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Ong J, Zarnegar A, Selvam A, Driban M, Chhablani J. The Complement System as a Therapeutic Target in Retinal Disease. MEDICINA (KAUNAS, LITHUANIA) 2024; 60:945. [PMID: 38929562 PMCID: PMC11205777 DOI: 10.3390/medicina60060945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2024] [Revised: 05/16/2024] [Accepted: 05/23/2024] [Indexed: 06/28/2024]
Abstract
The complement cascade is a vital system in the human body's defense against pathogens. During the natural aging process, it has been observed that this system is imperative for ensuring the integrity and homeostasis of the retina. While this system is critical for proper host defense and retinal integrity, it has also been found that dysregulation of this system may lead to certain retinal pathologies, including geographic atrophy and diabetic retinopathy. Targeting components of the complement system for retinal diseases has been an area of interest, and in vivo, ex vivo, and clinical trials have been conducted in this area. Following clinical trials, medications targeting the complement system for retinal disease have also become available. In this manuscript, we discuss the pathophysiology of complement dysfunction in the retina and specific pathologies. We then describe the results of cellular, animal, and clinical studies targeting the complement system for retinal diseases. We then provide an overview of complement inhibitors that have been approved by the Food and Drug Administration (FDA) for geographic atrophy. The complement system in retinal diseases continues to serve as an emerging therapeutic target, and further research in this field will provide additional insights into the mechanisms and considerations for treatment of retinal pathologies.
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Affiliation(s)
- Joshua Ong
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI 48105, USA
| | - Arman Zarnegar
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Amrish Selvam
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Matthew Driban
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Jay Chhablani
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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2
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Fu DJ, Glinton S, Lipkova V, Faes L, Liefers B, Zhang G, Pontikos N, McKeown A, Scheibler L, Patel PJ, Keane PA, Balaskas K. Deep-learning automated quantification of longitudinal OCT scans demonstrates reduced RPE loss rate, preservation of intact macular area and predictive value of isolated photoreceptor degeneration in geographic atrophy patients receiving C3 inhibition treatment. Br J Ophthalmol 2024; 108:536-545. [PMID: 37094835 PMCID: PMC10958254 DOI: 10.1136/bjo-2022-322672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 03/15/2023] [Indexed: 04/26/2023]
Abstract
OBJECTIVE To evaluate the role of automated optical coherence tomography (OCT) segmentation, using a validated deep-learning model, for assessing the effect of C3 inhibition on the area of geographic atrophy (GA); the constituent features of GA on OCT (photoreceptor degeneration (PRD), retinal pigment epithelium (RPE) loss and hypertransmission); and the area of unaffected healthy macula.To identify OCT predictive biomarkers for GA growth. METHODS Post hoc analysis of the FILLY trial using a deep-learning model for spectral domain OCT (SD-OCT) autosegmentation. 246 patients were randomised 1:1:1 into pegcetacoplan monthly (PM), pegcetacoplan every other month (PEOM) and sham treatment (pooled) for 12 months of treatment and 6 months of therapy-free monitoring. Only participants with Heidelberg SD-OCT were included (n=197, single eye per participant).The primary efficacy endpoint was the square root transformed change in area of GA as complete RPE and outer retinal atrophy (cRORA) in each treatment arm at 12 months, with secondary endpoints including RPE loss, hypertransmission, PRD and intact macular area. RESULTS Eyes treated PM showed significantly slower mean change of cRORA progression at 12 and 18 months (0.151 and 0.277 mm, p=0.0039; 0.251 and 0.396 mm, p=0.039, respectively) and RPE loss (0.147 and 0.287 mm, p=0.0008; 0.242 and 0.410 mm, p=0.00809). PEOM showed significantly slower mean change of RPE loss compared with sham at 12 months (p=0.0313). Intact macular areas were preserved in PM compared with sham at 12 and 18 months (p=0.0095 and p=0.044). PRD in isolation and intact macula areas was predictive of reduced cRORA growth at 12 months (coefficient 0.0195, p=0.01 and 0.00752, p=0.02, respectively) CONCLUSION: The OCT evidence suggests that pegcetacoplan slows progression of cRORA overall and RPE loss specifically while protecting the remaining photoreceptors and slowing the progression of healthy retina to iRORA.
