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Tang K, Hou Y, Cheng L, Zhang Y, Li J, Qin Q, Zheng X, Jia X, Zhang C, Zhuang R, Zhang Y, Jin B, Chen L, Ma Y. Increased blood CD226 - inflammatory monocytes with low antigen presenting potential correlate positively with severity of hemorrhagic fever with renal syndrome. Ann Med 2023; 55:2247000. [PMID: 37585670 PMCID: PMC10435008 DOI: 10.1080/07853890.2023.2247000] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 08/18/2023] Open
Abstract
BACKGROUND Hantaan virus (HTNV) infection can cause severe hemorrhagic fever with renal syndrome (HFRS). Inflammatory monocytes (iMOs) are involved in early antiviral responses. Previous studies have found that blood iMOs numbers increase in the acute phase of HFRS. Here, we further identified the phenotypic characteristics of iMOs in HFRS and explored whether phenotypic changes in iMOs were associated with HFRS severity. MATERIALS AND METHODS Blood samples from 85 HFRS patients were used for phenotypic analysis of iMOs by flow cytometry. Plasma HTNV load was determined using RT-PCR. THP-1 cells overexpressing CD226 were used to investigate the effects of CD226 on HLA-DR/DP/DQ and CD80 expression. A mouse model was used to test macrophage phenotype following HTNV infection. RESULTS The proportion of CD226- iMOs in the acute phase of HFRS was 66.83 (35.05-81.72) %, which was significantly higher than that in the convalescent phase (5.32 (1.36-13.52) %) and normal controls (7.39 (1.15-18.11) %) (p < 0.0001). In the acute phase, the proportion of CD226- iMOs increased more in patients with more severe HFRS and correlated positively with HTNV load and negatively with platelet count. Notably, CD226- iMOs expressed lower levels of HLA-DR/DP/DQ and CD80 than CD226+ iMOs, and overexpression CD226 could enhance the expression of HLA-DR/DP/DQ and CD80. In a mouse model, HTNV also induced the expansion of CD226- macrophages, with decreased expression of I-A/I-E and CD80. CONCLUSIONS CD226- iMOs increased during HTNV infection and the decrease in CD226 hampered the expression of HLA-DR/DP/DQ and CD80, which may promote the immune escape of HTNV and exacerbate clinical symptoms.
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Affiliation(s)
- Kang Tang
- Department of Immunology, The Fourth Military Medical University, Xincheng District, Xi’an, Shaanxi, P. R. China
| | - Yongli Hou
- Department of Immunology, The Fourth Military Medical University, Xincheng District, Xi’an, Shaanxi, P. R. China
| | - Linfeng Cheng
- Department of Microbiology, The Fourth Military Medical University, Xi’an, P. R. China
| | - Yusi Zhang
- Department of Immunology, The Fourth Military Medical University, Xincheng District, Xi’an, Shaanxi, P. R. China
| | - Juan Li
- Department of Immunology, The Fourth Military Medical University, Xincheng District, Xi’an, Shaanxi, P. R. China
| | - Qi Qin
- Department of Immunology, The Fourth Military Medical University, Xincheng District, Xi’an, Shaanxi, P. R. China
| | - Xuyang Zheng
- Center for Infectious Diseases, Tangdu Hospital, The Fourth Military Medical University, Xi’an, Shaanxi, P. R. China
| | - Xiaozhou Jia
- Eighth Hospital of Xi’an, Xi’an, Shaanxi, P. R. China
| | - Chunmei Zhang
- Department of Immunology, The Fourth Military Medical University, Xincheng District, Xi’an, Shaanxi, P. R. China
| | - Ran Zhuang
- Department of Immunology, The Fourth Military Medical University, Xincheng District, Xi’an, Shaanxi, P. R. China
| | - Yun Zhang
- Department of Immunology, The Fourth Military Medical University, Xincheng District, Xi’an, Shaanxi, P. R. China
| | - Boquan Jin
- Department of Immunology, The Fourth Military Medical University, Xincheng District, Xi’an, Shaanxi, P. R. China
| | - Lihua Chen
- Department of Immunology, The Fourth Military Medical University, Xincheng District, Xi’an, Shaanxi, P. R. China
| | - Ying Ma
- Department of Immunology, The Fourth Military Medical University, Xincheng District, Xi’an, Shaanxi, P. R. China
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2
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Bettke JA, Tam JW, Montoya V, Butler BP, van der Velden AWM. Inflammatory Monocytes Promote Granuloma-Mediated Control of Persistent Salmonella Infection. Infect Immun 2022;:e0007022. [PMID: 35311578 DOI: 10.1128/iai.00070-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Persistent infections generally involve a complex balance between protective immunity and immunopathology. We used a murine model to investigate the role of inflammatory monocytes in immunity and host defense against persistent salmonellosis. Mice exhibit increased susceptibility to persistent infection when inflammatory monocytes cannot be recruited into tissues or when they are depleted at specific stages of persistent infection. Inflammatory monocytes contribute to the pathology of persistent salmonellosis and cluster with other cells in pathogen-containing granulomas. Depletion of inflammatory monocytes during the chronic phase of persistent salmonellosis causes regression of already established granulomas with resultant pathogen growth and spread in tissues. Thus, inflammatory monocytes promote granuloma-mediated control of persistent salmonellosis and may be key to uncovering new therapies for granulomatous diseases.
