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Kim SH, Das D, Sillé FCM, Ramachandran G, Biswal S. Subchronic exposure to ambient PM 2.5 impairs novelty recognition and spatial memory. bioRxiv 2023:2023.09.07.556582. [PMID: 37745318 PMCID: PMC10515782 DOI: 10.1101/2023.09.07.556582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Air pollution remains a great challenge for public health, with the detrimental effects of air pollution on cardiovascular, rhinosinusitis, and pulmonary health increasingly well understood. Recent epidemiological associations point to the adverse effects of air pollution on cognitive decline and neurodegenerative diseases. Mouse models of subchronic exposure to PM 2.5 (ambient air particulate matter < 2.5 µm) provide an opportunity to demonstrate the causality of target diseases. Here, we subchronically exposed mice to concentrated ambient PM 2.5 for 7 weeks (5 days/week; 8h/day) and assessed its effect on behavior using standard tests measuring cognition or anxiety-like behaviors. Average daily PM 2.5 concentration was 200 µg/m 3 in the PM 2.5 group and 10 µg/m 3 in the filtered air group. The novel object recognition (NOR) test was used to assess the effect of PM 2.5 exposure on recognition memory. The increase in exploration time for a novel object versus a familiarized object was lower for PM 2.5 -exposed mice (42% increase) compared to the filtered air (FA) control group (110% increase). In addition, the calculated discrimination index for novel object recognition was significantly higher in FA mice (67 %) compared to PM 2.5 exposed mice (57.3%). The object location test (OLT) was used to examine the effect of PM 2.5 exposure on spatial memory. In contrast to the FA-exposed control mice, the PM 2.5 exposed mice exhibited no significant increase in their exploration time between novel location versus familiarized location indicating their deficit in spatial memory. Furthermore, the discrimination index for novel location was significantly higher in FA mice (62.6%) compared to PM 2.5 exposed mice (51%). Overall, our results demonstrate that subchronic exposure to higher levels of PM 2.5 in mice causes impairment of novelty recognition and spatial memory.
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Illingworth EJ, Maertens A, Sillé FCM. Transcriptomic Effects of Low-Dose Inorganic Arsenic Exposure on Murine Bone Marrow-Derived Macrophages. bioRxiv 2023:2023.07.26.550543. [PMID: 37546857 PMCID: PMC10402011 DOI: 10.1101/2023.07.26.550543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Both tissue-resident macrophages and monocytes recruited from the bone marrow that transform into tissue-resident cells play critical roles in mediating homeostasis as well as in the pathology of inflammatory diseases. Inorganic arsenic (iAs) is the most common drinking water contaminant worldwide and represents a major public health concern. Several diseases that macrophages have implicated involvement in are caused by iAs exposure, including cardiovascular disease, cancer, and increased risk of infectious disease. Therefore, understanding the effects of iAs exposure on macrophages can help us better grasp the full range of arsenic immunotoxicity and better design therapeutic targets for iAs-induced diseases particularly in exposed populations. In this study, we analyzed the transcriptome of low dose iAs-exposed male and female murine bone marrow-derived macrophages (BMDMs) with either M0, M1, or M2 stimulation. We identified differentially expressed genes by iAs in a sex- and stimulation-dependent manner and used bioinformatics tools to predict protein-protein interactions, transcriptional regulatory networks, and associated biological processes. Overall, our data suggest that M1-stimulated, especially female-derived, BMDMs are most susceptible to iAs exposure. Most notably, we observed significant downregulation of major proinflammatory transcription factors, like IRF8, and its downstream targets, as well as genes encoding proteins involved in pattern recognition and antigen presentation, such as TLR7, TLR8, and H2-D1, potentially providing causal insight regarding arsenic's role in perturbing immune responses to infectious diseases. We also observed significant downregulation of genes involved in processes crucial to coordinating a proinflammatory response including leukocyte migration, differentiation, and cytokine and chemokine production and response. Finally, we discovered that 24 X-linked genes were dysregulated in iAs-exposed female stimulation groups compared to only 3 across the iAs-exposed male stimulation groups. These findings elucidate the potential mechanisms underlying the sex-differential iAs-associated immune-related disease risk.
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Rychlik KA, Illingworth EJ, Sanchez IF, Attreed SE, Sinha P, Casin KM, Taube N, Loube J, Tasneen R, Kabir R, Nuermberger E, Mitzner W, Kohr MJ, Sillé FCM. Long-term effects of prenatal arsenic exposure from gestational day 9 to birth on lung, heart, and immune outcomes in the C57BL/6 mouse model. Toxicol Lett 2023; 383:17-32. [PMID: 37244563 PMCID: PMC10527152 DOI: 10.1016/j.toxlet.2023.05.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 04/21/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
Prenatal arsenic exposure is a major public health concern, associated with altered birth outcomes and increased respiratory disease risk. However, characterization of the long-term effects of mid-pregnancy (second trimester) arsenic exposure on multiple organ systems is scant. This study aimed to characterize the long-term impact of mid-pregnancy inorganic arsenic exposure on the lung, heart, and immune system, including infectious disease response using the C57BL/6 mouse model. Mice were exposed from gestational day 9 till birth to either 0 or 1000 µg/L sodium (meta)arsenite in drinking water. Male and female offspring assessed at adulthood (10-12 weeks of age) did not show significant effects on recovery outcomes after ischemia reperfusion injury but did exhibit increased airway hyperresponsiveness compared to controls. Flow cytometric analysis revealed significantly greater total numbers of cells in arsenic-exposed lungs, lower MHCII expression in natural killer cells, and increased percentages of dendritic cell populations. Activated interstitial (IMs) and alveolar macrophages (AMs) isolated from arsenic-exposed male mice produced significantly less IFN-γ than controls. Conversely, activated AMs from arsenic-exposed females produced significantly more IFN-γ than controls. Although systemic cytokine levels were higher upon Mycobacterium tuberculosis (Mtb) infection in prenatally arsenic-exposed offspring there was no difference in lung Mtb burden compared to controls. This study highlights significant long-term impacts of prenatal arsenic exposure on lung and immune cell function. These effects may contribute to the elevated risk of respiratory diseases associated with prenatal arsenic exposure in epidemiology studies and point to the need for more research into mechanisms driving these maintained responses.
