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Stephens WZ, Kubinak JL, Ghazaryan A, Bauer KM, Bell R, Buhrke K, Chiaro TR, Weis AM, Tang WW, Monts JK, Soto R, Ekiz HA, O'Connell RM, Round JL. Epithelial-myeloid exchange of MHC class II constrains immunity and microbiota composition. Cell Rep 2021; 37:109916. [PMID: 34731608 PMCID: PMC9012449 DOI: 10.1016/j.celrep.2021.109916] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/13/2021] [Accepted: 10/11/2021] [Indexed: 12/12/2022] Open
Abstract
Intestinal epithelial cells (IECs) have long been understood to express high levels of major histocompatibility complex class II (MHC class II) molecules but are not considered canonical antigen-presenting cells, and the impact of IEC-MHC class II signaling on gut homeostasis remains enigmatic. As IECs serve as the primary barrier between underlying host immune cells, we reasoned that IEC-intrinsic antigen presentation may play a role in responses toward the microbiota. Mice with an IEC-intrinsic deletion of MHC class II (IECΔMHC class II) are healthy but have fewer microbial-bound IgA, regulatory T cells (Tregs), and immune repertoire selection. This was associated with increased interindividual microbiota variation and altered proportions of two taxa in the ileum where MHC class II on IECs is highest. Intestinal mononuclear phagocytes (MNPs) have similar MHC class II transcription but less surface MHC class II and are capable of acquiring MHC class II from IECs. Thus, epithelial-myeloid interactions mediate development of adaptive responses to microbial antigens within the gastrointestinal tract.
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Affiliation(s)
- W Zac Stephens
- University of Utah School of Medicine, Department of Pathology, Division of Microbiology and Immunology, Salt Lake City, UT 84112, USA
| | - Jason L Kubinak
- University of South Carolina School of Medicine, Department of Pathology, Microbiology and Immunology, Columbia, SC 29209, USA
| | - Arevik Ghazaryan
- University of Utah School of Medicine, Department of Pathology, Division of Microbiology and Immunology, Salt Lake City, UT 84112, USA
| | - Kaylyn M Bauer
- University of Utah School of Medicine, Department of Pathology, Division of Microbiology and Immunology, Salt Lake City, UT 84112, USA
| | - Rickesha Bell
- University of Utah School of Medicine, Department of Pathology, Division of Microbiology and Immunology, Salt Lake City, UT 84112, USA
| | - Kate Buhrke
- University of Utah School of Medicine, Department of Pathology, Division of Microbiology and Immunology, Salt Lake City, UT 84112, USA
| | - Tyson R Chiaro
- University of Utah School of Medicine, Department of Pathology, Division of Microbiology and Immunology, Salt Lake City, UT 84112, USA
| | - Allison M Weis
- University of Utah School of Medicine, Department of Pathology, Division of Microbiology and Immunology, Salt Lake City, UT 84112, USA
| | - William W Tang
- University of Utah School of Medicine, Department of Pathology, Division of Microbiology and Immunology, Salt Lake City, UT 84112, USA
| | - Josh K Monts
- University of Utah School of Medicine, Flow Cytometry Core, Health Sciences Center, Salt Lake City, UT 84112, USA
| | - Ray Soto
- University of Utah School of Medicine, Department of Pathology, Division of Microbiology and Immunology, Salt Lake City, UT 84112, USA
| | - H Atakan Ekiz
- University of Utah School of Medicine, Department of Pathology, Division of Microbiology and Immunology, Salt Lake City, UT 84112, USA; Izmir Institute of Technology, Molecular Biology and Genetics Department, Gulbahce, Izmir 35430, Turkey
| | - Ryan M O'Connell
- University of Utah School of Medicine, Department of Pathology, Division of Microbiology and Immunology, Salt Lake City, UT 84112, USA.
| | - June L Round
- University of Utah School of Medicine, Department of Pathology, Division of Microbiology and Immunology, Salt Lake City, UT 84112, USA.
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Exosomes as a New Delivery Vehicle in Inflammatory Bowel Disease. Pharmaceutics 2021; 13:pharmaceutics13101644. [PMID: 34683937 PMCID: PMC8539337 DOI: 10.3390/pharmaceutics13101644] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 09/29/2021] [Accepted: 10/01/2021] [Indexed: 02/06/2023] Open
Abstract
Inflammatory bowel disease (IBD) is a type of chronic relapsing inflammatory disease. The pathogenesis of IBD is still unclear, which may involve environmental factors, genetic factors, intestinal microbiota disorder, and abnormal immune responses. Exosomes (30–150 nm) are found in various body fluids, including blood, saliva, urine, and cerebrospinal fluid. Exosomes mediate intercellular communication and regulate cell biological activity by carrying non-coding RNAs, proteins, and lipids. There is evidence that exosomes are involved in the pathogenesis of IBD. In view of the important roles of exosomes in the pathogenesis of IBD, this work systematically reviews the latest research progress of exosomes in IBD, especially the roles of exosomes as non-coding RNA delivery systems in the pathogenesis of IBD, including a disordered immune response, barrier function, and intestinal microbiota. The review will help to clarify the pathogenesis of IBD and explore new diagnostic markers and therapeutic targets for patients with IBD.
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Steven P, Schwab S, Kiesewetter A, Saban DR, Stern ME, Gehlsen U. Disease-Specific Expression of Conjunctiva Associated Lymphoid Tissue (CALT) in Mouse Models of Dry Eye Disease and Ocular Allergy. Int J Mol Sci 2020; 21:ijms21207514. [PMID: 33053795 PMCID: PMC7589149 DOI: 10.3390/ijms21207514] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/08/2020] [Accepted: 10/10/2020] [Indexed: 01/18/2023] Open
Abstract
Conjunctiva-associated tissue (CALT) is assumed to play a crucial role in the immune system of the ocular surface. Its function in several ocular surface diseases (OSD) is still not fully understood. This study investigates the function of CALT in mouse models of dry-eye disease and ocular allergy. Since antigen-presentation is the central similarity in the pathologies, this study focuses on antigen-presentation in CALT Morphology and the expression of CALT, which was investigated in mice after induction of dry-eye, ocular allergy, topical antigen-stimulation, and after local depletion of phagocytic cells. Antigen uptake was investigated after the application of fluorescent ovalbumin (OVA). OSD influences the appearance and morphology of CALT in a disease-dependent manner. Ocular allergy leads to an increase and dry-eye disease to a decrease in number and size of CALT. The development of CALT is dependent on the presence of APCs. Professional APCs are present in CALT, and soluble antigen is transported into the follicle. CALT appearance is disease-specific and indicative of differing functions. Although the specific involvement of CALT in OSD needs further study, the existence of functional APCS and antigen-uptake supports the hypothesis that CALT is an immunological key player at the ocular surface.
