http://www.jci.org/current en-us 2012 The American Society for Clinical Investigation http://www.jci.org/icons/banner/rss_title.gif http://content.jci.org http://www.jci.org/articles/view/64042 JCI and I have loved it truly, madly, and deeply for the last nine years. Alas, I’ll have to learn to love the Journal from afar, as tomorrow marks my last official day as Executive Editor. To quote Chaucer, “There is an end to everything, to good things as well.” ]]> info:doi/10.1172/JCI64042 American Society for Clinical Investigation http://www.jci.org/articles/view/64244 info:doi/10.1172/JCI64244 American Society for Clinical Investigation http://www.jci.org/articles/view/64110 info:doi/10.1172/JCI64110 American Society for Clinical Investigation http://www.jci.org/articles/view/60020 info:doi/10.1172/JCI60020 American Society for Clinical Investigation http://www.jci.org/articles/view/62990 info:doi/10.1172/JCI62990 American Society for Clinical Investigation http://www.jci.org/articles/view/62966 info:doi/10.1172/JCI62966 American Society for Clinical Investigation http://www.jci.org/articles/view/63066 JCI, Moiani et al. and Cesana et al. investigate how viral vectors can induce aberrant splicing, resulting in chimeric cellular-viral transcripts. The finding that this is a general phenomenon is concerning, but some of their results do suggest approaches for the development of safeguards in gene therapy vector design. ]]> info:doi/10.1172/JCI63066 American Society for Clinical Investigation http://www.jci.org/articles/view/63190 JCI, Gomez de Agüero et al. describe an elegant series of experiments that implicate LCs in tolerance induction, positioning these cells as key regulators of immunologic barrier function. ]]> info:doi/10.1172/JCI63190 American Society for Clinical Investigation http://www.jci.org/articles/view/63248 info:doi/10.1172/JCI63248 American Society for Clinical Investigation http://www.jci.org/articles/view/63417 JCI, De Luca and colleagues describe the ontogeny of adaptive immune responses to murine aspergillosis infection in relation to vaccination. Their thought-provoking findings reveal the complexities of vaccine-induced immunity and could be used to improve vaccine efficacy. ]]> info:doi/10.1172/JCI63417 American Society for Clinical Investigation http://www.jci.org/articles/view/63389 JCI, Dyavar Shetty et al. demonstrate that blocking PD-1 actually reduced proinflammatory responses and improved immunity in the gut of SIV-infected rhesus macaques, suggesting that this might have therapeutic potential to prevent opportunistic infections in HIV-infected patients. ]]> info:doi/10.1172/JCI63389 American Society for Clinical Investigation http://www.jci.org/articles/view/60644 + T cells. DNGR-1 regulated cross-priming in non-infectious settings such as immunization with antigen-bearing dead cells, as well as in highly immunogenic situations such as infection with herpes simplex virus type 1. Together, these results suggest that DNGR-1 is a dedicated receptor for cross-presentation of cell-associated antigens. Our work thus underscores the importance of cross-priming in immunity and indicates that antigenicity and adjuvanticity can be decoded by distinct innate immune receptors. The identification of specialized receptors that regulate antigenicity of virus-infected cells reveals determinants of antiviral immunity that might underlie the human response to infection and vaccination. ]]> info:doi/10.1172/JCI60644 American Society for Clinical Investigation http://www.jci.org/articles/view/60660 + T cells in vitro. Following injection of VACV or VACV-infected cells into mice, DNGR-1 detected the ligand in dying infected cells and mediated cross-priming of anti-VACV CD8⁺ T cells. Loss of DNGR-1 impaired the CD8⁺ cytotoxic response to VACV, especially against those virus strains that are most dependent on cross-presentation. The decrease in total anti-VACV CTL activity was associated with a profound increase in viral load and delayed resolution of the primary lesion. In addition, lack of DNGR-1 markedly diminished protection from infection induced by vaccination with the modified vaccinia Ankara (MVA) strain. DNGR-1 thus contributes to anti-VACV immunity, following both primary infection and vaccination. The non-redundant ability of DNGR-1 to regulate cross-presentation of viral antigens suggests that this form of regulation of antiviral immunity could be exploited for vaccination. ]]> info:doi/10.1172/JCI60660 American Society for Clinical Investigation http://www.jci.org/articles/view/61429 + T cells. Thus, naturally occurring SIVcpz strains are capable of infecting HLTs, the major site of HIV-1 replication in vivo. However, efficient replication requires the acquisition of a host-specific