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Affiliation(s)
- Kristal A Rychlik
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA; Public Health Program, School of Exercise and Sport Science, University of Mary Hardin-Baylor, Belton, TX, USA
| | - Emily J Illingworth
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Ian F Sanchez
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Sarah E Attreed
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA; Foreign Animal Disease Research Unit, USDA/ARS Plum Island Animal Disease Center, Plum Island, CT, USA
| | - Prithvi Sinha
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Kevin M Casin
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Nicole Taube
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Jeff Loube
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Rokeya Tasneen
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Raihan Kabir
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Eric Nuermberger
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Wayne Mitzner
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Mark J Kohr
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Fenna C M Sillé
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
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Sillé FCM, McCormack M, Hartung T. The Exposome Applied: A Step Toward Defining the Totality of Environmental Exposures in Asthma. Am J Respir Crit Care Med 2022; 206:1187-1188. [PMID: 35925019 DOI: 10.1164/rccm.202207-1430ed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Fenna C M Sillé
- Johns Hopkins University Bloomberg School of Public Health, Environmental Health and Engineering, Baltimore, Maryland, United States;
| | - Meredith McCormack
- Johns Hopkins University, Pulmonary and Critical Care, Baltimore, Maryland, United States
| | - Thomas Hartung
- Johns Hopkins University Bloomberg School of Public Health, Environmental Health and Engineering, Baltimore, Maryland, United States.,University of Konstanz, Department of Biology, Konstanz, Germany
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Bozack AK, Boileau P, Hubbard AE, Sillé FCM, Ferreccio C, Steinmaus CM, Smith MT, Cardenas A. The impact of prenatal and early-life arsenic exposure on epigenetic age acceleration among adults in Northern Chile. Environ Epigenet 2022; 8:dvac014. [PMID: 35769198 PMCID: PMC9235373 DOI: 10.1093/eep/dvac014] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/02/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Exposure to arsenic affects millions of people globally. Changes in the epigenome may be involved in pathways linking arsenic to health or serve as biomarkers of exposure. This study investigated associations between prenatal and early-life arsenic exposure and epigenetic age acceleration (EAA) in adults, a biomarker of morbidity and mortality. DNA methylation was measured in peripheral blood mononuclear cells (PBMCs) and buccal cells from 40 adults (median age = 49 years) in Chile with and without high prenatal and early-life arsenic exposure. EAA was calculated using the Horvath, Hannum, PhenoAge, skin and blood, GrimAge, and DNA methylation telomere length clocks. We evaluated associations between arsenic exposure and EAA using robust linear models. Participants classified as with and without arsenic exposure had a median drinking water arsenic concentration at birth of 555 and 2 μg/l, respectively. In PBMCs, adjusting for sex and smoking, exposure was associated with a 6-year PhenoAge acceleration [B (95% CI) = 6.01 (2.60, 9.42)]. After adjusting for cell-type composition, we found positive associations with Hannum EAA [B (95% CI) = 3.11 (0.13, 6.10)], skin and blood EAA [B (95% CI) = 1.77 (0.51, 3.03)], and extrinsic EAA [B (95% CI) = 4.90 (1.22, 8.57)]. The association with PhenoAge acceleration in buccal cells was positive but not statistically significant [B (95% CI) = 4.88 (-1.60, 11.36)]. Arsenic exposure limited to early-life stages may be associated with biological aging in adulthood. Future research may provide information on how EAA programmed in early life is related to health.