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Affiliation(s)
- Dun Jack Fu
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust & UCL, Institute of Ophthalmology, London, UK
| | - Sophie Glinton
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust & UCL, Institute of Ophthalmology, London, UK
| | - Veronika Lipkova
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust & UCL, Institute of Ophthalmology, London, UK
| | - Livia Faes
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust & UCL, Institute of Ophthalmology, London, UK
| | - Bart Liefers
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust & UCL, Institute of Ophthalmology, London, UK
- Department of Ophthalmology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Gongyu Zhang
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust & UCL, Institute of Ophthalmology, London, UK
| | - Nikolas Pontikos
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust & UCL, Institute of Ophthalmology, London, UK
| | - Alex McKeown
- Apellis Pharmaceuticals Inc, Waltham, Massachusetts, USA
| | | | - Praveen J Patel
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust & UCL, Institute of Ophthalmology, London, UK
| | - Pearse A Keane
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust & UCL, Institute of Ophthalmology, London, UK
| | - Konstantinos Balaskas
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust & UCL, Institute of Ophthalmology, London, UK
- University College London, London, UK
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Mastellos DC, Hajishengallis G, Lambris JD. A guide to complement biology, pathology and therapeutic opportunity. Nat Rev Immunol 2024; 24:118-141. [PMID: 37670180 DOI: 10.1038/s41577-023-00926-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/20/2023] [Indexed: 09/07/2023]
Abstract
Complement has long been considered a key innate immune effector system that mediates host defence and tissue homeostasis. Yet, growing evidence has illuminated a broader involvement of complement in fundamental biological processes extending far beyond its traditional realm in innate immunity. Complement engages in intricate crosstalk with multiple pattern-recognition and signalling pathways both in the extracellular and intracellular space. Besides modulating host-pathogen interactions, this crosstalk guides early developmental processes and distinct cell trajectories, shaping tissue immunometabolic and regenerative programmes in different physiological systems. This Review provides a guide to the system-wide functions of complement. It highlights illustrative paradigm shifts that have reshaped our understanding of complement pathobiology, drawing examples from evolution, development of the central nervous system, tissue regeneration and cancer immunity. Despite its tight spatiotemporal regulation, complement activation can be derailed, fuelling inflammatory tissue pathology. The pervasive contribution of complement to disease pathophysiology has inspired a resurgence of complement therapeutics with major clinical developments, some of which have challenged long-held dogmas. We thus highlight major therapeutic concepts and milestones in clinical complement intervention.
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Affiliation(s)
| | - George Hajishengallis
- Department of Basic and Translational Sciences, Penn Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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Lee IK, Xie R, Luz-Madrigal A, Min S, Zhu J, Jin J, Edwards KL, Phillips MJ, Ludwig AL, Gamm DM, Gong S, Ma Z. Micromolded honeycomb scaffold design to support the generation of a bilayered RPE and photoreceptor cell construct. Bioact Mater 2023; 30:142-153. [PMID: 37575875 PMCID: PMC10415596 DOI: 10.1016/j.bioactmat.2023.07.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 06/27/2023] [Accepted: 07/22/2023] [Indexed: 08/15/2023] Open
Abstract
Age-related macular degeneration (AMD) causes blindness due to loss of retinal pigment epithelium (RPE) and photoreceptors (PRs), which comprise the two outermost layers of the retina. Given the small size of the macula and the importance of direct contact between RPE and PRs, the use of scaffolds for targeted reconstruction of the outer retina in later stage AMD and other macular dystrophies is particularly attractive. We developed microfabricated, honeycomb-patterned, biodegradable poly(glycerol sebacate) (PGS) scaffolds to deliver organized, adjacent layers of RPE and PRs to the subretinal space. Furthermore, an optimized process was developed to photocure PGS, shortening scaffold production time from days to minutes. The resulting scaffolds robustly supported the seeding of human pluripotent stem cell-derived RPE and PRs, either separately or as a dual cell-layered construct. These advanced, economical, and versatile scaffolds can accelerate retinal cell transplantation efforts and benefit patients with AMD and other retinal degenerative diseases.
