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Ren X, Liu Y, Zhao Y, Li B, Bai D, Bou G, Zhang X, Du M, Wang X, Bou T, Shen Y, Dugarjaviin M. Analysis of the Whole-Genome Sequences from an Equus Parent-Offspring Trio Provides Insight into the Genomic Incompatibilities in the Hybrid Mule. Genes (Basel) 2022; 13:genes13122188. [PMID: 36553455 PMCID: PMC9778318 DOI: 10.3390/genes13122188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/07/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022] Open
Abstract
Interspecific hybridization often shows negative effects on hybrids. However, only a few multicellular species, limited to a handful of plants and animals, have shown partial genetic mechanisms by which hybridization leads to low fitness in hybrids. Here, to explore the outcome of combining the two genomes of a horse and donkey, we analyzed the whole-genome sequences from an Equus parent-offspring trio using Illumina platforms. We generated 41.39× and 46.21× coverage sequences for the horse and mule, respectively. For the donkey, a 40.38× coverage sequence was generated and stored in our laboratory. Approximately 24.86 million alleles were discovered that varied from the reference genome. Single nucleotide polymorphisms were used as polymorphic markers for assigning alleles to their parental genomic inheritance. We identified 25,703 Mendelian inheritance error single nucleotide polymorphisms in the mule genome that were not inherited from the parents through Mendelian inheritance. A total of 555 de novo single nucleotide polymorphisms were also identified. The rate of de novo single nucleotide polymorphisms was 2.21 × 10-7 in the mule from the Equus parent-offspring trio. This rate is obviously higher than the natural mutation rate for Equus, which is also consistent with the previous hypothesis that interracial crosses may have a high mutation rate. The genes associated with these single nucleotide polymorphisms are mainly involved in immune processes, DNA repair, and cancer processes. The results of the analysis of three genomes from an Equus parent-offspring trio improved our knowledge of the consequences of the integration of parental genomes in mules.
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Park JH, Kang I, Lee HK. γδ T Cells in Brain Homeostasis and Diseases. Front Immunol 2022; 13:886397. [PMID: 35693762 PMCID: PMC9181321 DOI: 10.3389/fimmu.2022.886397] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/25/2022] [Indexed: 11/30/2022] Open
Abstract
γδ T cells are a distinct subset of T cells expressing γδ T cell receptor (TCR) rather than αβTCR. Since their discovery, the critical roles of γδ T cells in multiple physiological systems and diseases have been investigated. γδ T cells are preferentially located at mucosal surfaces, such as the gut, although a small subset of γδ T cells can circulate the blood. Additionally, a subset of γδ T cells reside in the meninges in the central nervous system. Recent findings suggest γδ T cells in the meninges have critical roles in brain function and homeostasis. In addition, several lines of evidence have shown γδ T cells can infiltrate the brain parenchyma and regulate inflammatory responses in multiple diseases, including neurodegenerative diseases. Although the importance of γδ T cells in the brain is well established, their roles are still incompletely understood due to the complexity of their biology. Because γδ T cells rapidly respond to changes in brain status and regulate disease progression, understanding the role of γδ T cells in the brain will provide critical information that is essential for interpreting neuroimmune modulation. In this review, we summarize the complex role of γδ T cells in the brain and discuss future directions for research.
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Abstract
T cell activation is a critical event in the adaptive immune response, indispensable for cell-mediated and humoral immunity as well as for immune regulation. Recent years have witnessed an emerging trend emphasizing the essential role that physical force and mechanical properties play at the T cell interface. In this review, we integrate current knowledge of T cell antigen recognition and the different models of T cell activation from the perspective of mechanobiology, focusing on the interaction between the T cell receptor (TCR) and the peptide-major histocompatibility complex (pMHC) antigen. We address the shortcomings of TCR affinity alone in explaining T cell functional outcomes and the rising status of force-regulated TCR bond lifetimes, most notably the TCR catch bond. Ultimately, T cell activation and the ensuing physiological responses result from mechanical interaction between TCRs and the pMHC. Expected final online publication date for the Annual Review of Cell and Developmental Biology, Volume 37 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Baoyu Liu
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA; , ,
| | - Elizabeth M Kolawole
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA; , ,
| | - Brian D Evavold
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA; , ,
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Li X, Mizsei R, Tan K, Mallis RJ, Duke-Cohan JS, Akitsu A, Tetteh PW, Dubey A, Hwang W, Wagner G, Lang MJ, Arthanari H, Wang JH, Reinherz EL. Pre-T cell receptors topologically sample self-ligands during thymocyte β-selection. Science 2021; 371:181-185. [PMID: 33335016 PMCID: PMC8011828 DOI: 10.1126/science.abe0918] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 12/03/2020] [Indexed: 11/02/2022]
Abstract
Self-discrimination, a critical but ill-defined molecular process programmed during thymocyte development, requires myriad pre-T cell receptors (preTCRs) and αβTCRs. Using x-ray crystallography, we show how a preTCR applies the concave β-sheet surface of its single variable domain (Vβ) to "horizontally" grab the protruding MHC α2-helix. By contrast, αβTCRs purpose all six complementarity-determining region (CDR) loops of their paired VαVβ module to recognize peptides bound to major histocompatibility complex molecules (pMHCs) in "vertical" head-to-head binding. The preTCR topological fit ensures that CDR3β reaches the peptide's featured C-terminal segment for pMHC sampling, establishing the subsequent αβTCR canonical docking mode. "Horizontal" docking precludes germline CDR1β- and CDR2β-MHC binding to broaden β-chain repertoire diversification before αβTCR-mediated selection refinement. Thus, one subunit successively attunes the recognition logic of related multicomponent receptors.