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3
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Okamori S, Ishii M, Asakura T, Suzuki S, Namkoong H, Kagawa S, Hegab AE, Yagi K, Kamata H, Kusumoto T, Ogawa T, Takahashi H, Yoda M, Horiuchi K, Hasegawa N, Fukunaga K. ADAM10 partially protects mice against influenza pneumonia by suppressing specific myeloid cell population. Am J Physiol Lung Cell Mol Physiol 2021; 321:L872-L884. [PMID: 34523355 DOI: 10.1152/ajplung.00619.2020] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The influenza virus infection poses a serious health threat worldwide. Myeloid cells play pivotal roles in regulating innate and adaptive immune defense. A disintegrin and metalloproteinase (ADAM) family of proteins contributes to various immune responses; however, the role of a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) in influenza virus infection remains largely unknown. Herein, we investigated its role, focusing on myeloid cells, during influenza virus infection in mice. ADAM10 gene (Adam10)flox/flox/Lyz2-Cre (Adam10ΔLyz2) and control Adam10flox/flox mice were intranasally infected with 200 plaque-forming units of influenza virus A/H1N1/PR8/34. Adam10ΔLyz2 mice exhibited a significantly higher mortality rate, stronger lung inflammation, and a higher virus titer in the lungs than control mice. Macrophages and inflammatory cytokines, such as TNF-α, IL-1β, and CCL2, were increased in bronchoalveolar lavage fluid from Adam10ΔLyz2 mice following infection. CD11b+Ly6G-F4/80+ myeloid cells, which had an inflammatory monocyte/macrophage-like phenotype, were significantly increased in the lungs of Adam10ΔLyz2 mice. Adoptive transfer experiments suggested that these cells likely contributed to the poorer prognosis in Adam10ΔLyz2 mice. Seven days after infection, CD11b+Ly6G-F4/80+ lung cells exhibited significantly higher arginase-1 expression levels in Adam10ΔLyz2 mice than in control mice, whereas an arginase-1 inhibitor improved the prognosis of Adam10ΔLyz2 mice. Enhanced granulocyte-macrophage colony-stimulating factor (GM-CSF)/GM-CSF receptor signaling likely contributed to this process. Collectively, these results indicate that myeloid ADAM10 protects against influenza virus pneumonia and may be a promising therapeutic target.
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Affiliation(s)
- Satoshi Okamori
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.,Japan Society of Promotion of Science, Tokyo, Japan
| | - Makoto Ishii
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Takanori Asakura
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Shoji Suzuki
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Ho Namkoong
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Shizuko Kagawa
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Ahmed E Hegab
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan.,Medical Education Center, School of Medicine, International University of Health and Welfare, Chiba, Japan
| | - Kazuma Yagi
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Hirofumi Kamata
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Tatsuya Kusumoto
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Takunori Ogawa
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Hayato Takahashi
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan
| | - Masaki Yoda
- Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Keisuke Horiuchi
- Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan.,Department of Orthopedic Surgery, National Defence Medical College, Saitama, Japan
| | - Naoki Hasegawa
- Center for Infectious Diseases and Infection Control, Keio University School of Medicine, Tokyo, Japan
| | - Koichi Fukunaga
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
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4
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Xu J, Ganguly A, Zhao J, Ivey M, Lopez R, Osterholzer JJ, Cho CS, Olszewski MA. CCR2 Signaling Promotes Brain Infiltration of Inflammatory Monocytes and Contributes to Neuropathology during Cryptococcal Meningoencephalitis. mBio 2021; 12:e0107621. [PMID: 34311579 PMCID: PMC8406332 DOI: 10.1128/mbio.01076-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/25/2021] [Indexed: 12/21/2022] Open
Abstract
Cryptococcal meningoencephalitis (CM) is a leading cause of central nervous system (CNS) infection-related mortality worldwide, with surviving patients often developing neurological deficiencies. While CNS inflammation has been implicated in the pathogenesis of CM, little is known about the relative contribution of the specific inflammatory/immune pathways to CNS pathology versus fungal clearance. Increased cerebrospinal fluid level of C-C chemokine receptor 2 (CCR2) ligand CCL2 is associated with disease deterioration in patients with CM. Using a murine model, we investigated the role of the CCR2 pathway in the development of CNS inflammation and pathology during CM. We found that CCR2-deficient mice exhibited improved 28-day survival and alleviated neurological disease scores despite a brain fungal burden higher than that of the WT mice. Reduced CM pathology in CCR2-deficient mice was accompanied by markedly decreased neuronal cell death around cryptococcal microcysts and restored expression of genes involved in neurotransmission, connectivity, and neuronal cell structure in the brains. Results show that CCR2 axis is the major pathway recruiting CD45hiCD11b+Ly6C+ inflammatory monocyte to the brain and indirectly modulates the accumulation of CD4+ T cells and CD8+ T cells. In particular, CCR2 axis promotes recruitment of interferon gamma (IFN-γ)-producing CD4+ T cells and classical activation of myeloid cells. In this context, CCR2 deletion limits the immune network dysregulation we see in CM and attenuates neuropathology. Thus, the CCR2 axis is a potential target for interventions aimed to limit inflammatory CNS pathology in CM patients. IMPORTANCE Cryptococcal meningoencephalitis (CM) causes nearly 200,000 deaths worldwide each year, and survivors frequently develop long-lasting neurological sequelae. The high rate of mortality and neurologic sequelae in CM patients indicate that antifungal therapies alone are often insufficient to control disease progression. Here, we reveal that CM disease progression in mice is accompanied by inflammatory monocytes infiltration at the periphery of the infected foci that overlap locally perturbed neuronal function and death. Importantly, we identified that CCR2 signaling is a critical pathway driving neuroinflammation, especially inflammatory monocyte recruitment, as well as CNS pathology and mortality in CM mice. Our results imply that targeting the CCR2 pathway may be beneficial as a therapy complementary to antifungal drug treatment, helping to reduce CNS damage and mortality in CM patients.