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Affiliation(s)
- Anne K Bozack
- Division of Environmental Health Sciences, School of Public Health, University of California, 2121 Berkeley Way, Room 5302, Berkeley, CA 94720, USA
| | - Philippe Boileau
- Graduate Group in Biostatistics, University of California, 2121 Berkeley Way, Room 5302, Berkeley, CA 94720, USA
| | - Alan E Hubbard
- Graduate Group in Biostatistics, University of California, 2121 Berkeley Way, Room 5302, Berkeley, CA 94720, USA
| | - Fenna C M Sillé
- Department of Environmental Health and Engineering, The Johns Hopkins University Bloomberg School of Public Health, 615 N. Wolfe Street, Room E7527, Baltimore, MD 21205, USA
| | - Catterina Ferreccio
- Advanced Center for Chronic Diseases (ACCDiS), School of Medicine, Pontificia Universidad Católica de Chile, Sergio Livingstone 1007, Independencia, Santiago, Chile
| | - Craig M Steinmaus
- Division of Environmental Health Sciences, School of Public Health, University of California, 2121 Berkeley Way, Room 5302, Berkeley, CA 94720, USA
| | - Martyn T Smith
- Division of Environmental Health Sciences, School of Public Health, University of California, 2121 Berkeley Way, Room 5302, Berkeley, CA 94720, USA
| | - Andres Cardenas
- *Correspondence address. Division of Environmental Health Sciences, School of Public Health, University of California, 2121 Berkeley Way, Room 5302, Berkeley, CA 94720, USA. Tel: +510-643-0965; E-mail:
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Bozack AK, Boileau P, Wei L, Hubbard AE, Sillé FCM, Ferreccio C, Acevedo J, Hou L, Ilievski V, Steinmaus CM, Smith MT, Navas-Acien A, Gamble MV, Cardenas A. Exposure to arsenic at different life-stages and DNA methylation meta-analysis in buccal cells and leukocytes. Environ Health 2021; 20:79. [PMID: 34243768 PMCID: PMC8272372 DOI: 10.1186/s12940-021-00754-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 06/01/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Arsenic (As) exposure through drinking water is a global public health concern. Epigenetic dysregulation including changes in DNA methylation (DNAm), may be involved in arsenic toxicity. Epigenome-wide association studies (EWAS) of arsenic exposure have been restricted to single populations and comparison across EWAS has been limited by methodological differences. Leveraging data from epidemiological studies conducted in Chile and Bangladesh, we use a harmonized data processing and analysis pipeline and meta-analysis to combine results from four EWAS. METHODS DNAm was measured among adults in Chile with and without prenatal and early-life As exposure in PBMCs and buccal cells (N = 40, 850K array) and among men in Bangladesh with high and low As exposure in PBMCs (N = 32, 850K array; N = 48, 450K array). Linear models were used to identify differentially methylated positions (DMPs) and differentially variable positions (DVPs) adjusting for age, smoking, cell type, and sex in the Chile cohort. Probes common across EWAS were meta-analyzed using METAL, and differentially methylated and variable regions (DMRs and DVRs, respectively) were identified using comb-p. KEGG pathway analysis was used to understand biological functions of DMPs and DVPs. RESULTS In a meta-analysis restricted to PBMCs, we identified one DMP and 23 DVPs associated with arsenic exposure; including buccal cells, we identified 3 DMPs and 19 DVPs (FDR < 0.05). Using meta-analyzed results, we identified 11 DMRs and 11 DVRs in PBMC samples, and 16 DMRs and 19 DVRs in PBMC and buccal cell samples. One region annotated to LRRC27 was identified as a DMR and DVR. Arsenic-associated KEGG pathways included lysosome, autophagy, and mTOR signaling, AMPK signaling, and one carbon pool by folate. CONCLUSIONS Using a two-step process of (1) harmonized data processing and analysis and (2) meta-analysis, we leverage four DNAm datasets from two continents of individuals exposed to high levels of As prenatally and during adulthood to identify DMPs and DVPs associated with arsenic exposure. Our approach suggests that standardizing analytical pipelines can aid in identifying biological meaningful signals.
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Affiliation(s)
- Anne K Bozack
- Division of Environmental Health Sciences, School of Public Health, University of California, 2121 Berkeley Way, Room 5302, Berkeley, Berkeley, CA, 94720, USA.
| | - Philippe Boileau
- Graduate Group in Biostatistics, University of California, Berkeley, Berkeley, CA, USA
| | - Linqing Wei
- Graduate Group in Biostatistics, University of California, Berkeley, Berkeley, CA, USA
| | - Alan E Hubbard
- Graduate Group in Biostatistics, University of California, Berkeley, Berkeley, CA, USA
| | - Fenna C M Sillé
- Department of Environmental Health and Engineering, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Catterina Ferreccio
- Advanced Center for Chronic Diseases (ACCDiS), School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Johanna Acevedo
- Department of Public Health, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Health Planning Division in the Ministry of Health, Santiago, Chile
| | - Lifang Hou
- Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Vesna Ilievski
- Department of Environmental Health Science, Mailman School of Public Health, Columbia University, New York City, NY, USA
| | - Craig M Steinmaus
- Division of Environmental Health Sciences, School of Public Health, University of California, 2121 Berkeley Way, Room 5302, Berkeley, Berkeley, CA, 94720, USA
| | - Martyn T Smith
- Division of Environmental Health Sciences, School of Public Health, University of California, 2121 Berkeley Way, Room 5302, Berkeley, Berkeley, CA, 94720, USA
| | - Ana Navas-Acien
- Department of Environmental Health Science, Mailman School of Public Health, Columbia University, New York City, NY, USA
| | - Mary V Gamble
- Department of Environmental Health Science, Mailman School of Public Health, Columbia University, New York City, NY, USA
| | - Andres Cardenas
- Division of Environmental Health Sciences, School of Public Health, University of California, 2121 Berkeley Way, Room 5302, Berkeley, Berkeley, CA, 94720, USA
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Bullen CK, Hogberg HT, Bahadirli-Talbott A, Bishai WR, Hartung T, Keuthan C, Looney MM, Pekosz A, Romero JC, Sillé FCM, Um P, Smirnova L. Infectability of human BrainSphere neurons suggests neurotropism of SARS-CoV-2. ALTEX 2020; 37:665-671. [PMID: 32591839 DOI: 10.14573/altex.2006111] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 06/26/2020] [Indexed: 11/23/2022]
Abstract
Reports from Wuhan suggest that 36% of COVID-19 patients show neurological symptoms, and cases of viral encephalitis have been reported, suggesting that the virus is neurotropic under unknown circumstances. This is well established for other coronaviruses. In order to understand why some patients develop such symptoms and others do not, we address herein the infectability of the central nervous system (CNS). Reports that the ACE2 receptor – critical for virus entry into lung cells – is found in different neurons support this expectation. We employed a human induced pluripotent stem cell (iPSC)- derived BrainSphere model, which we used earlier for Zika, Dengue, HIV and John Cunningham virus infection studies. We detected the expression of the ACE2 receptor, but not TMPRSS2, in the model. Incubating the BrainSpheres for 6 hours with SARS-CoV-2 at a multiplicity of infection (MOI) of 0.1 led to infection of a fraction of neural cells with replication of the virus evident at 72 hpi. Virus particles were found in the neuronal cell body extending into apparent neurite structures. PCR measurements corroborated the replication of the virus, suggesting at least a tenfold increase in virus copies per total RNA. Leveraging state-of-the-art 3D organotypic cell culture, which has been shown to allow both virus infection and modeling of (developmental) neurotoxicity but is at the same time simple enough to be transferred and used in a BSL-3 environment, we demonstrate, for the first time, the potential critically important neurotropism of SARS-CoV-2.
