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Tajbakhsh A, Yousefi F, Abedi SM, Rezaee M, Savardashtaki A, Teng Y, Sahebkar A. The cross-talk between soluble "Find me" and "Keep out" signals as an initial step in regulating efferocytosis. J Cell Physiol 2022; 237:3113-3126. [PMID: 35578547 DOI: 10.1002/jcp.30770] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 04/16/2022] [Accepted: 04/21/2022] [Indexed: 12/20/2022]
Abstract
The rapid clearance of apoptotic cells (ACs), known as efferocytosis, prompts the inhibition of inflammatory responses and autoimmunity and maintains homeostatic cell turnover by controlling the release of intracellular contents. The fast clearance of ACs requires professional and nonprofessional phagocytic cells that can accurately and promptly recognize ACs and migrate towards them. Cells undergoing apoptosis alarm their presence by releasing special soluble chemotactic factors, such as lactoferrin, that act as "Find me," "Keep out," or "Stay away" signals to recruit phagocytic cells, such as macrophages or prevent granulocyte migration. Efferocytosis effectively serves to prevent damage-associated molecular pattern release and secondary necrosis and inhibit inflammation/autoimmunity at the very first step. Since less attention has been given to the cross-talk and balance of "Find me" and "Keep out" signals released from ACs in efferocytosis, we set out to investigate the current knowledge of the roles of "Find me" and "Keep out" signals in the efferocytosis process.
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Affiliation(s)
- Amir Tajbakhsh
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Fatemeh Yousefi
- Department of Biological Sciences, Faculty of Genetics, Tarbiat Modares University, Tehran, Iran
| | - Seyedeh M Abedi
- Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mehdi Rezaee
- Department of Medical Biotechnology, School of Advanced Technologies, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Amir Savardashtaki
- Infertility Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Department of Medical Biotechnology, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Yong Teng
- Department of Hematology and Medical Oncology, Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, USA
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.,Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,School of Medicine, The University of Western Australia, Perth, Western Australia, Australia.,Depatment of Biotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
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2
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Tajbakhsh A, Gheibihayat SM, Mortazavi D, Medhati P, Rostami B, Savardashtaki A, Momtazi-Borojeni AA. The Effect of Cigarette Smoke Exposure on Efferocytosis in Chronic Obstructive Pulmonary Disease; Molecular Mechanisms and Treatment Opportunities. COPD 2021; 18:723-736. [PMID: 34865568 DOI: 10.1080/15412555.2021.1978419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Cigarette smoking-related inflammation, cellular stresses, and tissue destruction play a key role in lung disease, such as chronic obstructive pulmonary disease (COPD). Notably, augmented apoptosis and impaired clearance of apoptotic cells, efferocytosis, contribute to the chronic inflammatory response and tissue destruction in patients with COPD. Of note, exposure to cigarette smoke can impair alveolar macrophages efferocytosis activity, which leads to secondary necrosis formation and tissue inflammation. A better understanding of the processes behind the effect of cigarette smoke on efferocytosis concerning lung disorders can help to design more efficient treatment approaches and also delay the development of lung disease, such as COPD. To this end, we aimed to seek mechanisms underlying the impairing effect of cigarette smoke on macrophages-mediated efferocytosis in COPD. Further, available therapeutic opportunities for restoring efferocytosis activity and ameliorating respiratory tract inflammation in smokers with COPD were also discussed.
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Affiliation(s)
- Amir Tajbakhsh
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Seyed Mohammad Gheibihayat
- Department of Medical Genetics, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Deniz Mortazavi
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Science, Isfahan, Iran
| | - Pourya Medhati
- Student research committee, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Behrouz Rostami
- Health & Treatment Center of Rostam, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Amir Savardashtaki
- Epilepsy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Department of Medical Biotechnology, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Amir Abbas Momtazi-Borojeni
- Department of Medical Biotechnology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Iran's National Elites Foundation, Tehran, Iran
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3
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Kayawake H, Chen-Yoshikawa TF, Tanaka S, Tanaka Y, Ohdan H, Yutaka Y, Yamada Y, Ohsumi A, Nakajima D, Hamaji M, Egawa H, Date H. Impacts of single nucleotide polymorphisms in Fc gamma receptor IIA (rs1801274) on lung transplant outcomes among Japanese lung transplant recipients. Transpl Int 2021; 34:2192-2204. [PMID: 34255889 DOI: 10.1111/tri.13974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 06/17/2021] [Accepted: 07/09/2021] [Indexed: 11/27/2022]
Abstract
This study aimed to analyze the influences of single nucleotide polymorphisms (SNPs) in Fc gamma receptor IIA (FCGR2A) on postoperative outcomes after lung transplantation (LTx). We enrolled 191 lung transplant recipients (80 undergoing living-donor lobar lung transplants [LDLLTs] and 111 undergoing deceased-donor lung transplants [DDLTs]) in this study. We identified SNPs in FCGR2A (131 histidine [H] or arginine [R]; rs1801274) and reviewed the infectious complication-free survival after ICU discharge. The SNPs in FCGR2A comprised H/H (n=53), H/R (n=24), and R/R (n=3) in LDLLT, and H/H (n=67), H/R (n=42), and R/R (n=2) in DDLT. Recipients with H/H (H/H group) and those with H/R or R/R (R group) were compared in the analyses of infectious complications. In multivariate analyses, the R group of SNPs in FCGR2A was associated with pneumonia-free survival (HR: 2.52 [95% confidence interval {CI}: 1.35-4.71], p=0.004), fungal infection-free survival (HR: 2.50 [95% CI: 1.07-5.84], p=0.035), and cytomegalovirus infection-free survival (HR: 2.24 [95% CI: 1.07-4.69], p=0.032) in LDLLT but it was not associated with infectious complication-free survival in DDLT. Therefore, in LDLLT, more attention to infectious complications might need to be paid for LTx recipients with H/R or R/R than for those with H/H.
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Affiliation(s)
- Hidenao Kayawake
- Department of Thoracic Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Toyofumi F Chen-Yoshikawa
- Department of Thoracic Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Department of Thoracic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Satona Tanaka
- Department of Thoracic Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yuka Tanaka
- Department of Gastroenterological and Transplant Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Hideki Ohdan
- Department of Gastroenterological and Transplant Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Yojiro Yutaka
- Department of Thoracic Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yoshito Yamada
- Department of Thoracic Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akihiro Ohsumi
- Department of Thoracic Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Daisuke Nakajima
- Department of Thoracic Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Masatsugu Hamaji
- Department of Thoracic Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Hiroto Egawa
- Department of Surgery, Institute of Gastroenterology, Tokyo Women's Medical University, Tokyo, Japan
| | - Hiroshi Date
- Department of Thoracic Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
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Tajbakhsh A, Farahani N, Gheibihayat SM, Mirkhabbaz AM, Savardashtaki A, Hamblin MR, Mirzaei H. Autoantigen-specific immune tolerance in pathological and physiological cell death: Nanotechnology comes into view. Int Immunopharmacol 2020; 90:107177. [PMID: 33249046 DOI: 10.1016/j.intimp.2020.107177] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/26/2020] [Accepted: 11/02/2020] [Indexed: 02/06/2023]
Abstract
Apoptotic cells are tolerogenic and can present self-antigens in the absence of inflammation, to antigen-presenting cells by the process of efferocytosis, resulting in anergy and depletion of immune effector cells. This tolerance is essential to maintain immune homeostasis and prevent systemic autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus. Consequently, effective efferocytosis can result in the induction of immune tolerance mediated via triggering modulatory lymphocytes and anti-inflammatory responses. Furthermore, several distinct soluble factors, receptors and pathways have been found to be involved in the efferocytosis, which are able to regulate immune tolerance by lessening antigen presentation, inhibition of T-cell proliferation and induction of regulatory T-cells. Some newly developed nanotechnology-based approaches can induce antigen-specific immunological tolerance without any systemic immunosuppression. These strategies have been explored to reverse autoimmune responses induced against various protein antigens in different diseases. In this review, we describe some nanotechnology-based approaches for the maintenance of self-tolerance using the apoptotic cell clearance process (efferocytosis) that may be able to induce immune tolerance and treat autoimmune diseases.