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Affiliation(s)
- Jintao Xu
- Research Service, Ann Arbor VA Health System, Department of Veterans Affairs Health System, Ann Arbor, Michigan, USA
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Anutosh Ganguly
- Research Service, Ann Arbor VA Health System, Department of Veterans Affairs Health System, Ann Arbor, Michigan, USA
- Division of Hepatopancreatobiliary and Advanced Gastrointestinal Surgery, Department of Surgery, University of Michigan, Ann Arbor, Michigan, USA
| | - Jessica Zhao
- Research Service, Ann Arbor VA Health System, Department of Veterans Affairs Health System, Ann Arbor, Michigan, USA
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Michel Ivey
- Research Service, Ann Arbor VA Health System, Department of Veterans Affairs Health System, Ann Arbor, Michigan, USA
| | - Rafael Lopez
- Research Service, Ann Arbor VA Health System, Department of Veterans Affairs Health System, Ann Arbor, Michigan, USA
| | - John J. Osterholzer
- Research Service, Ann Arbor VA Health System, Department of Veterans Affairs Health System, Ann Arbor, Michigan, USA
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
| | - Clifford S. Cho
- Research Service, Ann Arbor VA Health System, Department of Veterans Affairs Health System, Ann Arbor, Michigan, USA
- Division of Hepatopancreatobiliary and Advanced Gastrointestinal Surgery, Department of Surgery, University of Michigan, Ann Arbor, Michigan, USA
| | - Michal A. Olszewski
- Research Service, Ann Arbor VA Health System, Department of Veterans Affairs Health System, Ann Arbor, Michigan, USA
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, USA
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5
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Kitagawa A, Masuda T, Takahashi J, Tobo T, Noda M, Kuroda Y, Hu Q, Kouyama Y, Kobayashi Y, Kuramitsu S, Sato K, Fujii A, Yoshikawa Y, Wakiyama H, Shimizu D, Tsuruda Y, Eguchi H, Doki Y, Mori M, Mimori K. KIF15 Expression in Tumor-associated Monocytes Is a Prognostic Biomarker in Hepatocellular Carcinoma. Cancer Genomics Proteomics 2020; 17:141-149. [PMID: 32108036 DOI: 10.21873/cgp.20174] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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: 11/12/2019] [Revised: 12/01/2019] [Accepted: 12/04/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND/AIM Kinesin family member 15 (KIF15) participates in the transport of macromolecules in essential cellular processes. In this study we evaluated the clinical relevance of KIF15 expression in hepatocellular carcinoma (HCC). MATERIALS AND METHODS Association between KIF15 expression and clinical outcomes in HCC patients was analyzed using three independent cohorts. Localization of KIF15 expression was assessed by immunohistochemical analysis. Co-culture experiments were performed using healthy donor peripheral blood mononuclear cells (PBMC) and HCC cell lines. RESULTS Immunohistochemical analysis showed that KIF15 was mainly expressed in inflammatory monocytes around cancer cells. Multivariate analysis indicated high KIF15 expression was an independent poor prognostic factor for survival. HCC cells with high expression of minichromosome maintenance protein 2 (MCM2) were located close to KIF15-expressing inflammatory monocytes. The proliferation ability of HCC cells was increased by co-culture with PBMC. CONCLUSION High KIF15 expression in inflammatory monocytes in tumor tissues may serve as a prognostic marker for poor outcome in HCC.