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Affiliation(s)
- Philipp Steven
- Department of Ophthalmology, Faculty of Medicine and University Hospital, University of Cologne, 50924 Cologne, Germany; (P.S.); (A.K.); (M.E.S.)
- Division of Dry-Eye and ocular GvHD, Department of Ophthalmology, University of Cologne, 50924 Cologne, Germany
| | - Sebastian Schwab
- Department of Internal Medicine I, Faculty of Medicine, University Bonn, 53127 Bonn, Germany;
- Institute of Experimental Immunology, Faculty of Medicine, University Bonn, 53127 Bonn, Germany
| | - Anne Kiesewetter
- Department of Ophthalmology, Faculty of Medicine and University Hospital, University of Cologne, 50924 Cologne, Germany; (P.S.); (A.K.); (M.E.S.)
| | - Daniel R. Saban
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC 27701, USA;
| | - Michael E. Stern
- Department of Ophthalmology, Faculty of Medicine and University Hospital, University of Cologne, 50924 Cologne, Germany; (P.S.); (A.K.); (M.E.S.)
- Division of Dry-Eye and ocular GvHD, Department of Ophthalmology, University of Cologne, 50924 Cologne, Germany
- ImmunEyze, LLC., Irvine, CA 92606, USA
| | - Uta Gehlsen
- Department of Ophthalmology, Faculty of Medicine and University Hospital, University of Cologne, 50924 Cologne, Germany; (P.S.); (A.K.); (M.E.S.)
- Division of Dry-Eye and ocular GvHD, Department of Ophthalmology, University of Cologne, 50924 Cologne, Germany
- Correspondence: ; Tel.: +49-221-478-85618
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Zhao DY, Qi QQ, Long X, Li X, Chen FX, Yu YB, Zuo XL. Ultrastructure of intestinal mucosa in diarrhea-predominant irritable bowel syndrome. Physiol Int 2019; 106:225-235. [PMID: 31560236 DOI: 10.1556/2060.106.2019.20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVES Impaired intestinal barrier function has been demonstrated in the pathophysiology of diarrhea-predominant irritable bowel syndrome (IBS-D). This study aimed to describe the intestinal ultrastructural findings in the intestinal mucosal layer of IBS-D patients. METHODS In total, 10 healthy controls and 10 IBS-D patients were analyzed in this study. The mucosa of each patient's rectosigmoid colon was first assessed by confocal laser endomicroscopy (CLE); next, biopsied specimens of these sites were obtained. Intestinal tissues of IBS-D patients and healthy volunteers were examined to observe cellular changes by transmission electron microscopy (TEM). RESULTS CLE showed no visible epithelial damage or inflammatory changes in the colonic mucosa of IBS-D compared with healthy volunteers. On transmission electron microscopic examination, patients with IBS-D displayed a larger apical intercellular distance with a higher proportion of dilated (>20 nm) intercellular junctional complexes, which was indicative of impaired mucosal integrity. In addition, microvillus exfoliation, extracellular vesicle as well as increased presence of multivesicular bodies were visible in IBS-D patients. Single epithelial cells appeared necrotic, as characterized by cytoplasmic vacuolization, cytoplasmic swelling, and presence of autolysosome. A significant association between bowel habit, frequency of abdominal pain, and enlarged intercellular distance was found. CONCLUSION This study showed ultrastructural alterations in the architecture of intestinal epithelial cells and intercellular junctional complexes in IBS-D patients, potentially representing a pathophysiological mechanism in IBS-D.
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Affiliation(s)
- D-Y Zhao
- Department of Gastroenterology, Puyang Oilfield General Hospital, Puyang, P. R. China
| | - Q-Q Qi
- Department of Gastroenterology, Qilu Hospital, Shandong University, Shandong Province, P. R. China
| | - X Long
- Department of Gastroenterology, Qilu Hospital, Shandong University, Shandong Province, P. R. China
| | - X Li
- Department of Gastroenterology, Qilu Hospital, Shandong University, Shandong Province, P. R. China
| | - F-X Chen
- Department of Gastroenterology, Qilu Hospital, Shandong University, Shandong Province, P. R. China
| | - Y-B Yu
- Department of Gastroenterology, Qilu Hospital, Shandong University, Shandong Province, P. R. China
| | - X-L Zuo
- Department of Gastroenterology, Qilu Hospital, Shandong University, Shandong Province, P. R. China
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Gurunathan S, Kang MH, Jeyaraj M, Qasim M, Kim JH. Review of the Isolation, Characterization, Biological Function, and Multifarious Therapeutic Approaches of Exosomes. Cells 2019; 8:cells8040307. [PMID: 30987213 PMCID: PMC6523673 DOI: 10.3390/cells8040307] [Citation(s) in RCA: 642] [Impact Index Per Article: 128.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/22/2019] [Accepted: 04/01/2019] [Indexed: 12/18/2022] Open
Abstract
Exosomes are extracellular vesicles that contain a specific composition of proteins, lipids, RNA, and DNA. They are derived from endocytic membranes and can transfer signals to recipient cells, thus mediating a novel mechanism of cell-to-cell communication. They are also thought to be involved in cellular waste disposal. Exosomes play significant roles in various biological functions, including the transfer of biomolecules such as RNA, proteins, enzymes, and lipids and the regulation of numerous physiological and pathological processes in various diseases. Because of these properties, they are considered to be promising biomarkers for the diagnosis and prognosis of various diseases and may contribute to the development of minimally invasive diagnostics and next generation therapies. The biocompatible nature of exosomes could enhance the stability and efficacy of imaging probes and therapeutics. Due to their potential use in clinical applications, exosomes have attracted much research attention on their roles in health and disease. To explore the use of exosomes in the biomedical arena, it is essential that the basic molecular mechanisms behind the transport and function of these vesicles are well-understood. Herein, we discuss the history, biogenesis, release, isolation, characterization, and biological functions of exosomes, as well as the factors influencing their biogenesis and their technical and biological challenges. We conclude this review with a discussion on the future perspectives of exosomes.