adaptation in the viral matrix protein. These results identify Gag matrix as a major determinant of SIVcpz replication fitness in humans and suggest a critical role in the emergence of HIV/AIDS. ]]> info:doi/10.1172/JCI61429 American Society for Clinical Investigation http://www.jci.org/articles/view/61852 gag gene as well as in the β-globin gene and LCR. Compared with constitutively spliced transcripts, most aberrant transcripts accumulated at a low level, at least in part as a consequence of nonsense-mediated mRNA degradation. A limited set of cryptic splice sites caused the majority of aberrant splicing events, providing a strategy for recoding lentiviral vector backbones and transgenes to reduce their potential posttranscriptional genotoxicity. ]]> info:doi/10.1172/JCI61852 American Society for Clinical Investigation http://www.jci.org/articles/view/62189 HMGA2 gene induced the formation of an aberrantly spliced mRNA form that appeared to cause clonal dominance. Using a method that we developed, cDNA linear amplification-mediated PCR, in combination with high-throughput sequencing, we conducted a whole transcriptome analysis of chimeric LV-cellular fusion transcripts in transduced human lymphoblastoid cells and primary hematopoietic stem/progenitor cells. We observed a surprising abundance of read-through transcription originating outside and inside the provirus and identified the vector sequences contributing to the aberrant splicing process. We found that SIN LV has a sharply reduced propensity to engage in aberrant splicing compared with that of vectors carrying active LTRs. Moreover, by recoding the identified vector splice sites, we reduced residual read-through transcription and demonstrated an effective strategy for improving vectors. Characterization of the mechanisms and genetic features underlying vector-induced aberrant splicing will enable the generation of safer vectors, with low impact on the cellular transcriptome. ]]> info:doi/10.1172/JCI62189 American Society for Clinical Investigation http://www.jci.org/articles/view/61248 SORT1), which encodes a protein thought to be involved in apoB trafficking and degradation. Here, we investigated the regulation of Sort1 expression in mouse models of obesity. Sort1 expression was markedly repressed in both genetic (ob/ob) and high-fat diet models of obesity; restoration of hepatic sortilin-1 levels resulted in reduced triglyceride and apoB secretion. Mouse models of obesity also exhibit increased hepatic activity of mammalian target of rapamycin complex 1 (mTORC1) and ER stress, and we found that administration of the mTOR inhibitor rapamycin to ob/ob mice reduced ER stress and increased hepatic sortilin-1 levels. Conversely, genetically increased hepatic mTORC1 activity was associated with repressed Sort1 and increased apoB secretion. Treating WT mice with the ER stressor tunicamycin led to marked repression of hepatic sortilin-1 expression, while administration of the chemical chaperone PBA to ob/ob mice led to amelioration of ER stress, increased sortilin-1 expression, and reduced apoB and triglyceride secretion. Moreover, the ER stress target Atf3 acted at the SORT1 promoter region as a transcriptional repressor, whereas knockdown of Atf3 mRNA in ob/ob mice led to increased hepatic sortilin-1 levels and decreased apoB and triglyceride secretion. Thus, in mouse models of obesity, induction of mTORC1 and ER stress led to repression of hepatic Sort1 and increased VLDL secretion via Atf3. This pathway may contribute to dyslipidemia in metabolic disease. ]]> info:doi/10.1172/JCI61248 American Society for Clinical Investigation http://www.jci.org/articles/view/59817 info:doi/10.1172/JCI59817 American Society for Clinical Investigation http://www.jci.org/articles/view/59725 + T cell–mediated contact hypersensitivity (CHS) reactions triggered at the site of contact by a variety of chemicals, also known as weak haptens, present in fragrances, dyes, metals, preservatives, and drugs. Despite the myriad of potentially allergenic substances that can penetrate the skin, sensitization is relatively rare and immune tolerance to the substance is often induced by as yet poorly understood mechanisms. Here we show, using the innocuous chemical 2,4-dinitrothiocyanobenzene (DNTB), that cutaneous immune tolerance in mice critically depends on epidermal Langerhans cells (LCs), which capture DNTB and migrate to lymph nodes for direct presentation to CD8⁺ T cells. Depletion and adoptive transfer experiments revealed that LCs conferred protection from development of CHS by a mechanism involving both anergy and deletion of allergen-specific CD8⁺ T cells and activation of a population of T cells identified as ICOS⁺CD4⁺Foxp3⁺ Tregs. Our findings highlight the critical role of