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Affiliation(s)
- Akihiro Kitagawa
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan.,Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Takaaki Masuda
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan
| | - Junichi Takahashi
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan
| | - Taro Tobo
- Department of Clinical Laboratory Medicine, Kyushu University, Beppu Hospital, Oita, Japan
| | - Miwa Noda
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan
| | - Yosuke Kuroda
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan
| | - Qingjiang Hu
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan
| | - Yuta Kouyama
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan
| | - Yuta Kobayashi
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan.,Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Shotaro Kuramitsu
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan
| | - Kuniaki Sato
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan
| | - Atsushi Fujii
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan
| | - Yukihiro Yoshikawa
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan.,Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Hiroaki Wakiyama
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan
| | - Dai Shimizu
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan
| | - Yusuke Tsuruda
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan
| | - Hidetoshi Eguchi
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Yuichiro Doki
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Masaki Mori
- Department of Surgery and Science, Graduate School of Medical Science, Kyushu University, Fukuoka, Japan
| | - Koshi Mimori
- Department of Surgery, Kyushu University, Beppu Hospital, Oita, Japan
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6
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Bosteels C, Maes B, Van Damme K, De Leeuw E, Declercq J, Delporte A, Demeyere B, Vermeersch S, Vuylsteke M, Willaert J, Bollé L, Vanbiervliet Y, Decuypere J, Libeer F, Vandecasteele S, Peene I, Lambrecht B. Sargramostim to treat patients with acute hypoxic respiratory failure due to COVID-19 (SARPAC): A structured summary of a study protocol for a randomised controlled trial. Trials 2020; 21:491. [PMID: 32503663 PMCID: PMC7273817 DOI: 10.1186/s13063-020-04451-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 05/24/2020] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVES The hypothesis of the proposed intervention is that Granulocyte-macrophage colony-stimulating factor (GM-CSF) has profound effects on antiviral immunity, and can provide the stimulus to restore immune homeostasis in the lung with acute lung injury post COVID-19, and can promote lung repair mechanisms, that lead to a 25% improvement in lung oxygenation parameters. Sargramostim is a man-made form of the naturally-occurring protein GM-CSF. TRIAL DESIGN A phase 4 academic, prospective, 2 arm (1:1 ratio), randomized, open-label, controlled trial. PARTICIPANTS Patients aged 18-80 years admitted to specialized COVID-19 wards in 5 Belgian hospitals with recent (< 2 weeks prior to randomization) confirmed COVID-19 infection and acute respiratory failure defined as a PaO2/FiO2 below 350 mmHg or SpO2 below 93% on minimal 2 L/min supplemental oxygen. Patients were excluded from the trial in case of (1) known serious allergic reactions to yeast-derived products, (2) lithium carbonate therapy, (3) mechanical ventilation prior to randomization, (4) peripheral white blood cell count above 25.000/μL and/or active myeloid malignancy, (5) high dose systemic steroid therapy (> 20 mg methylprednisolone or equivalent), (6) enrolment in another investigational study, (7) pregnant or breastfeeding or (8) ferritin levels > 2000 μg/mL. INTERVENTION AND COMPARATOR Inhaled sargramostim 125 μg twice daily for 5 days in addition to standard care. Upon progression of disease requiring mechanical ventilation or to acute respiratory distress syndrome (ARDS) and initiation of mechanical ventilator support within the 5 day period, inhaled sargramostim will be replaced by intravenous sargramostim 125 μg/m2 body surface area once daily until the 5 day period is reached. From day 6 onwards, progressive patients in the active group will have the option to receive an additional 5 days of IV sargramostim, based on the treating physician's assessment. Intervention will be compared to standard of care. Subjects progressing to ARDS and requiring invasive mechanical ventilatory support, from day 6 onwards in the standard of care group will have the option (clinician's decision) to initiate IV sargramostim 125m μg/m2 body surface area once daily for 5 days. MAIN OUTCOMES The primary endpoint of this intervention is measuring oxygenation after 5 days of inhaled (and intravenous) treatment through assessment of a change in pretreatment and post-treatment ratio of PaO2/FiO2 and through measurement of the P(A-a)O2 gradient (PAO2= Partial alveolar pressure of oxygen, PaO2=Partial arterial pressure of oxygen; FiO2= Fraction of inspired oxygen). RANDOMISATION Patients will be randomized in a 1:1 ratio. Randomization will be done using REDCap (electronic IWRS system). BLINDING (MASKING) In this open-label trial neither participants, caregivers, nor those assessing the outcomes will be blinded to group assignment. NUMBERS TO BE RANDOMISED (SAMPLE SIZE) A total of 80 patients with confirmed COVID-19 and acute hypoxic respiratory failure will be enrolled, 40 in the active and 40 in the control group. TRIAL STATUS SARPAC protocol Version 2.0 (April 15 2020). Participant recruitment is ongoing in 5 Belgian Hospitals (i.e. University Hospital Ghent, AZ Sint-Jan Bruges, AZ Delta Roeselare, University Hospital Brussels and ZNA Middelheim Antwerp). Participant recruitment started on March 26th 2020. Given the current decline of the COVID-19 pandemic in Belgium, it is difficult to anticipate the rate of participant recruitment. TRIAL REGISTRATION The trial was registered on Clinical Trials.gov on March 30th, 2020 (ClinicalTrials.gov Identifier: NCT04326920) - retrospectively registered; https://clinicaltrials.gov/ct2/show/NCT04326920?term=sarpac&recrs=ab&draw=2&rank=1 and on EudraCT on March 24th, 2020 (Identifier: 2020-001254-22). FULL PROTOCOL The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.
