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Campbell BFN, Cruz-Ochoa N, Otomo K, Lukacsovich D, Espinosa P, Abegg A, Luo W, Bellone C, Földy C, Tyagarajan SK. Gephyrin phosphorylation facilitates sexually dimorphic development and function of parvalbumin interneurons in the mouse hippocampus. Mol Psychiatry 2024:10.1038/s41380-024-02517-5. [PMID: 38503929 DOI: 10.1038/s41380-024-02517-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 02/25/2024] [Accepted: 03/04/2024] [Indexed: 03/21/2024]
Abstract
The precise function of specialized GABAergic interneuron subtypes is required to provide appropriate synaptic inhibition for regulating principal neuron excitability and synchronization within brain circuits. Of these, parvalbumin-type (PV neuron) dysfunction is a feature of several sex-biased psychiatric and brain disorders, although, the underlying developmental mechanisms are unclear. While the transcriptional action of sex hormones generates sexual dimorphism during brain development, whether kinase signaling contributes to sex differences in PV neuron function remains unexplored. In the hippocampus, we report that gephyrin, the main inhibitory post-synaptic scaffolding protein, is phosphorylated at serine S268 and S270 in a developmentally-dependent manner in both males and females. When examining GphnS268A/S270A mice in which site-specific phosphorylation is constitutively blocked, we found that sex differences in PV neuron density in the hippocampal CA1 present in WT mice were abolished, coincident with a female-specific increase in PV neuron-derived terminals and increased inhibitory input onto principal cells. Electrophysiological analysis of CA1 PV neurons indicated that gephyrin phosphorylation is required for sexually dimorphic function. Moreover, while male and female WT mice showed no difference in hippocampus-dependent memory tasks, GphnS268A/S270A mice exhibited sex- and task-specific deficits, indicating that gephyrin phosphorylation is differentially required by males and females for convergent cognitive function. In fate mapping experiments, we uncovered that gephyrin phosphorylation at S268 and S270 establishes sex differences in putative PV neuron density during early postnatal development. Furthermore, patch-sequencing of putative PV neurons at postnatal day 4 revealed that gephyrin phosphorylation contributes to sex differences in the transcriptomic profile of developing interneurons. Therefore, these early shifts in male-female interneuron development may drive adult sex differences in PV neuron function and connectivity. Our results identify gephyrin phosphorylation as a new substrate organizing PV neuron development at the anatomical, functional, and transcriptional levels in a sex-dependent manner, thus implicating kinase signaling disruption as a new mechanism contributing to the sex-dependent etiology of brain disorders.
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Affiliation(s)
- Benjamin F N Campbell
- Institute of Pharmacology and Toxicology, University of Zürich, 8057, Zürich, Switzerland
| | - Natalia Cruz-Ochoa
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, 8057, Zürich, Switzerland
- Adaptive Brain Circuits in Development and Learning (AdaBD), University Research Priority Program (URPP), University of Zürich, 8057, Zürich, Switzerland
| | - Kanako Otomo
- Institute of Pharmacology and Toxicology, University of Zürich, 8057, Zürich, Switzerland
| | - David Lukacsovich
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, 8057, Zürich, Switzerland
| | - Pedro Espinosa
- Department of Basic Neuroscience, University of Geneva, 1211, Geneva, Switzerland
| | - Andrin Abegg
- Institute of Pharmacology and Toxicology, University of Zürich, 8057, Zürich, Switzerland
| | - Wenshu Luo
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, 8057, Zürich, Switzerland
| | - Camilla Bellone
- Department of Basic Neuroscience, University of Geneva, 1211, Geneva, Switzerland
| | - Csaba Földy
- Laboratory of Neural Connectivity, Brain Research Institute, Faculties of Medicine and Science, University of Zürich, 8057, Zürich, Switzerland
- Adaptive Brain Circuits in Development and Learning (AdaBD), University Research Priority Program (URPP), University of Zürich, 8057, Zürich, Switzerland
| | - Shiva K Tyagarajan
- Institute of Pharmacology and Toxicology, University of Zürich, 8057, Zürich, Switzerland.