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Affiliation(s)
- Sangiliyandi Gurunathan
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, 1 Hwayang-Dong, Gwangin-gu, Seoul 05029, Korea.
| | - Min-Hee Kang
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, 1 Hwayang-Dong, Gwangin-gu, Seoul 05029, Korea.
| | - Muniyandi Jeyaraj
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, 1 Hwayang-Dong, Gwangin-gu, Seoul 05029, Korea.
| | - Muhammad Qasim
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, 1 Hwayang-Dong, Gwangin-gu, Seoul 05029, Korea.
| | - Jin-Hoi Kim
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, 1 Hwayang-Dong, Gwangin-gu, Seoul 05029, Korea.
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Induction of Inflammatory Responses in Splenocytes by Exosomes Released from Intestinal Epithelial Cells following Cryptosporidium parvum Infection. Infect Immun 2019; 87:IAI.00705-18. [PMID: 30642905 DOI: 10.1128/iai.00705-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 01/05/2019] [Indexed: 12/12/2022] Open
Abstract
Cryptosporidium, a protozoan parasite that infects the gastrointestinal epithelium and other mucosal surfaces in humans and animals, is an important opportunistic pathogen in AIDS patients and one of the most common enteric pathogens affecting young children in developing regions. This parasite is referred to as a "minimally invasive" mucosal pathogen, and epithelial cells play a central role in activating and orchestrating host immune responses. We previously demonstrated that Cryptosporidium parvum infection stimulates host epithelial cells to release exosomes, and these released exosomes shuttle several antimicrobial peptides to carry out anti-C. parvum activity. In this study, we detected the upregulation of inflammatory genes in the liver and spleen following C. parvum intestinal infection in neonatal mice. Interestingly, exosomes released from intestinal epithelial cells following C. parvum infection could activate the nuclear factor kappa B signaling pathway and trigger inflammatory gene transcription in isolated primary splenocytes. Several epithelial cell-derived proteins and a subset of parasite RNAs were detected in the exosomes released from C. parvum-infected intestinal epithelial cells. Shuttling of these effector molecules, including the high mobility group box 1 protein, was involved in the induction of inflammatory responses in splenocytes induced by the exosomes released from infected cells. Our data indicate that exosomes released from intestinal epithelial cells upon C. parvum infection can activate immune cells by shuttling various effector molecules, a process that may be relevant to host systemic responses to Cryptosporidium infection.
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T lymphocytes in the intestinal mucosa: defense and tolerance. Cell Mol Immunol 2019; 16:216-224. [PMID: 30787416 DOI: 10.1038/s41423-019-0208-2] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 02/01/2019] [Indexed: 02/06/2023] Open
Abstract
Although lymphocytes are known to circulate throughout lymphoid tissues and blood, they also establish residency in nonlymphoid organs, most prominently in barrier tissues, such as the intestines. The adaptation of T lymphocytes to intestinal environments requires constant discrimination between natural stimulation from commensal flora and food and pathogens that need to be cleared. Genetic variations that cause a defective defense or a break in tolerance along with environmental cues, such as infection or imbalances in the gut microbiota known as dysbiosis, can trigger several immune disorders via the activation of T lymphocytes in the intestines. Elucidation of the immune mechanisms that distinguish between commensal flora and pathogenic organisms may reveal therapeutic targets for the prevention or modulation of inflammatory diseases and boost the efficacy of cancer immunotherapy. In this review, we discuss the development and adaptation of T lymphocytes in the intestine, how these cells protect the host against pathogenic infections while tolerating food antigens and commensal microbiota, and the potential implications of targeting these cells for disease management and therapeutics.
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Mastocytosis-derived extracellular vesicles exhibit a mast cell signature, transfer KIT to stellate cells, and promote their activation. Proc Natl Acad Sci U S A 2018; 115:E10692-E10701. [PMID: 30352845 DOI: 10.1073/pnas.1809938115] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Extracellular vesicles (EVs) have been implicated in the development and progression of hematological malignancies. We thus examined serum samples from patients with systemic mastocytosis (SM) and found EVs with a mast cell signature including the presence of tryptase, FcεRI, MRGX2, and KIT. The concentration of these EVs correlated with parameters of disease including levels of serum tryptase, IL-6, and alkaline phosphatase and physical findings including hepatosplenomegaly. Given reports that EVs from one cell type may influence another cell's behavior, we asked whether SM-EVs might affect hepatic stellate cells (HSCs), based on the abnormal liver pathology associated with mastocytosis. We found that KIT was transferred from SM-EVs into an HSC line eliciting proliferation, cytokine production, and differentiation, processes that have been associated with liver pathology. These effects were reduced by KIT inhibition or neutralization and recapitulated by enforced expression of KIT or constitutively active D816V-KIT, a gain-of-function variant associated with SM. Furthermore, HSCs in liver from mice injected with SM-EVs had increased expression of α-SMA and human KIT, particularly around portal areas, compared with mice injected with EVs from normal individuals, suggesting that SM-EVs can also initiate HSC activation in vivo. Our data are thus consistent with the conclusion that SM-EVs have the potential to influence cells outside the hematological compartment and that therapeutic approaches for treatment of SM may be effective in part through inhibition of effects of EVs on target tissues, findings important both to understanding complex disease pathology and in developing interventional agents for the treatment of hematologic diseases.
