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Kaminska P, Tempes A, Scholz E, Malik AR. Cytokines on the way to secretion. Cytokine Growth Factor Rev 2024; 79:52-65. [PMID: 39227243 DOI: 10.1016/j.cytogfr.2024.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2024] [Revised: 08/19/2024] [Accepted: 08/19/2024] [Indexed: 09/05/2024]
Abstract
The activation of immune cells by pro-inflammatory or immunosuppressive stimuli is followed by the secretion of immunoregulatory cytokines which serve as messengers to activate the immune response in target cells. Although the mechanisms that control the secretion of cytokines by immune cells are not yet fully understood, several key aspects of this process have recently emerged. This review focuses on cytokine release via exocytosis and highlights the routes of cytokine trafficking leading to constitutive and regulated secretion as well as the impact of sorting receptors on this process. We discuss the involvement of cytoskeletal rearrangements in vesicular transport, secretion, and formation of immunological synapses. Finally, we describe the non-classical pathways of cytokine release that are independent of vesicular ER-Golgi transport. Instead, these pathways are based on processing by inflammasome or autophagic mechanisms. Ultimately, understanding the molecular mechanisms behind cytokine release may help to identify potential therapeutic targets in diseases associated with altered immune responses.
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Affiliation(s)
- Paulina Kaminska
- Faculty of Biology, University of Warsaw, Miecznikowa 1, Warsaw 02-096, Poland; Nencki Institute of Experimental Biology, Polish Academy of Sciences, Pasteura 3, Warsaw 02-093, Poland
| | - Aleksandra Tempes
- Faculty of Biology, University of Warsaw, Miecznikowa 1, Warsaw 02-096, Poland
| | - Ela Scholz
- Faculty of Biology, University of Warsaw, Miecznikowa 1, Warsaw 02-096, Poland
| | - Anna R Malik
- Faculty of Biology, University of Warsaw, Miecznikowa 1, Warsaw 02-096, Poland.
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2
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Pathni A, Wagh K, Rey-Suarez I, Upadhyaya A. Mechanical regulation of lymphocyte activation and function. J Cell Sci 2024; 137:jcs219030. [PMID: 38995113 PMCID: PMC11267459 DOI: 10.1242/jcs.219030] [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] [Indexed: 07/13/2024] Open
Abstract
Mechanosensing, or how cells sense and respond to the physical environment, is crucial for many aspects of biological function, ranging from cell movement during development to cancer metastasis, the immune response and gene expression driving cell fate determination. Relevant physical stimuli include the stiffness of the extracellular matrix, contractile forces, shear flows in blood vessels, complex topography of the cellular microenvironment and membrane protein mobility. Although mechanosensing has been more widely studied in non-immune cells, it has become increasingly clear that physical cues profoundly affect the signaling function of cells of the immune system. In this Review, we summarize recent studies on mechanical regulation of immune cells, specifically lymphocytes, and explore how the force-generating cytoskeletal machinery might mediate mechanosensing. We discuss general principles governing mechanical regulation of lymphocyte function, spanning from the molecular scale of receptor activation to cellular responses to mechanical stimuli.
