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Schwinghamer K, Line S, Tesar DB, Miller DW, Sreedhara A, Siahaan TJ. Selective Uptake of Macromolecules to the Brain in Microfluidics and Animal Models Using the HAVN1 Peptide as a Blood-Brain Barrier Modulator. Mol Pharm 2024; 21:1639-1652. [PMID: 38395041 PMCID: PMC10984760 DOI: 10.1021/acs.molpharmaceut.3c00775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2024]
Abstract
Monoclonal antibodies (mAbs) possess favorable pharmacokinetic properties, high binding specificity and affinity, and minimal off-target effects, making them promising therapeutic agents for central nervous system (CNS) disorders. However, their development as effective therapeutic and diagnostic agents for brain disorders is hindered by their limited ability to efficiently penetrate the blood-brain barrier (BBB). Therefore, it is crucial to develop efficient delivery methods that enhance the penetration of antibodies into the brain. Previous studies have demonstrated the potential of cadherin-derived peptides (i.e., ADTC5, HAVN1 peptides) as BBB modulators (BBBMs) to increase paracellular porosities for penetration of molecules across the BBB. Here, we test the effectiveness of the leading BBBM peptide, HAVN1 (Cyclo(1,6)SHAVSS), in enhancing the permeation of various monoclonal antibodies through the BBB using both in vitro and in vivo systems. In vitro, HAVN1 has been shown to increase the permeability of fluorescently labeled macromolecules, such as a 70 kDa dextran, 50 kDa Fab1, and 150 kDa mAb1, by 4- to 9-fold in a three-dimensional blood-brain barrier (3D-BBB) microfluidics model using a human BBB endothelial cell line (i.e., hCMEC/D3). HAVN1 was selective in modulating the BBB endothelial cell, compared to the pulmonary vascular endothelial (PVE) cell barrier. Co-administration of HAVN1 significantly improved brain depositions of mAb1, mAb2, and Fab1 in C57BL/6 mice after 15 min in the systemic circulation. Furthermore, HAVN1 still significantly enhanced brain deposition of mAb2 when it was administered 24 h after the administration of the mAb. Lastly, we observed that multiple doses of HAVN1 may have a cumulative effect on the brain deposition of mAb2 within a 24-h period. These findings offer promising insights into optimizing HAVN1 and mAb dosing regimens to control or modulate mAb brain deposition for achieving desired mAb dose in the brain to provide its therapeutic effects.
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Affiliation(s)
- Kelly Schwinghamer
- Department of Pharmaceutical Chemistry, The University of Kansas, 2093 Constant Ave., Lawrence, KS 66047, USA
| | - Stacey Line
- Department of Pharmacology and Therapeutics, University of Manitoba, 753 McDermot Avenue Winnipeg, MB, R3E 0T6, Canada
| | - Devin B. Tesar
- Department of Pharmaceutical Development, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Donald W. Miller
- Department of Pharmacology and Therapeutics, University of Manitoba, 753 McDermot Avenue Winnipeg, MB, R3E 0T6, Canada
| | - Alavattam Sreedhara
- Department of Pharmaceutical Development, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Teruna J. Siahaan
- Department of Pharmaceutical Chemistry, The University of Kansas, 2093 Constant Ave., Lawrence, KS 66047, USA
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2
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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:pharmaceutics15020600. [PMID: 36839922 PMCID: PMC9959917 DOI: 10.3390/pharmaceutics15020600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [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
- Correspondence:
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3
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Kelley RF, Tesar DB, Wang Y, Agard NJ, Holder PG, Chan J, Comps-Agrar L, Horvath J, Horvath JD, Crowell SR. Generation of a Porcine Antibody Fab Fragment Using Protein Engineering to Facilitate the Evaluation of Ocular Sustained Delivery Technology. Mol Pharm 2022; 19:1540-1547. [PMID: 35393854 DOI: 10.1021/acs.molpharmaceut.2c00048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Treatment of age-related macular degeneration (AMD) with anti-vascular endothelial growth factor (VEGF) biologic agents has been shown to restore and maintain visual acuity for many patients afflicted with wet AMD. These agents are usually administered via intravitreal injection at a dosing interval of 4-8 weeks. Employment of long-acting delivery (LAD) technologies could improve the therapeutic outcome, ensure timely treatment, and reduce burden on patients, caregivers, and the health care system. Development of LAD approaches requires thorough testing in pre-clinical species; however, therapeutic proteins of human origin may not be well tolerated during testing in non-human species due to immunogenicity. Here, we have engineered a surrogate porcine antibody Fab fragment (pigG6.31) from a human antibody for testing ocular LAD technologies in a porcine model. The engineered Fab retains the VEGF-A-binding and inhibition properties of the parental human Fab and has stability properties suitable for LAD evaluation. Upon intravitreal injection in minipigs, pigG6.31 showed first-order clearance from the ocular compartments with vitreal elimination rates consistent with other molecules of this size. Application of the surrogate molecule in an in vivo evaluation in minipigs of a prototype of the port delivery (PD) platform indicated continuous ocular delivery from the implant, with release kinetics consistent with both the results from in vitro release studies and the efficacy observed in human clinical studies of the PD system with ranibizumab (PDS). Anti-drug antibodies in the serum against pigG6.31 were not detected over exposure durations up to 16 weeks, suggesting that this molecule has low porcine immunogenicity.
