Immunology
Abstract
Eosinophilic esophagitis (EE) is an emerging disorder with a poorly understood pathogenesis. In order to define disease mechanisms, we took an empirical approach analyzing esophageal tissue by a genome-wide microarray expression analysis. EE patients had a striking transcript signature involving 1% of the human genome that was remarkably conserved across sex, age, and allergic status and was distinct from that associated with non-EE chronic esophagitis. Notably, the gene encoding the eosinophil-specific chemoattractant eotaxin-3 (also known as CCL26) was the most highly induced gene in EE patients compared with its expression level in healthy individuals. Esophageal eotaxin-3 mRNA and protein levels strongly correlated with tissue eosinophilia and mastocytosis. Furthermore, a single-nucleotide polymorphism in the human eotaxin-3 gene was associated with disease susceptibility. Finally, mice deficient in the eotaxin receptor (also known as CCR3) were protected from experimental EE. These results implicate eotaxin-3 as a critical effector molecule for EE and provide insight into disease pathogenesis.
Authors
Carine Blanchard, Ning Wang, Keith F. Stringer, Anil Mishra, Patricia C. Fulkerson, J. Pablo Abonia, Sean C. Jameson, Cassie Kirby, Michael R. Konikoff, Margaret H. Collins, Mitchell B. Cohen, Rachel Akers, Simon P. Hogan, Amal H. Assa’ad, Philip E. Putnam, Bruce J. Aronow, Marc E. Rothenberg
Abstract
Authors
Quan Li Zhen, Chun Xie, Tianfu Wu, Meggan Mackay, Cynthia Aranow, Chaim Putterman, Chandra Mohan
Abstract
We previously reported that human CD4+ Tregs secrete high levels of IL-10 when stimulated in the presence of dexamethasone and calcitriol (vitamin D3). We now show that following stimulation by allergen, IL-10–secreting Tregs inhibit cytokine secretion by allergen-specific Th2 cells in an IL-10–dependent manner. A proportion of patients with severe asthma fail to demonstrate clinical improvement upon glucocorticoid therapy, and their asthma is characterized as glucocorticoid resistant (SR, abbreviation derived from “steroid resistant”). Dexamethasone does not enhance secretion of IL-10 by their CD4+ T cells. Addition of vitamin D3 with dexamethasone to cultures of SR CD4+ T cells enhanced IL-10 synthesis to levels observed in cells from glucocorticoid-sensitive patients cultured with dexamethasone alone. Furthermore, pretreatment with IL-10 fully restored IL-10 synthesis in these cells in response to dexamethasone. Vitamin D3 significantly overcame the inhibition of glucocorticoid-receptor expression by dexamethasone while IL-10 upregulated glucocorticoid-receptor expression by CD4+ T cells, suggesting potential mechanisms whereby these treatments may overcome poor glucocorticoid responsiveness. We show here that administration of vitamin D3 to healthy individuals and SR asthmatic patients enhanced subsequent responsiveness to dexamethasone for induction of IL-10. This strongly suggests that vitamin D3 could potentially increase the therapeutic response to glucocorticoids in SR patients.
Authors
Emmanuel Xystrakis, Siddharth Kusumakar, Sandra Boswell, Emma Peek, Zoë Urry, David F. Richards, Tonye Adikibi, Carol Pridgeon, Margaret Dallman, Tuck-Kay Loke, Douglas S. Robinson, Franck J. Barrat, Anne O’Garra, Paul Lavender, Tak H. Lee, Christopher Corrigan, Catherine M. Hawrylowicz
Abstract
V(D)J recombination of Ig and TCR loci is a stepwise process during which site-specific DNA double-strand breaks (DSBs) are made by RAG1/RAG2, followed by DSB repair by nonhomologous end joining. Defects in V(D)J recombination result in SCID characterized by absence of mature B and T cells. A subset of T–B–NK+ SCID patients is sensitive to ionizing radiation, and the majority of these patients have mutations in Artemis. We present a patient with a new type of radiosensitive T–B–NK+ SCID with a defect in DNA ligase IV (LIG4). To date, LIG4 mutations have only been described in a radiosensitive leukemia patient and in 4 patients with a designated LIG4 syndrome, which is associated with chromosomal instability, pancytopenia, and developmental and growth delay. The patient described here shows that a LIG4 mutation can also cause T–B–NK+ SCID without developmental defects. The LIG4-deficient SCID patient had an incomplete but severe block in precursor B cell differentiation, resulting in extremely low levels of blood B cells. The residual DH-JH junctions showed extensive nucleotide deletions, apparently caused by prolonged exonuclease activity during the delayed DH-JH ligation process. In conclusion, different LIG4 mutations can result in either a developmental defect with minor immunological abnormalities or a SCID picture with normal development.