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Tsai YC, Hleihil M, Otomo K, Abegg A, Cavaccini A, Panzanelli P, Cramer T, Ferrari KD, Barrett MJP, Bosshard G, Karayannis T, Weber B, Tyagarajan SK, Stobart JL. The gephyrin scaffold modulates cortical layer 2/3 pyramidal neuron responsiveness to single whisker stimulation. Sci Rep 2024; 14:4169. [PMID: 38379020 PMCID: PMC10879104 DOI: 10.1038/s41598-024-54720-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 02/15/2024] [Indexed: 02/22/2024] Open
Abstract
Gephyrin is the main scaffolding protein at inhibitory postsynaptic sites, and its clusters are the signaling hubs where several molecular pathways converge. Post-translational modifications (PTMs) of gephyrin alter GABAA receptor clustering at the synapse, but it is unclear how this affects neuronal activity at the circuit level. We assessed the contribution of gephyrin PTMs to microcircuit activity in the mouse barrel cortex by slice electrophysiology and in vivo two-photon calcium imaging of layer 2/3 (L2/3) pyramidal cells during single-whisker stimulation. Our results suggest that, depending on the type of gephyrin PTM, the neuronal activities of L2/3 pyramidal neurons can be differentially modulated, leading to changes in the size of the neuronal population responding to the single-whisker stimulation. Furthermore, we show that gephyrin PTMs have their preference for selecting synaptic GABAA receptor subunits. Our results identify an important role of gephyrin and GABAergic postsynaptic sites for cortical microcircuit function during sensory stimulation.
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Affiliation(s)
- Yuan-Chen Tsai
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
- Center for Neuroscience Zurich (ZNZ), Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Mohammad Hleihil
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
- Center for Neuroscience Zurich (ZNZ), Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Kanako Otomo
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Andrin Abegg
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Anna Cavaccini
- Brain Research Institute, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Patrizia Panzanelli
- Department of Neuroscience Rita Levi Montalcini, University of Turin, Turin, Italy
| | - Teresa Cramer
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
- Center for Neuroscience Zurich (ZNZ), Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Kim David Ferrari
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
- Center for Neuroscience Zurich (ZNZ), Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Matthew J P Barrett
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
- Center for Neuroscience Zurich (ZNZ), Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Giovanna Bosshard
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Theofanis Karayannis
- Brain Research Institute, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Bruno Weber
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
- Center for Neuroscience Zurich (ZNZ), Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Shiva K Tyagarajan
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
- Center for Neuroscience Zurich (ZNZ), Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Jillian L Stobart
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
- College of Pharmacy, University of Manitoba, Winnipeg, MB, R3E 0T5, Canada.
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Ramsaran AI, Wang Y, Golbabaei A, Aleshin S, de Snoo ML, Yeung BRA, Rashid AJ, Awasthi A, Lau J, Tran LM, Ko SY, Abegg A, Duan LC, McKenzie C, Gallucci J, Ahmed M, Kaushik R, Dityatev A, Josselyn SA, Frankland PW. A shift in the mechanisms controlling hippocampal engram formation during brain maturation. Science 2023; 380:543-551. [PMID: 37141366 DOI: 10.1126/science.ade6530] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The ability to form precise, episodic memories develops with age, with young children only able to form gist-like memories that lack precision. The cellular and molecular events in the developing hippocampus that underlie the emergence of precise, episodic-like memory are unclear. In mice, the absence of a competitive neuronal engram allocation process in the immature hippocampus precluded the formation of sparse engrams and precise memories until the fourth postnatal week, when inhibitory circuits in the hippocampus mature. This age-dependent shift in precision of episodic-like memories involved the functional maturation of parvalbumin-expressing interneurons in subfield CA1 through assembly of extracellular perineuronal nets, which is necessary and sufficient for the onset of competitive neuronal allocation, sparse engram formation, and memory precision.