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Affiliation(s)
- Amir Tajbakhsh
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Najmeh Farahani
- Department of Genetics and Molecular Biology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Sayed Mohammad Gheibihayat
- Department of Medical Genetics, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | | | - Amir Savardashtaki
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran; Department of Medical Biotechnology, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Michael R Hamblin
- Laser Research Centre, Faculty of Health Science, University of Johannesburg, Doornfontein, Johannesburg 2028, South Africa.
| | - Hamed Mirzaei
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, I.R., Iran.
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Reprogramming the Constant Region of Immunoglobulin G Subclasses for Enhanced Therapeutic Potency against Cancer. Biomolecules 2020; 10:biom10030382. [PMID: 32121592 PMCID: PMC7175108 DOI: 10.3390/biom10030382] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 02/21/2020] [Accepted: 02/24/2020] [Indexed: 12/18/2022] Open
Abstract
The constant region of immunoglobulin (Ig) G antibodies is responsible for their effector immune mechanism and prolongs serum half-life, while the fragment variable (Fv) region is responsible for cellular or tissue targeting. Therefore, antibody engineering for cancer therapeutics focuses on both functional efficacy of the constant region and tissue- or cell-specificity of the Fv region. In the functional aspect of therapeutic purposes, antibody engineers in both academia and industry have capitalized on the constant region of different IgG subclasses and engineered the constant region to enhance therapeutic efficacy against cancer, leading to a number of successes for cancer patients in clinical settings. In this article, we review IgG subclasses for cancer therapeutics, including (i) IgG1, (ii) IgG2, 3, and 4, (iii) recent findings on Fc receptor functions, and (iv) future directions of reprogramming the constant region of IgG to maximize the efficacy of antibody drug molecules in cancer patients.
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6
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Paul P, Pedini P, Lyonnet L, Di Cristofaro J, Loundou A, Pelardy M, Basire A, Dignat-George F, Chiaroni J, Thomas P, Reynaud-Gaubert M, Picard C. FCGR3A and FCGR2A Genotypes Differentially Impact Allograft Rejection and Patients' Survival After Lung Transplant. Front Immunol 2019; 10:1208. [PMID: 31249568 PMCID: PMC6582937 DOI: 10.3389/fimmu.2019.01208] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 05/13/2019] [Indexed: 01/10/2023] Open
Abstract
Fc gamma receptors (FcγRs) play a major role in the regulation of humoral immune responses. Single-nucleotide polymorphisms (SNPs) of FCGR2A and FCGR3A can impact the expression level, IgG affinity and function of the CD32 and CD16 FcγRs in response to their engagement by the Fc fragment of IgG. The CD16 isoform encoded by FCGR3A [158V/V] controls the intensity of antibody-dependent cytotoxic alloimmune responses of natural killer cells (NK) and has been identified as a susceptibility marker predisposing patients to cardiac allograft vasculopathy after heart transplant. This study aimed to investigate whether FCGR2A and FCGR3A polymorphisms can also be associated with the clinical outcome of lung transplant recipients (LTRs). The SNPs of FCGR2A ([131R/H], rs1801274) and FCGR3A ([158V/F], rs396991) were identified in 158 LTRs and 184 Controls (CTL). The corresponding distribution of genotypic and allelic combinations was analyzed for potential links with the development of circulating donor-specific anti-HLA alloantibodies (DSA) detected at months 1 and 3 after lung transplant (LTx), the occurrence of acute rejection (AR) and chronic lung allograft dysfunction (CLAD), and the overall survival of LTRs. The FCGR3A [158V/V] genotype was identified as an independent susceptibility factor associated with higher rates of AR during the first trimester after LTx (HR 4.8, p < 0.0001, 95% CI 2.37-9.61), but it could not be associated with the level of CD16- mediated NK cell activation in response to the LTR's DSA, whatever the MFI intensity and C1q binding profiles of the DSA evaluated. The FCGR2A [131R/R] genotype was associated with lower CLAD-free survival of LTRs, independently of the presence of DSA at 3 months (HR 1.8, p = 0.024, 95% CI 1.08-3.03). Our data indicate that FCGR SNPs differentially affect the clinical outcome of LTRs and may be of use to stratify patients at higher risk of experiencing graft rejection. Furthermore, these data suggest that in the LTx setting, specific mechanisms of humoral alloreactivity, which cannot be solely explained by the complement and CD16-mediated pathogenic effects of DSA, may be involved in the development of acute and chronic lung allograft rejection.
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Affiliation(s)
- Pascale Paul
- Department of Hematology, Hopital de la Conception, INSERM CIC-1409, Assistance Publique-Hôpitaux Marseille (AP-HM), Marseille, France.,INSERM 1263, INRA, C2VN, Aix-Marseille Université (AMU), INSERM, Marseille, France
| | - Pascal Pedini
- Établissement Français du Sang PACA-Corse 13005, Marseille, France
| | - Luc Lyonnet
- Department of Hematology, Hopital de la Conception, INSERM CIC-1409, Assistance Publique-Hôpitaux Marseille (AP-HM), Marseille, France
| | - Julie Di Cristofaro
- "Biologie des Groupes Sanguins", UMR 7268 ADÉS Aix-Marseille Université/EFS/CNRS, Marseille, France
| | - Anderson Loundou
- Département de santé Publique - EA 3279, Assistance Publique-Hôpitaux Marseille (AP-HM), Aix-Marseille Université, Marseille, France
| | - Mathieu Pelardy
- Établissement Français du Sang PACA-Corse 13005, Marseille, France
| | - Agnes Basire
- Établissement Français du Sang PACA-Corse 13005, Marseille, France
| | - Françoise Dignat-George
- Department of Hematology, Hopital de la Conception, INSERM CIC-1409, Assistance Publique-Hôpitaux Marseille (AP-HM), Marseille, France.,INSERM 1263, INRA, C2VN, Aix-Marseille Université (AMU), INSERM, Marseille, France
| | - Jacques Chiaroni
- Établissement Français du Sang PACA-Corse 13005, Marseille, France.,"Biologie des Groupes Sanguins", UMR 7268 ADÉS Aix-Marseille Université/EFS/CNRS, Marseille, France
| | - Pascal Thomas
- Service de Chirurgie Thoracique et Transplantation Pulmonaire, CHU Nord Assistance Publique-Hôpitaux Marseille (AP-HM), Aix-Marseille Université, Marseille, France
| | - Martine Reynaud-Gaubert
- Service de Pneumologie et Transplantation Pulmonaire, CHU Nord Assistance Publique-Hôpitaux Marseille (AP-HM) - IHU Méditerranée Infection Aix-Marseille-Université, Marseille, France
| | - Christophe Picard
- Établissement Français du Sang PACA-Corse 13005, Marseille, France.,"Biologie des Groupes Sanguins", UMR 7268 ADÉS Aix-Marseille Université/EFS/CNRS, Marseille, France
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7
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Dong M, Jin H, Zuo M, Bai H, Wang L, Shi C, Niu W. The potential effect of Bruton's tyrosine kinase in refractory periapical periodontitis. Biomed Pharmacother 2019; 112:108710. [PMID: 30818138 DOI: 10.1016/j.biopha.2019.108710] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 02/06/2019] [Accepted: 02/19/2019] [Indexed: 01/17/2023] Open
Abstract
To determine the expression of Bruton's tyrosine kinase (BTK) in refractory periapical periodontitis and analyze the relationship between BTK and bone resorption in refractory periapical periodontitis. The mechanism of bone resorption is also discussed. The OneArray Plus expression microarray was used to screen for genes related to refractory periapical periodontitis. Real-time PCR was used to detect the expression of BTK in refractory periapical periodontitis tissues. A model of periapical periodontitis was established by sealing E.faecalis into the pulp of rats. To establish a model of E.faecalis LTA infection of osteoclasts, the relationship between BTK and bone destruction during refractory periapical periodontitis was analyzed. OneArray Plus expression microarray results showed that we found that the expression of 1787 genes in the two samples was different. After validating these samples, we found that BTK was closely related to refractory periapical periodontitis. The results showed that the expression of BTK in refractory periapical periodontitis tissues was higher than that in normal tissues. Immunohistochemistry, enzyme histochemistry and real-time PCR showed that the BTK expression curve in the experimental model resembled a reverse V shape from week 1 to week 4. Osteoclasts were cultured in vitro and treated with E. faecalis LTA. The expression of BTK in the E. faecalis model was greater than that in the control group. BTK played an important role in the progression of refractory periapical periodontitis.