Authors
Mirjam van der Burg, Lieneke R. van Veelen, Nicole S. Verkaik, Wouter W. Wiegant, Nico G. Hartwig, Barbara H. Barendregt, Linda Brugmans, Anja Raams, Nicolaas G.J. Jaspers, Malgorzata Z. Zdzienicka, Jacques J.M. van Dongen, Dik C. van Gent
Abstract
DC-based tumor vaccine research has largely focused on enhancing DC maturation/costimulation and antigen presentation in order to break tolerance against self tumor-associated antigens. DC immunization can activate autoreactive T cells but rarely causes autoimmune pathologies, indicating that self tolerance at the host level is still maintained in the vaccinated hosts. This study in mice reveals a novel regulatory mechanism for the control of self tolerance at the host level by DCs through the restriction of positive cytokine feedback loops by cytokine signaling inhibitor SOCS1. The study further finds the requirement of persistent antigen presentation by DCs for inducing pathological autoimmune responses against normal tissues and tumor, which can be achieved by silencing SOCS1 to unleash the unbridled signaling of IL-12 and the downstream cytokine cascade. However, the use of higher-affinity self peptides, enhancement of DC maturation, and persistent stimulation with cytokines or TLR agonists fail to break tolerance and induce pathological antitumor immunity. Thus, this study indicates the necessity of inhibiting SOCS1, an antigen presentation attenuator, to break self tolerance and induce effective antitumor responses.
Authors
Kevin Evel-Kabler, Xiao-Tong Song, Melissa Aldrich, Xue F. Huang, Si-Yi Chen
Abstract
Missense mutations in perforin, a critical effector of lymphocyte cytotoxicity, lead to a spectrum of diseases, from familial hemophagocytic lymphohistiocytosis to an increased risk of tumorigenesis. Understanding of the impact of mutations has been limited by an inability to express human perforin in vitro. We have shown, for the first time to our knowledge, that recombinant human perforin is expressed, processed appropriately, and functional in rat basophilic leukemia (RBL) cells following retroviral transduction. Subsequently, we have addressed how perforin missense mutations lead to absent perforin detection and impaired cytotoxicity by analyzing 21 missense mutations by flow cytometry, immunohistochemistry, and immunoblot. We identified perforin missense mutations with partial maturation (class 1), no apparent proteolytic maturation (class 2), and no recognizable forms of perforin (class 3). Class 1 mutations exhibit lytic function when expressed in RBL cells and are associated with residual protein detection and variable cytotoxic function in affected individuals, suggesting that carriers of class 1 alleles may exhibit more subtle immune defects. By contrast, class 3 mutations cause severely diminished perforin detection and cytotoxicity, while class 2 mutations have an intermediate phenotype. Thus, the pathologic mechanism of perforin missense mutation likely involves a protein dosage effect of the mature protein.
Authors
Kimberly A. Risma, Robert W. Frayer, Alexandra H. Filipovich, Janos Sumegi
Abstract
Rare cases of stable allograft acceptance after discontinuation of immunosuppression are often accompanied by macrochimerism (> 1% donor cells in blood) or microchimerism (< 1% donor cells in blood). Here, we have investigated whether persistence of donor cells is the cause or the consequence of long-lasting CTL unresponsiveness. We found that engraftment of splenocytes bearing a single foreign MHC class I–restricted epitope resulted in lifelong donor cell microchimerism and specific CTL unresponsiveness. This status was reversed in a strictly time- and thymus-dependent fashion when the engrafted cells were experimentally removed. The results presented herein show that microchimerism actively maintains CTL unresponsiveness toward a minor histocompatibility antigen by deleting the specific repertoire and thus excluding dominant, T cell extrinsic mechanisms of CTL unresponsiveness independent of systemically persisting donor cell antigen.