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Affiliation(s)
- C Korin Bullen
- Johns Hopkins University, School of Medicine, Department of Medicine, Division of Infectious Diseases, Baltimore, MD, USA
| | - Helena T Hogberg
- Johns Hopkins University, Bloomberg School of Public Health, Center for Alternatives to Animal Testing (CAAT), Baltimore, MD, USA
| | - Asli Bahadirli-Talbott
- Johns Hopkins University, School of Medicine, Department of Medicine, Division of Infectious Diseases, Baltimore, MD, USA
| | - William R Bishai
- Johns Hopkins University, School of Medicine, Department of Medicine, Division of Infectious Diseases, Baltimore, MD, USA
| | - Thomas Hartung
- Johns Hopkins University, Bloomberg School of Public Health, Center for Alternatives to Animal Testing (CAAT), Baltimore, MD, USA.,CAAT-Europe, University of Konstanz, Konstanz, Germany.,Johns Hopkins University, Bloomberg School of Public Health, Department of Molecular Microbiology and Immunology, Baltimore, MD, USA
| | - Casey Keuthan
- Johns Hopkins University, School of Medicine, Department of Ophthalmology, Wilmer Eye Institute, Baltimore, MD, USA
| | - Monika M Looney
- Johns Hopkins University, School of Medicine, Department of Medicine, Division of Infectious Diseases, Baltimore, MD, USA
| | - Andrew Pekosz
- Johns Hopkins University, Bloomberg School of Public Health, Department of Molecular Microbiology and Immunology, Baltimore, MD, USA
| | - J Carolina Romero
- Johns Hopkins University, Bloomberg School of Public Health, Center for Alternatives to Animal Testing (CAAT), Baltimore, MD, USA
| | - Fenna C M Sillé
- Johns Hopkins University, Bloomberg School of Public Health, Center for Alternatives to Animal Testing (CAAT), Baltimore, MD, USA.,Johns Hopkins University, Bloomberg School of Public Health, Department of Environmental Health & Engineering, Baltimore, MD, USA
| | - Peter Um
- Johns Hopkins University, School of Medicine, Department of Medicine, Division of Infectious Diseases, Baltimore, MD, USA
| | - Lena Smirnova
- Johns Hopkins University, Bloomberg School of Public Health, Center for Alternatives to Animal Testing (CAAT), Baltimore, MD, USA
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Rychlik KA, Sillé FCM. Environmental exposures during pregnancy: Mechanistic effects on immunity. Birth Defects Res 2019; 111:178-196. [PMID: 30708400 DOI: 10.1002/bdr2.1469] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 01/16/2019] [Indexed: 12/21/2022]
Abstract
In human studies, it is well established that exposures during embryonic and fetal development periods can influence immune health. Coupled with genetic predisposition, these exposures can alter lifetime chronic and infectious disease trajectory, and, ultimately, life expectancy. Fortunately, as research advances, mechanisms governing long-term effects of prenatal exposures are coming to light and providing the opportunity for intervention and risk reduction. For instance, human association studies have provided a foundation for the association of prenatal exposure to particulate matter with early immunosuppression and later allergic disease in the offspring. Only recently, the mechanisms mediating this response have been revealed and there is much we have yet to discover. Although cellular immune response is understood for many exposure scenarios, molecular pathways are still unidentified. This review will provide commentary and synthesis of the current literature regarding environmental exposures during pregnancy and mechanisms determining immune outcomes. Shared mechanistic features and current gaps in the state of the science are identified and discussed. To such purpose, we address exposures by their immune effect type: immunosuppression, autoimmunity, inflammation and tissue damage, hypersensitivity, and general immunomodulation.