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Affiliation(s)
- In-Kyu Lee
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, 53715, USA
| | - Ruosen Xie
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, 53715, USA
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, 53705, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Agustin Luz-Madrigal
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, 53705, USA
- Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA
- Department of Comparative Biomedical Sciences, University of Wisconsin–Madison, Madison, WI, 53706, USA
| | - Seunghwan Min
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, 53715, USA
| | - Jingcheng Zhu
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, 53715, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Jiahe Jin
- Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | | | - M. Joseph Phillips
- Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Allison L. Ludwig
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - David M. Gamm
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, 53705, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, 53705, USA
- Waisman Center, University of Wisconsin-Madison, Madison, WI, 53705, USA
- Department of Comparative Biomedical Sciences, University of Wisconsin–Madison, Madison, WI, 53706, USA
| | - Shaoqin Gong
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, 53715, USA
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, 53705, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Zhenqiang Ma
- Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Engineering Physics, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Grainger Institute for Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
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5
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Rathi S, Hasan R, Ueffing M, Clark SJ. Therapeutic targeting of the complement system in ocular disease. Drug Discov Today 2023; 28:103757. [PMID: 37657753 DOI: 10.1016/j.drudis.2023.103757] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 08/18/2023] [Accepted: 08/25/2023] [Indexed: 09/03/2023]
Abstract
The complement system is involved in the pathogenesis of several ocular diseases, providing a rationale for the investigation of complement-targeting therapeutics for these conditions. Dry age-related macular degeneration, as characterised by geographic atrophy (GA), is currently the most active area of research for complement-targeting therapeutics, with a complement C3 inhibitor approved in the United States earlier this year marking the first approved therapy for GA. This review discusses the role of complement in ocular disease, provides an overview of the complement-targeting agents currently under development for ocular conditions, and reflects on the lessons that can be learned from the preclinical investigations and clinical trials conducted in this field to date.
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Affiliation(s)
- Sonika Rathi
- Institute for Ophthalmic Research, Department for Ophthalmology, University Medical Center, Eberhard Karls University of Tübingen, Tübingen, Germany
| | | | - Marius Ueffing
- Institute for Ophthalmic Research, Department for Ophthalmology, University Medical Center, Eberhard Karls University of Tübingen, Tübingen, Germany.
| | - Simon J Clark
- Institute for Ophthalmic Research, Department for Ophthalmology, University Medical Center, Eberhard Karls University of Tübingen, Tübingen, Germany; University Eye Clinic, University Hospital Tübingen, Tübingen, Germany; Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK.