LCs in tolerance induction in mice to the prototype innocuous hapten DNTB and suggest that strategies targeting LCs might be valuable for prevention of cutaneous allergy. ]]> info:doi/10.1172/JCI59725 American Society for Clinical Investigation http://www.jci.org/articles/view/60612 + T cells during chronic infections, and in vivo PD-1 blockade has been shown to improve viral control of SIV. Here, we show that PD-1 blockade during chronic SIV infection markedly reduced the expression of transcripts associated with type I IFN signaling in the blood and colorectal tissue of rhesus macaques (RMs). The effect of PD-1 blockade on type I IFN signaling was durable and persisted even under conditions of high viremia. Reduced type I IFN signaling was associated with enhanced expression of some of the junction-associated genes in colorectal tissue and with a profound decrease in plasma LPS levels, suggesting a possible repair of gut-associated junctions and decreased microbial translocation into the blood. PD-1 blockade enhanced immunity to gut-resident pathogenic bacteria, control of gut-associated opportunistic infections, and survival of SIV-infected RMs. Our results suggest PD-1 blockade as a potential novel therapeutic approach to enhance combination antiretroviral therapy by suppressing hyperimmune activation in HIV-infected individuals. ]]> info:doi/10.1172/JCI60612 American Society for Clinical Investigation http://www.jci.org/articles/view/60530 Lactococcus lactis genetically modified to secrete the whole proinsulin autoantigen along with the immunomodulatory cytokine IL-10. We show that combination therapy with low-dose systemic anti-CD3 stably reverted diabetes in NOD mice and increased frequencies of local Tregs, which not only accumulated in the pancreatic islets, but also suppressed immune response in an autoantigen-specific way. Cured mice remained responsive to disease-unrelated antigens, which argues against excessive immunosuppression. Application of this therapeutic tool achieved gut mucosal delivery of a diabetes-relevant autoantigen and a biologically active immunomodulatory cytokine, IL-10, and, when combined with a low dose of systemic anti-CD3, was well tolerated and induced autoantigen-specific long-term tolerance, allowing reversal of established autoimmune diabetes. Therefore, we believe this method could be an effective treatment strategy for type 1 diabetes in humans. ]]> info:doi/10.1172/JCI60530 American Society for Clinical Investigation http://www.jci.org/articles/view/61403 RB gene mutations, but the subsequent cooperating mutational events leading to tumorigenesis are poorly characterized. We investigated what these additional genomic alterations might be using human retinoblastoma samples and mouse models. Array-based comparative genomic hybridization studies revealed deletions in the CDKN2A locus that include ARF and P16INK4A, both of which encode tumor suppressor proteins, in both human and mouse retinoblastoma. Through mouse genetic analyses, we found that Arf was the critical tumor suppressor gene in the deleted region. In mice, inactivation of one allele of Arf cooperated with Rb and p107 loss to rapidly accelerate retinoblastoma, with frequent loss of heterozygosity (LOH) at the Arf locus. Arf has been reported to exhibit p53-independent tumor suppressor roles in other systems; however, our results showed no additive effect of p53 and Arf coinactivation in promoting retinoblastoma. Moreover, p53 inactivation completely eliminated any selection for Arf LOH. Thus, our data reveal important insights into the p53 pathway in retinoblastoma and show that Arf is a key collaborator with Rb in retinoblastoma suppression. ]]> info:doi/10.1172/JCI61403 American Society for Clinical Investigation http://www.jci.org/articles/view/62385 info:doi/10.1172/JCI62385 American Society for Clinical Investigation http://www.jci.org/articles/view/61976 FERMT1) and clinically characterized by patchy skin pigmentation and atrophy. All patients presented duplication mutations (c.456dupA and c.676dupC) in FERMT1, and slipped mispairing in direct nucleotide repeats was identified as the reversion mechanism in all investigated revertant skin spots. The sequence around the mutations demonstrated high propensity to mutations, favoring both microinsertions and microdeletions. Additionally, in some revertant patches, mitotic recombination generated areas with homozygous normal keratinocytes. Restoration of kindlin-1 expression led to clinically and structurally normal skin. Since loss of kindlin-1 severely impairs keratinocyte proliferation, we predict that revertant cells have a selective advantage that allows their clonal expansion and, consequently, the improvement of the skin condition. ]]> info:doi/10.1172/JCI61976 