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Lindenbergh MFS, Stoorvogel W. Antigen Presentation by Extracellular Vesicles from Professional Antigen-Presenting Cells. Annu Rev Immunol 2018; 36:435-459. [PMID: 29400984 DOI: 10.1146/annurev-immunol-041015-055700] [Citation(s) in RCA: 232] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The initiation and maintenance of adaptive immunity require multifaceted modes of communication between different types of immune cells, including direct intercellular contact, secreted soluble signaling molecules, and extracellular vesicles (EVs). EVs can be formed as microvesicles directly pinched off from the plasma membrane or as exosomes secreted by multivesicular endosomes. Membrane receptors guide EVs to specific target cells, allowing directional transfer of specific and complex signaling cues. EVs are released by most, if not all, immune cells. Depending on the type and status of their originating cell, EVs may facilitate the initiation, expansion, maintenance, or silencing of adaptive immune responses. This review focusses on EVs from professional antigen-presenting cells, their demonstrated and speculated roles, and their potential for cancer immunotherapy.
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Affiliation(s)
- Marthe F S Lindenbergh
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, NL-3508 TD Utrecht, The Netherlands;
| | - Willem Stoorvogel
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, NL-3508 TD Utrecht, The Netherlands;
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Serino G, Pesce F, Sallustio F, De Palma G, Cox SN, Curci C, Zaza G, Lai KN, Leung JCK, Tang SCW, Papagianni A, Stangou M, Goumenos D, Gerolymos M, Takahashi K, Yuzawa Y, Maruyama S, Imai E, Schena FP. In a retrospective international study, circulating miR-148b and let-7b were found to be serum markers for detecting primary IgA nephropathy. Kidney Int 2016; 89:683-92. [PMID: 26581012 DOI: 10.1038/ki.2015.333] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 09/04/2015] [Accepted: 09/17/2015] [Indexed: 12/14/2022]
Abstract
Immunoglobulin A nephropathy (IgAN) is a worldwide disease characterized by the presence of galactose-deficient IgA1 deposits in the glomerular mesangium. A kidney biopsy for diagnosis is required. Here, we measured two miRNAs (let-7b and miR-148b), previously identified as regulators of the O-glycosylation process of IgA1, in serum samples from patients with IgAN and healthy blood donors (controls) recruited in an international multicenter study. Two predictive models, based on these miRNAs, were developed and the diagnostic accuracy of the combined biomarkers was assessed by the area under the receiver operating characteristic (ROC) curve (AUC) carried out in three steps. In a training study, the combined miRNAs were able to discriminate between 100 patients with IgAN and 119 controls (AUC, 0.82). A validation study confirmed the model in an independent cohort of 145 patients with IgAN and 64 controls (AUC, 0.78). Finally, in a test study, the combined biomarkers were able to discriminate patients with IgAN from 105 patients affected by other forms of primary glomerulonephritis, supporting the specificity (AUC, 0.76). Using the same study design, we also performed two subgroup analyses (one for Caucasians and one for East Asians) and found that race-specific models were the best fit to distinguish IgAN patients from controls. Thus, serum levels of the combined miRNA biomarker, let-7b and miR-148b, appears to be a novel, reliable, and noninvasive test to predict the probability of having IgAN.
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Endocytosis in enterocytes. Wien Med Wochenschr 2016; 166:205-10. [DOI: 10.1007/s10354-016-0448-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 02/18/2016] [Indexed: 10/22/2022]
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Exosomes Released from Cells Infected with Crohn's Disease-associated Adherent-Invasive Escherichia coli Activate Host Innate Immune Responses and Enhance Bacterial Intracellular Replication. Inflamm Bowel Dis 2016; 22:516-28. [PMID: 26595556 DOI: 10.1097/mib.0000000000000635] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Crohn's disease is a chronic inflammatory bowel disease, of which the etiology involves environmental, genetic, and microbial factors. A high prevalence of adherent-invasive Escherichia coli, named AIEC, has been reported in the intestinal mucosa of patients with Crohn's disease. Exosomes are extracellular vesicles that function in intercellular communication and have been implicated in host responses to intracellular pathogens. We investigated the potential involvement of exosomes in host response to AIEC infection. METHODS Human intestinal epithelial T84 cells, THP-1 macrophages, and CEABAC10 transgenic mice were infected with the AIEC reference strain LF82 or the nonpathogenic E. coli K-12 MG1655 strain. Exosomes were purified using the ExoQuick reagent. RESULTS LF82 infection induced the release of exosomes by T84 and THP-1 cells. Compared with exosomes released from the uninfected or MG1655-infected T84 cells, those released from LF82-infected cells activated nuclear factor-kappa B, mitogen-activated protein kinases p38, and c-Jun N-terminal kinase and increased the secretion of proinflammatory cytokines in naive THP-1 macrophages. LF82 infection of THP-1 macrophages also induced the release of exosomes that triggered a proinflammatory response in recipient THP-1 cells. Importantly, stimulation of T84 or THP-1 cells with exosomes released from LF82-infected cells increased LF82 intracellular replication compared with stimulation with exosomes secreted by uninfected cells. Exosomes purified from intestinal lumen of CEABAC10 transgenic mice infected with LF82 increased proinflammatory responses in murine RAW 264.7 macrophages compared with those from uninfected or MG1655-infected mice. CONCLUSIONS Exosomes are new mediators of host-AIEC interaction with their capacity to activate innate immune responses and subvert the control of AIEC replication.
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Singh PP, Li L, Schorey JS. Exosomal RNA from Mycobacterium tuberculosis-Infected Cells Is Functional in Recipient Macrophages. Traffic 2015; 16:555-71. [PMID: 25753779 DOI: 10.1111/tra.12278] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 02/04/2015] [Accepted: 02/06/2015] [Indexed: 12/31/2022]
Abstract
Exosomes are extracellular vesicles released by cells that carry proteins, lipids and nucleic acids and function in intercellular communication. Previously, we determined that exosomes released from Mycobacterium tuberculosis (M.tb)-infected macrophages carry mycobacterial proteins and lipids. However, the RNA composition within these exosomes has not been defined. In this study, we characterized the exosomes released from M.tb-infected macrophages and identified a cohort of mouse messenger RNA (mRNA) and microRNA (miRNA). Quantitative reverse-transcriptase polymerase chain reaction analysis showed less abundance of miRNAs in exosomes released from infected compared with uninfected macrophages. Moreover, more than 100 transcripts were found to be enriched or unique to exosomes from infected cells including transcripts involved in regulating an immune response. The exosomal RNA could be transferred and expressed in naïve macrophages and was biologically active, stimulating production of inflammatory mediators and inducing apoptosis in recipient cells. Interestingly, we also identified mycobacterial transcripts in exosomes released from infected macrophages. To our knowledge, this is the first study to identify bacterial-derived RNA in exosomes. Our results suggest that exosomal RNA released from M.tb-infected macrophages may have functional and diagnostic potential in the context of a mycobacterial infection.