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6
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Holz E, Darwish M, Tesar DB, Shatz-Binder W. A Review of Protein- and Peptide-Based Chemical Conjugates: Past, Present, and Future. Pharmaceutics 2023; 15:600. [PMID: 36839922 PMCID: PMC9959917 DOI: 10.3390/pharmaceutics15020600] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/04/2023] [Accepted: 02/07/2023] [Indexed: 02/12/2023] Open
Abstract
Over the past few decades, the complexity of molecular entities being advanced for therapeutic purposes has continued to evolve. A main propellent fueling innovation is the perpetual mandate within the pharmaceutical industry to meet the needs of novel disease areas and/or delivery challenges. As new mechanisms of action are uncovered, and as our understanding of existing mechanisms grows, the properties that are required and/or leveraged to enable therapeutic development continue to expand. One rapidly evolving area of interest is that of chemically enhanced peptide and protein therapeutics. While a variety of conjugate molecules such as antibody-drug conjugates, peptide/protein-PEG conjugates, and protein conjugate vaccines are already well established, others, such as antibody-oligonucleotide conjugates and peptide/protein conjugates using non-PEG polymers, are newer to clinical development. This review will evaluate the current development landscape of protein-based chemical conjugates with special attention to considerations such as modulation of pharmacokinetics, safety/tolerability, and entry into difficult to access targets, as well as bioavailability. Furthermore, for the purpose of this review, the types of molecules discussed are divided into two categories: (1) therapeutics that are enhanced by protein or peptide bioconjugation, and (2) protein and peptide therapeutics that require chemical modifications. Overall, the breadth of novel peptide- or protein-based therapeutics moving through the pipeline each year supports a path forward for the pursuit of even more complex therapeutic strategies.
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Affiliation(s)
- Emily Holz
- Department of Pharmaceutical Development, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Martine Darwish
- Department of Protein Chemistry, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Devin B. Tesar
- Department of Pharmaceutical Development, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Whitney Shatz-Binder
- Department of Pharmaceutical Development, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
- Department of Protein Chemistry, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
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7
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Pfau M, Schmitz-Valckenberg S, Ribeiro R, Safaei R, McKeown A, Fleckenstein M, Holz FG. Association of complement C3 inhibitor pegcetacoplan with reduced photoreceptor degeneration beyond areas of geographic atrophy. Sci Rep 2022; 12:17870. [PMID: 36284220 PMCID: PMC9596427 DOI: 10.1038/s41598-022-22404-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 10/14/2022] [Indexed: 01/20/2023] Open
Abstract
Preservation of photoreceptors beyond areas of retinal pigment epithelium atrophy is a critical treatment goal in eyes with geographic atrophy (GA) to prevent vision loss. Thus, we assessed the association of treatment with the complement C3 inhibitor pegcetacoplan with optical coherence tomography (OCT)-based photoreceptor laminae thicknesses in this post hoc analysis of the FILLY trial (NCT02503332). Retinal layers in OCT were segmented using a deep-learning-based pipeline and extracted along evenly spaced contour-lines surrounding areas of GA. The primary outcome measure was change from baseline in (standardized) outer nuclear layer (ONL) thickness at the 5.16°-contour-line at month 12. Participants treated with pegcetacoplan monthly had a thicker ONL along the 5.16° contour-line compared to the pooled sham arm (mean difference [95% CI] + 0.29 z-score units [0.16, 0.42], P < 0.001). The same was evident for eyes treated with pegcetacoplan every other month (+ 0.26 z-score units [0.13, 0.4], P < 0.001). Additionally, eyes treated with pegcetacoplan exhibited a thicker photoreceptor inner segment layer along the 5.16°-contour-line at month 12. These findings suggest that pegcetacoplan could slow GA progression and lead to reduced thinning of photoreceptor layers beyond the GA boundary. Future trials in earlier disease stages, i.e., intermediate AMD, aiming to slow photoreceptor degeneration warrant consideration.
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Affiliation(s)
- Maximilian Pfau
- Department of Ophthalmology, University of Bonn, Bonn, Germany
- GRADE Reading Center, Bonn, Germany
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
| | - Steffen Schmitz-Valckenberg
- Department of Ophthalmology, University of Bonn, Bonn, Germany.
- GRADE Reading Center, Bonn, Germany.
