CNS GL261 glioma received subcutaneous (s.c.) vaccinations with synthetic peptides encoding CTL epitopes with or without intramuscular (i.m.) injections of poly-ICLC. The combinational treatment induced a robust transcription of CXCL10 in the glioma site. Blockade of CXCL10 with a specific monoclonal antibody (mAb) abrogated the efficient CNS homing of antigen-specific type-1 CTL (Tc1). Both IFN-alphaR(-/-) and IFN-gamma(-/-) hosts failed to up-regulate the CXCL10 mRNA and recruit Tc1 cells to the tumor site, indicating non-redundant roles of type-1 and type-2 IFNs in the effects of poly-ICLC-assisted vaccines. The efficient trafficking of Tc1 also required Tc1-derived IFN-gamma. Our data point to critical roles of the host-IFN-alpha and IFN-gamma pathways in the modulation of CNS glioma microenvironment, and the therapeutic effectiveness of poly-ICLC-assisted glioma vaccines.

in vivo inhibition of T cell recruitment

Campanella GS, Luster AD. (2009). "Chapter 18. A chemokine-mediated in vivo T-cell recruitment assay" Methods Enzymol . PubMed

The ability of chemokines to induce the migration of cells expressing their cognate G-protein-coupled receptor is a characteristic property of chemokine function. To study this important function, in vitro chemotaxis assays are most often used, which, although useful, lack many components of the complex in vivo trafficking process. Reliable in vivo recruitment assays have been very difficult to establish. We describe a robust in vivo T-cell recruitment assay for adoptively transferred T lymphocytes in mice. Instillation of the CXCR3 chemokine ligands IP-10/CXCL10 or I-TAC/CXCL11 into the airways results in robust recruitment of transferred T lymphocytes. The assay thereby models the natural environment of chemokine function, as chemokines are expressed in the airways during inflammation, inducing selective leukocyte homing. This assay is particularly useful for the analysis of chemokine and chemokine receptor mutants in structure function studies and for testing the in vivo efficacy of inhibitory chemokine and chemokine receptor antibodies and small molecule antagonists.

in vivo neutralization of CXCL10

Fujita M, Zhu X, Sasaki K, Ueda R, Low KL, Pollack IF, Okada H. (2008). "Inhibition of STAT3 promotes the efficacy of adoptive transfer therapy using type-1 CTLs by modulation of the immunological microenvironment in a murine intracranial glioma" J Immunol 180(4):2089-98. PubMed

A variety of cancers, including malignant gliomas, show aberrant activation of STAT3, which plays a pivotal role in negative regulation of antitumor immunity. We hypothesized that inhibition of STAT3 signals would improve the efficacy of T cell adoptive transfer therapy by reversal of STAT3-induced immunosuppression in a murine GL261 intracranial glioma model. In vitro treatment of GL261 cells with JSI-124, a STAT3 inhibitor, reversed highly phosphorylated status of STAT3. Systemic i.p. administration of JSI-124 in glioma-bearing immunocompetent mice, but not athymic mice, resulted in prolonged survival, suggesting a role of adaptive immunity in the antitumor effect. Furthermore, JSI-124 promoted maturation of tumor-infiltrating CD11c(+) dendritic cells and activation of tumor-conditioned cytotoxic T cells, enhanced dendritic cells and GL261 production of CXCL-10, a critical chemokine for attraction of Tc1 cells. When i.p. JSI-124 administration was combined with i.v. transfer of Pmel-I mouse-derived type-1 CTLs (Tc1), glioma-bearing mice exhibited prolonged survival compared with i.p. JSI-124 or i.v. Tc1 therapy alone. Flow cytometric analyses of brain infiltrating lymphocytes revealed that JSI-124-treatment enhanced the tumor-homing of i.v. transferred Tc1 cells in a CXCL-10-dependent fashion. Systemic JSI-124 administration also up-regulated serum IL-15 levels, and promoted the persistence of transferred Tc1 in the host. These data suggest that systemic inhibition of STAT3 signaling can reverse the suppressive immunological environment of intracranial tumor bearing mice both systemically and locally, thereby promoting the efficacy of adoptive transfer therapy with Tc1.

in vivo inhibition of T cell recruitment

Campanella GS, Medoff BD, Manice LA, Colvin RA, Luster AD. (2008). "Development of a novel chemokine-mediated in vivo T cell recruitment assay" J Immunol Methods 331(1-2):127-39. PubMed

