Stimulation of lymphangiogenesis via VEGFR-3 inhibits chronic skin inflammationHuggenberger, Reto; Ullmann, Stefan; Proulx, Steven T.; Pytowski, Bronislaw; Alitalo, Kari; Detmar, Michael
doi: 10.1084/jem.20100559pmid: 20837699
The role of lymphangiogenesis in inflammation has remained unclear. To investigate the role of lymphatic versus blood vasculature in chronic skin inflammation, we inhibited vascular endothelial growth factor (VEGF) receptor (VEGFR) signaling by function-blocking antibodies in the established keratin 14 (K14)–VEGF-A transgenic (Tg) mouse model of chronic cutaneous inflammation. Although treatment with an anti–VEGFR-2 antibody inhibited skin inflammation, epidermal hyperplasia, inflammatory infiltration, and angiogenesis, systemic inhibition of VEGFR-3, surprisingly, increased inflammatory edema formation and inflammatory cell accumulation despite inhibition of lymphangiogenesis. Importantly, chronic Tg delivery of the lymphangiogenic factor VEGF-C to the skin of K14-VEGF-A mice completely inhibited development of chronic skin inflammation, epidermal hyperplasia and abnormal differentiation, and accumulation of CD8 T cells. Similar results were found after Tg delivery of mouse VEGF-D that only activates VEGFR-3 but not VEGFR-2. Moreover, intracutaneous injection of recombinant VEGF-C156S, which only activates VEGFR-3, significantly reduced inflammation. Although lymphatic drainage was inhibited in chronic skin inflammation, it was enhanced by Tg VEGF-C delivery. Together, these results reveal an unanticipated active role of lymphatic vessels in controlling chronic inflammation. Stimulation of functional lymphangiogenesis via VEGFR-3, in addition to antiangiogenic therapy, might therefore serve as a novel strategy to treat chronic inflammatory disorders of the skin and possibly also other organs. Submitted: 19 March 2010 Accepted: 19 August 2010 This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms ). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/ ).
Engulfment of cerebral apoptotic bodies controls the course of prion disease in a mouse strain–dependent mannerKranich, Jan; Krautler, Nike Julia; Falsig, Jeppe; Ballmer, Boris; Li, Shulei; Hutter, Gregor; Schwarz, Petra; Moos, Rita; Julius, Christian; Miele, Gino; Aguzzi, Adriano
doi: 10.1084/jem.20092401pmid: 20837697
Progressive accumulation of PrP Sc , a hallmark of prion diseases, occurs when conversion of PrP C into PrP Sc is faster than PrP Sc clearance. Engulfment of apoptotic bodies by phagocytes is mediated by Mfge8 (milk fat globule epidermal growth factor 8). In this study, we show that brain Mfge8 is primarily produced by astrocytes. Mfge8 ablation induced accelerated prion disease and reduced clearance of cerebellar apoptotic bodies in vivo, as well as excessive PrP Sc accumulation and increased prion titers in prion-infected C57BL/6 × 129Sv mice and organotypic cerebellar slices derived therefrom. These phenotypes correlated with the presence of 129Sv genomic markers in hybrid mice and were not observed in inbred C57BL/6 Mfge8 −/− mice, suggesting the existence of additional strain-specific genetic modifiers. Because Mfge8 receptors are expressed by microglia and depletion of microglia increases PrP Sc accumulation in organotypic cerebellar slices, we conclude that engulfment of apoptotic bodies by microglia may be an important pathway of prion clearance controlled by astrocyte-borne Mfge8. Submitted: 9 November 2009 Accepted: 11 August 2010 This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites licen se for the first six months after the publication date (see http://www.rupress.org/terms ). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/ ).
Somatic hypermutation as a generator of antinuclear antibodies in a murine model of systemic autoimmunityGuo, Wenzhong; Smith, Diana; Aviszus, Katja; Detanico, Thiago; Heiser, Ryan A.; Wysocki, Lawrence J.
doi: 10.1084/jem.20092712pmid: 20805563
Systemic lupus erythematosus (SLE) is characterized by high-avidity IgG antinuclear antibodies (ANAs) that are almost certainly products of T cell–dependent immune responses. Whether critical amino acids in the third complementarity-determining region (CDR3) of the ANA originate from V(D)J recombination or somatic hypermutation (SHM) is not known. We studied a mouse model of SLE in which all somatic mutations within ANA V regions, including those in CDR3, could be unequivocally identified. Mutation reversion analyses revealed that ANA arose predominantly from nonautoreactive B cells that diversified immunoglobulin genes via SHM. The resolution afforded by this model allowed us to demonstrate that one ANA clone was generated by SHM after a V H gene replacement event. Mutations producing arginine substitutions were frequent and arose largely (66%) from base changes in just two codons: AGC and AGT. These codons are abundant in the repertoires of mouse and human V genes. Our findings reveal the predominant role of SHM in the development of ANA and underscore the importance of self-tolerance checkpoints at the postmutational stage of B cell differentiation. Submitted: 21 December 2009 Accepted: 12 July 2010 This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms ). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/ ).