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Affiliation(s)
- Cedric Bosteels
- VIB-UGent Inflammatie-researchcentrum, Oost-Vlaanderen, Ghent, Belgium
| | - Bastiaan Maes
- VIB-UGent Inflammatie-researchcentrum, Oost-Vlaanderen, Ghent, Belgium.
| | - Karel Van Damme
- VIB-UGent Inflammatie-researchcentrum, Oost-Vlaanderen, Ghent, Belgium
| | | | - Jozefien Declercq
- VIB-UGent Inflammatie-researchcentrum, Oost-Vlaanderen, Ghent, Belgium
| | - Anja Delporte
- VIB-UGent Inflammatie-researchcentrum, Oost-Vlaanderen, Ghent, Belgium
| | | | | | - Marnik Vuylsteke
- VIB-UGent Inflammatie-researchcentrum, Oost-Vlaanderen, Ghent, Belgium
| | - Joren Willaert
- VIB-UGent Inflammatie-researchcentrum, Oost-Vlaanderen, Ghent, Belgium
| | - Laura Bollé
- VIB-UGent Inflammatie-researchcentrum, Oost-Vlaanderen, Ghent, Belgium
| | - Yuri Vanbiervliet
- VIB-UGent Inflammatie-researchcentrum, Oost-Vlaanderen, Ghent, Belgium
| | - Jana Decuypere
- VIB-UGent Inflammatie-researchcentrum, Oost-Vlaanderen, Ghent, Belgium
| | - Frederick Libeer
- VIB-UGent Inflammatie-researchcentrum, Oost-Vlaanderen, Ghent, Belgium
| | | | - Isabelle Peene
- VIB-UGent Inflammatie-researchcentrum, Oost-Vlaanderen, Ghent, Belgium
| | - Bart Lambrecht
- VIB-UGent Inflammatie-researchcentrum, Oost-Vlaanderen, Ghent, Belgium
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7
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McGinley AM, Sutton CE, Edwards SC, Leane CM, DeCourcey J, Teijeiro A, Hamilton JA, Boon L, Djouder N, Mills KHG. Interleukin-17A Serves a Priming Role in Autoimmunity by Recruiting IL-1β-Producing Myeloid Cells that Promote Pathogenic T Cells. Immunity 2020; 52:342-356.e6. [PMID: 32023490 DOI: 10.1016/j.immuni.2020.01.002] [Citation(s) in RCA: 133] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 04/19/2019] [Accepted: 01/10/2020] [Indexed: 12/12/2022]
Abstract
Interleukin-17A (IL-17A) is a major mediator of tissue inflammation in many autoimmune diseases. Anti-IL-17A is an effective treatment for psoriasis and is showing promise in clinical trials in multiple sclerosis. In this study, we find that IL-17A-defective mice or mice treated with anti-IL-17A at induction of experimental autoimmune encephalomyelitis (EAE) are resistant to disease and have defective priming of IL-17-secreting γδ T (γδT17) cells and Th17 cells. However, T cells from Il17a-/- mice induce EAE in wild-type mice following in vitro culture with autoantigen, IL-1β, and IL-23. Furthermore, treatment with IL-1β or IL-17A at induction of EAE restores disease in Il17a-/- mice. Importantly, mobilization of IL-1β-producing neutrophils and inflammatory monocytes and activation of γδT17 cells is reduced in Il17a-/- mice. Our findings demonstrate that a key function of IL-17A in central nervous system (CNS) autoimmunity is to recruit IL-1β-secreting myeloid cells that prime pathogenic γδT17 and Th17 cells.
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Affiliation(s)
- Aoife M McGinley
- Immune Regulation Research Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Caroline E Sutton
- Immune Regulation Research Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Sarah C Edwards
- Immune Regulation Research Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Charlotte M Leane
- Immune Regulation Research Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Joseph DeCourcey
- Immune Regulation Research Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Ana Teijeiro
- Molecular Oncology Programme, Growth Factors, Nutrients and Cancer Group, Centro Nacional de Investigaciones Oncológicas, CNIO, Madrid 28029, Spain
| | - John A Hamilton
- Department of Medicine, University of Melbourne, Royal Melbourne Hospital, Parkville, VIC 3050, Australia
| | | | - Nabil Djouder
- Molecular Oncology Programme, Growth Factors, Nutrients and Cancer Group, Centro Nacional de Investigaciones Oncológicas, CNIO, Madrid 28029, Spain
| | - Kingston H G Mills
- Immune Regulation Research Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
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8
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Benevides L, Saltarelli VM, Pioto F, Sacramento LA, Dias MS, Rodríguez GR, Viola JPB, Carregaro V, Silva JS. NFAT1 Regulates Ly6C hi Monocyte Recruitment to the CNS and Plays an Essential Role in Resistance to Toxoplasma gondii Infection. Front Immunol 2019; 10:2105. [PMID: 31555297 PMCID: PMC6742953 DOI: 10.3389/fimmu.2019.02105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 08/21/2019] [Indexed: 12/24/2022] Open
Abstract
Monocytes play key roles in the maintenance of homeostasis and in the control of the infection. Monocytes are recruited from the bone marrow to inflammatory sites and are essential for antimicrobial activity to limit tissue damage and promote adaptive T cell responses. Here, we investigated the role of Nuclear Factor of Activated T cells 1 (NFAT1) in the regulation of Ly6Chi inflammatory monocyte recruitment to the CNS upon T. gondii infection. We show that NFAT-1-deficient monocytes are unable to migrate to the CNS of T. gondii-infected mice. Moreover, NFAT1−/− mice are highly susceptible to chronic T. gondii infection due to a failure to control parasite replication in the CNS. The inhibition of Ly6Chi inflammatory monocyte recruitment to the CNS severely blocked CXCL10 production and consequently the migration of IFN-γ-producing CD4+ T cells. Moreover, the transfer of Ly6Chi monocytes to infected NFAT1−/− mice favored CD4+ T cell migration to the CNS and resulted in the inhibition of parasite replication and host defense. Together, these results demonstrated for the first time the contribution of NFAT1 to the regulation of Ly6Chi monocyte recruitment to the CNS and to resistance during chronic T. gondii infection.