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Affiliation(s)
- Ming Dong
- College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, Liaoning, China.
| | - Haiwei Jin
- Department of Oral Anatomy and Physiology, Dalian Medical University, Dalian 116044, Liaoning, China.
| | - Meina Zuo
- Department of Endodontics and Periodontics, Dalian Medical University, Dalian 116044, Liaoning, China.
| | - Hua Bai
- Department of Endodontics and Periodontics, Dalian Medical University, Dalian 116044, Liaoning, China.
| | - Lina Wang
- Department of Endodontics and Periodontics, Dalian Medical University, Dalian 116044, Liaoning, China.
| | - Chun Shi
- Department of Endodontics and Periodontics, Dalian Medical University, Dalian 116044, Liaoning, China.
| | - Weidong Niu
- Department of Endodontics and Periodontics, Dalian Medical University, Dalian 116044, Liaoning, China.
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8
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Stein MM, Hrusch CL, Sperling AI, Ober C. Effects of an FcγRIIA polymorphism on leukocyte gene expression and cytokine responses to anti-CD3 and anti-CD28 antibodies. Genes Immun 2018; 20:462-472. [PMID: 29977032 DOI: 10.1038/s41435-018-0038-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 05/21/2018] [Accepted: 05/23/2018] [Indexed: 02/06/2023]
Abstract
The low affinity Fcγ receptor, FcγRIIA, harbors a common missense mutation, rs1801274 (G>A, Arg131His) that modifies binding affinity to human IgG2 and mouse IgG1 antibodies and is associated with increased risk of autoimmune disease. Despite the important role of the Arg131His variant, little is understood about heterozygous genotype effects on global gene expression and cytokine production during an FcγR-dependent response. To address this gap in knowledge, we treated human whole-blood samples from 130 individuals with mouse IgG1 anti-CD3 and anti-CD28 antibodies and characterized the genome-wide gene expression profiles and cytokine production among individuals stratified by rs1801274 genotype. Our analysis revealed that the levels of four cytokines (IFNγ, IL-12, IL-2, TNFα) and global gene expression patterns differed between all three genotype classes. Surprisingly, the heterozygotes showed suboptimal T cell activation compared to cells from individuals homozygous for the higher-affinity FcγRIIA allele (GG; Arg/Arg). The results of this study demonstrate that IgG response varies among all rs1801274 genotype classes and results in profound differences in both cytokine responses and gene expression patterns in blood leukocytes. Because even heterozygotes showed dampened global responses, our data may provide insight into the heterogeneity of outcomes in cytokine release assays and immunotherapy efficacy.
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Affiliation(s)
- Michelle M Stein
- Department of Human Genetics, University of Chicago, Chicago, IL, 60637, USA.
| | - Cara L Hrusch
- Department of Medicine, Section of Pulmonary and Critical Care Medicine, and the Committee on Immunology, University of Chicago, Chicago, IL, 60637, USA
| | - Anne I Sperling
- Department of Medicine, Section of Pulmonary and Critical Care Medicine, and the Committee on Immunology, University of Chicago, Chicago, IL, 60637, USA
| | - Carole Ober
- Department of Human Genetics, University of Chicago, Chicago, IL, 60637, USA
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9
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Katzenmeyer KN, Szott LM, Bryers JD. Artificial opsonin enhances bacterial phagocytosis, oxidative burst and chemokine production by human neutrophils. Pathog Dis 2018; 75:3934653. [PMID: 28859309 DOI: 10.1093/femspd/ftx075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 07/04/2017] [Indexed: 12/23/2022] Open
Abstract
Here, we describe the application of an 'artificial opsonin' to stimulate the innate immune response against Gram-positive bacteria. The artificial opsonin comprises a poly(L-lysine)-graft-poly(ethylene glycol) backbone displaying multiple copies of vancomycin and human IgG-Fc. The vancomycin targets bacteria by recognizing d-Ala-d-Ala-terminated peptides present in the bacterial cell wall. The human IgG-Fc antibody fragments serve as phagocyte recognition moieties that recognize the Fcγ cell surface receptors expressed by professional human phagocytes. Staphylococcus epidermidis RP62A, a biofilm-forming, methicillin-resistant strain, was utilized to investigate the effects of opsonization on phagocytosis, oxidative burst and IL-8 chemokine production by human neutrophils. Results show that opsonization of S. epidermidis RP62A with the artificial opsonin resulted in an ∼2-fold increase in neutrophil phagocytosis. Analysis of the cell supernatant found a 2- to 3-fold increase in neutrophil IL-8 secretion. The neutrophil oxidative burst was investigated using the oxidation-sensitive fluorophore dihydrorhodamine-123. Bacterial opsonization resulted in a 20% increase in fluorescence intensity, indicating a significant increase in the production of reactive oxygen species by the neutrophils. These studies suggest that artificial opsonins may be a novel immunostimulation therapeutic strategy to control infections caused by Gram-positive bacteria, particularly those that are known to be immune evasive and/or antibiotic resistant.
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Affiliation(s)
- Kristy N Katzenmeyer
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
| | - Luisa M Szott
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
| | - James D Bryers
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
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10
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Cho SH, Contreras LM, Ju SH. Synthetic chimeras with orthogonal ribosomal proteins increase translation yields by recruiting mRNA for translation as measured by profiling active ribosomes. Biotechnol Prog 2016; 32:285-93. [PMID: 26749267 DOI: 10.1002/btpr.2227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 12/19/2015] [Indexed: 12/20/2022]
Abstract
In addition to their roles in protein biosynthesis, components of cellular ribosomes perform roles that contribute to a number of important cellular processes. Exploitation of processes has led to the use of ribosomal parts as solubility enhancer partners and purification matrices in protein expression. In this work, an engineered version of the E. coli ribosomal protein L29 (L4H2) as a fusion partner for enhancing cellular expression of proteins that are poorly expressed in bacteria was exploited. It was demonstrated that a chimeric fusion of L4H2 with various Fcγ receptors increases total expression up to 3.2-fold, relative to Fcγ receptors expressed without the fusion. Mechanistic insights using a novel application of in vivo ribosome display suggested that, although total cellular mRNA levels of L4H2-Fcγ receptor remained unchanged relative to wild-type Fcγ receptors, mRNA levels of actively translated L4H2-Fcγ transcript increased about 3.8-fold relative to actively translated levels of wild-type Fcγ transcript. Similar increases in protein expression in the context of the other proteins tested, showing the generality of this approach for proteins beyond human receptors was observed. These results extended the number of potential schemes by which orthogonal ribosomal parts can be used to enhance complex protein expression in bacterial platforms. Within a larger scope, this study features the possibility of engineering 5' tags that enhance mRNA affinity to ribosomes as strategies to augment translation. It was envisioned that the successful application of profiling active ribosomes in a highly targeted manner could be beneficial for mechanistic translation studies concerning synthesis of target proteins. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:285-293, 2016.