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Affiliation(s)
- Aashli Pathni
- Biological Sciences Graduate Program, University of Maryland, College Park, MD 20742, USA
| | - Kaustubh Wagh
- Department of Physics, University of Maryland, College Park, MD 20742, USA
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ivan Rey-Suarez
- Insitute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA
- Microcore, Universidad de Los Andes, Bogota, DC 111711, USA
| | - Arpita Upadhyaya
- Biological Sciences Graduate Program, University of Maryland, College Park, MD 20742, USA
- Department of Physics, University of Maryland, College Park, MD 20742, USA
- Insitute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA
- Biophysics Program, University of Maryland, College Park, MD 20742, USA
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3
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Tati S, Alisaraie L. Recruitment of dynein and kinesin to viral particles. FASEB J 2022; 36:e22311. [DOI: 10.1096/fj.202101900rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 03/14/2022] [Accepted: 03/29/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Sayi’Mone Tati
- School of Pharmacy Memorial University of Newfoundland St. John’s Newfoundland Canada
| | - Laleh Alisaraie
- School of Pharmacy Memorial University of Newfoundland St. John’s Newfoundland Canada
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4
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LPA suppresses T cell function by altering the cytoskeleton and disrupting immune synapse formation. Proc Natl Acad Sci U S A 2022; 119:e2118816119. [PMID: 35394866 PMCID: PMC9169816 DOI: 10.1073/pnas.2118816119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Cancer and chronic infections often increase levels of the bioactive lipid, lysophosphatidic acid (LPA), that we have demonstrated acts as an inhibitory ligand upon binding LPAR5 on CD8 T cells, suppressing cytotoxic activity and tumor control. This study, using human and mouse primary T lymphocytes, reveals how LPA disrupts antigen-specific CD8 T cell:target cell immune synapse (IS) formation and T cell function via competing for cytoskeletal regulation. Specifically, we find upon antigen-specific T cell:target cell formation, IP3R1 localizes to the IS by a process dependent on mDia1 and actin and microtubule polymerization. LPA not only inhibited IP3R1 from reaching the IS but also altered T cell receptor (TCR)–induced localization of RhoA and mDia1 impairing F-actin accumulation and altering the tubulin code. Consequently, LPA impeded calcium store release and IS-directed cytokine secretion. Thus, targeting LPA signaling in chronic inflammatory conditions may rescue T cell function and promote antiviral and antitumor immunity.
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5
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Pathni A, Özçelikkale A, Rey-Suarez I, Li L, Davis S, Rogers N, Xiao Z, Upadhyaya A. Cytotoxic T Lymphocyte Activation Signals Modulate Cytoskeletal Dynamics and Mechanical Force Generation. Front Immunol 2022; 13:779888. [PMID: 35371019 PMCID: PMC8966475 DOI: 10.3389/fimmu.2022.779888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 02/23/2022] [Indexed: 11/20/2022] Open
Abstract
Cytotoxic T lymphocytes (CTLs) play an integral role in the adaptive immune response by killing infected cells. Antigen presenting cells (APCs), such as dendritic cells, present pathogenic peptides to the T cell receptor on the CTL surface and co-stimulatory signals required for complete activation. Activated CTLs secrete lytic granules containing enzymes that trigger target cell death at the CTL-target contact, also known as the immune synapse (IS). The actin and microtubule cytoskeletons are instrumental in the killing of CTL targets. Lytic granules are transported along microtubules to the IS, where granule secretion is facilitated by actin depletion and recovery. Furthermore, actomyosin contractility promotes target cell death by mediating mechanical force exertion at the IS. Recent studies have shown that inflammatory cytokines produced by APCs, such as interleukin-12 (IL-12), act as a third signal for CTL activation and enhance CTL proliferation and effector function. However, the biophysical mechanisms mediating such enhanced effector function remain unclear. We hypothesized that the third signal for CTL activation, IL-12, modulates cytoskeletal dynamics and force exertion at the IS, thus potentiating CTL effector function. Here, we used live cell total internal reflection fluorescence (TIRF) microscopy to study actomyosin and microtubule dynamics at the IS of murine primary CTLs activated in the presence of peptide-MHC and co-stimulation alone (two signals), or additionally with IL-12 (three signals). We found that three signal-activated CTLs have altered actin flows, myosin dynamics and microtubule growth rates as compared to two signal-activated CTLs. We further showed that lytic granules in three-signal activated CTLs are less clustered and have lower velocities than in two-signal activated CTLs. Finally, we used traction force microscopy to show that three signal-activated CTLs exert greater traction forces than two signal-activated CTLs. Our results demonstrate that activation of CTLs in the presence of IL-12 leads to differential modulation of the cytoskeleton, thereby augmenting the mechanical response of CTLs to their targets. This indicates a potential physical mechanism via which the third signal can enhance the CTL response.