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Affiliation(s)
- Robert F Kelley
- Pharmaceutical Development, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Devin B Tesar
- Pharmaceutical Development, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Yue Wang
- Pharmaceutical Development, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Nicholas J Agard
- Antibody Engineering, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Patrick G Holder
- Protein Chemistry, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Joyce Chan
- Biochemical and Cellular Pharmacology, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Laetitia Comps-Agrar
- Biochemical and Cellular Pharmacology, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Judit Horvath
- Pharmaceutical Development, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Joshua D Horvath
- Device Development, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Susan R Crowell
- Preclinical and Translational Pharmacokinetics and Pharmacodynamics Department, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, United States
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4
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Yip V, Palma E, Tesar DB, Mundo EE, Bumbaca D, Torres EK, Reyes NA, Shen BQ, Fielder PJ, Prabhu S, Khawli LA, Boswell CA. Quantitative cumulative biodistribution of antibodies in mice: effect of modulating binding affinity to the neonatal Fc receptor. MAbs 2014; 6:689-96. [PMID: 24572100 PMCID: PMC4011913 DOI: 10.4161/mabs.28254] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The neonatal Fc receptor (FcRn) plays an important and well-known role in antibody recycling in endothelial and hematopoietic cells and thus it influences the systemic pharmacokinetics (PK) of immunoglobulin G (IgG). However, considerably less is known about FcRn's role in the metabolism of IgG within individual tissues after intravenous administration. To elucidate the organ distribution and gain insight into the metabolism of humanized IgG1 antibodies with different binding affinities FcRn, comparative biodistribution studies in normal CD-1 mice were conducted. Here, we generated variants of herpes simplex virus glycoprotein D-specific antibody (humanized anti-gD) with increased and decreased FcRn binding affinity by genetic engineering without affecting antigen specificity. These antibodies were expressed in Chinese hamster ovary cell lines, purified and paired radiolabeled with iodine-125 and indium-111. Equal amounts of I-125-labeled and In-111-labeled antibodies were mixed and intravenously administered into mice at 5 mg/kg. This approach allowed us to measure both the real-time IgG uptake (I-125) and cumulative uptake of IgG and catabolites (In-111) in individual tissues up to 1 week post-injection. The PK and distribution of the wild-type IgG and the variant with enhanced binding for FcRn were largely similar to each other, but vastly different for the rapidly cleared low-FcRn-binding variant. Uptake in individual tissues varied across time, FcRn binding affinity, and radiolabeling method. The liver and spleen emerged as the most concentrated sites of IgG catabolism in the absence of FcRn protection. These data provide an increased understanding of FcRn's role in antibody PK and catabolism at the tissue level.