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Affiliation(s)
- Seung Hee Cho
- Inst. for Cellular & Molecular Biology, The University of Texas at Austin, Molecular Biology Building, 2500 Speedway Stop A4800, Austin, TX, 78712
| | - Lydia M Contreras
- Inst. for Cellular & Molecular Biology, The University of Texas at Austin, Molecular Biology Building, 2500 Speedway Stop A4800, Austin, TX, 78712.,McKetta Dept. of Chemical Engineering, Cockrell School of Engineering, The University of Texas at Austin, 200 E. Dean Keeton St. Stop C0400, Austin, TX, 78712
| | - Sang Hyun Ju
- McKetta Dept. of Chemical Engineering, Cockrell School of Engineering, The University of Texas at Austin, 200 E. Dean Keeton St. Stop C0400, Austin, TX, 78712
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Abstract
BACKGROUND Treatment with rituximab may be accompanied by a systemic cytokine release. We studied the effects of a single dose of rituximab on cytokine levels in transplant patients and examined the underlying mechanism. METHODS Twenty renal transplant recipients (10 rituximab-treated, 10 placebo-treated) were recruited from a randomized clinical trial. Rituximab or placebo was infused during surgery, and blood samples were taken before, during, and after surgery and analyzed for interleukin (IL)-2, IL-4, IL-6, IL-10, IL-12, IL-17, interferon-γ, macrophage inflammatory protein (MIP)-1β, transforming growth factor-β, and tumor necrosis factor-α. in vitro, healthy donor peripheral blood mononuclear cells, purified B cells, monocytes, natural killer (NK) cells, or combinations thereof were incubated with rituximab, rituximab-F(ab')2, or medium and MIP-1β, IL-10, interferon-γ, and tumor necrosis factor-α levels were measured in the supernatant. RESULTS Rituximab-treated patients had higher serum levels of IL-10 (101 ± 35 pg/mL vs 41 ± 9 pg/mL; P < 0.01) and MIP-1β (950 ± 418 pg/mL vs 125 ± 32 pg/mL; P < 0.001) compared to placebo-treated patients at 2 hours after start of infusion. There was no difference in the level of other cytokines. In vitro, the addition of rituximab, but not rituximab-F(ab')2 fragments, only led to significantly increased levels of MIP-1β in co-cultures of B and NK cells. Levels of MIP-1β were higher in patients with a high affinity Fc-receptor compared to those with a lower affinity FcγRIIIa (1356 ± 184 pg/mL vs 679 ± 273 pg/mL; P < 0.01). CONCLUSIONS In addition to B-cell depletion, rituximab can modulate the immune response by inducing cytokine secretion, especially IL-10 and MIP-1β. Rituximab-induced MIP-1β secretion depends on the combined presence of B cells and FcR-bearing cells, especially NK cells.
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Boero S, Morabito A, Banelli B, Cardinali B, Dozin B, Lunardi G, Piccioli P, Lastraioli S, Carosio R, Salvi S, Levaggi A, Poggio F, D'Alonzo A, Romani M, Del Mastro L, Poggi A, Pistillo MP. Analysis of in vitro ADCC and clinical response to trastuzumab: possible relevance of FcγRIIIA/FcγRIIA gene polymorphisms and HER-2 expression levels on breast cancer cell lines. J Transl Med 2015; 13:324. [PMID: 26450443 PMCID: PMC4598965 DOI: 10.1186/s12967-015-0680-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 09/24/2015] [Indexed: 11/10/2022] Open
Abstract
Background Trastuzumab is a humanized monoclonal antibody (mAb) currently used for the treatment of breast cancer (BC) patients with HER-2 overexpressing tumor subtype. Previous data reported the involvement of FcγRIIIA/IIA gene polymorphisms and/or antibody-dependent cellular cytotoxicity (ADCC) in the therapeutic efficacy of trastuzumab, although results on these issues are still controversial. This study was aimed to evaluate in vitro the functional relationships among FcγRIIIA/IIA polymorphisms, ADCC intensity and HER-2 expression on tumor target cells and to correlate them with response to trastuzumab. Patients and methods Twenty-five patients with HER-2 overexpressing BC, receiving trastuzumab in a neoadjuvant (NEO) or metastatic (MTS) setting, were genotyped for the FcγRIIIA 158V>F and FcγRIIA 131H>R polymorphisms by a newly developed pyrosequencing assay and by multiplex Tetra-primer-ARMS PCR, respectively. Trastuzumab-mediated ADCC of patients’ peripheral blood mononuclear cells (PBMCs) was evaluated prior to therapy and measured by 51Chromium release using as targets three human BC cell lines showing different levels of reactivity with trastuzumab. Results We found that the FcγRIIIA 158F and/or the FcγRIIA 131R variants, commonly reported as unfavorable in BC, may actually behave as ADCC favorable genotypes, in both the NEO (P ranging from 0.009 to 0.039 and from 0.007 to 0.047, respectively) and MTS (P ranging from 0.009 to 0.032 and P = 0.034, respectively) patients. The ADCC intensity was affected by different levels of trastuzumab reactivity with BC target cells. In this context, the MCF-7 cell line, showing the lowest reactivity with trastuzumab, resulted the most suitable cell line for evaluating ADCC and response to trastuzumab. Indeed, we found a statistically significant correlation between an increased frequency of patients showing ADCC of MCF-7 and complete response to trastuzumab in the NEO setting (P = 0.006). Conclusions Although this study was performed in a limited number of patients, it would indicate a correlation of FcγR gene polymorphisms to the ADCC extent in combination with the HER-2 expression levels on tumor target cells in BC patients. However, to confirm our findings further experimental evidences obtained from a larger cohort of BC patients are mandatory. Electronic supplementary material The online version of this article (doi:10.1186/s12967-015-0680-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Silvia Boero
- Unit of Molecular Oncology and Angiogenesis, IRCCS AOU San Martino-IST, Genoa, Italy.
| | - Anna Morabito
- Unit of Tumor Epigenetics, IRCCS AOU San Martino-IST, Genoa, Italy.
| | - Barbara Banelli
- Unit of Tumor Epigenetics, IRCCS AOU San Martino-IST, Genoa, Italy.
| | - Barbara Cardinali
- Development of Innovative Therapies Unit, IRCCS AOU San Martino-IST, Genoa, Italy.
| | - Beatrice Dozin
- Clinical Epidemiology Unit, IRCCS AOU San Martino-IST, Genoa, Italy.
| | - Gianluigi Lunardi
- Medical Oncology Unit, Sacro Cuore Don Calabria Hospital, Negrar, Verona, Italy.
| | | | - Sonia Lastraioli
- Laboratory of Molecular Diagnostics, IRCCS AOU San Martino-IST, Genoa, Italy.
| | - Roberta Carosio
- Unit of Tumor Epigenetics, IRCCS AOU San Martino-IST, Genoa, Italy.
| | - Sandra Salvi
- Unit of Pathology, IRCCS AOU San Martino-IST, Genoa, Italy.
| | - Alessia Levaggi
- Development of Innovative Therapies Unit, IRCCS AOU San Martino-IST, Genoa, Italy.
| | - Francesca Poggio
- Unit of Medical Oncology 2, IRCCS AOU San Martino-IST, Genoa, Italy.
| | - Alessia D'Alonzo
- Development of Innovative Therapies Unit, IRCCS AOU San Martino-IST, Genoa, Italy.
| | - Massimo Romani
- Unit of Tumor Epigenetics, IRCCS AOU San Martino-IST, Genoa, Italy.
| | - Lucia Del Mastro
- Development of Innovative Therapies Unit, IRCCS AOU San Martino-IST, Genoa, Italy.
| | - Alessandro Poggi
- Unit of Molecular Oncology and Angiogenesis, IRCCS AOU San Martino-IST, Genoa, Italy.
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Avila-Pedretti G, Tornero J, Fernández-Nebro A, Blanco F, González-Alvaro I, Cañete JD, Maymó J, Alperiz M, Fernández-Gutiérrez B, Olivé A, Corominas H, Erra A, Aterido A, López Lasanta M, Tortosa R, Julià A, Marsal S. Variation at FCGR2A and functionally related genes is associated with the response to anti-TNF therapy in rheumatoid arthritis. PLoS One 2015; 10:e0122088. [PMID: 25848939 PMCID: PMC4388501 DOI: 10.1371/journal.pone.0122088] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 02/18/2015] [Indexed: 11/29/2022] Open
Abstract
Objective Anti-TNF therapies have been highly efficacious in the management of rheumatoid arthritis (RA), but 25–30% of patients do not show a significant clinical response. There is increasing evidence that genetic variation at the Fc receptor FCGR2A is associated with the response to anti-TNF therapy. We aimed to validate this genetic association in a patient cohort from the Spanish population, and also to identify new genes functionally related to FCGR2A that are also associated with anti-TNF response. Methods A total of 348 RA patients treated with an anti-TNF therapy were included and genotyped for FCGR2A polymorphism rs1081274. Response to therapy was determined at 12 weeks, and was tested for association globally and independently for each anti-TNF drug (infliximab, etanercept and adalimumab). Using gene expression profiles from macrophages obtained from synovial fluid of RA patients, we searched for genes highly correlated with FCGR2A expression. Tag SNPs were selected from each candidate gene and tested for association with the response to therapy. Results We found a significant association between FCGR2A and the response to adalimumab (P=0.022). Analyzing the subset of anti-CCP positive RA patients (78%), we also found a significant association between FCGR2A and the response to infliximab (P=0.035). DHX32 and RGS12 were the most consistently correlated genes with FCGR2A expression in RA synovial fluid macrophages (P<0.001). We found a significant association between the genetic variation at DHX32 (rs12356233, corrected P=0.019) and a nominally significant association between RGS12 and the response to adalimumab (rs4690093, uncorrected P=0.040). In the anti-CCP positive group of patients, we also found a nominally significant association between RGS12 and the response to infliximab (rs2857859, uncorrected P=0.042). Conclusions In the present study we have validated the FCGR2A association in an independent population, and we have identified new genes associated with the response to anti-TNF therapy in RA.