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Affiliation(s)
- Adam I Ramsaran
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada
| | - Ying Wang
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Ali Golbabaei
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Stepan Aleshin
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases, Magdeburg, Germany
| | - Mitchell L de Snoo
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Bi-Ru Amy Yeung
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Asim J Rashid
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ankit Awasthi
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jocelyn Lau
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Lina M Tran
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Vector Institute, Toronto, Ontario, Canada
| | - Sangyoon Y Ko
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Andrin Abegg
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Lana Chunan Duan
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Cory McKenzie
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada
| | - Julia Gallucci
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Moriam Ahmed
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Rahul Kaushik
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Alexander Dityatev
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Magdeburg, Germany
- Medical Faculty, Otto von Guericke University, Magdeburg, Germany
| | - Sheena A Josselyn
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Brain, Mind, & Consciousness Program, Canadian Institute for Advanced Research, Toronto, Ontario, Canada
| | - Paul W Frankland
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Child & Brain Development Program, Canadian Institute for Advanced Research, Toronto, Ontario, Canada
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Wegleiter T, Buthey K, Gonzalez-Bohorquez D, Hruzova M, Bin Imtiaz MK, Abegg A, Mebert I, Molteni A, Kollegger D, Pelczar P, Jessberger S. Palmitoylation of BMPR1a regulates neural stem cell fate. Proc Natl Acad Sci U S A 2019; 116:25688-25696. [PMID: 31772009 PMCID: PMC6926058 DOI: 10.1073/pnas.1912671116] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Neural stem cells (NSCs) generate neurons and glial cells throughout embryonic and postnatal brain development. The role of S-palmitoylation (also referred to as S-acylation), a reversible posttranslational lipid modification of proteins, in regulating the fate and activity of NSCs remains largely unknown. We used an unbiased screening approach to identify proteins that are S-acylated in mouse NSCs and showed that bone morphogenic protein receptor 1a (BMPR1a), a core mediator of BMP signaling, is palmitoylated. Genetic manipulation of S-acylated sites affects the localization and trafficking of BMPR1a and leads to altered BMP signaling. Strikingly, defective palmitoylation of BMPR1a modulates NSC function within the mouse brain, resulting in enhanced oligodendrogenesis. Thus, we identified a mechanism regulating the behavior of NSCs and provided the framework to characterize dynamic posttranslational lipid modifications of proteins in the context of NSC biology.
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Affiliation(s)
- Thomas Wegleiter
- Laboratory of Neural Plasticity, Faculties of Medicine and Science, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland;
| | - Kilian Buthey
- Laboratory of Neural Plasticity, Faculties of Medicine and Science, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Daniel Gonzalez-Bohorquez
- Laboratory of Neural Plasticity, Faculties of Medicine and Science, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Martina Hruzova
- Laboratory of Neural Plasticity, Faculties of Medicine and Science, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Muhammad Khadeesh Bin Imtiaz
- Laboratory of Neural Plasticity, Faculties of Medicine and Science, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Andrin Abegg
- Laboratory of Neural Plasticity, Faculties of Medicine and Science, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Iliana Mebert
- Laboratory of Neural Plasticity, Faculties of Medicine and Science, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Adriano Molteni
- Laboratory of Neural Plasticity, Faculties of Medicine and Science, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Dominik Kollegger
- Laboratory of Neural Plasticity, Faculties of Medicine and Science, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
| | - Pawel Pelczar
- Center for Transgenic Models, University of Basel, 4001 Basel, Switzerland
| | - Sebastian Jessberger
- Laboratory of Neural Plasticity, Faculties of Medicine and Science, Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland;
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Lee SC, Parthasarathy R, Botwin K, Kunneman D, Rowold E, Lange G, Klover J, Abegg A, Zobel J, Beck T, Miller T, Hood W, Monahan J, McKearn JP, Jansson R, Voliva CF. Biochemical and immunological properties of cytokines conjugated to dendritic polymers. Biomed Microdevices 2005; 6:191-202. [PMID: 15377828 DOI: 10.1023/b:bmmd.0000042048.18186.ff] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Here we describe a post-translational modification of SC-63032, a variant of the species restricted, multi-lineage hematopoeitic factor human interleukin-3 (hIL-3). We have made two new dendritic polymer (polyamidoamine or PAMAM dendrimers, generation 5)-SC-63032 bioconjugates. Using two distinct chemistries (one of which is novel to this work), we achieved site-specific conjugation with respect to the amino acid in the proteins ligated to the dendrimers. In both bioconjugates, conjugated cytokine maintains its ability to bind the hIL-3 alpha receptor subunit, but is significantly (about 10-fold) less potent in inducing hIL-3 dependent in vitro cell proliferation than is the free cytokine. In vivo data indicates that conjugation decreases the immunogenicity of the conjugated cytokine modestly. In the absence of pharmacokinetic or biodistribution effects associated with the bioconjugates that increase their potency in vivo (which can only be tested in a higher primate, due to the species restriction of hIL-3 and its derivatives), these immune mitigation effects may be too small to be therapeutically significant. Though unmodified PAMAM dendrimers fail to elicit an antibody response in mice, protein conjugation to dendrimers haptenizes them, and a dendrimer-specific antibody response is produced. In toto, the principal limitation of the dendrimer-cytokine bioconjugates herein is in their reduced receptor affinity and potency in vitro. Were the in vivo potency of the bioconjugates to parallel the in vitro potency of the conjugates reported here, it is likely that particular dendrimer bioconjugates could not justify their higher costs of goods relative to the parent SC-63032 molecule, though retention of SC-63032 biological activities in conjugates suggests that other cytokine-dendrimer bioconjugates may be bioactive. This is good news to the nanotechnology community, in as much as PAMAM dendrimers are among the monodisperse polymeric nanomaterials available, and these results show that they can be used successfully in conjugates to bioactive proteins.