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Affiliation(s)
- Aashli Pathni
- Biological Sciences Graduate Program, University of Maryland, College Park, MD, United States
| | - Altuğ Özçelikkale
- Institute for Physical Science and Technology, University of Maryland, College Park, MD, United States.,Department of Mechanical Engineering, Middle East Technical University, Ankara, Turkey
| | - Ivan Rey-Suarez
- Institute for Physical Science and Technology, University of Maryland, College Park, MD, United States
| | - Lei Li
- Department of Animal and Avian Sciences, University of Maryland, College Park, MD, United States
| | - Scott Davis
- Department of Physics, University of Maryland, College Park, MD, United States
| | - Nate Rogers
- Department of Physics, University of Maryland, College Park, MD, United States
| | - Zhengguo Xiao
- Biological Sciences Graduate Program, University of Maryland, College Park, MD, United States.,Department of Animal and Avian Sciences, University of Maryland, College Park, MD, United States
| | - Arpita Upadhyaya
- Biological Sciences Graduate Program, University of Maryland, College Park, MD, United States.,Institute for Physical Science and Technology, University of Maryland, College Park, MD, United States.,Department of Physics, University of Maryland, College Park, MD, United States
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6
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Matsumori H, Watanabe K, Tachiwana H, Fujita T, Ito Y, Tokunaga M, Sakata-Sogawa K, Osakada H, Haraguchi T, Awazu A, Ochiai H, Sakata Y, Ochiai K, Toki T, Ito E, Goldberg IG, Tokunaga K, Nakao M, Saitoh N. Ribosomal protein L5 facilitates rDNA-bundled condensate and nucleolar assembly. Life Sci Alliance 2022; 5:5/7/e202101045. [PMID: 35321919 PMCID: PMC8942980 DOI: 10.26508/lsa.202101045] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/01/2022] [Accepted: 03/02/2022] [Indexed: 11/24/2022] Open
Abstract
High content image analysis, single molecule tracking, modeling, and DBA patient analysis revealed that ribosomal protein L5 facilitates rDNA-bundled condensate and nucleolar assembly. The nucleolus is the site of ribosome assembly and formed through liquid–liquid phase separation. Multiple ribosomal DNA (rDNA) arrays are bundled in the nucleolus, but the underlying mechanism and significance are unknown. In the present study, we performed high-content screening followed by image profiling with the wndchrm machine learning algorithm. We revealed that cells lacking a specific 60S ribosomal protein set exhibited common nucleolar disintegration. The depletion of RPL5 (also known as uL18), the liquid–liquid phase separation facilitator, was most effective, and resulted in an enlarged and un-separated sub-nucleolar compartment. Single-molecule tracking analysis revealed less-constrained mobility of its components. rDNA arrays were also unbundled. These results were recapitulated by a coarse-grained molecular dynamics model. Transcription and processing of ribosomal RNA were repressed in these aberrant nucleoli. Consistently, the nucleoli were disordered in peripheral blood cells from a Diamond–Blackfan anemia patient harboring a heterozygous, large deletion in RPL5. Our combinatorial analyses newly define the role of RPL5 in rDNA array bundling and the biophysical properties of the nucleolus, which may contribute to the etiology of ribosomopathy.