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Affiliation(s)
| | - Jesús Tornero
- Hospital Universitario De Guadalajara, Rheumatology Department, Guadalajara, Spain
| | - Antonio Fernández-Nebro
- UGC Reumatología, Instituto de Investigación Biomédica en Málaga, Hospital Regional Universitario de Málaga, Universidad de Málaga, Málaga, Spain
| | - Francisco Blanco
- INIBIC-Hospital Universitario A Coruña, Rheumatology Department, A Coruña, Spain
| | - Isidoro González-Alvaro
- Hospital Universitario de La Princesa, IIS La Princesa, Rheumatology Department, Madrid, Spain
| | - Juan D Cañete
- Hospital Clínic de Barcelona, Rheumatology Department, Barcelona, Spain
| | - Joan Maymó
- Hospital del Mar, Barcelona, Rheumatology Department, Barcelona, Spain
| | - Mercedes Alperiz
- Hospital Universitario Central de Asturias, Rheumatology Department, Oviedo, Spain
| | | | - Alex Olivé
- Hospital Universitari Germans Trias i Pujol, Rheumatology Department, Barcelona, Spain
| | - Héctor Corominas
- Hospital Moisès Broggi, Rheumatology Department, Barcelona, Spain
| | - Alba Erra
- Hospital Sant Rafael, Rheumatology Department, Barcelona, Spain
| | - Adrià Aterido
- Vall d'Hebron Hospital Research Institute, Rheumatology Research Group. Barcelona, Spain
| | - María López Lasanta
- Vall d'Hebron Hospital Research Institute, Rheumatology Research Group. Barcelona, Spain
| | - Raül Tortosa
- Vall d'Hebron Hospital Research Institute, Rheumatology Research Group. Barcelona, Spain
| | - Antonio Julià
- Vall d'Hebron Hospital Research Institute, Rheumatology Research Group. Barcelona, Spain
| | - Sara Marsal
- Vall d'Hebron Hospital Research Institute, Rheumatology Research Group. Barcelona, Spain
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Phagocyte dysfunction, tissue aging and degeneration. Ageing Res Rev 2013; 12:1005-12. [PMID: 23748186 DOI: 10.1016/j.arr.2013.05.006] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 05/28/2013] [Indexed: 12/11/2022]
Abstract
Immunologically-silent phagocytosis of apoptotic cells is critical to maintaining tissue homeostasis and innate immune balance. Aged phagocytes reduce their functional activity, leading to accumulation of unphagocytosed debris, chronic sterile inflammation and exacerbation of tissue aging and damage. Macrophage dysfunction plays an important role in immunosenescence. Microglial dysfunction has been linked to age-dependent neurodegenerations. Retinal pigment epithelial (RPE) cell dysfunction has been implicated in the pathogenesis of age-related macular degeneration (AMD). Despite several reports on the characterization of aged phagocytes, the role of phagocyte dysfunction in tissue aging and degeneration is yet to be fully appreciated. Lack of knowledge of molecular mechanisms by which aging reduces phagocyte function has hindered our capability to exploit the therapeutic potentials of phagocytosis for prevention or delay of tissue degeneration. This review summarizes our current knowledge of phagocyte dysfunction in aged tissues and discusses possible links to age-related diseases. We highlight the challenges to decipher the molecular mechanisms, present new research approaches and envisage future strategies to prevent phagocyte dysfunction, tissue aging and degeneration.
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15
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Tailoring immunoglobulin Fc for highly potent and serum-stable therapeutic antibodies. BIOTECHNOL BIOPROC E 2013. [DOI: 10.1007/s12257-012-0711-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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16
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Brencicova E, Diebold SS. Nucleic acids and endosomal pattern recognition: how to tell friend from foe? Front Cell Infect Microbiol 2013; 3:37. [PMID: 23908972 PMCID: PMC3726833 DOI: 10.3389/fcimb.2013.00037] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 07/10/2013] [Indexed: 12/18/2022] Open
Abstract
The innate immune system has evolved endosomal and cytoplasmic receptors for the detection of viral nucleic acids as sensors for virus infection. Some of these pattern recognition receptors (PRR) detect features of viral nucleic acids that are not found in the host such as long stretches of double-stranded RNA (dsRNA) and uncapped single-stranded RNA (ssRNA) in case of Toll-like receptor (TLR) 3 and RIG-I, respectively. In contrast, TLR7/8 and TLR9 are unable to distinguish between viral and self-nucleic acids on the grounds of distinct molecular patterns. The ability of these endosomal TLR to act as PRR for viral nucleic acids seems to rely solely on the mode of access to the endolysosomal compartment in which recognition takes place. The current dogma states that self-nucleic acids do not enter the TLR-sensing compartment under normal physiological conditions. However, it is still poorly understood how dendritic cells (DC) evade activation by self-nucleic acids, in particular with regard to specific DC subsets, which are specialized in taking up material from dying cells for cross-presentation of cell-associated antigens. In this review we discuss the current understanding of how the immune system distinguishes between foreign and self-nucleic acids and point out some of the key aspects that still require further research and clarification.
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Affiliation(s)
- Eva Brencicova
- Peter Gorer Department of Immunobiology, Guy's Hospital, King's College London, London, UK
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Abuqayyas L, Zhang X, Balthasar JP. Application of knockout mouse models to investigate the influence of FcγR on the pharmacokinetics and anti-platelet effects of MWReg30, a monoclonal anti-GPIIb antibody. Int J Pharm 2013; 444:185-92. [PMID: 23370434 DOI: 10.1016/j.ijpharm.2013.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 12/12/2012] [Accepted: 01/02/2013] [Indexed: 11/26/2022]
Abstract
This work evaluates the influence of FcγR on the pharmacokinetics and pharmacodynamics of a rat anti-integrin-αIIb IgG1 monoclonal antibody, MWReg30, in mice. The pharmacokinetics and pharmacodynamics of MWReg30 were investigated in C57BL/6 control mice, FcγRI/RIII knockout mice, and FcγRIIb knockout mice, following intravenous doses of 0.04-0.4mg/kg. MWReg30 treatment resulted in a dose-dependent induction of thrombocytopenia in all strains, but sensitivity to MWReg30 was increased in FcγRIIb knockout mice and decreased in FcγRI/RIII knockout mice, relative to results found in control mice. Expressed as a percentage of pre-treatment platelet counts, nadir platelet counts were 28.6±5.0, 88.7±16.6 and 25.3±6.1% at 0.05mg/kg, 28.4±13.7, 56.7±5.1, and 20.6±9.5% at 0.2mg/kg, and 24.9±7.2, 38.7±7.5, and 7.4±2.2% at 0.4mg/kg in control, FcγRI/RIII(-/-) and FcγRIIb(-/-) mice. However, knocking out FcγR did not affect MWReg30 pharmacokinetics. Plasma areas under the concentration vs. time curves (AUC0-10 days) ±SD for MWReg30 were: 5.24±0.68, 5.51±0.24, and 5.39±1.05 nM×d at 0.04mg/kg, and 12.7±0.5, 13.6±1.1, and 14.5±2.0nM×d at 0.1mg/kg in control, FcγRI/RIII(-/-) and FcγRIIb(-/-) mice. The findings further emphasize the role of activating vs. inhibitory FcγR in processing immune complexes (i.e., MWReg30-platelets), while also providing an example where monoclonal antibody pharmacokinetics are not substantially influenced by FcγR expression.