MHC class I–deficient natural killer cells acquire a licensed phenotype after transfer into an MHC class I–sufficient environmentElliott, Julie M.; Wahle, Joseph A.; Yokoyama, Wayne M.
doi: 10.1084/jem.20100986pmid: 20819924
In MHC class I–deficient hosts, natural killer (NK) cells are hyporesponsive to cross-linking of activation receptors. Functional competence requires engagement of a self–major histocompatability complex (MHC) class I–specific inhibitory receptor, a process referred to as “licensing.” We previously suggested that licensing is developmentally determined in the bone marrow. In this study, we find that unlicensed mature MHC class I–deficient splenic NK cells show gain-of-function and acquire a licensed phenotype after adoptive transfer into wild-type (WT) hosts. Transferred NK cells produce WT levels of interferon-γ after engagement of multiple activation receptors, and degranulate at levels equivalent to WT NK cells upon coincubation with target cells. Only NK cells expressing an inhibitory Ly49 receptor specific for a cognate host MHC class I molecule show this gain-of-function. Therefore, these findings, which may be relevant to clinical bone marrow transplantation, suggest that neither exposure to MHC class I ligands during NK development in the BM nor endogenous MHC class I expression by NK cells themselves is absolutely required for licensing. Submitted: 18 May 2010 Accepted: 4 August 2010 This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms ). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/ ).
CD11c depletion severely disrupts Th2 induction and development in vivoPhythian-Adams, Alexander T.; Cook, Peter C.; Lundie, Rachel J.; Jones, Lucy H.; Smith, Katherine A.; Barr, Tom A.; Hochweller, Kristin; Anderton, Stephen M.; Hämmerling, Günter J.; Maizels, Rick M.; MacDonald, Andrew S.
doi: 10.1084/jem.20100734pmid: 20819926
Although dendritic cells (DCs) are adept initiators of CD4 + T cell responses, their fundamental importance in this regard in Th2 settings remains to be demonstrated. We have used CD11c–diphtheria toxin (DTx) receptor mice to deplete CD11c + cells during the priming stage of the CD4 + Th2 response against the parasitic helminth Schistosoma mansoni . DTx treatment significantly depleted CD11c + DCs from all tissues tested, with 70–80% efficacy. Even this incomplete depletion resulted in dramatically impaired CD4 + T cell production of Th2 cytokines, altering the balance of the immune response and causing a shift toward IFN-γ production. In contrast, basophil depletion using Mar-1 antibody had no measurable effect on Th2 induction in this system. These data underline the vital role that CD11c + antigen-presenting cells can play in orchestrating Th2 development against helminth infection in vivo, a response that is ordinarily balanced so as to prevent the potentially damaging production of inflammatory cytokines. Submitted: 15 April 2010 Accepted: 6 August 2010 This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms ). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/ ).
The Ets-1 transcription factor controls the development and function of natural regulatory T cellsMouly, Enguerran; Chemin, Karine; Nguyen, Hai Vu; Chopin, Martine; Mesnard, Laurent; Leite-de-Moraes, Maria; Burlen-defranoux, Odile; Bandeira, Antonio; Bories, Jean-Christophe
doi: 10.1084/jem.20092153pmid: 20855499
Regulatory T cells (T reg cells) constitute a population of CD4 + T cells that limits immune responses. The transcription factor Foxp3 is important for determining the development and function of T reg cells; however, the molecular mechanisms that trigger and maintain its expression remain incompletely understood. In this study, we show that mice deficient for the Ets-1 transcription factor ( Ets-1 −/− ) developed T cell–mediated splenomegaly and systemic autoimmunity that can be blocked by functional wild-type T reg cells. Spleens of Ets-1 −/− mice contained mostly activated T cells, including Th2-polarized CD4 + cells and had reduced percentages of T reg cells. Splenic and thymic Ets-1 −/− T reg cells expressed low levels of Foxp3 and displayed the CD103 marker that characterizes antigen-experienced T reg cells. Thymic development of Ets-1 −/− T reg cells appeared intrinsically altered as Foxp3-expressing cells differentiate poorly in mixed fetal liver reconstituted chimera and fetal thymic organ culture. Ets-1 −/− T reg cells showed decreased in vitro suppression activity and did not protect Rag2 −/− hosts from naive T cell–induced inflammatory bowel disease. Furthermore, in T reg cells, Ets-1 interacted with the Foxp3 intronic enhancer and was required for demethylation of this regulatory sequence. These data demonstrate that Ets-1 is required for the development of natural T reg cells and suggest a role for this transcription factor in the regulation of Foxp3 expression. Submitted: 5 October 2009 Accepted: 11 August 2010 This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms ). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/ ).