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Affiliation(s)
- Prachi Pratap Singh
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Li Li
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Jeffrey Scott Schorey
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA
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Xiao H, Lässer C, Shelke GV, Wang J, Rådinger M, Lunavat TR, Malmhäll C, Lin LH, Li J, Li L, Lötvall J. Mast cell exosomes promote lung adenocarcinoma cell proliferation - role of KIT-stem cell factor signaling. Cell Commun Signal 2014; 12:64. [PMID: 25311367 PMCID: PMC4206705 DOI: 10.1186/s12964-014-0064-8] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 09/30/2014] [Indexed: 12/21/2022] Open
Abstract
Background Human cells release nano-sized vesicles called exosomes, containing mRNA, miRNA and specific proteins. Exosomes from one cell can be taken up by another cell, which is a recently discovered cell-to-cell communication mechanism. Also, exosomes can be taken up by different types of cancer cells, but the potential functional effects of mast cell exosomes on tumor cells remain unknown. Methods and results Exosomes were isolated from the human mast cell line, HMC-1, and uptake of PKH67-labelled exosomes by the lung epithelial cell line, A549, was examined using flow cytometry and fluorescence microscopy. The RNA cargo of the exosomes was analyzed with a Bioanalyzer and absence or presence of the c-KIT mRNA was determined by RT-PCR. The cell proliferation was determined in a BrdU incorporation assay, and proteins in the KIT-SCF signaling pathway were detected by Western blot. Our result demonstrates that exosomes from mast cells can be taken up by lung cancer cells. Furthermore, HMC-1 exosomes contain and transfer KIT protein, but not the c-KIT mRNA to A549 cells and subsequently activate KIT-SCF signal transduction, which increase cyclin D1 expression and accelerate the proliferation in the human lung adenocarcinoma cells. Conclusions Our results indicate that exosomes can transfer KIT as a protein to tumor cells, which can affect recipient cell signaling events through receptor-ligand interactions.
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Abstract
Eosinophilic esophagitis is rapidly increasing in incidence. It is associated with food antigen-triggered, eosinophil-predominant inflammation, and the pathogenic mechanisms have many similarities to other chronic atopic diseases. Studies in animal models and from patients have suggested that allergic sensitization leads to food-specific IgE and T-helper lymphocyte type 2 cells, both of which seem to contribute to the pathogenesis along with basophils, mast cells, and antigen-presenting cells. In this review our current understandings of the allergic mechanisms that drive eosinophilic esophagitis are outlined, drawing from clinical and translational studies in humans as well as experimental animal models.
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Jones-Hall YL, Grisham MB. Immunopathological characterization of selected mouse models of inflammatory bowel disease: Comparison to human disease. ACTA ACUST UNITED AC 2014; 21:267-88. [PMID: 24935242 DOI: 10.1016/j.pathophys.2014.05.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 05/16/2014] [Accepted: 05/17/2014] [Indexed: 12/19/2022]
Abstract
Inflammatory bowel diseases (IBD) are chronic, relapsing conditions of multifactorial etiology. The two primary diseases of IBD are Crohn's disease (CD) and ulcerative colitis (UC). Both entities are hypothesized to occur in genetically susceptible individuals due to microbial alterations and environmental contributions. The exact etiopathogenesis, however, is not known for either disease. A variety of mouse models of CD and UC have been developed to investigate the pathogenesis of these diseases and evaluate treatment modalities. Broadly speaking, the mouse models can be divided into 4 categories: genetically engineered, immune manipulated, spontaneous and erosive/chemically induced. No one mouse model completely recapitulates the immunopathology of CD or UC, however each model possesses particular similarities to human IBD and offers advantageous for specific details of IBD pathogenesis. Here we discuss the more commonly used models in each category and critically evaluate how the immunopathology induced compares to CD or UC, as well as the advantages and disadvantages associated with each model.
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Affiliation(s)
- Yava L Jones-Hall
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47906, United States.
| | - Matthew B Grisham
- Department of Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX 79430, United States
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17
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Bär F, Sina C, Hundorfean G, Pagel R, Lehnert H, Fellermann K, Büning J. Inflammatory bowel diseases influence major histocompatibility complex class I (MHC I) and II compartments in intestinal epithelial cells. Clin Exp Immunol 2013; 172:280-9. [PMID: 23574324 DOI: 10.1111/cei.12047] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2012] [Indexed: 12/19/2022] Open
Abstract
Antigen presentation by intestinal epithelial cells (IEC) is crucial for intestinal homeostasis. Disturbances of major histocompatibility complex class I (MHC I)- and II-related presentation pathways in IEC appear to be involved in an altered activation of CD4(+) and CD8(+) T cells in inflammatory bowel disease. However, a comprehensive analysis of MHC I- and II-enriched compartments in IEC of the small and large bowel in the healthy state as opposed to inflammatory bowel diseases is lacking. The aim of this study was to characterize the subcellular expression of MHC I and II in the endocytic pathway of IEC throughout all parts of the intestinal tract, and to identify differences between the healthy state and inflammatory bowel diseases. Biopsies were taken by endoscopy from the duodenum, jejunum, ileum and colon in healthy individuals (n = 20). In Crohn's disease (CD), biopsies were obtained from the ileum and colon and within the colon from ulcerative colitis (UC) patients (n = 15). Analysis of IEC was performed by immunoelectron microscopy. MHC I and II were identified in early endosomes and multi-vesicular, multi-lamellar, electrondense and vacuolar late endosomes. Both molecules were enriched in multi-vesicular bodies. No differences were found between the distinct parts of the gut axis. In CD and UC the expression of MHC I and II showed a shift from multi-vesicular bodies towards the basolateral membranes. Within the multi-vesicular bodies, MHC I and II moved from internal vesicles to the limiting membranes upon inflammation in CD and UC. MHC I- and II-enriched compartments in IEC were identical in all parts of the small and large bowel. CD and UC appear to modulate the MHC I- and II-related presentation pathways of exogenous antigens in IEC.