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Affiliation(s)
- Luciana Benevides
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.,Fiocruz-Bi-Institutional Translational Medicine Plataform, Ribeirão Preto, Brazil
| | - Verônica M Saltarelli
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Franciele Pioto
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.,Fiocruz-Bi-Institutional Translational Medicine Plataform, Ribeirão Preto, Brazil
| | - Laís A Sacramento
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Murilo S Dias
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Gretel R Rodríguez
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - João P B Viola
- Program of Immunology and Tumor Biology, Brazilian National Cancer Institute (INCA), Rio de Janeiro, Brazil
| | - Vanessa Carregaro
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - João S Silva
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.,Fiocruz-Bi-Institutional Translational Medicine Plataform, Ribeirão Preto, Brazil
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9
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Matta SK, Olias P, Huang Z, Wang Q, Park E, Yokoyama WM, Sibley LD. Toxoplasma gondii effector TgIST blocks type I interferon signaling to promote infection. Proc Natl Acad Sci U S A 2019; 116:17480-91. [PMID: 31413201 DOI: 10.1073/pnas.1904637116] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In contrast to the importance of type II interferon-γ (IFN-γ) in control of toxoplasmosis, the role of type I IFN is less clear. We demonstrate here that TgIST, a secreted effector previously implicated in blocking type II IFN-γ signaling, also blocked IFN-β responses by inhibiting STAT1/STAT2-mediated transcription in infected cells. Consistent with a role for type I IFN in cell intrinsic control, ∆Tgist mutants were more susceptible to growth inhibition by murine and human macrophages activated with IFN-β. Additionally, type I IFN was important for production of IFN-γ by natural killer (NK) cells and recruitment of inflammatory monocytes at the site of infection. Mice lacking type I IFN receptors (Ifnar1-/-) showed increased mortality following infection with wild-type parasites and decreased virulence of ∆Tgist parasites was restored in Ifnar1-/- mice. The findings highlight the importance of type I IFN in control of toxoplasmosis and illuminate a parasite mechanism to counteract the effects of both type I and II IFN-mediated host defenses.
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10
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Grossman JG, Nywening TM, Belt BA, Panni RZ, Krasnick BA, DeNardo DG, Hawkins WG, Goedegebuure SP, Linehan DC, Fields RC. Recruitment of CCR2 + tumor associated macrophage to sites of liver metastasis confers a poor prognosis in human colorectal cancer. Oncoimmunology 2018; 7:e1470729. [PMID: 30228938 PMCID: PMC6140580 DOI: 10.1080/2162402x.2018.1470729] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 04/17/2018] [Accepted: 04/25/2018] [Indexed: 02/06/2023] Open
Abstract
The tumor microenvironment (TME) represents a significant barrier to creating effective therapies for metastatic colorectal cancer (mCRC). In several malignancies, bone marrow derived CCR2+ inflammatory monocytes (IM) are recruited to the TME by neoplastic cells, where they become immunosuppressive tumor associated macrophages (TAM). Here we report that mCRC expression of the chemokine CCL2 facilitates recruitment of CCR2+ IM from the bone marrow to the peripheral blood. Immune monitoring of circulating monocytes in patients with mCRC found this influx was a prognostic biomarker and correlated with worse clinical outcomes. At the metastatic site, mCRC liver tumors were heavily infiltrated by TAM, which displayed a robust ability to dampen endogenous anti-tumor lymphocyte activity. Using a murine model of mCRC that recapitulates these findings from human disease, we show that targeting CCR2 reduces TAM accumulation in liver metastasis and restores anti-tumor immunity. Additional quantitative analysis of hepatic metastatic tumor burden and treatment efficacy found that administration of a small molecule CCR2 inhibitor (CCR2i) improves chemotherapeutic responses and increases overall survival in mice with mCRC liver tumors. Our study suggests that targeting the CCL2/CCR2 chemokine axis decreases TAM at the metastatic site, disrupting the immunosuppressive TME and rendering mCRC susceptible to anti-tumor T-cell responses.