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Affiliation(s)
- Lubna Abuqayyas
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, the State University of New York, Buffalo, NY 14260, USA
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Huang Y, Yin H, Wang J, Liu Q, Wu C, Chen K. Aberrant expression of FcγRIIIA (CD16) contributes to the development of atherosclerosis. Gene 2012; 498:91-5. [DOI: 10.1016/j.gene.2012.02.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 01/30/2012] [Accepted: 02/07/2012] [Indexed: 12/19/2022]
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The interactions of human neutrophils with shiga toxins and related plant toxins: danger or safety? Toxins (Basel) 2012; 4:157-90. [PMID: 22741061 PMCID: PMC3381930 DOI: 10.3390/toxins4030157] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 02/11/2012] [Accepted: 02/19/2012] [Indexed: 11/16/2022] Open
Abstract
Shiga toxins and ricin are well characterized similar toxins belonging to quite different biological kingdoms. Plant and bacteria have evolved the ability to produce these powerful toxins in parallel, while humans have evolved a defense system that recognizes molecular patterns common to foreign molecules through specific receptors expressed on the surface of the main actors of innate immunity, namely monocytes and neutrophils. The interactions between these toxins and neutrophils have been widely described and have stimulated intense debate. This paper is aimed at reviewing the topic, focusing particularly on implications for the pathogenesis and diagnosis of hemolytic uremic syndrome.
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Katzenmeyer KN, Bryers JD. Multivalent artificial opsonin for the recognition and phagocytosis of Gram-positive bacteria by human phagocytes. Biomaterials 2011; 32:4042-51. [PMID: 21388677 DOI: 10.1016/j.biomaterials.2011.02.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Accepted: 02/04/2011] [Indexed: 12/30/2022]
Abstract
Hospital-acquired infections (HAIs) remain a leading cause of death in the United States. Unfortunately, treatment of HAIs is complicated by the emergence of antibiotic-resistant bacterial strains. In an effort to enhance the body's natural immune response to infection, we have developed an artificial opsonin to promote the recognition, phagocytosis, and destruction of pathogenic bacteria by human phagocytes. The artificial opsonin is constructed from multivalent conjugates of poly(L-lysine)-graft-poly(ethylene glycol) with vancomycin and human IgG-Fc. Our approach utilizes vancomycin's inherent ability to bind to D-Ala-D-Ala terminated peptides present in the cell wall of Gram-positive bacteria. Here, we show that conjugation of vancomycin to PLL-g-PEG prevents its action as an antibiotic and allows vancomycin to function solely as a recognition molecule. Human IgG-Fc antibody fragment serves as a phagocyte recognition molecule and is recognized by the Fcγ cell surface receptors expressed on professional human phagocytes. Using flow cytometry, we found that a polysaccharide-encapsulated, methicillin-resistant strain of Staphylococcus epidermidis is efficiently recognized by the artificial opsonin (nearly 100% of cells were opsonized) and that opsonin binding is specific since it can be inhibited by the soluble cell wall peptide analog acetyl-Lys-D-Ala-D-Ala. Opsonization of S. epidermidis resulted in an approximate 2-fold increase in phagocytosis by a human neutrophil cell line. Notably, Enterococcus faecalis VanB, a bacterial strain with inducible vancomycin resistance, was used to show that the artificial opsonin does not unintentionally induce antibiotic resistance mechanisms.
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Affiliation(s)
- Kristy N Katzenmeyer
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
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21
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Correlation between Fc γ R III a and aortic atherosclerotic plaque destabilization in ApoE knockout mice and intervention effects of effective components of Chuanxiong Rhizome and Red Peony Root. Chin J Integr Med 2011; 17:355-60. [DOI: 10.1007/s11655-011-0726-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Indexed: 10/18/2022]
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Tsuboi N, Ernandez T, Li X, Nishi H, Cullere X, Mekala D, Hazen M, Köhl J, Lee DM, Mayadas TN. Regulation of human neutrophil Fcγ receptor IIa by C5a receptor promotes inflammatory arthritis in mice. ACTA ACUST UNITED AC 2011; 63:467-78. [PMID: 21280001 DOI: 10.1002/art.30141] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE Rheumatoid arthritis culminates in joint destruction that, in mouse models of disease, is supported by innate immune molecules, including Fcγ receptors (FcγR) and complement. However, these findings may not be predictive of the outcome in humans, given the structural differences between murine and human activating FcγR on neutrophils, a prominent component of joint exudates. The aim of this study was to examine the role of human neutrophil FcγRIIa in the development of arthritis and probe the underlying mechanism by which FcγRIIa initiates disease. METHODS K/BxN mouse serum transfer-induced arthritis was examined in mice expressing human FcγRIIa on neutrophils but lacking their own activating FcγR (γ-chain-deficient mice). The role of mast cells, complement (C3 and C5a), and CD18 integrins in FcγRIIa-initiated disease was examined using cell reconstitution approaches, inhibitors, and functional blocking antibodies, respectively. Crosstalk between the complement receptor C5aR and FcγRIIa on neutrophils was evaluated in vitro. RESULTS The expression of human FcγRIIa on neutrophils was sufficient to restore susceptibility to K/BxN serum-induced neutrophil recruitment, synovitis, and bone destruction in γ-chain-deficient mice. Joint inflammation was robust and proceeded even in the absence of mast cells and vascular permeability, features shown to contribute to disease in wild-type mice. Neutrophil recruitment was dependent on the presence of a CD18 integrin, lymphocyte function-associated antigen 1, and C5aR. In addition, C5aR significantly enhanced FcγRIIa-mediated phagocytosis and oxidative burst in vitro. CONCLUSION Human and murine activating FcγR on neutrophils are not functionally equivalent, and in humans, they may play a primary role in arthritis. Crosstalk between neutrophil C5aR and FcγRIIa is essential for disease progression, thus highlighting a new aspect of complement during the effector phase of inflammatory arthritis.
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Affiliation(s)
- Naotake Tsuboi
- Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
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Iwanaga R, Sugita N, Hirano E, Sasahara J, Kikuchi A, Tanaka K, Yoshie H. FcγRIIB polymorphisms, periodontitis and preterm birth in Japanese pregnant women. J Periodontal Res 2011; 46:292-302. [DOI: 10.1111/j.1600-0765.2010.01338.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Jung ST, Kang TH, Georgiou G. Efficient expression and purification of human aglycosylated Fcgamma receptors in Escherichia coli. Biotechnol Bioeng 2010; 107:21-30. [PMID: 20506277 DOI: 10.1002/bit.22785] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Effector Fc gamma receptors (FcgammaRs) are expressed on the surface of a variety of cells of hematopoietic lineage and serve as a bridge between adaptive and innate immune responses. The interaction between immune complexes, formed by IgG class antibodies that are crosslinked with antigen, and FcgammaRs triggers signaling cascades that result in numerous cellular responses including the activation or donwregulation of cytotoxic responses, cytokine release, and antibody synthesis. Here, the extracellular domains of the human type I transmembrane FcgammaRs were expressed in Escherichia coli and their interactions to subclass IgGs (IgG1, IgG2, IgG3, and IgG4) antibodies were analyzed. Expression using fully synthetic E. coli codon optimized FcgammaR genes and optimization of sequences for N-terminal translation initiation region through mRNA secondary structure prediction enabled us to achieve high yield of purified, bacterially expressed receptors, including FcgammaRI and FcgammaRIIIa which have not been successfully expressed in bacteria until now. The aglycosylated FcgammaRs showed similar IgG subclass binding selectivity compared to the respective glycosylated FcgammaRs expressed in mammalian cells.