Trafficking of leukocytes to sites of inflammation is an important step in the establishment of an immune response. Chemokines are critical regulators of leukocyte trafficking and are widely studied molecules for their important role in disease and for their potential as new therapeutic targets. The ability of chemokines to induce leukocyte recruitment has been mainly measured by in vitro chemotaxis assays, which lack many components of the complex biological process of leukocyte migration and therefore provide incomplete information about chemokine function in vivo. In vivo assays to study the activity of chemokines to induce leukocyte recruitment have been difficult to establish. We describe here the development of a robust in vivo recruitment assay for CD8(+) and CD4(+) T lymphocytes induced by the CXCR3 ligands IP-10 (CXCL10) and I-TAC (CXCL11). For this assay, in vitro activated T lymphocytes were adoptively transferred into the peritoneum of naïve mice. Homing of these transferred T lymphocytes into the airways was measured following intratracheal instillation of chemokines. High recruitment indices were achieved that were dependent on chemokine concentration and CXCR3 expression on the transferred lymphocytes. Recruitment was also inhibited by antibodies to the chemokine. The assay models the natural condition of chemokine-mediated lymphocyte migration into the airways as chemokines are expressed in the airways during inflammation. The nature of this model allows flexibility to study wildtype and mutant chemokines and chemokine receptors and the ability to evaluate chemokine antagonists and antibodies in vivo. This assay will therefore help elucidate a deeper understanding of the chemokine system in vivo.

in vivo neutralization of CXCL10

Shimizu M, Shimamura M, Owaki T, Asakawa M, Fujita K, Kudo M, Iwakura Y, Takeda Y, Luster AD, Mizuguchi J, Yoshimoto T. (2006). "Antiangiogenic and antitumor activities of IL-27" J Immunol 176(12):7317-24. PubMed

IL-27 is a novel IL-6/IL-12 family cytokine playing an important role in the early regulation of Th1 responses. We have recently demonstrated that IL-27 has potent antitumor activity, which is mainly mediated through CD8(+) T cells, against highly immunogenic murine colon carcinoma. In this study, we further evaluated the antitumor and antiangiogenic activities of IL-27, using poorly immunogenic murine melanoma B16F10 tumors, which were engineered to overexpress single-chain IL-27 (B16F10 + IL-27). B16F10 + IL-27 cells exerted antitumor activity against not only s.c. tumor but also experimental pulmonary metastasis. Similar antitumor and antimetastatic activities of IL-27 were also observed in IFN-gamma knockout mice. In NOD-SCID mice, these activities were decreased, but were still fairly well-retained, suggesting that different mechanisms other than the immune response are also involved in the exertion of these activities. Immunohistochemical analyses with Abs against vascular endothelial growth factor and CD31 revealed that B16F10 + IL-27 cells markedly suppressed tumor-induced neovascularization in lung metastases. Moreover, B16F10 + IL-27 cells clearly inhibited angiogenesis by dorsal air sac method, and IL-27 exhibited dose-dependent inhibition of angiogenesis on chick embryo chorioallantoic membrane. IL-27 was revealed to directly act on HUVECs and induce production of the antiangiogenic chemokines, IFN-gamma-inducible protein (IP-10) and monokine induced by IFN-gamma. Finally, augmented mRNA expression of IP-10 and monokine induced by IFN-gamma was detected at the s.c. B16F10 + IL-27 tumor site, and antitumor activity of IL-27 was partially inhibited by the administration of anti-IP-10. These results suggest that IL-27 possesses potent antiangiogenic activity, which plays an important role in its antitumor and antimetastatic activities.

in vitro neutralization of CXCL10, in vivo neutralization of CXCL10

Hyun JG, Lee G, Brown JB, Grimm GR, Tang Y, Mittal N, Dirisina R, Zhang Z, Fryer JP, Weinstock JV, Luster AD, Barrett TA. (2005). "Anti-interferon-inducible chemokine, CXCL10, reduces colitis by impairing T helper-1 induction and recruitment in mice" Inflamm Bowel Dis 11(9):799-805. PubMed

Background: Colitis in interleukin (IL)-10 mice is a CD4 T helper 1 (TH1)-mediated disease characterized by intermittent, transmural inflammation reminiscent of human Crohn's disease. In this study, we investigated the hypothesis that production of the CXC chemokine CXCL10 (interferon [IFN]gamma-inducible protein 10) enhances induction of inflammatory responses in draining lymph nodes (LNs) and promotes colonic TH1 cell recruitment. Methods: Colitis was induced in B6 IL-10 mice. Mice were given anti-CXCL10 mAb in 2-week intervals before and after peak colitis. Colitis severity was graded and cytokine/chemokine levels were analyzed by real-time polymerase chain reaction. Cell yields were quantitated and effector cell recruitment was assessed by recovery of transferred D011.10 TH1 cells shortly (72 h) after transfer. Results: Treatment with anti-CXCL10 during colitis development decreased clinical and histologic disease severity as well as cytokine/chemokine mRNA and accumulation of mononuclear cells in LNs and colon. Treatment of mice with severe colitis reduced colitis scores and cell yields to lesser degrees. Anti-CXCL10 specifically decreased recruitment of transferred TH1 cells into mesenteric LNs (MLNs) and colon of IL-10 mice by 75% (P<0.05). Conclusion: These results suggest that CXCL10 plays a dual role in colitis development by enhancing TH1 cell generation in inductive sites and promoting effector cell recruitment to inflamed tissue. Blockade of CXCL10 may be a useful adjunct to remission-inducing therapies in inflammatory bowel disease (IBD) by impairing disease recurrence through selective inhibition of effector cell generation and trafficking in vivo.