American Society for Clinical Investigation http://www.jci.org/articles/view/60688 2 regulates many proinflammatory processes, including swelling and pain, and it is induced by LPS, we hypothesized that PGE₂ mediates the local generation of edema following LPS exposure. Here, we show that tissue-resident DCs are the main source of PGE₂ and the main controllers of tissue edema formation in a mouse model of LPS-induced inflammation. LPS exposure induced expression of microsomal PGE synthase-1 (mPGES-1), a key enzyme in PGE₂ biosynthesis. mPGES-1 activation, PGE₂ production, and edema formation required CD14 (a component of the LPS receptor) and NFAT. Therefore, tissue edema formation induced by LPS is DC and CD14/NFAT dependent. Moreover, DCs can regulate free antigen arrival at the draining lymph nodes by controlling edema formation and interstitial fluid pressure in the presence of LPS. We therefore suggest that the CD14/NFAT/mPGES-1 pathway represents a possible target for antiinflammatory therapies. ]]> info:doi/10.1172/JCI60688 American Society for Clinical Investigation http://www.jci.org/articles/view/59408 info:doi/10.1172/JCI59408 American Society for Clinical Investigation http://www.jci.org/articles/view/59581 Trim32 knockout mice (Trim32^–/– mice) and showed that they display a myopathic phenotype accompanied by neurogenic features. Here, we used these mice to investigate the muscle-specific defects arising from the absence of TRIM32, which underlie the myopathic phenotype. Using 2 models of induced atrophy, we showed that TRIM32 is dispensable for muscle atrophy. Conversely, TRIM32 was necessary for muscle regrowth after atrophy. Furthermore, TRIM32-deficient primary myoblasts underwent premature senescence and impaired myogenesis due to accumulation of PIAS4, an E3 SUMO ligase and TRIM32 substrate that was previously shown to be associated with senescence. Premature senescence of myoblasts was also observed in vivo in an atrophy/regrowth model. Trim32^–/– muscles had substantially fewer activated satellite cells, increased PIAS4 levels, and growth failure compared with wild-type muscles. Moreover, Trim32^–/– muscles exhibited features of premature sarcopenia, such as selective type II fast fiber atrophy. These results imply that premature senescence of muscle satellite cells is an underlying pathogenic feature of LGMD2H and reveal what we believe to be a new mechanism of muscular dystrophy associated with reductions in available satellite cells and premature sarcopenia. ]]> info:doi/10.1172/JCI59581 American Society for Clinical Investigation http://www.jci.org/articles/view/46490 info:doi/10.1172/JCI46490 American Society for Clinical Investigation http://www.jci.org/articles/view/59920 info:doi/10.1172/JCI59920 American Society for Clinical Investigation http://www.jci.org/articles/view/60975 info:doi/10.1172/JCI60975 American Society for Clinical Investigation http://www.jci.org/articles/view/45890 2D], which can elicit calcium mobilization from bone when intestinal calcium absorption is decreased. The skeletal adaptations, however, are still poorly characterized. To gain insight into these issues, we analyzed the consequences of specific vitamin D receptor (Vdr) inactivation in the intestine and in mature osteoblasts on calcium and bone homeostasis. We report here that decreased intestinal calcium absorption in intestine-specific Vdr knockout mice resulted in severely reduced skeletal calcium levels so as to ensure normal levels of calcium in the serum. Furthermore, increased 1,25(OH)₂D levels not only stimulated bone turnover, leading to osteopenia, but also suppressed bone matrix mineralization. This resulted in extensive hyperosteoidosis, also surrounding the osteocytes, and hypomineralization of the entire bone cortex, which may have contributed to the increase in bone fractures. Mechanistically, osteoblastic VDR signaling suppressed calcium incorporation in bone by directly stimulating the transcription of genes encoding mineralization inhibitors. Ablation of skeletal Vdr signaling precluded this calcium transfer from bone to serum, leading to better preservation of bone mass and mineralization. These findings indicate that in mice, maintaining normocalcemia has priority over skeletal integrity, and that to minimize skeletal calcium storage, 1,25(OH)₂D not only increases calcium release from bone, but also inhibits calcium incorporation in bone. ]]> info:doi/10.1172/JCI45890 American Society for Clinical Investigation http://www.jci.org/articles/view/60862 Aspergillus fumigatus is a model fungal pathogen and a common cause of infection in individuals with the primary immunodeficiency chronic granulomatous disease (CGD). Although primarily considered a deficiency of innate