- Department of Ophthalmology & Visual Sciences, John A. Moran Eye Center, University of Utah, 65 North Mario Capecchi Drive, Salt Lake City, UT, 84312, USA.
| | | | | | | | - Monika Fleckenstein
- GRADE Reading Center, Bonn, Germany
- Department of Ophthalmology & Visual Sciences, John A. Moran Eye Center, University of Utah, 65 North Mario Capecchi Drive, Salt Lake City, UT, 84312, USA
| | - Frank G Holz
- Department of Ophthalmology, University of Bonn, Bonn, Germany
- GRADE Reading Center, Bonn, Germany
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8
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Patel PN, Patel PA, Land MR, Bakerkhatib-Taha I, Ahmed H, Sheth V. Targeting the Complement Cascade for Treatment of Dry Age-Related Macular Degeneration. Biomedicines 2022; 10:1884. [PMID: 36009430 PMCID: PMC9405256 DOI: 10.3390/biomedicines10081884] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/28/2022] [Accepted: 08/01/2022] [Indexed: 11/16/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss in the elderly population. AMD is characterized in its late form by neovascularization (wet type) or geographic atrophy of the retinal pigment epithelium cell layer (dry type). Regarding the latter type, there is growing evidence supporting an association between the pathophysiology of dry AMD and key proteins in the complement cascade. The complement cascade works as a central part of the innate immune system by defending against foreign pathogens and modified self-tissues. Through three distinct pathways, a series of plasma and membrane-associated serum proteins are activated upon identification of a foreign entity. Several of these proteins have been implicated in the development and progression of dry AMD. Potential therapeutic targets include C1q, C3, C5, complement factors (B, D, H, I), membrane attack complex, and properdin. In this review, we provide an understanding of the role of the complement system in dry AMD and discuss the emerging therapies in early phase clinical trials. The tentative hope is that these drugs may offer the potential to intervene at earlier stages in dry AMD pathogenesis, thereby preventing progression to late disease.
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Affiliation(s)
- Prem N. Patel
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Parth A. Patel
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Matthew R. Land
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | | | - Harris Ahmed
- Department of Ophthalmology, Loma Linda University Medical Center, Loma Linda, CA 92350, USA
| | - Veeral Sheth
- University Retina and Macula Associates, Oak Forest, IL 60452, USA
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9
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Mollnes TE, Storm BS, Brekke OL, Nilsson PH, Lambris JD. Application of the C3 inhibitor compstatin in a human whole blood model designed for complement research - 20 years of experience and future perspectives. Semin Immunol 2022; 59:101604. [PMID: 35570131 DOI: 10.1016/j.smim.2022.101604] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 04/23/2022] [Indexed: 01/15/2023]
Abstract
The complex molecular and cellular biological systems that maintain host homeostasis undergo continuous crosstalk. Complement, a component of innate immunity, is one such system. Initially regarded as a system to protect the host from infection, complement has more recently been shown to have numerous other functions, including involvement in embryonic development, tissue modeling, and repair. Furthermore, the complement system plays a major role in the pathophysiology of many diseases. Through interactions with other plasma cascades, including hemostasis, complement activation leads to the broad host-protective response known as thromboinflammation. Most complement research has been limited to reductionistic models of purified components and cells and their interactions in vitro. However, to study the pathophysiology of complement-driven diseases, including the interaction between the complement system and other inflammatory systems, holistic models demonstrating only minimal interference with complement activity are needed. Here we describe two such models; whole blood anticoagulated with either the thrombin inhibitor lepirudin or the fibrin polymerization peptide blocker GPRP, both of which retain complement activity and preserve the ability of complement to be mutually reactive with other inflammatory systems. For instance, to examine the relative roles of C3 and C5 in complement activation, it is possible to compare the effects of the C3 inhibitor compstatin effects to those of inhibitors of C5 and C5aR1. We also discuss how complement is activated by both pathogen-associated molecular patterns, inducing infectious inflammation caused by organisms such as Gram-negative and Gram-positive bacteria, and by sterile damage-associated molecular patterns, including cholesterol crystals and artificial materials used in clinical medicine. When C3 is inhibited, it is important to determine the mechanism by which inflammation is attenuated, i.e., whether the attenuation derives directly from C3 activation products or via downstream activation of C5, since the mechanism involved may determine the appropriate choice of inhibitor under various conditions. With some exceptions, most inflammatory responses are dependent on C5 and C5aR1; one exception is venous air embolism, in which air bubbles enter the blood circulation and trigger a mainly C3-dependent thromboembolism, with the formation of an active C3 convertase, without a corresponding C5 activation. Under such conditions, an inhibitor of C3 is needed to attenuate the inflammation. Our holistic blood models will be useful for further studies of the inhibition of any complement target, not just C3 or C5. The focus here will be on targeting the critical complement component, activation product, or receptor that is important for the pathophysiology in a variety of disease conditions.