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Affiliation(s)
- Haruka Matsumori
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Kenji Watanabe
- Cancer Institute of Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Hiroaki Tachiwana
- Cancer Institute of Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Tomoko Fujita
- Cancer Institute of Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Yuma Ito
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Makio Tokunaga
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Kumiko Sakata-Sogawa
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Hiroko Osakada
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe, Japan
| | - Tokuko Haraguchi
- Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe, Japan.,Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Akinori Awazu
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Japan.,Research Center for the Mathematics on Chromatin Live Dynamics (RcMcD), Hiroshima University, Higashi-Hiroshima, Japan
| | - Hiroshi Ochiai
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Japan
| | - Yuka Sakata
- Cancer Institute of Japanese Foundation for Cancer Research, Tokyo, Japan
| | | | - Tsutomu Toki
- Department of Pediatrics, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Etsuro Ito
- Department of Pediatrics, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Ilya G Goldberg
- Image Informatics and Computational Biology Unit, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Kazuaki Tokunaga
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Mitsuyoshi Nakao
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Noriko Saitoh
- Cancer Institute of Japanese Foundation for Cancer Research, Tokyo, Japan
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7
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Uchino S, Ito Y, Sato Y, Handa T, Ohkawa Y, Tokunaga M, Kimura H. Live imaging of transcription sites using an elongating RNA polymerase II-specific probe. J Cell Biol 2022; 221:212888. [PMID: 34854870 PMCID: PMC8647360 DOI: 10.1083/jcb.202104134] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 10/12/2021] [Accepted: 11/10/2021] [Indexed: 12/15/2022] Open
Abstract
In eukaryotic nuclei, most genes are transcribed by RNA polymerase II (RNAP2), whose regulation is a key to understanding the genome and cell function. RNAP2 has a long heptapeptide repeat (Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7), and Ser2 is phosphorylated on an elongation form. To detect RNAP2 Ser2 phosphorylation (RNAP2 Ser2ph) in living cells, we developed a genetically encoded modification-specific intracellular antibody (mintbody) probe. The RNAP2 Ser2ph-mintbody exhibited numerous foci, possibly representing transcription “factories,” and foci were diminished during mitosis and in a Ser2 kinase inhibitor. An in vitro binding assay using phosphopeptides confirmed the mintbody’s specificity. RNAP2 Ser2ph-mintbody foci were colocalized with proteins associated with elongating RNAP2 compared with factors involved in the initiation. These results support the view that mintbody localization represents the sites of RNAP2 Ser2ph in living cells. RNAP2 Ser2ph-mintbody foci showed constrained diffusional motion like chromatin, but they were more mobile than DNA replication domains and p300-enriched foci, suggesting that the elongating RNAP2 complexes are separated from more confined chromatin domains.
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Affiliation(s)
- Satoshi Uchino
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Yuma Ito
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Yuko Sato
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan.,Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Tetsuya Handa
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Yasuyuki Ohkawa
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Makio Tokunaga
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Hiroshi Kimura
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan.,Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
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8
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Liu Y, Zhao N, Kanemaki MT, Yamamoto Y, Sadamura Y, Ito Y, Tokunaga M, Stasevich TJ, Kimura H. Visualizing looping of two endogenous genomic loci using synthetic zinc-finger proteins with anti-FLAG and anti-HA frankenbodies in living cells. Genes Cells 2021; 26:905-926. [PMID: 34465007 PMCID: PMC8893316 DOI: 10.1111/gtc.12893] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 08/25/2021] [Accepted: 08/25/2021] [Indexed: 12/17/2022]
Abstract
In eukaryotic nuclei, chromatin loops mediated through cohesin are critical structures that regulate gene expression and DNA replication. Here, we demonstrate a new method to see endogenous genomic loci using synthetic zinc-finger proteins harboring repeat epitope tags (ZF probes) for signal amplification via binding of tag-specific intracellular antibodies, or frankenbodies, fused with fluorescent proteins. We achieve this in two steps: First, we develop an anti-FLAG frankenbody that can bind FLAG-tagged proteins in diverse live-cell environments. The anti-FLAG frankenbody complements the anti-HA frankenbody, enabling two-color signal amplification from FLAG- and HA-tagged proteins. Second, we develop a pair of cell-permeable ZF probes that specifically bind two endogenous chromatin loci predicted to be involved in chromatin looping. By coupling our anti-FLAG and anti-HA frankenbodies with FLAG- and HA-tagged ZF probes, we simultaneously see the dynamics of the two loci in single living cells. This shows a close association between the two loci in the majority of cells, but the loci markedly separate from the triggered degradation of the cohesin subunit RAD21. Our ability to image two endogenous genomic loci simultaneously in single living cells provides a proof of principle that ZF probes coupled with frankenbodies are useful new tools for exploring genome dynamics in multiple colors.