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Affiliation(s)
- Kristal A Rychlik
- Department of Environmental Health and Engineering, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland
| | - Fenna C M Sillé
- Department of Environmental Health and Engineering, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland
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Regazzoni LG, Grigoryan H, Ji Z, Chen X, Daniels SI, Huang D, Sanchez S, Tang N, Sillé FCM, Iavarone AT, Williams ER, Zhang L, Rappaport SM. Using lysine adducts of human serum albumin to investigate the disposition of exogenous formaldehyde in human blood. Toxicol Lett 2017; 268:26-35. [PMID: 28104429 DOI: 10.1016/j.toxlet.2017.01.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/19/2016] [Accepted: 01/04/2017] [Indexed: 12/20/2022]
Abstract
Formaldehyde is a human carcinogen that readily binds to nucleophiles, including proteins and DNA. To investigate whether exogenous formaldehyde produces adducts in extracellular fluids, we characterized modifications to human serum albumin (HSA) following incubation of whole blood, plasma, and saliva with formaldehyde at concentrations of 1, 10 and 100μM. The only HSA locus that showed the presence of formaldehyde modifications was Lys199. A N(6)-Lys adduct with added mass of 12Da, representing a putative intramolecular crosslink, was detected in biological fluids that had been incubated with formaldehyde but not in control fluids. An adduct representing N(6)-Lys formylation was detected in all fluids, but levels did not increase above control values over the tested range of formaldehyde concentrations. An adduct representing N(6)-Lys199 acetylation was also measured in all samples. We then applied the assay to repeated samples of human plasma from 6 nonsmoking volunteer subjects (from Berkeley, CA), and single samples of serum from 15 workers exposed to airborne formaldehyde at about 1.5ppm in a production facility and 15 control workers from Tianjin, China. Although all human plasma/serum samples contained basal levels of the products of N(6)-Lys formylation and acetylation, the putative crosslink product was not detected. Since the putative crosslink was observed in plasma incubated with formaldehyde at 1μM, this suggests that the endogenous concentration of formaldehyde in serum was much lower than reported in the literature. Furthermore, concentrations of the formyl adduct were not higher in workers exposed to formaldehyde at about 1.5ppm than in controls. Follow-up in vitro experiments with gaseous formaldehyde at 1.4ppm detected the putative crosslink in plasma but not whole blood. This combination of results suggests that N(6) formylation occurs within cells with subsequent release of adducted HSA to the systemic circulation. Comparing across human samples, levels of N(6)-Lys199 formyl adducts were present at similar concentrations in subjects from California and China (about 1mmol/mol HSA), but N(6)-Lys199 acetyl adducts were present at higher concentrations in Chinese subjects (0.34 vs. 0.13mmol/mol HSA).
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Affiliation(s)
- Luca G Regazzoni
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, United States
| | - Hasmik Grigoryan
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, United States
| | - Zhiying Ji
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, United States
| | - Xi Chen
- Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Sarah I Daniels
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, United States
| | - Deyin Huang
- Institute of Occupational Health, School of Public Health, Tianjin Bohai Chemical Industry Group Co. Ltd., Tianjin, China
| | - Sylvia Sanchez
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, United States
| | - Naijun Tang
- Department of Occupational and Environmental Health, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Fenna C M Sillé
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, United States
| | - Anthony T Iavarone
- California Institute for Quantitative Biosciences and Department of Chemistry, University of California, Berkeley, CA, United States
| | - Evan R Williams
- California Institute for Quantitative Biosciences and Department of Chemistry, University of California, Berkeley, CA, United States
| | - Luoping Zhang
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, United States
| | - Stephen M Rappaport
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, United States.
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10
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Daniels SI, Sillé FCM, Goldbaum A, Yee B, Key EF, Zhang L, Smith MT, Thomas R. Improving power to detect changes in blood miRNA expression by accounting for sources of variability in experimental designs. Cancer Epidemiol Biomarkers Prev 2015; 23:2658-66. [PMID: 25472674 DOI: 10.1158/1055-9965.epi-14-0623] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Blood miRNAs are a new promising area of disease research, but variability in miRNA measurements may limit detection of true-positive findings. Here, we measured sources of miRNA variability and determine whether repeated measures can improve power to detect fold-change differences between comparison groups. METHODS Blood from healthy volunteers (N = 12) was collected at three time points. The miRNAs were extracted by a method predetermined to give the highest miRNA yield. Nine different miRNAs were quantified using different qPCR assays and analyzed using mixed models to identify sources of variability. A larger number of miRNAs from a publicly available blood miRNA microarray dataset with repeated measures were used for a bootstrapping procedure to investigate effects of repeated measures on power to detect fold changes in miRNA expression for a theoretical case-control study. RESULTS Technical variability in qPCR replicates was identified as a significant source of variability (P < 0.05) for all nine miRNAs tested. Variability was larger in the TaqMan qPCR assays (SD = 0.15-0.61) versus the qScript qPCR assays (SD = 0.08-0.14). Inter- and intraindividual and extraction variability also contributed significantly for two miRNAs. The bootstrapping procedure demonstrated that repeated measures (20%-50% of N) increased detection of a 2-fold change for approximately 10% to 45% more miRNAs. CONCLUSION Statistical power to detect small fold changes in blood miRNAs can be improved by accounting for sources of variability using repeated measures and choosing appropriate methods to minimize variability in miRNA quantification. IMPACT This study demonstrates the importance of including repeated measures in experimental designs for blood miRNA research. See all the articles in this CEBP Focus section, "Biomarkers, Biospecimens, and New Technologies in Molecular Epidemiology."