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Affiliation(s)
- Victor Yip
- Preclinical and Translational Pharmacokinetics; Genentech Research & Early Development; South San Francisco, CA USA
| | - Enzo Palma
- Preclinical and Translational Pharmacokinetics; Genentech Research & Early Development; South San Francisco, CA USA
| | - Devin B Tesar
- Drug Delivery Department; Pharma Technical Development, Genentech; South San Francisco, CA USA
| | - Eduardo E Mundo
- Preclinical and Translational Pharmacokinetics; Genentech Research & Early Development; South San Francisco, CA USA
| | - Daniela Bumbaca
- Preclinical and Translational Pharmacokinetics; Genentech Research & Early Development; South San Francisco, CA USA
| | - Elizabeth K Torres
- Non-Clinical Operations; Genentech Research & Early Development; South San Francisco, CA USA
| | - Noe A Reyes
- Preclinical and Translational Pharmacokinetics; Genentech Research & Early Development; South San Francisco, CA USA
| | - Ben Q Shen
- Preclinical and Translational Pharmacokinetics; Genentech Research & Early Development; South San Francisco, CA USA
| | - Paul J Fielder
- Preclinical and Translational Pharmacokinetics; Genentech Research & Early Development; South San Francisco, CA USA
| | - Saileta Prabhu
- Preclinical and Translational Pharmacokinetics; Genentech Research & Early Development; South San Francisco, CA USA
| | - Leslie A Khawli
- Preclinical and Translational Pharmacokinetics; Genentech Research & Early Development; South San Francisco, CA USA
| | - C Andrew Boswell
- Preclinical and Translational Pharmacokinetics; Genentech Research & Early Development; South San Francisco, CA USA
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5
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Zheng Y, Tesar DB, Benincosa L, Birnböck H, Boswell CA, Bumbaca D, Cowan KJ, Danilenko DM, Daugherty AL, Fielder PJ, Grimm HP, Joshi A, Justies N, Kolaitis G, Lewin-Koh N, Li J, McVay S, O'Mahony J, Otteneder M, Pantze M, Putnam WS, Qiu ZJ, Ruppel J, Singer T, Stauch O, Theil FP, Visich J, Yang J, Ying Y, Khawli LA, Richter WF. Minipig as a potential translatable model for monoclonal antibody pharmacokinetics after intravenous and subcutaneous administration. MAbs 2012; 4:243-55. [PMID: 22453096 DOI: 10.4161/mabs.4.2.19387] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Subcutaneous (SC) delivery is a common route of administration for therapeutic monoclonal antibodies (mAbs) with pharmacokinetic (PK)/pharmacodynamic (PD) properties requiring long-term or frequent drug administration. An ideal in vivo preclinical model for predicting human PK following SC administration may be one in which the skin and overall physiological characteristics are similar to that of humans. In this study, the PK properties of a series of therapeutic mAbs following intravenous (IV) and SC administration in Göttingen minipigs were compared with data obtained previously from humans. The present studies demonstrated: (1) minipig is predictive of human linear clearance; (2) the SC bioavailabilities in minipigs are weakly correlated with those in human; (3) minipig mAb SC absorption rates are generally higher than those in human and (4) the SC bioavailability appears to correlate with systemic clearance in minipigs. Given the important role of the neonatal Fc-receptor (FcRn) in the PK of mAbs, the in vitro binding affinities of these IgGs against porcine, human and cynomolgus monkey FcRn were tested. The result showed comparable FcRn binding affinities across species. Further, mAbs with higher isoelectric point tended to have faster systemic clearance and lower SC bioavailability in both minipig and human. Taken together, these data lend increased support for the use of the minipig as an alternative predictive model for human IV and SC PK of mAbs.