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Affiliation(s)
- Tom E Mollnes
- Research Laboratory, Nordland Hospital, Bodø, Norway; Department of Immunology, Oslo University Hospital and University of Oslo, Norway; Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway.
| | - Benjamin S Storm
- Research Laboratory, Nordland Hospital, Bodø, Norway; Institute of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway; Faculty of Nursing and Health Sciences, Nord University, Bodø, Norway
| | - Ole L Brekke
- Research Laboratory, Nordland Hospital, Bodø, Norway; Institute of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway; Department of Laboratory Medicine, Nordland Hospital, Bodø, Norway
| | - Per H Nilsson
- Department of Immunology, Oslo University Hospital and University of Oslo, Norway; Linnaeus Centre for Biomaterials Chemistry, Linnaeus University, 39182 Kalmar, Sweden; Department of Chemistry and Biomedical Sciences, Linnaeus University, 39182 Kalmar, Sweden
| | - John D Lambris
- Department of Pathology & Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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10
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Compstatins: the dawn of clinical C3-targeted complement inhibition. Trends Pharmacol Sci 2022; 43:629-640. [PMID: 35090732 PMCID: PMC9553322 DOI: 10.1016/j.tips.2022.01.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 02/08/2023]
Abstract
Despite the growing recognition of the complement system as a major contributor to a variety of clinical conditions, the therapeutic arsenal has remained scarce. The introduction of an anti-C5 antibody in 2007 raised confidence in complement-targeted therapy. However, it became apparent that inhibition of late-stage effector generation might not be sufficient in multifactorial complement disorders. Upstream intervention at the level of C3 activation has therefore been considered promising. The approval of pegcetacoplan, a C3 inhibitor of the compstatin family, in 2021 served as critical validation of C3-targeted treatment. This review delineates the evolution of the compstatin family from its academic origins to the clinic and highlights current and potential future applications of this promising drug class in complement diseases.
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11
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Abstract
The eye presents a unique opportunity for complement component 3 (C3) therapeutics. Drugs can be delivered directly to specific parts of the eye, and growing evidence has established a pivotal role for C3 in age-related macular degeneration (AMD). Emerging data show that C3 may be important to the pathophysiology of other eye diseases as well. This article will discuss the location of C3 expression in the eye as well as the preclinical and clinical data regarding C3's functions in AMD. We will provide a comprehensive review of developing C3 inhibitors for the eye, including the Phase 2 and 3 data for the C3 inhibitor pegcetacoplan as a treatment for the geographic atrophy of AMD. Developing evidence also points toward C3 as a therapeutic target for stages of AMD preceding geographic atrophy. We will also discuss data illuminating C3's relationship to other eye diseases, such as Stargardt disease, diabetic retinopathy, and glaucoma. In addition to being a converging point and centerpiece of the complement cascade, C3 has broad effects as a multifaceted controller of opsonophagocytosis, microglia/macrophage recruitment, and downstream terminal pathway activity. C3 is a crucial player in the pathophysiology of AMD but also seems to have importance in other diseases that are major causes of blindness. Directions for further investigation will be highlighted, as culminating evidence suggests that we may be approaching an era of C3 therapeutics for the eye.