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Affiliation(s)
- Yang Liu
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Ning Zhao
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Masato T Kanemaki
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems, Mishima, Japan.,Department of Genetics, SOKENDAI, Mishima, Japan
| | - Yotaro Yamamoto
- Life Science Research Laboratories, Fujifilm Wako Pure Chemical, Amagasaki, Japan
| | - Yoshifusa Sadamura
- Life Science Research Laboratories, Fujifilm Wako Pure Chemical, Amagasaki, Japan
| | - Yuma Ito
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Makio Tokunaga
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Timothy J Stasevich
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA.,Cell Biology Center and World Research Hub Initiative, Tokyo Institute of Technology, Yokohama, Japan
| | - Hiroshi Kimura
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan.,Cell Biology Center and World Research Hub Initiative, Tokyo Institute of Technology, Yokohama, Japan
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9
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Rey-Suarez I, Rogers N, Kerr S, Shroff H, Upadhyaya A. Actomyosin dynamics modulate microtubule deformation and growth during T-cell activation. Mol Biol Cell 2021; 32:1641-1653. [PMID: 33826369 PMCID: PMC8684730 DOI: 10.1091/mbc.e20-10-0685] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Activation of T-cells leads to the formation of immune synapses (ISs) with antigen-presenting cells. This requires T-cell polarization and coordination between the actomyosin and microtubule cytoskeletons. The interactions between these two cytoskeletal components during T-cell activation are not well understood. Here, we elucidate the interactions between microtubules and actin at the IS with high-resolution fluorescence microscopy. We show that microtubule growth dynamics in the peripheral actin-rich region is distinct from that in the central actin-free region. We further demonstrate that these differences arise from differential involvement of Arp2/3- and formin-nucleated actin structures. Formin inhibition results in a moderate decrease in microtubule growth rates, which is amplified in the presence of integrin engagement. In contrast, Arp2/3 inhibition leads to an increase in microtubule growth rates. We find that microtubule filaments are more deformed and exhibit greater shape fluctuations in the periphery of the IS than at the center. Using small molecule inhibitors, we show that actin dynamics and actomyosin contractility play key roles in defining microtubule deformations and shape fluctuations. Our results indicate a mechanical coupling between the actomyosin and microtubule systems during T-cell activation, whereby different actin structures influence microtubule dynamics in distinct ways.
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Affiliation(s)
- Ivan Rey-Suarez
- Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742
| | - Nate Rogers
- Department of Physics, University of Maryland, College Park, MD 20742
| | - Sarah Kerr
- Department of Physics, University of Colorado, Boulder, CO 80302
| | - Hari Shroff
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892
| | - Arpita Upadhyaya
- Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742.,Department of Physics, University of Maryland, College Park, MD 20742
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10
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Spencer PS. Neuroprotein Targets of γ-Diketone Metabolites of Aliphatic and Aromatic Solvents That Induce Central-Peripheral Axonopathy. Toxicol Pathol 2020; 48:411-421. [PMID: 32162603 DOI: 10.1177/0192623320910960] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Peripheral neuropathy associated with chronic occupational and deliberate overexposure to neurotoxic organic solvents results from axonal degeneration in the central and peripheral nervous system. Human and experimental studies show that axonopathy is triggered by the action of neuroprotein-reactive γ-diketone metabolites formed from exposure to certain aliphatic solvents (n-hexane, 2-hexanone) and aromatic compounds (1,2-diethylbenzene, 1,2-4-triethylbenzene, 6-acetyl-1,1,4,4-tetramethyl-7-ethyl-1,2,3,4-tetralin). Neuroprotein susceptibility is related primarily to their differential content of lysine, the ∊-amino group of which is targeted by γ-diketones. Specific neuroprotein targets have been identified, and the sequence of molecular mechanisms leading to axonal pathology has been illuminated. While occupational n-hexane neuropathy continues to be reported, lessons learned from its experimental study may have relevance to other causes of peripheral neuropathy, including those associated with aging and diabetes mellitus.