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Affiliation(s)
- Julie G Grossman
- Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA
| | - Timothy M Nywening
- Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA
| | - Brian A Belt
- Department of Surgery, University of Rochester Medical Center, Rochester, NY, USA
- Tumor Immunology Program, University of Rochester Medical Center, Rochester, NY, USA
- Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, NY, USA
| | - Roheena Z Panni
- Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA
| | - Bradley A Krasnick
- Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA
| | - David G DeNardo
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
- Alvin J Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, USA
| | - William G Hawkins
- Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA
- Alvin J Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, USA
| | - S Peter Goedegebuure
- Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA
- Alvin J Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, USA
| | - David C Linehan
- Department of Surgery, University of Rochester Medical Center, Rochester, NY, USA
- Tumor Immunology Program, University of Rochester Medical Center, Rochester, NY, USA
- Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, NY, USA
| | - Ryan C Fields
- Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA
- Alvin J Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, USA
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11
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Bakst RL, Xiong H, Chen CH, Deborde S, Lyubchik A, Zhou Y, He S, McNamara W, Lee SY, Olson OC, Leiner IM, Marcadis AR, Keith JW, Al-Ahmadie HA, Katabi N, Gil Z, Vakiani E, Joyce JA, Pamer E, Wong RJ. Inflammatory Monocytes Promote Perineural Invasion via CCL2-Mediated Recruitment and Cathepsin B Expression. Cancer Res 2017; 77:6400-6414. [PMID: 28951461 PMCID: PMC5831809 DOI: 10.1158/0008-5472.can-17-1612] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [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: 06/01/2017] [Revised: 08/21/2017] [Accepted: 09/18/2017] [Indexed: 12/14/2022]
Abstract
Perineural invasion (PNI) is an ominous event strongly linked to poor clinical outcome. Cells residing within peripheral nerves collaborate with cancer cells to enable PNI, but the contributing conditions within the tumor microenvironment are not well understood. Here, we show that CCR2-expressing inflammatory monocytes (IM) are preferentially recruited to sites of PNI, where they differentiate into macrophages and potentiate nerve invasion through a cathepsin B-mediated process. A series of adoptive transfer experiments with genetically engineered donors and recipients demonstrated that IM recruitment to nerves was driven by CCL2 released from Schwann cells at the site of PNI, but not CCL7, an alternate ligand for CCR2. Interruption of either CCL2-CCR2 signaling or cathepsin B function significantly impaired PNI in vivo Correlative studies in human specimens demonstrated that cathepsin B-producing macrophages were enriched in invaded nerves, which was associated with increased local tumor recurrence. These findings deepen our understanding of PNI pathogenesis and illuminate how PNI is driven in part by corruption of a nerve repair program. Further, they support the exploration of inhibiting IM recruitment and function as a targeted therapy for PNI. Cancer Res; 77(22); 6400-14. ©2017 AACR.
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MESH Headings
- Animals
- Cathepsin B/metabolism
- Cell Line
- Cell Line, Tumor
- Chemokine CCL2/genetics
- Chemokine CCL2/metabolism
- Humans
- Macrophages/metabolism
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Nude
- Monocytes/metabolism
- Monocytes/pathology
- Neoplasm Invasiveness
- Neoplasms, Experimental/genetics
- Neoplasms, Experimental/metabolism
- Neoplasms, Experimental/pathology
- Pancreatic Neoplasms/genetics
- Pancreatic Neoplasms/metabolism
- Pancreatic Neoplasms/pathology
- Peripheral Nerves/metabolism
- Peripheral Nerves/pathology
- Receptors, CCR2/genetics
- Receptors, CCR2/metabolism
- Schwann Cells/metabolism
- Transplantation, Heterologous
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Affiliation(s)
- Richard L Bakst
- Department of Radiation Oncology, Mount Sinai School of Medicine, New York, New York
| | - Huizhong Xiong
- Immunology Program, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - Chun-Hao Chen
- Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - Sylvie Deborde
- Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - Anna Lyubchik
- Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - Yi Zhou
- Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - Shizhi He
- Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - William McNamara
- Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - Sei-Young Lee
- Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - Oakley C Olson
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Ingrid M Leiner
- Immunology Program, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - Andrea R Marcadis
- Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - James W Keith
- Immunology Program, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - Hikmat A Al-Ahmadie
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Nora Katabi
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Ziv Gil
- Department of Otolaryngology, Rambam Healthcare Campus, The Technion-Israel Institute of Technology, Haifa, Israel
| | - Efsevia Vakiani
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Johanna A Joyce
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, New York
- Ludwig Institute for Cancer Research, University of Lausanne, Lausanne, Switzerland
| | - Eric Pamer
- Immunology Program, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - Richard J Wong
- Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York.