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Affiliation(s)
- Sarah I Daniels
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California.
| | - Fenna C M Sillé
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California
| | - Audrey Goldbaum
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California
| | - Brenda Yee
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California
| | - Ellen F Key
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California
| | - Luoping Zhang
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California
| | - Martyn T Smith
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California
| | - Reuben Thomas
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California
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11
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Sillé FCM, Conde L, Zhang J, Akers NK, Sanchez S, Maltbaek J, Riby JE, Smith MT, Skibola CF. Follicular lymphoma-protective HLA class II variants correlate with increased HLA-DQB1 protein expression. Genes Immun 2013; 15:133-6. [PMID: 24304973 DOI: 10.1038/gene.2013.64] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 10/30/2013] [Accepted: 10/30/2013] [Indexed: 11/09/2022]
Abstract
Multiple follicular lymphoma (FL) susceptibility single-nucleotide polymorphisms in the human leukocyte antigen (HLA) class I and II regions have been identified, including rs6457327, rs3117222, rs2647012, rs10484561, rs9268853 and rs2621416. Here we validated previous expression quantitative trait loci results with real-time reverse transcription quantitative PCR and investigated protein expression in B-lymphoblastoid cell lines and primary dendritic cells using flow cytometry, cell-based enzyme-linked immunosorbent assay and western blotting. We confirmed that FL-protective rs2647012-linked variants, in high linkage disequilibrium with the extended haplotype DRB1*15:01-DQA1*01:02-DQB1*06:02, correlate with increased HLA-DQB1 expression. This association remained significant at the protein level and was reproducible across different cell types. We also found that differences in HLA-DQB1 expression were not related to changes in activation markers or class II, major histocompatibility complex, transactivator expression, suggesting the role of an alternative regulatory mechanism. However, functional analysis using RegulomeDB did not reveal any relevant regulatory candidates. Future studies should focus on the clinical relevance of increased HLA-DQB1 protein expression facilitating tumor cell removal through increased immune surveillance.
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Affiliation(s)
- F C M Sillé
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA
| | - L Conde
- Department of Epidemiology, Comprehensive Cancer Center, University of Alabama, Birmingham, AL, USA
| | - J Zhang
- Department of Epidemiology, Comprehensive Cancer Center, University of Alabama, Birmingham, AL, USA
| | - N K Akers
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA
| | - S Sanchez
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA
| | - J Maltbaek
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA
| | - J E Riby
- Department of Epidemiology, Comprehensive Cancer Center, University of Alabama, Birmingham, AL, USA
| | - M T Smith
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA
| | - C F Skibola
- Department of Epidemiology, Comprehensive Cancer Center, University of Alabama, Birmingham, AL, USA
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12
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Skibola CF, Conde L, Foo JN, Riby J, Humphreys K, Sillé FCM, Darabi H, Sanchez S, Hjalgrim H, Liu J, Bracci PM, Smedby KE. A meta-analysis of genome-wide association studies of follicular lymphoma. BMC Genomics 2012; 13:516. [PMID: 23025665 PMCID: PMC3534234 DOI: 10.1186/1471-2164-13-516] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 09/25/2012] [Indexed: 11/29/2022] Open
Abstract
Background B-cell non-Hodgkin lymphoma represents a diverse group of hematological malignancies, of which follicular lymphoma (FL) is one of the most common subtypes. Family and epidemiological studies suggest an important genetic role in the etiology of FL. In recent genome-wide association studies (GWAS) of FL, several genetic susceptibility loci have been identified on chromosome 6p21.33 (rs6457327) and 6p21.32 (rs10484561, rs2647012) in the human leukocyte antigen class I and class II regions. To identify new genetic variants and further elucidate the genetic basis of FL, a meta-analysis was performed of the top 1000 SNPs associated with FL risk from two GWAS in the US, Denmark and Sweden (592 cases, 1541 controls), with independent validation in 107 cases and 681 controls. Results rs9275517 and rs3117222 in the HLA class II region were validated and inversely associated with FL risk (rs9275517: OR = 0.63, 95% CI = 0.55-0.73, p = 4.03 × 10-11; rs3117222: OR = 0.66, 95% CI = 0.57-0.77, p = 1.45 × 10-7). rs9275517, which is in high linkage disequilibrium with rs2647012 (r2 = 0.9), was no longer associated with FL after conditioning on rs2647012. The rs3117222 association was independent of established FL SNPs, but not of the HLA-DPB1*0301 allele. Using publicly available gene expression profiles with matching genotype information, we found that rs3117222 also was significantly correlated with increased HLA-DPB1 expression. Conclusions By performing a meta-analysis of two GWAS of FL, we further validated the relevance of HLA-DPB1*0301 as a protective allele in the pathogenesis of FL. Moreover, the protective rs3117222 A allele correlated with increased levels of HLA-DPB1, suggesting a possible disease mechanism involving HLA-DPB1 expression regulation. Our results add further support to the major role of HLA genetic variation in the pathogenesis of FL.
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Affiliation(s)
- Christine F Skibola
- School of Public Health, Division of Environmental Health Sciences, University of California, Berkeley, 94720, USA.