Upregulation of Tim-3 and PD-1 expression is associated with tumor antigen–specific CD8+ T cell dysfunction in melanoma patientsFourcade, Julien; Sun, Zhaojun; Benallaoua, Mourad; Guillaume, Philippe; Luescher, Immanuel F.; Sander, Cindy; Kirkwood, John M.; Kuchroo, Vijay; Zarour, Hassane M.
doi: 10.1084/jem.20100637pmid: 20819923
The paradoxical coexistence of spontaneous tumor antigen–specific immune responses with progressive disease in cancer patients furthers the need to dissect the molecular pathways involved in tumor-induced T cell dysfunction. In patients with advanced melanoma, we have previously shown that the cancer-germline antigen NY-ESO-1 stimulates spontaneous NY-ESO-1–specific CD8 + T cells that up-regulate PD-1 expression. We also observed that PD-1 regulates NY-ESO-1–specific CD8 + T cell expansion upon chronic antigen stimulation. In the present study, we show that a fraction of PD-1 + NY-ESO-1–specific CD8 + T cells in patients with advanced melanoma up-regulates Tim-3 expression and that Tim-3 + PD-1 + NY-ESO-1–specific CD8 + T cells are more dysfunctional than Tim-3 − PD-1 + and Tim-3 − PD-1 − NY-ESO-1–specific CD8 + T cells, producing less IFN-γ, TNF, and IL-2. Tim-3–Tim-3L blockade enhanced cytokine production by NY-ESO-1–specific CD8 + T cells upon short ex vivo stimulation with cognate peptide, thus enhancing their functional capacity. In addition, Tim-3–Tim-3L blockade enhanced cytokine production and proliferation of NY-ESO-1–specific CD8 + T cells upon prolonged antigen stimulation and acted in synergy with PD-1–PD-L1 blockade. Collectively, our findings support the use of Tim-3–Tim-3L blockade together with PD-1–PD-L1 blockade to reverse tumor-induced T cell exhaustion/dysfunction in patients with advanced melanoma. Submitted: 31 March 2010 Accepted: 3 August 2010 This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms ). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/ ).
IAP inhibitors enhance co-stimulation to promote tumor immunityDougan, Michael; Dougan, Stephanie; Slisz, Joanna; Firestone, Brant; Vanneman, Matthew; Draganov, Dobrin; Goyal, Girija; Li, Weibo; Neuberg, Donna; Blumberg, Richard; Hacohen, Nir; Porter, Dale; Zawel, Leigh; Dranoff, Glenn
doi: 10.1084/jem.20101123pmid: 20837698
The inhibitor of apoptosis proteins (IAPs) have recently been shown to modulate nuclear factor κB (NF-κB) signaling downstream of tumor necrosis factor (TNF) family receptors, positioning them as essential survival factors in several cancer cell lines, as indicated by the cytotoxic activity of several novel small molecule IAP antagonists. In addition to roles in cancer, increasing evidence suggests that IAPs have an important function in immunity; however, the impact of IAP antagonists on antitumor immune responses is unknown. In this study, we examine the consequences of IAP antagonism on T cell function in vitro and in the context of a tumor vaccine in vivo. We find that IAP antagonists can augment human and mouse T cell responses to physiologically relevant stimuli. The activity of IAP antagonists depends on the activation of NF-κB2 signaling, a mechanism paralleling that responsible for the cytotoxic activity in cancer cells. We further show that IAP antagonists can augment both prophylactic and therapeutic antitumor vaccines in vivo. These findings indicate an important role for the IAPs in regulating T cell–dependent responses and suggest that targeting IAPs using small molecule antagonists may be a strategy for developing novel immunomodulating therapies against cancer. Submitted: 4 June 2010 Accepted: 10 August 2010 This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms ). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/ ).
Re-educating natural killer cellsSun, Joseph C.
doi: 10.1084/jem.20101748pmid: 20876314
The development and function of natural killer (NK) cells is dictated by signals received through activating and inhibitory receptors expressed on the cell surface. During their maturation in the bone marrow, NK cells undergo an education process that ensures they are tolerant to healthy peripheral tissues. Several recent studies advance our understanding of self-tolerance mechanisms at work in NK cells. These studies demonstrate that the developmental programming in NK cells is not fixed, and that perturbations to the peripheral environment (via transplantation or viral infection, for example) greatly influence the ability of mature NK cells to mount an effector response. This newfound ability of mature NK cells to be “re-educated” may be clinically applicable in the immunotherapeutic use of NK cells against infection and cancer. Submitted: 19 August 2010 Accepted: 30 August 2010 This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms ). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/ ).