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Affiliation(s)
- Benjamin J Kim
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Tianyu Liu
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | - John D Lambris
- Department of Laboratory Medicine and Pathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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12
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Kim BJ, Mastellos DC, Li Y, Dunaief JL, Lambris JD. Targeting complement components C3 and C5 for the retina: Key concepts and lingering questions. Prog Retin Eye Res 2021; 83:100936. [PMID: 33321207 PMCID: PMC8197769 DOI: 10.1016/j.preteyeres.2020.100936] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/07/2020] [Accepted: 12/09/2020] [Indexed: 12/13/2022]
Abstract
Age-related macular degeneration (AMD) remains a major cause of legal blindness, and treatment for the geographic atrophy form of AMD is a significant unmet need. Dysregulation of the complement cascade is thought to be instrumental for AMD pathophysiology. In particular, C3 and C5 are pivotal components of the complement cascade and have become leading therapeutic targets for AMD. In this article, we discuss C3 and C5 in detail, including their roles in AMD, biochemical and structural aspects, locations of expression, and the functions of C3 and C5 fragments. Further, the article critically reviews developing therapeutics aimed at C3 and C5, underscoring the potential effects of broad inhibition of complement at the level of C3 versus more specific inhibition at C5. The relationships of complement biology to the inflammasome and microglia/macrophage activity are highlighted. Concepts of C3 and C5 biology will be emphasized, while we point out questions that need to be settled and directions for future investigations.
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Affiliation(s)
- Benjamin J Kim
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | | | - Yafeng Li
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Joshua L Dunaief
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - John D Lambris
- Department of Laboratory Medicine and Pathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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13
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Annamalai B, Parsons N, Nicholson C, Obert E, Jones B, Rohrer B. Subretinal Rather Than Intravitreal Adeno-Associated Virus-Mediated Delivery of a Complement Alternative Pathway Inhibitor Is Effective in a Mouse Model of RPE Damage. Invest Ophthalmol Vis Sci 2021; 62:11. [PMID: 33830174 PMCID: PMC8039473 DOI: 10.1167/iovs.62.4.11] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 03/04/2021] [Indexed: 12/14/2022] Open
Abstract
Purpose The risk for age-related macular degeneration has been tied to an overactive complement system. Despite combined attempts by academia and industry to develop therapeutics that modulate the complement response, particularly in the late geographic atrophy form of advanced AMD, to date, there is no effective treatment. We have previously demonstrated that pathology in the smoke-induced ocular pathology (SIOP) model, a model with similarities to dry AMD, is dependent on activation of the alternative complement pathway and that a novel complement activation site targeted inhibitor of the alternative pathway can be delivered to ocular tissues via an adeno-associated virus (AAV). Methods Two different viral vectors for specific tissue targeting were compared: AAV5-VMD2-CR2-fH for delivery to the retinal pigment epithelium (RPE) and AAV2YF-smCBA-CR2-fH for delivery to retinal ganglion cells (RGCs). Efficacy was tested in SIOP (6 months of passive smoke inhalation), assessing visual function (optokinetic responses), retinal structure (optical coherence tomography), and integrity of the RPE and Bruch's membrane (electron microscopy). Protein chemistry was used to assess complement activation, CR2-fH tissue distribution, and CR2-fH transport across the RPE. Results RPE- but not RGC-mediated secretion of CR2-fH was found to reduce SIOP and complement activation in RPE/choroid. Bioavailability of CR2-fH in RPE/choroid could be confirmed only after AAV5-VMD2-CR2-fH treatment, and inefficient, adenosine triphosphate-dependent transport of CR2-fH across the RPE was identified. Conclusions Our results suggest that complement inhibition for AMD-like pathology is required basal to the RPE and argues in favor of AAV vector delivery to the RPE or outside the blood-retina barrier.