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Affiliation(s)
- Yanan Zheng
- Research and Early Development; Genentech; South San Francisco, CA USA; These authors contributed equally to this work
| | - Devin B Tesar
- Research and Early Development; Genentech; South San Francisco, CA USA; These authors contributed equally to this work
| | - Lisa Benincosa
- Drug Metabolism and Pharmacokinetics; Pharma Research and Early Development; Hoffmann-La Roche Inc.; Nutley, NJ USA
| | - Herbert Birnböck
- Pharma Research and Early Development; F. Hoffmann-La Roche Ltd.; Basel, Switzerland
| | - C Andrew Boswell
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Daniela Bumbaca
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Kyra J Cowan
- Research and Early Development; Genentech; South San Francisco, CA USA
| | | | - Ann L Daugherty
- Drug Delivery, Pharma Technical Development; Genentech; South San Francisco, CA USA
| | - Paul J Fielder
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Hans Peter Grimm
- Pharma Research and Early Development; F. Hoffmann-La Roche Ltd.; Basel, Switzerland
| | - Amita Joshi
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Nicole Justies
- Pharma Research and Early Development; F. Hoffmann-La Roche Ltd.; Basel, Switzerland
| | - Gerry Kolaitis
- Drug Metabolism and Pharmacokinetics; Pharma Research and Early Development; Hoffmann-La Roche Inc.; Nutley, NJ USA
| | | | - Jing Li
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Sami McVay
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Jennifer O'Mahony
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Michael Otteneder
- Pharma Research and Early Development; F. Hoffmann-La Roche Ltd.; Basel, Switzerland
| | - Michael Pantze
- Pharma Research and Early Development; F. Hoffmann-La Roche Ltd.; Basel, Switzerland
| | - Wendy S Putnam
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Zhihua J Qiu
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Jane Ruppel
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Thomas Singer
- Pharma Research and Early Development; F. Hoffmann-La Roche Ltd.; Basel, Switzerland
| | - Oliver Stauch
- Pharma Research and Early Development; F. Hoffmann-La Roche Ltd.; Basel, Switzerland
| | - Frank-Peter Theil
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Jennifer Visich
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Jihong Yang
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Yong Ying
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Leslie A Khawli
- Research and Early Development; Genentech; South San Francisco, CA USA
| | - Wolfgang F Richter
- Pharma Research and Early Development; F. Hoffmann-La Roche Ltd.; Basel, Switzerland
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6
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Boswell CA, Tesar DB, Mukhyala K, Theil FP, Fielder PJ, Khawli LA. Effects of Charge on Antibody Tissue Distribution and Pharmacokinetics. Bioconjug Chem 2010; 21:2153-63. [DOI: 10.1021/bc100261d] [Citation(s) in RCA: 273] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- C. Andrew Boswell
- Department of Pharmacokinetic and Pharmacodynamic Sciences, Department of Antibody Engineering, and Department of Bioinformatics, Genentech Research and Early Development, South San Francisco, California 94080, United States
| | - Devin B. Tesar
- Department of Pharmacokinetic and Pharmacodynamic Sciences, Department of Antibody Engineering, and Department of Bioinformatics, Genentech Research and Early Development, South San Francisco, California 94080, United States
| | - Kiran Mukhyala
- Department of Pharmacokinetic and Pharmacodynamic Sciences, Department of Antibody Engineering, and Department of Bioinformatics, Genentech Research and Early Development, South San Francisco, California 94080, United States
| | - Frank-Peter Theil
- Department of Pharmacokinetic and Pharmacodynamic Sciences, Department of Antibody Engineering, and Department of Bioinformatics, Genentech Research and Early Development, South San Francisco, California 94080, United States
| | - Paul J. Fielder
- Department of Pharmacokinetic and Pharmacodynamic Sciences, Department of Antibody Engineering, and Department of Bioinformatics, Genentech Research and Early Development, South San Francisco, California 94080, United States
| | - Leslie A. Khawli
- Department of Pharmacokinetic and Pharmacodynamic Sciences, Department of Antibody Engineering, and Department of Bioinformatics, Genentech Research and Early Development, South San Francisco, California 94080, United States
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7
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Jerdeva GV, Tesar DB, Huey-Tubman KE, Ladinsky MS, Fraser SE, Bjorkman PJ. Comparison of FcRn- and pIgR-mediated transport in MDCK cells by fluorescence confocal microscopy. Traffic 2010; 11:1205-20. [PMID: 20525015 PMCID: PMC2975666 DOI: 10.1111/j.1600-0854.2010.01083.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Protein delivery across polarized epithelia is controlled by receptor-mediated transcytosis. Many studies have examined basolateral-to-apical trafficking of polymeric IgA (pIgA) by the polymeric immunoglobulin receptor (pIgR). Less is known about apical-to-basolateral transcytosis, the direction the neonatal Fc receptor (FcRn) transports maternal IgGs across intestinal epithelia. To compare apical-to-basolateral and basolateral-to-apical transcytosis, we co-expressed FcRn and pIgR in Madin-Darby canine kidney (MDCK) cells and used pulse-chase experiments with confocal microscopy to examine transport of apically applied IgG Fcgamma and basolaterally applied pIgA. Fcgamma and pIgA trafficking routes were initially separate but intermixed at later chase times. Fcgamma was first localized near the apical surface, but became more equally distributed across the cell, consistent with concomitant transcytosis and recycling. By contrast, pIgA transport was strongly unidirectional: pIgA shifted from near the basolateral surface to an apical location with increasing time. Some Fcgamma and pIgA fluorescence colocalized in early (EEA1-positive), recycling (Rab11a-positive), and transferrin (Tf)-positive common/basolateral recycling endosomes. Fcgamma became more enriched in Tf-positive endosomes with time, whereas pIgA was sorted from these compartments. Live-cell imaging revealed that vesicles containing Fcgamma or pIgA shared similar mobility characteristics and were equivalently affected by depolymerizing microtubules, indicating that both trafficking routes depended to roughly the same extent on intact microtubules.