immunity, CGD is also linked to dysfunctional T cell reactivity. Both CD4⁺ and CD8⁺ T cells mediate vaccine-induced protection from experimental aspergillosis, but the molecular mechanisms leading to the generation of protective immunity and whether these mechanisms are dysregulated in individuals with CGD have not been determined. Here, we show that activation of either T cell subset in a mouse model of CGD is contingent upon the nature of the fungal vaccine, the involvement of distinct innate receptor signaling pathways, and the mode of antigen routing and presentation in DCs. Aspergillus conidia activated CD8⁺ T cells upon sorting to the Rab14⁺ endosomal compartment required for alternative MHC class I presentation. Cross-priming of CD8⁺ T cells failed to occur in mice with CGD due to defective DC endosomal alkalinization and autophagy. However, long-lasting antifungal protection and disease control were successfully achieved upon vaccination with purified fungal antigens that activated CD4⁺ T cells through the endosome/lysosome pathway. Our study thus indicates that distinct intracellular pathways are exploited for the priming of CD4⁺ and CD8⁺ T cells to A. fumigatus and suggests that CD4⁺ T cell vaccination may be able to overcome defective antifungal CD8⁺ T cell memory in individuals with CGD. ]]> info:doi/10.1172/JCI60862 American Society for Clinical Investigation http://www.jci.org/articles/view/58976 2 mice. By improving cancer tissue oxygenation and extending the normalization window, Sema3A counteracted sunitinib-induced activation of HIF-1α, Met tyrosine kinase receptor, epithelial-mesenchymal transition (EMT), and other hypoxia-dependent signaling pathways. Sema3A also reduced tumor hypoxia and halted cancer dissemination induced by DC101, a specific inhibitor of the VEGF pathway. As a result, reexpressing Sema3A in cancer cells converts metastatic PNETs and cervical carcinomas into benign lesions. We therefore suggest that this strategy could be developed to safely harnesses the therapeutic potential of the antiangiogenic treatment. ]]> info:doi/10.1172/JCI58976 American Society for Clinical Investigation http://www.jci.org/articles/view/59218 info:doi/10.1172/JCI59218 American Society for Clinical Investigation http://www.jci.org/articles/view/61492 info:doi/10.1172/JCI61492 American Society for Clinical Investigation http://www.jci.org/articles/view/45661 info:doi/10.1172/JCI45661 American Society for Clinical Investigation http://www.jci.org/articles/view/59858 info:doi/10.1172/JCI59858 American Society for Clinical Investigation http://www.jci.org/articles/view/58540 info:doi/10.1172/JCI58540 American Society for Clinical Investigation http://www.jci.org/articles/view/57477 Ink4a/Arf-independent manner. This process also modulated the DNA damage response and affected genomic stability. Together, our findings demonstrate the etiological role of Bmi1 in PCa, unravel an oncogenic collaboration between Bmi1 and the PI3K/Akt pathway, and provide mechanistic insights into the modulation of Bmi1 function by phosphorylation during prostate carcinogenesis. ]]> info:doi/10.1172/JCI57477 American Society for Clinical Investigation http://www.jci.org/articles/view/40591 FOXP3 gene result in Treg deficiency in mice and humans, which leads to the development of a multisystem autoimmune inflammatory disease. The contribution of dysregulated innate immune responses to the pathogenesis of Foxp3 deficiency disease is unknown. In this study, we examined the role of microbial signals in the pathogenesis of Foxp3 deficiency disease by studying Foxp3 mutant mice that had concurrent deficiencies in TLR signaling pathways. Global deficiency of the common TLR adaptor MyD88 offered partial protection from Foxp3 deficiency disease. Specifically, it protected from disease at the environmental interfaces of the skin, lungs, and gut. In contrast, systemic disease, in the form of unrestrained lymphoproliferation, continued unabated. The effect of MyD88 deficiency at environmental interfaces involved the disruption of chemokine gradients that recruit effector T cells and DCs, resulting in their entrapment in secondary lymphoid tissues. These results suggests that Tregs have a key role in maintaining tolerance at host-microbial interfaces by restraining tonic MyD88-dependent proinflammatory signals. Moreover, microbial factors may play a substantial role in the pathogenesis of human autoimmune disease resulting from Treg deficiency. ]]> info:doi/10.1172/JCI40591 American Society for Clinical Investigation http://www.jci.org/articles/view/63474 info:doi/10.1172/JCI63474 American Society for Clinical Investigation http://www.jci.org/articles/view/63413 info:doi/10.1172/JCI63413 American Society for Clinical Investigation