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Affiliation(s)
- F Bär
- Department of Internal Medicine I, University Hospital of Schleswig-Holstein, Institute of Anatomy, University of Lübeck, Lübeck, Germany
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18
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Hu G, Gong AY, Roth AL, Huang BQ, Ward HD, Zhu G, LaRusso NF, Hanson ND, Chen XM. Release of luminal exosomes contributes to TLR4-mediated epithelial antimicrobial defense. PLoS Pathog 2013; 9:e1003261. [PMID: 23592986 PMCID: PMC3617097 DOI: 10.1371/journal.ppat.1003261] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 02/05/2013] [Indexed: 12/11/2022] Open
Abstract
Exosomes are membranous nanovesicles released by most cell types from multi-vesicular endosomes. They are speculated to transfer molecules to neighboring or distant cells and modulate many physiological and pathological procedures. Exosomes released from the gastrointestinal epithelium to the basolateral side have been implicated in antigen presentation. Here, we report that luminal release of exosomes from the biliary and intestinal epithelium is increased following infection by the protozoan parasite Cryptosporidium parvum. Release of exosomes involves activation of TLR4/IKK2 signaling through promoting the SNAP23-associated vesicular exocytotic process. Downregulation of let-7 family miRNAs by activation of TLR4 signaling increases SNAP23 expression, coordinating exosome release in response to C. parvum infection. Intriguingly, exosomes carry antimicrobial peptides of epithelial cell origin, including cathelicidin-37 and beta-defensin 2. Activation of TLR4 signaling enhances exosomal shuttle of epithelial antimicrobial peptides. Exposure of C. parvum sporozoites to released exosomes decreases their viability and infectivity both in vitro and ex vivo. Direct binding to the C. parvum sporozoite surface is required for the anti-C. parvum activity of released exosomes. Biliary epithelial cells also increase exosomal release and display exosome-associated anti-C. parvum activity following LPS stimulation. Our data indicate that TLR4 signaling regulates luminal exosome release and shuttling of antimicrobial peptides from the gastrointestinal epithelium, revealing a new arm of mucosal immunity relevant to antimicrobial defense. Exosomes are secreted membranous nanovesicles produced by a variety of cells. Exosomes shuttle various molecules to transfer them to neighboring or distant cells, and have been implicated as mediators in cell-cell communications to modulate physiological and pathological procedures. Here, we report that luminal release of exosomal vesicles is an important component of Toll-like receptor 4 (TLR4)-associated gastrointestinal epithelial defense against infection by Cryptosporidium parvum, an obligate intracellular protozoan that infects gastrointestinal epithelial cells. Activation of TLR4 signaling in host epithelial cells following C. parvum infection promotes luminal release of epithelial exosomes and exosomal shuttling of antimicrobial peptides from the epithelium. By direct binding to the C. parvum surface, exosomal vesicles reveal anti-C. parvum activity. Activation of TLR4 signaling in epithelial cells after LPS stimulation also increases exosomal release and exosome-associated anti-C. parvum activity. Therefore, we speculate that TLR4-mediated exosome release may be relevant to innate mucosal immunity in general, representing a new target for therapeutic intervention for infectious diseases at the mucosal surface.
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Affiliation(s)
- Guoku Hu
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, Nebraska, United States of America
| | - Ai-Yu Gong
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, Nebraska, United States of America
| | - Amanda L. Roth
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, Nebraska, United States of America
| | - Bing Q. Huang
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
| | - Honorine D. Ward
- Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Boston, Massachusetts, United States of America
| | - Guan Zhu
- Department of Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, Texas, United States of America
| | - Nicholas F. LaRusso
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota, United States of America
| | - Nancy D. Hanson
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, Nebraska, United States of America
| | - Xian-Ming Chen
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, Nebraska, United States of America
- * E-mail:
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Romarheim OH, Hetland DL, Skrede A, Øverland M, Mydland LT, Landsverk T. Prevention of soya-induced enteritis in Atlantic salmon (Salmo salar) by bacteria grown on natural gas is dose dependent and related to epithelial MHC II reactivity and CD8α+ intraepithelial lymphocytes. Br J Nutr 2013; 109:1062-70. [PMID: 22813713 DOI: 10.1017/s0007114512002899] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
An experiment was carried out to study the preventive effect of bacterial meal (BM) produced from natural gas against plant-induced enteropathy in Atlantic salmon (Salmo salar). Salmon were fed a diet based on fish meal (FM) or seven diets with 200 g/kg solvent-extracted soyabean meal (SBM) to induce enteritis in combination with increasing levels of BM from 0 to 300 g/kg. Salmon fed a SBM-containing diet without BM developed typical SBM-induced enteritis. The enteritis gradually disappeared with increasing inclusion of BM. By morphometry, no significant (P>0.05) differences in the size of stretches stained for proliferating cell nuclear antigen were found with 150 g/kg BM compared with the FM diet. Increasing BM inclusion caused a gradual decline in the number of cluster of differentiation 8 α positive (CD8α+) intraepithelial lymphocytes, and fish fed BM at 200 g/kg or higher revealed no significant difference from the FM diet. Histological sections stained with antibody for MHC class II (MHC II) showed that fish with intestinal inflammation had more MHC II-reactive cells in the lamina propria and submucosa, but less in the epithelium and brush border, compared with fish without inflammation. There were no significant (P>0.05) differences in growth among the diets, but the highest levels of BM slightly reduced protein digestibility and increased the weight of the distal intestine. In conclusion, the prevention of SBM-induced enteritis by BM is dose dependent and related to intestinal levels of MHC II- and CD8α-reactive cells.
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Affiliation(s)
- Odd H Romarheim
- Department of Animal and Aquacultural Sciences, Aquaculture Protein Centre, CoE, Norwegian University of Life Sciences, Ås, Norway.