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Affiliation(s)
- Sang Taek Jung
- Department of Chemical Engineering, University of Texas, Austin, 78712, USA
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Carreño LJ, Pacheco R, Gutierrez MA, Jacobelli S, Kalergis AM. Disease activity in systemic lupus erythematosus is associated with an altered expression of low-affinity Fc gamma receptors and costimulatory molecules on dendritic cells. Immunology 2010; 128:334-41. [PMID: 20067533 DOI: 10.1111/j.1365-2567.2009.03138.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Dendritic cells (DCs) play a pivotal role in the interface between immunity and maintenance of peripheral tolerance. The capture of immunoglobulin G (IgG)-containing immune complexes (ICs) by low-affinity Fc gamma receptors (Fc gammaRs) expressed on DCs may influence the immunogenicity/tolerogenicity of these cells, depending on the activating/inhibitory potential of Fc gammaRs. Because of the key role that low-affinity Fc gammaRs play in determining the magnitude of the response in IC-driven inflammation, these receptors are likely to play a role in autoimmune diseases, such as systemic lupus erythematosus (SLE). To evaluate if an altered expression of costimulatory molecules and/or Fc gammaRs could account for disease severity, we evaluated the expression of these molecules on immature and mature DCs derived from peripheral blood monocytes of SLE patients and healthy donors. Our results show an increased expression of the costimulatory molecules CD40 and CD86. Furthermore, the ratio of CD86/CD80 is higher in SLE patients compared with healthy donors. Conversely, while the expression of activating Fc gammaRs was higher on DCs from SLE patients, expression of inhibitory Fc gammaRs was lower, compared with DCs obtained from healthy donors. As a result, the activating to inhibitory Fc gammaR ratio was significantly higher in DCs from SLE patients. The altered ratio of activating/inhibitory Fc gammaRs on mature DCs showed a significant correlation with the activity of SLE, as determined by the SLE Disease Activity Index (SLEDAI) score. We postulate that the increased ratio of activating/inhibitory Fc gammaRs expressed on DCs from SLE patients can contribute to the failure of peripheral tolerance in the IC-mediated phase of autoimmune pathogenesis.
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Affiliation(s)
- Leandro J Carreño
- Millennium Nucleus on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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Does activation of the FcgammaRIIa play a role in the pathogenesis of the acute lung injury/acute respiratory distress syndrome? Clin Sci (Lond) 2010; 118:519-26. [PMID: 20088831 PMCID: PMC2811426 DOI: 10.1042/cs20090422] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
ALI (acute lung injury) and its more severe form ARDS (acute respiratory distress syndrome) are inflammatory diseases of the lung characterized by hypoxaemia and diffuse bilateral infiltrates. Disruption of epithelial integrity and injury to endothelium are contributing factors of the development of ALI/ARDS, and alveolar damage is the most pronounced feature of ALI/ARDS. The resulting increase in lung microvascular permeability promotes influx of inflammatory cells to the alveolar spaces. Oedema fluid contains pro-nflammatory mediators and plasma proteins, including Igs (immunoglobulins). Moreover, several reports describe the presence of autoantibodies and immune complexes [anti-IL-8 (interleukin-8) autoantibody/IL-8 complexes] in lung fluids (oedema and bronchoalveolar lavage fluids) from patients with ALI/ARDS. These immune complexes associate with FcgammaRIIa (Fcgamma IIa receptor) in lungs of patients with ARDS. Furthermore, the expression of FcgammaRIIa is substantially elevated in lungs of these patients. FcgammaRIIa appears on virtually all myeloid cells, platelets and endothelial cells. It is a low-affinity receptor for IgG that preferentially binds aggregated immunoglobulins and immune complexes. FcgammaRs regulate phagocytosis and cell-mediated cytotoxicity, and initiate the release of inflammatory mediators. It should be noted that immune complexes formed between either anti-neutrophil autoantibodies and their specific antigens or anti-HLA (human leucocyte antigen) antibodies and target antigens are implicated in the pathogenesis of TRALI (transfusion-related acute lung injury), and importantly, animal studies indicate that FcgammaRs are essential for these complexes to cause damage to the lungs. Therefore, we hypothesize that FcgammaRs such as FcgammaRIIa could contribute to the pathogenesis of ALI/ARDS.
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Clark AJ, Petty HR. A cell permeant peptide containing the cytoplasmic tail sequence of Fc receptor type IIA reduces calcium signaling and phagolysosome formation in neutrophils. Cell Immunol 2009; 261:153-8. [PMID: 20038460 DOI: 10.1016/j.cellimm.2009.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 11/30/2009] [Accepted: 12/02/2009] [Indexed: 11/29/2022]
Abstract
Receptors for the Fc domain of IgG mediate target recognition, signal transduction, and effector functions including antibody-dependent cytolysis, phagocytosis, and phagolysosome formation. To better understand FcR-mediated functions and to identify potential therapeutic strategies, we employed cell-penetrating ("Trojan") peptides to deliver "wild-type" (LTL) or modified (AAA) FcgammaRIIA tail sequences to the neutrophil's cytoplasm. The Trojan-LTL peptide appeared to label the endoplasmic reticulum whereas the Trojan-AAA peptide distributed throughout the cytoplasm. The Trojan-LTL peptide, but not the Trojan-AAA peptide, decreased Ca(2+) signaling at the phagosome and reduced phagolysosome formation. These studies suggest that FcgammaRIIA's tail can act as a peptide decoy thereby blunting FcgammaRIIA-mediated processes, which, in turn, suggests a possible route in managing inflammatory tissue damage.
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Affiliation(s)
- Andrea J Clark
- Department of Ophthalmology and Visual Sciences, The University of Michigan Medical School, Ann Arbor, 48105, USA
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Surrogate approaches in development of monoclonal antibodies. Drug Discov Today 2009; 14:1159-65. [DOI: 10.1016/j.drudis.2009.09.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 09/10/2009] [Accepted: 09/10/2009] [Indexed: 12/31/2022]
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JOVANOVIC V, DAI X, LIM YT, KEMENY DM, MacARY PA. Fcγ receptor biology and systemic lupus erythematosus. Int J Rheum Dis 2009; 12:293-8. [DOI: 10.1111/j.1756-185x.2009.01426.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Fc receptor-targeted mucosal vaccination as a novel strategy for the generation of enhanced immunity against mucosal and non-mucosal pathogens. Arch Immunol Ther Exp (Warsz) 2009; 57:311-23. [PMID: 19688186 DOI: 10.1007/s00005-009-0040-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Accepted: 03/30/2009] [Indexed: 12/22/2022]
Abstract
Numerous studies have demonstrated that targeting immunogens to Fcgamma receptors (FcgammaR) on antigen (Ag)-presenting cells (APC) can enhance humoral and cellular immunity in vitro and in vivo. FcgammaR are classified based on their molecular weight, IgG-Fc binding affinities, IgG subclass binding specificity, and cellular distribution and they consist of activating and inhibitory receptors. However, despite the potential advantages of targeting Ag to FcR at mucosal sites, very little is known regarding the role of FcR in mucosal immunity or the efficacy of FcR-targeted mucosal vaccines. In addition, recent work has suggested that FcRn is present in the lungs of adult mice and humans and can transport FcRn-targeted Ag to FcgammaR-bearing APC within mucosal lymphoid tissue. In this review we will discuss the need for new vaccine strategies, the potential for FcR-targeted vaccines to fill this need, the impact of activating versus inhibitory FcgammaR on FcR-targeted vaccination, the significance of focusing on mucosal immunity, as well as caveats that could impact the use of FcR targeting as a mucosal vaccine strategy.
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Kahn F, Mörgelin M, Shannon O, Norrby-Teglund A, Herwald H, Olin AI, Björck L. Antibodies against a surface protein of Streptococcus pyogenes promote a pathological inflammatory response. PLoS Pathog 2008; 4:e1000149. [PMID: 18787689 PMCID: PMC2522270 DOI: 10.1371/journal.ppat.1000149] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Accepted: 08/11/2008] [Indexed: 01/11/2023] Open
Abstract
Streptococcal toxic shock syndrome (STSS) caused by Streptococcus pyogenes is a clinical condition with a high mortality rate despite modern intensive care. A key feature of STSS is excessive plasma leakage leading to hypovolemic hypotension, disturbed microcirculation and multiorgan failure. Previous work has identified a virulence mechanism in STSS where M1 protein of S. pyogenes forms complexes with fibrinogen that activate neutrophils to release heparin-binding protein (HBP), an inducer of vascular leakage. Here, we report a marked inter-individual difference in the response to M1 protein-induced HBP release, a difference found to be related to IgG antibodies directed against the central region of the M1 protein. To elicit massive HBP release, such antibodies need to be part of the M1 protein-fibrinogen complexes. The data add a novel aspect to bacterial pathogenesis where antibodies contribute to the severity of disease by promoting a pathologic inflammatory response.