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Affiliation(s)
- Balasubramaniam Annamalai
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Nathaniel Parsons
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Crystal Nicholson
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Elisabeth Obert
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Bryan Jones
- Department of Ophthalmology, University of Utah, Salt Lake City, Utah, United States
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States
- Division of Research, Ralph H. Johnson VA Medical Center, Charleston, South Carolina, United States
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina, United States
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14
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Liu X, Li S, Meng Y, Fan Y, Liu J, Shi C, Ren F, Wu L, Wang J, Sun H. Osteoclast differentiation and formation induced by titanium implantation through complement C3a. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2021; 122:111932. [PMID: 33641923 DOI: 10.1016/j.msec.2021.111932] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 01/26/2021] [Accepted: 01/28/2021] [Indexed: 12/21/2022]
Abstract
Titanium implantation is widely used for dental replacement with advantages of excellent mechanical strength, corrosion resistance, chemical stability and biocompatibility. Some patients, however, are subject to the failure of implantation due to bone resorption, which closely related to the inflammatory responses without clear mechanisms. In this study, first we found that there were inflammatory responses and increases of osteoclasts in the surrounding tissues near by the titanium implant. Further, data revealed that the C3 was increased in the serum and surrounding tissues near by the titanium implant, and activated by classical and alternative pathways. Next, we recognized that the C3a/C3aR, no C3b played an important role in stimulating secretions of pro-inflammatory cytokines of TNF-α and MMP9 via transcription factors NF-kB and NFATc1. This cascade of responses to titanium implant leaded the differentiation and proliferation of osteoclasts in vivo and in vitro, bone resorption of surrounding tissues of Ti implant. These suggest that the cleaved C3a fragment plays predominant roles in the activation of osteoclast. Therefore, the blocking C3a activation should provide potential to prevent bone resorption and prolong the survival of biomaterial implants.
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Affiliation(s)
- Xiaohan Liu
- Department of Oral Pathology, School and Hospital of Stomatology, China Medical University, Shenyang, 110002, China; Department of Prosthodontics, School and Hospital of Stomatology, China Medical University, Shenyang, 110002, China; Liaoning Provincial Key Laboratory of Oral Diseases, China Medical University, Shenyang, 110002, China
| | - Siwen Li
- Department of Oral Pathology, School and Hospital of Stomatology, China Medical University, Shenyang, 110002, China; Department of Prosthodontics, School and Hospital of Stomatology, China Medical University, Shenyang, 110002, China; Liaoning Provincial Key Laboratory of Oral Diseases, China Medical University, Shenyang, 110002, China
| | - Yuan Meng
- Department of Oral Pathology, School and Hospital of Stomatology, China Medical University, Shenyang, 110002, China; Liaoning Provincial Key Laboratory of Oral Diseases, China Medical University, Shenyang, 110002, China
| | - Yu Fan
- Department of Oral Pathology, School and Hospital of Stomatology, China Medical University, Shenyang, 110002, China; Liaoning Provincial Key Laboratory of Oral Diseases, China Medical University, Shenyang, 110002, China
| | - Jie Liu
- Centre of Science Experiment, China Medical University, Shenyang, 110122, China
| | - Ce Shi
- Department of Oral Pathology, School and Hospital of Stomatology, Jilin University, Changchun, 130021, China
| | - Feilong Ren
- Department of Oral Pathology, School and Hospital of Stomatology, Jilin University, Changchun, 130021, China
| | - Lin Wu
- Department of Prosthodontics, School and Hospital of Stomatology, China Medical University, Shenyang, 110002, China; Liaoning Provincial Key Laboratory of Oral Diseases, China Medical University, Shenyang, 110002, China.
| | - Jinyan Wang
- Department of Immunology, Basic Medical Sciences, China Medical University, Shenyang, 110122, China.
| | - Hongchen Sun
- Department of Oral Pathology, School and Hospital of Stomatology, China Medical University, Shenyang, 110002, China; Liaoning Provincial Key Laboratory of Oral Diseases, China Medical University, Shenyang, 110002, China.
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