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Affiliation(s)
- Galina V Jerdeva
- Division of Biology, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
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8
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Tesar DB, Björkman PJ. An intracellular traffic jam: Fc receptor-mediated transport of immunoglobulin G. Curr Opin Struct Biol 2010; 20:226-33. [PMID: 20171874 DOI: 10.1016/j.sbi.2010.01.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 01/20/2010] [Accepted: 01/22/2010] [Indexed: 10/19/2022]
Abstract
Recent advances in imaging techniques along with more powerful in vitro and in vivo models of receptor-mediated ligand transport are facilitating advances in our understanding of how cells efficiently direct receptors and their cargo to target destinations within the cytoplasm and at the plasma membrane. Specifically, light and 3D electron microscopy studies examining the trafficking behavior of the neonatal Fc receptor (FcRn), a transport receptor for immunoglobulin G (IgG), have given us new insights into the dynamic interplay between the structural components of the cytosolic trafficking machinery, its protein regulators, and the receptors it directs to various locations within the cell. These studies build upon previous biochemical characterizations of FcRn transport and are allowing us to begin formulation of a more complete model for the intracellular trafficking of receptor-ligand complexes.
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Affiliation(s)
- Devin B Tesar
- Department of Antibody Engineering, Genentech, South San Francisco, CA 94080, USA.
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9
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Tesar DB, Cheung EJ, Bjorkman PJ. The chicken yolk sac IgY receptor, a mammalian mannose receptor family member, transcytoses IgY across polarized epithelial cells. Mol Biol Cell 2008; 19:1587-93. [PMID: 18256279 DOI: 10.1091/mbc.e07-09-0972] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
In mammals the transfer of passive immunity from mother to young is mediated by the MHC-related receptor FcRn, which transports maternal IgG across epithelial cell barriers. In birds, maternal IgY in egg yolk is transferred across the yolk sac to passively immunize chicks during gestation and early independent life. The chicken yolk sac IgY receptor (FcRY) is the ortholog of the mammalian phospholipase A2 receptor, a mannose receptor family member, rather than an FcRn or MHC homolog. FcRn and FcRY both exhibit ligand binding at the acidic pH of endosomes and ligand release at the slightly basic pH of blood. Here we show that FcRY expressed in polarized mammalian epithelial cells functioned in endocytosis, bidirectional transcytosis, and recycling of chicken FcY/IgY. Confocal immunofluorescence studies demonstrated that IgY binding and endocytosis occurred at acidic but not basic pH, mimicking pH-dependent uptake of IgG by FcRn. Colocalization studies showed FcRY-mediated internalization via clathrin-coated pits and transport involving early and recycling endosomes. Disruption of microtubules partially inhibited apical-to-basolateral and basolateral-to-apical transcytosis, but not recycling, suggesting the use of different trafficking machinery. Our results represent the first cell biological evidence of functional equivalence between FcRY and FcRn and provide an intriguing example of how evolution can give rise to systems in which similar biological requirements in different species are satisfied utilizing distinct protein folds.