Authors
Weldy V. Bonilla, Markus B. Geuking, Peter Aichele, Burkhard Ludewig, Hans Hengartner, Rolf M. Zinkernagel
Abstract
Nephrophilic autoantibodies dominate the seroprofile in lupus, but their fine specificities remain ill defined. We constructed a multiplexed proteome microarray bearing about 30 antigens known to be expressed in the glomerular milieu and used it to study serum autoantibodies in lupus. Compared with normal serum, serum from B6.Sle1.lpr lupus mice (C57BL/6 mice homozygous for the NZM2410/NZW allele of Sle1 as well as the FASlpr defect) exhibited high levels of IgG and IgM antiglomerular as well as anti–double-stranded DNA/chromatin Abs and variable levels of Abs to α-actinin, aggrecan, collagen, entactin, fibrinogen, hemocyanin, heparan sulphate, laminin, myosin, proteoglycans, and histones. The use of these glomerular proteome arrays also revealed 5 distinct clusters of IgG autoreactivity in the sera of lupus patients. Whereas 2 of these IgG reactivity clusters (DNA/chromatin/glomeruli and laminin/myosin/Matrigel/vimentin/heparan sulphate) showed association with disease activity, the other 3 reactivity clusters (histones, vitronectin/collagen/chondroitin sulphate, and entactin/fibrinogen/hyaluronic acid) did not. Human lupus sera also displayed 2 distinct IgM autoantibody clusters, one reactive to DNA and the other apparently polyreactive. Interestingly, the presence of IgM polyreactivity in patient sera was associated with reduced disease severity. Hence, the glomerular proteome array promises to be a powerful analytical tool for uncovering novel autoantibody disease associations and for distinguishing patients at high risk for end-organ disease.
Authors
Quan Li Zhen, Chun Xie, Tianfu Wu, Meggan Mackay, Cynthia Aranow, Chaim Putterman, Chandra Mohan
Abstract
Numerous mechanisms of action have been proposed for intravenous Ig (IVIG). In this study, we used IgG passive transfer murine models of bullous pemphigoid (BP), pemphigus foliaceus (PF), and pemphigus vulgaris (PV) to test the hypothesis that the effect of IVIG in autoantibody-mediated cutaneous bullous diseases is to accelerate the degradation of pathogenic IgG by saturation of the MHC-like Fc receptor neonatal Fc receptor (FcRn). BP, PF, and PV are organ-specific antibody-mediated diseases in which autoantibodies target the hemidesmosomal antigen BP180 and desmosomal antigens Dsg1 and Dsg3, respectively. Antibodies against BP180, Dsg1, and Dsg3, when injected into neonatal mice, induce the BP, PF, and PV disease phenotypes, respectively. We found that FcRn-deficient mice were resistant to experimental BP, PF, and PV. Circulating levels of pathogenic IgG in FcRn-deficient mice were significantly reduced compared with those in WT mice. Administration of high-dose human IgG (HDIG) to WT mice also drastically reduced circulating pathogenic IgG levels and prevented blistering. In FcRn-deficient mice, no additional protective effect with HDIG was realized. These data demonstrate that the therapeutic efficacy of HDIG treatment in the pemphigus and pemphigoid models is dependent on FcRn. Thus, FcRn is a promising therapeutic target for treating such IgG-mediated autoimmune diseases.
Authors
Ning Li, Minglang Zhao, Julio Hilario-Vargas, Phillip Prisayanh, Simon Warren, Luis A. Diaz, Derry C. Roopenian, Zhi Liu
Abstract
Th1 inflammation and remodeling characterized by tissue destruction frequently coexist in human diseases. To further understand the mechanisms of these responses, we defined the role(s) of CCR5 in the pathogenesis of IFN-γ–induced inflammation and remodeling in a murine emphysema model. IFN-γ was a potent stimulator of the CCR5 ligands macrophage inflammatory protein–1α/CCL-3 (MIP-1α/CCL-3), MIP-1β/CCL-4, and RANTES/CCL-5, among others. Antibody neutralization or null mutation of CCR5 decreased IFN-γ–induced inflammation, DNA injury, apoptosis, and alveolar remodeling. These interventions decreased the expression of select chemokines, including CCR5 ligands and MMP-9, and increased levels of secretory leukocyte protease inhibitor. They also decreased the expression and/or activation of Fas, FasL, TNF, caspase-3, -8, and -9, Bid, and Bax. In accordance with these findings, cigarette smoke induced pulmonary inflammation, DNA injury, apoptosis, and emphysema via an IFN-γ–dependent pathway(s), and a null mutation of CCR5 decreased these responses. These studies demonstrate that IFN-γ is a potent stimulator of CC and CXC chemokines and highlight the importance of CCR5 in the pathogenesis of IFN-γ–induced and cigarette smoke–induced inflammation, tissue remodeling, and emphysema. They also demonstrate that CCR5 is required for optimal IFN-γ stimulation of its own ligands, other chemokines, MMPs, caspases, and cell death regulators and the inhibition of antiproteases.
Authors
Bing Ma, Min-Jong Kang, Chun Geun Lee, Svetlana Chapoval, Wei Liu, Qingsheng Chen, Anthony J. Coyle, José M. Lora, Dominic Picarella, Robert J. Homer, Jack A. Elias
Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)