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13
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Sillé FCM, Thomas R, Smith MT, Conde L, Skibola CF. Post-GWAS functional characterization of susceptibility variants for chronic lymphocytic leukemia. PLoS One 2012; 7:e29632. [PMID: 22235315 PMCID: PMC3250464 DOI: 10.1371/journal.pone.0029632] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 12/01/2011] [Indexed: 11/18/2022] Open
Abstract
Recent genome-wide association studies (GWAS) have identified several gene variants associated with sporadic chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Many of these CLL/SLL susceptibility loci are located in non-coding or intergenic regions, posing a significant challenge to determine their potential functional relevance. Here, we review the literature of all CLL/SLL GWAS and validation studies, and apply eQTL analysis to identify putatively functional SNPs that affect gene expression that may be causal in the pathogenesis of CLL/SLL. We tested 12 independent risk loci for their potential to alter gene expression through cis-acting mechanisms, using publicly available gene expression profiles with matching genotype information. Sixteen SNPs were identified that are linked to differential expression of SP140, a putative tumor suppressor gene previously associated with CLL/SLL. Three additional SNPs were associated with differential expression of DACT3 and GNG8, which are involved in the WNT/β-catenin- and G protein-coupled receptor signaling pathways, respectively, that have been previously implicated in CLL/SLL pathogenesis. Using in silico functional prediction tools, we found that 14 of the 19 significant eQTL SNPs lie in multiple putative regulatory elements, several of which have prior implications in CLL/SLL or other hematological malignancies. Although experimental validation is needed, our study shows that the use of existing GWAS data in combination with eQTL analysis and in silico methods represents a useful starting point to screen for putatively causal SNPs that may be involved in the etiology of CLL/SLL.
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Affiliation(s)
- Fenna C. M. Sillé
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
| | - Reuben Thomas
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
| | - Martyn T. Smith
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
| | - Lucia Conde
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
| | - Christine F. Skibola
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
- * E-mail:
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14
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Sillé FCM, Martin C, Jayaraman P, Rothchild A, Besra GS, Behar SM, Boes M. Critical role for invariant chain in CD1d-mediated selection and maturation of Vα14-invariant NKT cells. Immunol Lett 2011; 139:33-41. [PMID: 21565221 DOI: 10.1016/j.imlet.2011.04.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 04/20/2011] [Accepted: 04/26/2011] [Indexed: 11/29/2022]
Abstract
The development and maturation of Vα14 invariant (i)NKT cells in mice requires CD1d-mediated lipid antigen presentation in the thymus and the periphery. Cortical thymocytes mediate positive selection, while professional APCs are involved in thymic negative selection and in terminal maturation of iNKT cells in the periphery. CD1d requires entry in the endosomal pathway to allow antigen acquisition for assembly as lipid/CD1d complexes for display to iNKT cells. This process involves tyrosine-based sorting motifs in the CD1d cytoplasmic tail and invariant chain (Ii) that CD1d associates with in the endoplasmic reticulum. The function of Ii in iNKT cell thymic development and peripheral maturation had not been fully understood. Using mice deficient in Ii and the Ii-processing enzyme cathepsin S (catS), we addressed this question. Ii(-/-) mice but not catS(-/-) mice developed significantly fewer iNKT cells in thymus, that were less mature as measured by CD44 and NK1.1 expression. Ii(-/-) mice but not catS(-/-) mice developed fewer Vβ7(+) cells in their iNKT TCR repertoire than WT counterparts, indicative of a change in endogenous glycolipid antigen/CD1d-mediated iNKT cell selection. Finally, using a Mycobacterium tuberculosis infection model in macrophages, we show that iNKT developed in Ii(-/-) but not catS(-/-) mice have defective effector function. Our data support a role for professional APCs expressing Ii, but no role for catS in the thymic development and peripheral terminal maturation of iNKT cells.
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Affiliation(s)
- Fenna C M Sillé
- Department of Dermatology, Brigham and Women's Hospital, Boston, MA 02115, USA
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15
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Boes M, Stoppelenburg AJ, Sillé FCM. Endosomal processing for antigen presentation mediated by CD1 and Class I major histocompatibility complex: roads to display or destruction. Immunology 2009; 127:163-70. [PMID: 19476512 DOI: 10.1111/j.1365-2567.2009.03078.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The presentation of antigen in a form that can be recognized by T lymphocytes of the immune system requires antigen processing and association of antigen-derived fragments with molecules encoded by the major histocompatibility complex (MHC) locus or by the CD1 locus. Much emphasis on antigen processing and presentation in the last decades has focused on what we consider 'conventional routes' of antigen processing and presentation, whereby extracellular antigens are processed for presentation via Class II MHC complexes and cytosolic antigens are presented as peptide-Class I MHC complexes. We here highlight two other pathways in myeloid dendritic cells, those of lipid antigen presentation in association with CD1 and of peptide cross-presentation via Class I MHC complexes. Some pathogens evade immune recognition through inhibition of antigen presentation of phagosomal origin. Deviations in endosomal antigen processing and presentation are also seen in individuals suffering from glycosphingolipid lysosomal lipid storage diseases. We summarize recent developments in the endosomal antigen processing and presentation pathway, for display as lipid-CD1 complexes to natural killer T cells and as peptide-Class I MHC complexes to CD8 T cells.
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Affiliation(s)
- Marianne Boes
- Department of Pediatric Immunology, University Medical Center Utrecht, Wilhelmina Children's Hospital, the Netherlands.