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Affiliation(s)
- S C Lee
- Department of Cellular and Molecular Biochemistry, and the Dorothy M. Davis Heart and Lung Research Institute, 473 W. 12th Avenue, Ohio State University, Columbus, OH 43210, USA.
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Lee SC, Ibdah R, Van Valkenburgh C, Rowold E, Abegg A, Donnelly A, Klover J, Merlin S, McKearn JP. Phage display mutagenesis of the chimeric dual cytokine receptor agonist myelopoietin. Leukemia 2001; 15:1277-85. [PMID: 11480572 DOI: 10.1038/sj.leu.2402163] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Myelopoietins comprise a class of chimeric cytokine receptor agonists consisting of an hIL-3 (human interleukin-3) receptor agonist and an hG-CSF (human granulocyte colony-stimulating factor) receptor agonist linked head-to-tail at their respective carboxy and amino termini. The combination of an early acting cytokine (hIL-3) with a late acting one (hG-CSF) allows efficient hematopoeitic reconstruction following myeloablative insult, and drives differentiation of non-myelocytic lineages (ie thrombocytic lineages) that are inaccessible using hG-CSF alone, in both preclinical models and clinical settings. A myelopoietin species was displayed and mutagenized on filamentous bacteriophage: both component agonists of myelopoietin were presented in biologically functional conformations as each recognized its corresponding receptor. Five amino acid positions in a short region of the hG-CSF receptor agonist module of myelopoietin that had been identified as important for proliferative activity were mutagenized. Display was used because it allows very 'deep' mutagenesis at selected residues: >10(5) substitution variants were affinity-screened using the hG-CSF receptor and 130 new, active variants of myelopoietin were identified and characterized. None of the selected variants were significantly more active than the parental myelopoietin species in a hG-CSF-dependent cell proliferation assay, though many were as active. Many of these relatively high-activity variants contained parental amino acids at several positions, suggesting the parental sequence may already be optimal at these positions for the assays used, and potentially accounting for the failure to identify enhanced bioactivity variants. Analysis of substitutions of high-activity variants complements and extends previous alanine scanning, and other genetic and biochemical data for hG-CSF variants.
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Affiliation(s)
- S C Lee
- GD Searle Pharmacia Company, St Louis, MO 63196, USA
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Merlin S, Rowold E, Abegg A, Berglund C, Klover J, Staten N, McKearn JP, Lee SC. Phage presentation and affinity selection of a deletion mutant of human interleukin-3. Appl Biochem Biotechnol 1997; 67:199-214. [PMID: 9332969 DOI: 10.1007/bf02788798] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A deletion derivative of the cytokine human interleukin-3 (hIL-3(15-125), comprising amino acids 15-125 of the native protein) was produced as a fusion to the filamentous phage surface protein pIII. The cytokine was detected in association with phage particles by protein immunoblotting. Compared to an equivalent quantity of soluble-cytokine, phage-presented hIL-3(15-125) exhibited reduced biological activity in a hIL-3-dependent cell proliferation assay. The reduction in activity was attributable to presence of phage particles in the assay, rather than directly owing to physical incorporation of the cytokine into the phage particle. Owing to the position of the amber codon in the phagemid vector, the phagemid-produced free hIL-3(15-125) species (designated hIL-3(15-125) epsilon) had 20 amino acids appended to its C-terminus; hIL-3(15-125) epsilon did not exhibit reduced bioactivity. hIL-3(15-125)-presenting phage were affinity-selected with either a hIL-3-reactive polyclonal antibody or with cells expressing the heterodimeric hIL-3 receptor. These data are consistent with the use of phage-display technology for the affinity selection of hIL-3 variants with modified biological properties.