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Affiliation(s)
- Devin B Tesar
- Division of Biology and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA
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10
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He W, Kivork C, Machinani S, Morphew MK, Gail AM, Tesar DB, Tiangco NE, McIntosh JR, Bjorkman PJ. A freeze substitution fixation-based gold enlarging technique for EM studies of endocytosed Nanogold-labeled molecules. J Struct Biol 2007; 160:103-13. [PMID: 17723309 PMCID: PMC2076746 DOI: 10.1016/j.jsb.2007.07.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Revised: 07/05/2007] [Accepted: 07/17/2007] [Indexed: 11/28/2022]
Abstract
We have developed methods to locate individual ligands that can be used for electron microscopy studies of dynamic events during endocytosis and subsequent intracellular trafficking. The methods are based on enlargement of 1.4 nm Nanogold attached to an endocytosed ligand. Nanogold, a small label that does not induce misdirection of ligand-receptor complexes, is ideal for labeling ligands endocytosed by live cells, but is too small to be routinely located in cells by electron microscopy. Traditional pre-embedding enhancement protocols to enlarge Nanogold are not compatible with high pressure freezing/freeze substitution fixation (HPF/FSF), the most accurate method to preserve ultrastructure and dynamic events during trafficking. We have developed an improved enhancement procedure for chemically fixed samples that reduced auto-nucleation, and a new pre-embedding gold enlarging technique for HPF/FSF samples that preserved contrast and ultrastructure and can be used for high-resolution tomography. We evaluated our methods using labeled Fc as a ligand for the neonatal Fc receptor. Attachment of Nanogold to Fc did not interfere with receptor binding or uptake, and gold-labeled Fc could be specifically enlarged to allow identification in 2D projections and in tomograms. These methods should be broadly applicable to many endocytosis and transcytosis studies.
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Affiliation(s)
- Wanzhong He
- Division of Biology 114-96, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
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11
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Abstract
The neonatal Fc receptor (FcRn) transports IgG across epithelial cell barriers to provide maternal antibodies to offspring and serves as a protection receptor by rescuing endocytosed IgG and albumin from lysosomal degradation. Here we describe the generation of polarized Madin-Darby canine kidney (MDCK) cells expressing rat FcRn (rFcRn) to investigate the potential requirement for ligand bivalency in FcRn-mediated transport. The rFcRn-MDCK cells bind, internalize and bidirectionally transcytose the bivalent ligands IgG and Fc across polarized cell monolayers. However, they cannot be used to study FcRn-mediated transport of the monovalent ligand albumin, as we observe no specific binding, internalization or transcytosis of rat albumin. To address whether ligand bivalency is required for transport, the ability of rFcRn to transcytose and recycle wild-type Fc homodimers (wtFc; two FcRn-binding sites) and a heterodimeric Fc (hdFc; one FcRn-binding site) was compared. We show that ligand bivalency is not required for transcytosis or recycling, but that wtFc is transported more efficiently than hdFc, particularly at lower concentrations. We also demonstrate that hdFc and wtFc have different intracellular fates, with more hdFc than wtFc being trafficked to lysosomes and degraded, suggesting a role for avidity effects in FcRn-mediated IgG transport.
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Affiliation(s)
- Devin B Tesar
- Division of Biology and California Institute of TechnologyPasadena, CA 91125, USA
| | - Noreen E Tiangco
- Division of Biology and California Institute of TechnologyPasadena, CA 91125, USA
- Howard Hughes Medical Institute, California Institute of TechnologyPasadena, CA 91125, USA
| | - Pamela J Bjorkman
- Division of Biology and California Institute of TechnologyPasadena, CA 91125, USA
- Howard Hughes Medical Institute, California Institute of TechnologyPasadena, CA 91125, USA
- *Corresponding author: Pamela J. Bjorkman,
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12
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Abstract
BACKGROUND Implantation of coronary stents after predilatation is a standard approach in the treatment of most coronary lesions. Stenting without predilatation could be a possible alternative way of treating a certain subset of patients. OBJECTIVE To identify a group of patients suitable for this optional method, to evaluate their immediate clinical and angiographic outcomes and to test the feasibility and safety of this new therapeutic concept. METHODS Ninety selected patients with 91 lesions were treated by implantation of coronary stents without predilatation. RESULTS The mean duration of this procedure was 12.3 +/- 9.1 min and the fluoroscopic time was 3.6 +/- 2.9 min. The stenoses before and after this procedure were 77 +/- 10 and 5 +/- 9%, respectively. Predilatation, postdilatation or implantation of an additional stent was necessary for seven patients. Primary success rate was 92% with an excellent immediate clinical and angiographic outcome. No major complications occurred during direct stenting. CONCLUSION Direct stenting is feasible using commercially available stents and could be performed for about 20% of patients for whom coronary intervention is indicated. The proper selection of lesions is of crucial importance. Lesions eligible for direct stenting should be without visible calcifications and on vessels without proximal tortuosity. This procedure proved to be safe and successful in this series of coronary interventions.
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Affiliation(s)
- J Veselka
- Division of Cardiac Surgery, University Hospital Motol, Praha, Czech Republic.
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