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16
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Sillé FCM, Boxem M, Sprengers D, Veerapen N, Besra G, Boes M. Distinct requirements for CD1d intracellular transport for development of V(alpha)14 iNKT cells. J Immunol 2009; 183:1780-8. [PMID: 19587020 DOI: 10.4049/jimmunol.0901354] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The positive selection of V(alpha)14 invariant (i)NKT cells in mice requires CD1d-mediated Ag presentation by CD4(+)CD8(+) thymocytes. Maturation of newly selected iNKT cells continues in the periphery and also involves CD1d expression. CD1d molecules acquire Ags for presentation in endosomal compartments, to which CD1d molecules have access through an intrinsic CD1d-encoded tyrosine motif and by association with the class II MHC chaperone, invariant chain. In this study, we report the generation of mice in which all CD1d is replaced by CD1d-enhanced yellow fluorescent fusion protein (EYFP). CD1d-EYFP molecules are stable, present lipid Ags, and have near normal subcellular distribution. CD1d-EYFP molecules mediated positive selection of V(alpha)14 iNKT cell precursors at decreased efficiency, caused a delay in their terminal maturation, and did not invoke V(alpha)14iNKT cell effector function as wild-type CD1d could. Using these mice, we show that the intrinsic CD1d-encoded sorting motif mediates thymic selection and activation of V(alpha)14 iNKT cells by professional APCs, while for peripheral terminal differentiation the intrinsic CD1d sorting motif is dispensable.
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Affiliation(s)
- Fenna C M Sillé
- Department of Dermatology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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17
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Sprengers D, Sillé FCM, Derkow K, Besra GS, Janssen HLA, Schott E, Boes M. Critical role for CD1d-restricted invariant NKT cells in stimulating intrahepatic CD8 T-cell responses to liver antigen. Gastroenterology 2008; 134:2132-43. [PMID: 18549881 DOI: 10.1053/j.gastro.2008.02.037] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Revised: 02/04/2008] [Accepted: 02/14/2008] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS V alpha14 invariant natural killer T cells (iNKT) are localized in peripheral tissues such as the liver rather than lymphoid tissues. Therefore, their role in modulating the stimulation of conventional, major histocompatibility complex (MHC)-restricted T-cell responses has remained ambiguous. We here describe a role for V alpha14 iNKT cells in modulating conventional T-cell responses to antigen expressed in liver, using transferrin-mOVA (Tf-mOVA) mice. METHODS Naïve ovalbumin-specific class I MHC-restricted T cells (OTI) were adoptively transferred into Tf-mOVA mice in the presence or absence of iNKT-cell agonist alpha-galactosylceramide, after which OTI T-cell priming, antigen-specific cytokine production, cytotoxic killing ability, and liver damage were analyzed. RESULTS Transfer of OTI cells resulted in robust intrahepatic, antigen-specific proliferation of T cells. OTI T cells were activated in liver, and antigen-specific effector function was stimulated by coactivation of Valpha14 iNKT cells using alpha-galactosylceramide. This stimulation was absent in CD1d(-/-)Tf-mOVA mice, which lack V alpha14 iNKT cells, and was prevented when interferon-gamma and tumor necrosis factor-alpha production by V alpha14 iNKT cells was blocked. CONCLUSIONS CD1d-restricted V alpha14 iNKT cells stimulate intrahepatic CD8 T-cell effector responses to antigen expressed in liver. Our findings elucidate a previously unknown intervention point for targeted immunotherapy to autoimmune and possibly infectious liver diseases.
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Affiliation(s)
- Dave Sprengers
- Department of Dermatology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
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18
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Majewski M, Bose TO, Sillé FCM, Pollington AM, Fiebiger E, Boes M. Protein kinase C delta stimulates antigen presentation by Class II MHC in murine dendritic cells. Int Immunol 2007; 19:719-32. [PMID: 17446207 DOI: 10.1093/intimm/dxm034] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Maturation of dendritic cells (DCs) regulates protein sorting in endosomal compartments to promote the surface expression of molecules involved in T cell activation. MHC Class II complexes are mobilized to the surface via intracellular effector molecules that remain largely unknown. We here show that protein kinase C (PKC) stimulates Class II antigen surface expression, using knock-in mice that express a Class II-green fluorescent protein fusion protein as a read out. Selective inhibition of PKCdelta counteracts the ability of DCs to stimulate Class II MHC-restricted antigen-specific T cells. Activation of PKC does not affect antigen uptake, peptide loading and surface display of Class I MHC and transferrin receptor in DCs. We show that activation-induced Class II MHC surface expression is dependent on activation of PKCdelta and conclude that this event is pivotal for optimal CD4 T cell activation.
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Affiliation(s)
- Michael Majewski
- Department of Dermatology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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19
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Sillé FCM, Visser A, Boes M. T cell priming by tissue-derived dendritic cells: New insights from recent murine studies. Cell Immunol 2005; 237:77-85. [PMID: 16360134 DOI: 10.1016/j.cellimm.2005.10.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2005] [Accepted: 10/26/2005] [Indexed: 10/25/2022]
Abstract
Dendritic cells (DCs) act as sentinels in peripheral tissues, continuously scavenging for antigens in their immediate surroundings. Their involvement in T cell responses is generally thought to consist of a linear progression of events, starting with capture of antigen in peripheral tissues such as the skin followed by migration to draining lymphoid organs and MHC-restricted presentation of antigen-derived peptide to induce T cell priming. The role of tissue-derived DCs in the direct priming of immune responses has lately been challenged. It now appears that, at least in some instances, a non-migratory subtype of DCs in the secondary lymphoid tissue presents tissue-derived antigen to T cells. Here, we review recent developments in research on DC function in the priming of immune responses.
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Affiliation(s)
- Fenna C M Sillé
- Department of Dermatology, Brigham and Women's Hospital and Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
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