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12
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Mackos AR, Galley JD, Eubank TD, Easterling RS, Parry NM, Fox JG, Lyte M, Bailey MT. Social stress-enhanced severity of Citrobacter rodentium-induced colitis is CCL2-dependent and attenuated by probiotic Lactobacillus reuteri. Mucosal Immunol 2016; 9:515-26. [PMID: 26422754 DOI: 10.1038/mi.2015.81] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 08/01/2015] [Indexed: 02/04/2023]
Abstract
Psychological stressors are known to affect colonic diseases but the mechanisms by which this occurs, and whether probiotics can prevent stressor effects, are not understood. Because inflammatory monocytes that traffic into the colon can exacerbate colitis, we tested whether CCL2, a chemokine involved in monocyte recruitment, was necessary for stressor-induced exacerbation of infectious colitis. Mice were exposed to a social disruption stressor that entails repeated social defeat. During stressor exposure, mice were orally challenged with Citrobacter rodentium to induce a colonic inflammatory response. Exposure to the stressor during challenge resulted in significantly higher colonic pathogen levels, translocation to the spleen, increases in colonic macrophages, and increases in inflammatory cytokines and chemokines. The stressor-enhanced severity of C. rodentium-induced colitis was not evident in CCL2(-/-) mice, indicating the effects of the stressor are CCL2-dependent. In addition, we tested whether probiotic intervention could attenuate stressor-enhanced infectious colitis by reducing monocyte/macrophage accumulation. Treating mice with probiotic Lactobacillus reuteri reduced CCL2 mRNA levels in the colon and attenuated stressor-enhanced infectious colitis. These data demonstrate that probiotic L. reuteri can prevent the exacerbating effects of stressor exposure on pathogen-induced colitis, and suggest that one mechanism by which this occurs is through downregulation of the chemokine CCL2.
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13
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Samstein M, Schreiber HA, Leiner IM, Susac B, Glickman MS, Pamer EG. Essential yet limited role for CCR2⁺ inflammatory monocytes during Mycobacterium tuberculosis-specific T cell priming. eLife 2013; 2:e01086. [PMID: 24220507 PMCID: PMC3820971 DOI: 10.7554/elife.01086] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Defense against infection by Mycobacterium tuberculosis (Mtb) is mediated by CD4 T cells. CCR2+ inflammatory monocytes (IMs) have been implicated in Mtb-specific CD4 T cell responses but their in vivo contribution remains unresolved. Herein, we show that transient ablation of IMs during infection prevents Mtb delivery to pulmonary lymph nodes, reducing CD4 T cell responses. Transfer of MHC class II-expressing IMs to MHC class II-deficient, monocyte-depleted recipients, while restoring Mtb transport to mLNs, does not enable Mtb-specific CD4 T cell priming. On the other hand, transfer of MHC class II-deficient IMs corrects CD4 T cell priming in monocyte-depleted, MHC class II-expressing mice. Specific depletion of classical DCs does not reduce Mtb delivery to pulmonary lymph nodes but markedly reduces CD4 T cell priming. Thus, although IMs acquire characteristics of DCs while delivering Mtb to lymph nodes, cDCs but not moDCs induce proliferation of Mtb-specific CD4 T cells. DOI:http://dx.doi.org/10.7554/eLife.01086.001 Tuberculosis is a disease that kills more than one million people every year. It is caused by mycobacteria, notably Mycobacterium tuberculosis, and the World Health Organization estimates that about one third of the world’s population has latent tuberculosis, although only one person in 10 goes on to develop an active infection. Understanding why some individuals develop active infections, whereas most do not, could help with the development of a vaccine to prevent tuberculosis and/or new treatments for the disease. Disappointing results from vaccine trials and the emergence of drug-resistant strains of tuberculosis have increased the need for more research into the interactions between mycobacteria and the human immune system. Tuberculosis is spread when an infected person coughs or sneezes and someone else inhales the mycobacteria spread by the first person. When M. tuberculosis first enters the human respiratory tract, the innate immune system tries to identify and destroy cells that have been infected. However, if this initial response is not effective, the M. tuberculosis can persist in the lungs and trigger the adaptive immune response. This involves CD4 T cells working to eliminate the infection, but our understanding of the adaptive immune response is not complete. Samstein et al. probed the role that immune cells known as inflammatory monocytes play in the adaptive immune response. Previous research has suggested that inflammatory monocytes may develop into dendritic cells that directly prime the CD4 T cells to respond when the lung has been infected. However, Samstein et al. demonstrate that the inflammatory monocytes carry M. tuberculosis from the lungs of infected mice to the draining lymph nodes during the second week of infection. These monocytes develop many of the characteristics of dendritic cells, but they do not activate the CD4 T cells. Samstein et al. show that dendritic cells, contrary to previous evidence, are not necessary for the transport of the M. tuberculosis from the lungs to the draining lymph nodes. Without the dendritic cells, however, fewer CD4 T cell are primed in the lymph nodes. Samstein et al. suggest that the inflammatory monocytes play a crucial role by transporting the live bacteria to the lymph nodes. And once in the lymph nodes, the monocytes transfer invading antigens to dendritic cells to initiate the production of the CD4 T cells to lead the fight against the infection. DOI:http://dx.doi.org/10.7554/eLife.01086.002
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Affiliation(s)
- Miriam Samstein
- Program in Immunology and Microbial Pathogenesis, Weill Cornell Graduate School of Medical Sciences, New York, United States
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