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Affiliation(s)
- S Merlin
- Searle Research and Development, Monsanto Company, St. Louis, MO 63198, USA
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Abstract
The antifungal polyene amphotericin B (AmB) and its methyl ester derivative (AME) both show potent murine immunostimulant as well as B-cell activating effects. Under certain experimental conditions, AME is a much more potent polyclonal B-cell activator (PBA) than AmB. Notable features of the murine B-cell stimulation induced by AME include: (i) High concentrations of AME (50-100 microgram/ml) are required and even at this level exhibit little or no spleen cell toxicity. (ii) Several lines of evidence suggest that the B-cell activating properties of AME are not involved in the cellular mechanism of adjuvant activity in vivo. (iii) There is a strong correlation between the magnitude of the in vitro PBA effects and the in vivo adjuvant effects of AME in a survey of different mouse strains. This evidence suggests that there is genetic control of the murine lymphoid cell-stimulatory effects of AME and that a small number of genes determines the responsive phenotype.
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Abegg A, Enzler P, Grob PJ. [Antibodies against native deoxyribonucleic acid (anti-nDNA) without antinuclear antibodies: clinical significance (author's transl)]. Dtsch Med Wochenschr 1980; 105:1273-9. [PMID: 6998692 DOI: 10.1055/s-2008-1070854] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Antinuclear antibodies (ANA) by indirect immunofluorescence and antibodies against native deoxyribonucleic acid (anti-nDNA) by radiommunoassay were measured simultaneously in 6,000 sera from about 5,000 patients. Usual findings about 5,000 patients. Usual findings were: (a) both tests negative (75%), (b) only ANA positive (20%), and (c) both tests positive (3%). The unusual combination of ANA-negative/anti-nDNA positive was found in 117 sera from 24 patients. These patients were examined more closely clinically and the mentioned tests repeated. In five with systemic lupus erythematosus, in two with chronic rheumatoid arthritis and one with chronic urticaria this finding occurred repeatedly over some time. In five additional patients (two with chronic hepatitis, one each with drug-induced systemic lupus erythematosus, chronic rheumatoid arthritis, and drug related haemolytic anaemia) this unusual finding occurred only once but with high levels of anti-nDNA. In 11 patients with various diseases the combination of ANA-negative/anti-nDNA positive occurred only once, with the anti-nDNA value being low. In a control group of patients with mononucleosis, cytomegalic disease, acute or chronic hepatitis or hepatoma, anti-nDNA results were never positive.
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Abstract
Cholesterol and certain lipoproteins have regulatory effects on the primary immune responses of murine spleen cells in vitro. The plaque-forming cell (PFC) responses to sheep red blood cells of trinitrophenylated Brucella abortus were studied in complete, lipid-depleted or lipoprotein-reconstituted media. The requirement for exogenous low density lipoprotein (LDL) and its cholesterol moiety was established by comparison of the yield of PFC in cell cultures deprived of lipoproteins with that in cultures to which specific classes of lipoproteins were added. The spleen cells in complete medium yielded about 10-fold greater PFC responses than cells in lipoprotein-deficient medium. In lipoprotein-deficient media, human LDL completely reversed the decreased immune response, LDL lipids and free cholesterol partially reversed the deficit, the human high density lipoproteins and an apo B phospholipid complex were ineffective. In complete media, cholesterol at higher concentrations (100--200 microgram/ml) and LDL lipids partially inhibited the primary immune response. Exogenous cholesterol was required for the in vitro response to both thymus-dependent and thymus-independent antigens.
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Abstract
In 48 patients with schizophrenia and 32 patients with affective disorders, different immune parameters were tested. Compared to blood-donors, IgG and IgM serum concentrations were increased in both the schizophrenic and affective disorders. However, these abnormalities did not differ from hospital control populations. The patients failed to show an association of antibodies considered to be characteristic of autoimmune diseases. In addition, no increased incidence of circulating immune compexes was detected. The only substantial serologic abnormality froun was an elevation of C4 levels in patients with biopolar psychosis.
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