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Affiliation(s)
- Fredrik Kahn
- Department of Clinical Sciences, Division of Infection Medicine, Lund University, BMC, B14, Lund, Sweden.
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Fc receptor engagement mediates differentiation of cardiac fibroblast precursor cells. Proc Natl Acad Sci U S A 2008; 105:10179-84. [PMID: 18632582 DOI: 10.1073/pnas.0804910105] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
We previously described a critical role for a fibroblast precursor population in the development of a murine fibrotic cardiomyopathy model (I/RC). These precursors arose from circulating bone marrow-derived cells of monocytic origin. Administration of serum amyloid P (SAP) prevented the presence of this cell population in the heart and the cardiomyopathy. Because SAP binds to Fc receptors (FcRs) expressed on monocytes, we investigated the involvement of FcR signaling. We chose mice lacking the FcRgamma chain protein (FcRgamma(-/-)), a common membrane-signaling component of activating FcRs. Like wild-type mice, FcRgamma(-/-) mice developed fibrosis and cardiac dysfunction when subjected to I/RC. However, unlike wild-type mice, SAP in FcRgamma(-/-) mice failed to inhibit the development of fibrosis and cardiac dysfunction and did not diminish the numbers of alpha-smooth muscle actin(+) and CD34(+), CD45(+) fibroblasts that were typical for I/RC. To further examine the role of SAP in monocyte-to-fibroblast transition, we performed in vitro assays in which human peripheral blood mononuclear cells (PBMCs) migrated through human umbilical vein endothelial cells (HUVECs). We found that MCP-1-dependent transendothelial migration of monocytes markedly accelerated their differentiation into fibroblasts. This monocyte differentiation to fibroblasts was eliminated when SAP was added to the PBMC suspension before endothelial transmigration. Adding SAP to cells after successful migration did not inhibit fibroblast maturation. These data indicate that SAP inhibits the differentiation of a blood-borne, myeloid cell population into fibroblasts by signaling through activating FcRs before transendothelial migration has occurred. We suggest that FcR activation of circulating precursor cells may represent a new treatment target for adverse remodeling and cardiac fibrosis.
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Lisi S, D'Amore M, Lofrumento D, Mitolo V, Frassanito MA, Dammacco F, Scagliusi P, Sisto M. Modulation of the Fcgamma receptors induced by anti-Ro and anti-La autoantibodies: observations in salivary gland cells. Rheumatol Int 2008; 28:943-8. [PMID: 18264709 DOI: 10.1007/s00296-008-0536-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Accepted: 01/14/2008] [Indexed: 01/17/2023]
Abstract
Only few reports have shown protein expression of the Fcgamma receptors (FcgammaRs) molecules on human salivary gland cells. In this study we investigate a possible upregulation of FcgammaRs following anti-Ro and anti-La autoantibodies treatment. Anti-Ro and anti-La autoantibodies were purified from IgG fractions obtained from 14 patients with primary Sjögren's syndrome (SS), using Sepharose 4B-Ro and Sepharose 4B-La affinity columns. Flow cytometry and RT-PCR were used to study the FCgammaRI, FCgammaRII and FCgammaRIII receptors expression and upregulation by anti-Ro and anti-La on a salivary gland cell line. The present data document that the anti-Ro and anti-La autoantibodies determine an increase of the FcgammaRs expression on salivary gland cells, and provide evidence that both the high affinity FcgammaRI and the low affinity FcgammaRII and FcgammaRIII are overexpressed. Treatment with IgG isolated from healthy donors had no effect on the basal FCgammaRs expression.
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Affiliation(s)
- Sabrina Lisi
- Department of Human Anatomy and Histology, University of Bari, p.zza G. Cesare 1, 70124, Bari, Italy.
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Abstract
It is said that a gun has only one "business end" but not so for antibodies. The end with the antigen binding sites (the Fab) certainly has gained a great deal of deserved attention; this is, after all, where the humoral immune system uses its much vaunted "antigen specificity" to engage the outside (and sometimes, unfortunately, the inside) world. The other end (Fc--no the "c" does not stand for "constant," it stands for "crystallizable" because that part of rabbit IgG crystallized for the initial investigators) consists of the other end of heavy chain of the immunoglobulin chains, bearing markers that define an antibody as IgG, IgA, IgM, IgE, or IgD. The Fc component contains sequences that have the capacity to undertake a number of biologic activities, most of which, aside from complement fixation, depend upon the Fc component attaching to a cell via that cell's Fc receptors. Fc receptors (FcR) come in a number of specificities (defined by the Fc they bind and by the status of that Fc) and have different functions which are worthy of attention in this series. This report focused on the various FcgammaR, the receptors for IgG.
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Hoehlig K, Lampropoulou V, Roch T, Neves P, Calderon-Gomez E, Anderton SM, Steinhoff U, Fillatreau S. Immune regulation by B cells and antibodies a view towards the clinic. Adv Immunol 2008; 98:1-38. [PMID: 18772002 DOI: 10.1016/s0065-2776(08)00401-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
B lymphocytes contribute to immunity in multiple ways, including production of antibodies, presentation of antigen to T cells, organogenesis of secondary lymphoid organs, and secretion of cytokines. Recent clinical trials have shown that depleting B cells can be highly beneficial for patients with autoimmune diseases, implicating B cells and antibodies as key drivers of pathology. However, it should be kept in mind that B cell responses and antibodies also have important regulatory roles in limiting autoimmune pathology. Here, we analyze clinical examples illustrating the potential of antibodies as treatment for immune-mediated disorders and discuss the underlying mechanisms. Furthermore, we examine the regulatory functions of activated B cells, their involvement in the termination of some experimental autoimmune diseases, and their use in cell-based therapy for such pathologies. These suppressive functions of B cells and antibodies do not only open new ways for harnessing autoimmune illnesses, but they also should be taken into account when designing new strategies for vaccination against microbes and tumors.
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Affiliation(s)
- Kai Hoehlig
- Laboratory of immune regulation, Deutsches Rheuma-Forschungszentrum, Charitéplatz 1, Berlin, Germany
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Jayagopal A, Russ PK, Haselton FR. Surface engineering of quantum dots for in vivo vascular imaging. Bioconjug Chem 2007; 18:1424-33. [PMID: 17760416 PMCID: PMC2853010 DOI: 10.1021/bc070020r] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Quantum dot-antibody bioconjugates (QD-mAb) were synthesized incorporating PEG cross-linkers and Fc-shielding mAb fragments to increase in vivo circulation times and targeting efficiency. Microscopy of endothelial cell cultures incubated with QD-mAb directed against cell adhesion molecules (CAMs), when shielded to reduce Fc-mediated interactions, were more specific for their molecular targets. In vitro flow cytometry indicated that surface engineered QD-mAb labeled leukocyte subsets with minimal Fc-mediated binding. Nontargeted QD-mAb nanoparticles with Fc-blockade featured 64% (endothelial cells) and 53% (leukocytes) lower nonspecific binding than non-Fc-blocked nanoparticles. Spectrally distinct QD-mAb targeted to the cell adhesion molecules (CAMs) PECAM-1, ICAM-1, and VCAM-1 on the retinal endothelium in a rat model of diabetes were imaged in vivo using fluorescence angiography. Endogenously labeled circulating and adherent leukocyte subsets were imaged in rat models of diabetes and uveitis using QD-mAb targeted to RP-1 and CD45. Diabetic rats exhibited increased fluorescence in the retinal vasculature from QD bioconjugates to ICAM-1 and VCAM-1 but not PECAM-1. Both animal models exhibited leukocyte rolling and leukostasis in capillaries. Examination of retinal whole mounts prepared after in vivo imaging confirmed the fluorescence patterns seen in vivo. Comparison of the timecourse of retinal fluorescence from Fc-shielded and non-Fc-shielded bioconjugates indicated nonspecific uptake and increased clearance of the non-Fc-shielded QD-mAb. This combination of QD surface design elements offers a promising new in vivo approach to specifically label vascular cells and biomolecules of interest.
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Affiliation(s)
| | | | - Frederick R. Haselton
- Corresponding author. Frederick R. Haselton, VU Station B Box 351510, Nashville, Tennessee 37235, Phone: 615-322-6622, Fax 615-343-7919,
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