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20
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Tan A, Rajadas J, Seifalian AM. Exosomes as nano-theranostic delivery platforms for gene therapy. Adv Drug Deliv Rev 2013; 65:357-67. [PMID: 22820532 DOI: 10.1016/j.addr.2012.06.014] [Citation(s) in RCA: 183] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 05/27/2012] [Accepted: 06/20/2012] [Indexed: 12/22/2022]
Abstract
Exosomes are biological membrane vesicles measuring 30 to 100 nm. They contain an abundance of small molecules like tetraspanins, receptors for targeting and adhesion, lipids, and RNA. They are secreted by most biological cells, and are involved in a plethora of physiological functions including, but not limited to, transport of genetic material, modulation of the immune system, and cell-to-cell communication. It has been further reported that exosomes utilize a mechanism similar to that of viruses for gaining entry into cells. Due to their viral-like transfection efficiency and inherent biological function, compelling evidence indicates that exosomes can be used as novel delivery platforms for gene therapy. Furthermore, RNA-containing exosomes derived from cells can serve as functional genetic biomarkers for diseases. This twin modality of therapeutic and diagnostic is termed theranostics in the emerging field of nanomedicine. Hence in this review, we seek to expound on the various facets of exosomes, highlighting their significance in and relevance to nano-theranostic platforms for gene therapy.
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Affiliation(s)
- Aaron Tan
- UCL Centre for Nanotechnology & Regenerative Medicine, UCL Division of Surgery & Interventional Science, University College London, London NW3 2QG, UK
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21
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Collins CB, Aherne CM, Kominsky D, McNamee EN, Lebsack MD, Eltzschig H, Jedlicka P, Rivera-Nieves J. Retinoic acid attenuates ileitis by restoring the balance between T-helper 17 and T regulatory cells. Gastroenterology 2011; 141:1821-31. [PMID: 22027263 PMCID: PMC3684415 DOI: 10.1053/j.gastro.2011.05.049] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 05/11/2011] [Accepted: 05/26/2011] [Indexed: 12/23/2022]
Abstract
BACKGROUND & AIMS Retinoic acid (RA), produced by intestinal epithelial cells (IECs) and dendritic cells (DCs) promotes the induction of regulatory T cells (Tregs) and decreases the induction of T-helper (Th)17 cells. METHODS We studied the roles of RA in mice that overproduce tumor necrosis factor (TNF) and develop chronic ileitis (TNF_ARE mice). We assessed the frequency and function of CD103+ DCs, Th17 cells, and Tregs by flow cytometry, and we measured expression of cytokines and retinaldehyde dehydrogenase (RALDH) enzymes in ileum samples, DCs, and IECs by real-time polymerase chain reaction. We quantified RA by electrochemical analysis and examined the effect of RA supplementation on TNF-induced ileitis using histologic, coculture, and suppression assays and flow cytometry. RESULTS Numbers of CD103+ DCs decreased in the inflamed ilea of mice with chronic disease; RA synthetic machinery (RALDH1,2) was down-regulated. Nevertheless, the proportion of CD4+, CD25+, FoxP3+ Tregs increased, indicating an alternate source for RA. IECs responded to reduced levels of RA by up-regulating RALDH3 in vivo and in vitro. Net tissue levels of RA remained lower in TNF+ARE than wild-type mice, indicating that epithelial up-regulation of RALDH3 could not maintain adequate concentrations of RA, probably because of loss of IEC mass. RA supplementation significantly attenuated disease by increasing the number and function of CD103+ DCs and Tregs and reducing Th17 cells. CONCLUSIONS Reduced levels of RA appear to induce IECs to up-regulate synthesis of RA. RA supplementation attenuates ileitis through its effects on CD103+ DCs, Tregs, and Th17 cells. RA supplementation might offer therapeutic benefit in Crohn's disease.
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Affiliation(s)
- Colm B. Collins
- Mucosal Inflammation Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045
| | - Carol M. Aherne
- Mucosal Inflammation Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045,Department of Anesthesiology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045
| | - Douglas Kominsky
- Mucosal Inflammation Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045,Department of Anesthesiology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045
| | - Eóin N. McNamee
- Mucosal Inflammation Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045
| | - Matthew D.P. Lebsack
- Mucosal Inflammation Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045
| | - Holger Eltzschig
- Mucosal Inflammation Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045,Department of Anesthesiology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045
| | - Paul Jedlicka
- Department of Pathology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045
| | - Jesús Rivera-Nieves
- Mucosal Inflammation Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045,Division of Gastroenterology and Hepatology, University of California San Diego
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22
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Mulder DJ, Pooni A, Mak N, Hurlbut DJ, Basta S, Justinich CJ. Antigen presentation and MHC class II expression by human esophageal epithelial cells: role in eosinophilic esophagitis. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 178:744-53. [PMID: 21281807 DOI: 10.1016/j.ajpath.2010.10.027] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 10/14/2010] [Accepted: 10/28/2010] [Indexed: 12/13/2022]
Abstract
Professional antigen-presenting cells (APCs) play a crucial role in initiating immune responses. Under pathological conditions, epithelial cells at mucosal surfaces act as nonprofessional APCs, thereby regulating immune responses at the site of exposure. Epithelial cells in the esophagus may contribute to the pathogenesis of eosinophilic esophagitis (EoE) by presenting antigens on the major histocompatibility complex (MHC) class II. Our goal was to demonstrate the ability of esophageal epithelial cells to process and present antigens on the MHC class II system and to investigate the contribution of epithelial cell antigen presentation to EoE. Immunohistochemistry detected HLA-DR, CD80, and CD86 expression and enzyme-linked immunosorbent assay detected interferon-γ (IFNγ) in esophageal biopsies. Antigen presentation was studied using the human esophageal epithelial cell line HET-1A by reverse transcriptase-PCR, flow cytometry, and confocal microscopy. T helper cell lymphocyte proliferation was assessed by flow cytometry and IL-2 secretion. IFNγ and MHC class II were increased in mucosa of patients with EoE. IFNγ increased mRNA of HLA-DP, HLA-DQ, HLA-DR, and CIITA in HET-1A cells. HET-1A engulfed cell debris and processed ovalbumin. HET-1A cells expressed HLA-DR after IFNγ treatment. HET-1A stimulated T helper cell activation. In this study, we demonstrated the ability of esophageal epithelial cells to act as nonprofessional APCs in the presence of IFNγ. Esophageal epithelial cell antigen presentation may contribute to the pathophysiology of eosinophilic esophagitis.