in vivo neutralization of CXCL10

Klein RS, Lin E, Zhang B, Luster AD, Tollett J, Samuel MA, Engle M, Diamond MS. (2005). "Neuronal CXCL10 directs CD8+ T-cell recruitment and control of West Nile virus encephalitis" J Virol 79(17):11457-66. PubMed

The activation and entry of antigen-specific CD8(+) T cells into the central nervous system is an essential step towards clearance of West Nile virus (WNV) from infected neurons. The molecular signals responsible for the directed migration of virus-specific T cells and their cellular sources are presently unknown. Here we demonstrate that in response to WNV infection, neurons secrete the chemokine CXCL10, which recruits effector T cells via the chemokine receptor CXCR3. Neutralization or a genetic deficiency of CXCL10 leads to a decrease in CXCR3(+) CD8(+) T-cell trafficking, an increase in viral burden in the brain, and enhanced morbidity and mortality. These data support a new paradigm in chemokine neurobiology, as neurons are not generally considered to generate antiviral immune responses, and CXCL10 may represent a novel neuroprotective agent in response to WNV infection in the central nervous system.

in vivo neutralization of CXCL10, in vivo inhibition of T cell recruitment

Christen U, McGavern DB, Luster AD, von Herrath MG, Oldstone MB. (2003). "Among CXCR3 chemokines, IFN-gamma-inducible protein of 10 kDa (CXC chemokine ligand (CXCL) 10) but not monokine induced by IFN-gamma (CXCL9) imprints a pattern for the subsequent development of autoimmune disease" J Immunol 171(12):6838-45. PubMed

Infection of the pancreas with lymphocytic choriomeningitis virus results in rapid and differential expression among CXCR3 chemokines. IFN-gamma-inducible protein of 10 kDa (IP-10), in contrast with monokine induced by IFN-gamma and IFN-inducible T cell-alpha chemoattractant, is strongly expressed within 24 h postinfection. Blocking of IP-10, but not monokine induced by IFN-gamma, aborts severity of Ag-specific injury of pancreatic beta cells and abrogates type 1 diabetes. Mechanistically, IP-10 blockade impedes the expansion of peripheral Ag-specific T cells and hinders their migration into the pancreas. IP-10 expression was restricted to viruses infecting the pancreas and that are capable of causing diabetes. Hence, virus-induced organ-specific autoimmune diseases may be dependent on virus tropism and its ability to alter the local milieu by selectively inducing chemokines that prepare the infected tissue for the subsequent destruction by the adaptive immune response.

ELISA

Krug A, Uppaluri R, Facchetti F, Dorner BG, Sheehan KC, Schreiber RD, Cella M, Colonna M. (2002). "IFN-producing cells respond to CXCR3 ligands in the presence of CXCL12 and secrete inflammatory chemokines upon activation" J Immunol 169(11):6079-83. PubMed

Human natural IFN-producing cells (IPC) circulate in the blood and cluster in chronically inflamed lymph nodes around high endothelial venules (HEV). Although L-selectin, CXCR4, and CCR7 are recognized as critical IPC homing mediators, the role of CXCR3 is unclear, since IPC do not respond to CXCR3 ligands in vitro. In this study, we show that migration of murine and human IPC to CXCR3 ligands in vitro requires engagement of CXCR4 by CXCL12. We also demonstrate that CXCL12 is present in human HEV in vivo. Moreover, after interaction with pathogenic stimuli, murine and human IPC secrete high levels of inflammatory chemokines. Thus, IPC migration into inflamed lymph nodes may be initially mediated by L-selectin, CXCL12, and CXCR3 ligands. Upon pathogen encounter, IPC positioning within the lymph node may be further directed by CCR7 and IPC secretion of inflammatory chemokines may attract other IPC, promoting cluster formation in lymph nodes.

in vivo neutralization of CXCL10, in vivo inhibition of T cell recruitment

Zhang Z, Kaptanoglu L, Haddad W, Ivancic D, Alnadjim Z, Hurst S, Tishler D, Luster AD, Barrett TA, Fryer J. (2002). "Donor T cell activation initiates small bowel allograft rejection through an IFN-gamma-inducible protein-10-dependent mechanism" J Immunol 168(7):3205-12. PubMed