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Affiliation(s)
- Peter S Spencer
- Oregon Institute of Occupational Health Sciences and Department of Neurology, School of Medicine, Oregon Health & Science University, Portland, OR, USA
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11
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Verma NK, Chalasani MLS, Scott JD, Kelleher D. CG-NAP/Kinase Interactions Fine-Tune T Cell Functions. Front Immunol 2019; 10:2642. [PMID: 31781123 PMCID: PMC6861388 DOI: 10.3389/fimmu.2019.02642] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 10/24/2019] [Indexed: 01/04/2023] Open
Abstract
CG-NAP, also known as AKAP450, is an anchoring/adaptor protein that streamlines signal transduction in various cell types by localizing signaling proteins and enzymes with their substrates. Great efforts are being devoted to elucidating functional roles of this protein and associated macromolecular signaling complex. Increasing understanding of pathways involved in regulating T lymphocytes suggests that CG-NAP can facilitate dynamic interactions between kinases and their substrates and thus fine-tune T cell motility and effector functions. As a result, new binding partners of CG-NAP are continually being uncovered. Here, we review recent advances in CG-NAP research, focusing on its interactions with kinases in T cells with an emphasis on the possible role of this anchoring protein as a target for therapeutic intervention in immune-mediated diseases.
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Affiliation(s)
- Navin Kumar Verma
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Singapore, Singapore
| | | | - John D Scott
- Department of Pharmacology, University of Washington School of Medicine, Seattle, WA, United States
| | - Dermot Kelleher
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Singapore, Singapore.,Departments of Medicine and Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
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12
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Cassioli C, Baldari CT. A Ciliary View of the Immunological Synapse. Cells 2019; 8:E789. [PMID: 31362462 PMCID: PMC6721628 DOI: 10.3390/cells8080789] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/15/2019] [Accepted: 07/25/2019] [Indexed: 12/28/2022] Open
Abstract
The primary cilium has gone from being a vestigial organelle to a crucial signaling hub of growing interest given the association between a group of human disorders, collectively known as ciliopathies, and defects in its structure or function. In recent years many ciliogenesis proteins have been observed at extraciliary sites in cells and likely perform cilium-independent functions ranging from regulation of the cytoskeleton to vesicular trafficking. Perhaps the most striking example is the non-ciliated T lymphocyte, in which components of the ciliary machinery are repurposed for the assembly and function of the immunological synapse even in the absence of a primary cilium. Furthermore, the specialization traits described at the immunological synapse are similar to those seen in the primary cilium. Here, we review common regulators and features shared by the immunological synapse and the primary cilium that document the remarkable homology between these structures.
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Affiliation(s)
- Chiara Cassioli
- Department of Life Sciences, University of Siena, 53100 Siena, Italy
| | - Cosima T Baldari
- Department of Life Sciences, University of Siena, 53100 Siena, Italy.
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13
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Abstract
For over a century, the centrosome has been an organelle more easily tracked than understood, and the study of its peregrinations within the cell remains a chief underpinning of its functional investigation. Increasing attention and new approaches have been brought to bear on mechanisms that control centrosome localization in the context of cleavage plane determination, ciliogenesis, directional migration, and immunological synapse formation, among other cellular and developmental processes. The Golgi complex, often linked with the centrosome, presents a contrasting case of a pleiomorphic organelle for which functional studies advanced somewhat more rapidly than positional tracking. However, Golgi orientation and distribution has emerged as an area of considerable interest with respect to polarized cellular function. This chapter will review our current understanding of the mechanism and significance of the positioning of these organelles.
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