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Affiliation(s)
- Daniel J Mulder
- Department of Anatomy and Cell Biology, Queen's University, Kingston, Ontario, Canada
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23
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Barreto A, Rodríguez LS, Rojas OL, Wolf M, Greenberg HB, Franco MA, Angel J. Membrane vesicles released by intestinal epithelial cells infected with rotavirus inhibit T-cell function. Viral Immunol 2011; 23:595-608. [PMID: 21142445 DOI: 10.1089/vim.2009.0113] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Rotavirus (RV) predominantly replicates in intestinal epithelial cells (IEC), and "danger signals" released by these cells may modulate viral immunity. We have recently shown that human model IEC (Caco-2 cells) infected with rhesus-RV release a non-inflammatory group of immunomodulators that includes heat shock proteins (HSPs) and TGF-β1. Here we show that both proteins are released in part in association with membrane vesicles (MV) obtained from filtrated Caco-2 supernatants concentrated by ultracentrifugation. These MV express markers of exosomes (CD63 and others), but not of the endoplasmic reticulum (ER) or nuclei. Larger quantities of proteins associated with MV were released by RV-infected cells than by non-infected cells. VP6 co-immunoprecipitated with CD63 present in these MV, and VP6 co-localized with CD63 in RV-infected cells, suggesting that this viral protein is associated with the MV, and that this association occurs intracellularly. CD63 present in MV preparations from stool samples from 36 children with gastroenteritis due or not due to RV were analyzed. VP6 co-immunoprecipitated with CD63 in 3/8 stool samples from RV-infected children, suggesting that these MV are released by RV-infected cells in vivo. Moreover, fractions that contained MV from RV-infected cells induced death and inhibited proliferation of CD4(+) T cells to a greater extent than fractions from non-infected cells. These effects were in part due to TGF-β, because they were reversed by treatment of the T cells with the TGF-β-receptor inhibitor ALK5i. MV from RV-infected and non-infected cells were heterogeneous, with morphologies and typical flotation densities described for exosomes (between 1.10 and 1.18 g/mL), and denser vesicles (>1.24 g/mL). Both types of MV from RV-infected cells were more efficient at inhibiting T-cell function than were those from non-infected cells. We propose that RV infection of IEC releases MV that modulate viral immunity.
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Affiliation(s)
- Alfonso Barreto
- Instituto de Genética Humana, Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia
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Henderson P, van Limbergen JE, Schwarze J, Wilson DC. Function of the intestinal epithelium and its dysregulation in inflammatory bowel disease. Inflamm Bowel Dis 2011; 17:382-95. [PMID: 20645321 DOI: 10.1002/ibd.21379] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The intestinal epithelium not only acts as a physical barrier to commensal bacteria and foreign antigens but is also actively involved in antigen processing and immune cell regulation. The inflammatory bowel diseases (IBDs) are characterized by inflammation at this mucosal surface with well-recognized defects in barrier and secretory function. In addition to this, defects in intraepithelial lymphocytes, chemokine receptors, and pattern recognition receptors promote an abnormal immune response, with increased differentiation of proinflammatory cells and a dysregulated relationship with professional antigen-presenting cells. This review focuses on recent developments in the structure of the epithelium, including a detailed account of the apical junctional complex in addition to the role of the enterocyte in antigen recognition, uptake, processing, and presentation. Recently described cytokines such as interleukin-22 and interleukin-31 are highlighted as is the dysregulation of chemokines and secretory IgA in IBD. Finally, the effect of the intestinal epithelial cell on T effector cell proliferation and differentiation are examined in the context of IBD with particular focus on T regulatory cells and the two-way interaction between the intestinal epithelial cell and certain immune cell populations.
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Affiliation(s)
- Paul Henderson
- Department of Child Life and Health, University of Edinburgh, Edinburgh, UK.
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25
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Rescigno M. Functional specialization of antigen presenting cells in the gastrointestinal tract. Curr Opin Immunol 2010; 22:131-6. [DOI: 10.1016/j.coi.2009.12.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 12/22/2009] [Accepted: 12/23/2009] [Indexed: 01/21/2023]
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Abstract
MicroRNAs are required for development and maintenance of the epithelial barrier. It is hypothesized that microRNAs are involved in regulating epithelial anti-microbial defenses by targeting key epithelial effector molecules and/or influencing intracellular signaling pathways. Additionally, aberrant microRNA expression has been implicated in the pathogenesis of various diseases at the skin and mucosa. Increased understanding of the role of microRNAs in epithelial immunoregulation and identification of microRNAs of pathogenetic significance will enhance our understanding of epithelial immunobiology and immunopathology.
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Affiliation(s)
- Jun Liu
- Department of Medical Microbiology and Immunology, Creighton University Medical Center, Omaha, Nebraska 68178, USA
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Michael A, Bajracharya SD, Yuen PST, Zhou H, Star RA, Illei GG, Alevizos I. Exosomes from human saliva as a source of microRNA biomarkers. Oral Dis 2009; 16:34-8. [PMID: 19627513 DOI: 10.1111/j.1601-0825.2009.01604.x] [Citation(s) in RCA: 527] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE The aim of this study was to examine the presence of microRNAs (miRNAs) within exosomes isolated from human saliva and to optimize and test methods for successful downstream applications. DESIGN Exosomes isolated from fresh and frozen glandular and whole human saliva were used as a source of miRNAs. The presence of miRNAs was validated with TaqMan quantitative PCR and miRNA microarrays. RESULTS We successfully isolated exosomes from human saliva from healthy controls and a patient with Sjögren's syndrome. microRNAs extracted from the exosomal fraction were sufficient for quantitative PCR and microarray profiling. CONCLUSIONS The isolation of miRNAs from easily and non-invasively obtained salivary exosomes with subsequent characterization of the miRNA expression patterns is promising for the development of future biomarkers of the diagnosis and prognosis of various salivary gland pathologies.
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Affiliation(s)
- A Michael
- Sjögren's Syndrome Clinic, Molecular Physiology & Therapeutics Branch, National Institute of Dental and Craniofacial Research, Bethesda, MD 20892, USA
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