The poor success in controlling small bowel (SB) allograft rejection is partially attributed to the unique immune environment in the donor intestine. We hypothesized that Ag-induced activation of donor-derived T cells contributes to the initiation of SB allograft rejection. To address the role of donor T cell activation in SB transplantation, SB grafts from DO11.10 TCR transgenic mice (BALB/c, H-2L(d+)) were transplanted into BALB/c (isografts), or single class I MHC-mismatched (L(d)-deficient) BALB/c H-2(dm2) (dm2, H-2L(d-)) mutant mice (allografts). Graft survival was followed after injection of control or antigenic OVA(323-339) peptide. Eighty percent of SB allografts developed severe rejection in mice treated with antigenic peptide, whereas <20% of allografts were rejected in mice treated with control peptide (p < 0.05). Isografts survived >30 days regardless of OVA(323-339) administration. Activation of donor T cells increased intragraft expression of proinflammatory cytokine (IFN-gamma) and CXC chemokine IFN-gamma-inducible protein-10 mRNA and enhanced activation and accumulation of host NK and T cells in SB allografts. Treatment of mice with neutralizing anti-IFN-gamma-inducible protein-10 mAb increased SB allograft survival in Ag-treated mice (67%; p < 0.05) and reduced accumulation of host T cells and NK cells in the lamina propria but not mesenteric lymph nodes. These results suggest that activation of donor T cells after SB allotransplantation induces production of a Th1-like profile of cytokines and CXC chemokines that enhance infiltration of host T cells and NK cells in SB allografts. Blocking this pathway may be of therapeutic value in controlling SB allograft rejection.

in vivo neutralization of CXCL10, in vivo inhibition of T cell recruitment

Pertl U, Luster AD, Varki NM, Homann D, Gaedicke G, Reisfeld RA, Lode HN. (2001). "IFN-gamma-inducible protein-10 is essential for the generation of a protective tumor-specific CD8 T cell response induced by single-chain IL-12 gene therapy" J Immunol 166(11):6944-51. PubMed

The successful induction of T cell-mediated protective immunity against poorly immunogenic malignancies remains a major challenge for cancer immunotherapy. Here, we demonstrate that the induction of tumor-protective immunity by IL-12 in a murine neuroblastoma model depends entirely on the CXC chemokine IFN-gamma-inducible protein 10 (IP-10). This was established by in vivo depletion of IP-10 with mAbs in mice vaccinated against NXS2 neuroblastoma by gene therapy with a linearized, single-chain (sc) version of the heterodimeric cytokine IL-12 (scIL-12). The efficacy of IP-10 depletion was indicated by the effective abrogation of scIL-12-mediated antiangiogenesis and T cell chemotaxis in mice receiving s.c. injections of scIL-12-producing NXS2 cells. These findings were extended by data demonstrating that IP-10 is directly involved in the generation of a tumor-protective CD8+ T cell-mediated immune response during the early immunization phase. Four lines of evidence support this contention: First, A/J mice vaccinated with NXS2 scIL-12 and depleted of IP-10 by two different anti-IP-10 mAbs revealed an abrogation of systemic-protective immunity against disseminated metastases. Second, CD8+ T cell-mediated MHC class I Ag-restricted tumor cell lysis was inhibited in such mice. Third, intracellular IFN-gamma expressed by proliferating CD8+ T cells was substantially inhibited in IP-10-depleted, scIL-12 NXS2-vaccinated mice. Fourth, systemic tumor protective immunity was completely abrogated in mice depleted of IP-10 in the early immunization phase, but not if IP-10 was depleted only in the effector phase. These findings suggest that IP-10 plays a crucial role during the early immunization phase in the induction of immunity against neuroblastoma by scIL-12 gene therapy.

in vivo neutralization of CXCL10, in vitro neutralization of CXCL10, ELISA, Western Blot, Functional Assays

Khan IA, MacLean JA, Lee FS, Casciotti L, DeHaan E, Schwartzman JD, Luster AD. (2000). "IP-10 is critical for effector T cell trafficking and host survival in Toxoplasma gondii infection" Immunity 12(5):483-94. PubMed

The generation of an adaptive immune response against intracellular pathogens requires the recruitment of effector T cells to sites of infection. Here we show that the chemokine IP-10, a specific chemoattractant for activated T cells, controls this process in mice naturally infected with Toxoplasma gondii. Neutralization of IP-10 in infected mice inhibited the massive influx of T cells into tissues and impaired antigen-specific T cell effector functions. This resulted in >1000-fold increase in tissue parasite burden and a marked increase in mortality compared to control antibody-treated mice. These observations suggest that IP-10 may play a broader role in the localization and function of effector T cells at sites of Th1 inflammation.