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Affiliation(s)
- Xiaolong Li
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA.
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Réka Mizsei
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA.
| | - Kemin Tan
- Structural Biology Center, X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, USA
| | - Robert J Mallis
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Dermatology, Harvard Medical School, Boston, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Jonathan S Duke-Cohan
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Aoi Akitsu
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Paul W Tetteh
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Abhinav Dubey
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Wonmuk Hwang
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
- Department of Materials Science & Engineering, Texas A&M University, College Station, TX, USA
- Department of Physics & Astronomy, Texas A&M University, College Station, TX, USA
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul, Republic of Korea
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Matthew J Lang
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Haribabu Arthanari
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Jia-Huai Wang
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA.
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Ellis L Reinherz
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA.
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
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Sharma P, Kranz DM. Subtle changes at the variable domain interface of the T-cell receptor can strongly increase affinity. J Biol Chem 2017; 293:1820-1834. [PMID: 29229779 DOI: 10.1074/jbc.m117.814152] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 12/03/2017] [Indexed: 11/06/2022] Open
Abstract
Most affinity-maturation campaigns for antibodies and T-cell receptors (TCRs) operate on the residues at the binding site, located within the loops known as complementarity-determining regions (CDRs). Accordingly, mutations in contact residues, or so-called "second shell" residues, that increase affinity are typically identified by directed evolution involving combinatorial libraries. To determine the impact of residues located at a distance from the binding site, here we used single-codon libraries of both CDR and non-CDR residues to generate a deep mutational scan of a human TCR against the cancer antigen MART-1·HLA-A2. Non-CDR residues included those at the interface of the TCR variable domains (Vα and Vβ) and surface-exposed framework residues. Mutational analyses showed that both Vα/Vβ interface and CDR residues were important in maintaining binding to MART-1·HLA-A2, probably due to either structural requirements for proper Vα/Vβ association or direct contact with the ligand. More surprisingly, many Vα/Vβ interface substitutions yielded improved binding to MART-1·HLA-A2. To further explore this finding, we constructed interface libraries and selected them for improved stability or affinity. Among the variants identified, one conservative substitution (F45βY) was most prevalent. Further analysis of F45βY showed that it enhanced thermostability and increased affinity by 60-fold. Thus, introducing a single hydroxyl group at the Vα/Vβ interface, at a significant distance from the TCR·peptide·MHC-binding site, remarkably affected ligand binding. The variant retained a high degree of specificity for MART-1·HLA-A2, indicating that our approach provides a general strategy for engineering improvements in either soluble or cell-based TCRs for therapeutic purposes.
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Affiliation(s)
- Preeti Sharma
- From the Department of Biochemistry, University of Illinois, Urbana, Illinois 61801
| | - David M Kranz
- From the Department of Biochemistry, University of Illinois, Urbana, Illinois 61801
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T cell receptor repertoire usage in cancer as a surrogate marker for immune responses. Semin Immunopathol 2017; 39:255-268. [PMID: 28074285 DOI: 10.1007/s00281-016-0614-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 12/15/2016] [Indexed: 12/21/2022]
Abstract
Characterizing the interaction of cancer cells with the host adaptive immune system is critical for understanding tumor immunology and the modus operandi of immunotherapeutic interventions to treat cancer. As the key cellular effectors of adaptive immunity, T cells are endowed with specialized receptors (the T cell receptor; TCR), to recognize and to eliminate cancer cells. The diversity of the TCR repertoire results from specialized genetic diversification mechanisms that generate an incredible variability allowing recognizing extensive collections of antigens. Based on the attainment and function of the TCR, the TCR repertoire is a mirror of the human immune response, and the dynamic changes of its usage can be assumed as a promising biomarker to monitor immunomodulatory therapies. Recent advances in multiplexed PCR amplification and massive parallel sequencing technologies have facilitated the characterization of TCR repertoires at high resolution even when only biomaterial of limited quantity and quality, such as formalin-fixed paraffin-embedded (FFPE) archived tissues, is available. Here, we review the concept framework and current experimental approaches to characterize the TCR repertoire usage in cancer including inherent technical and biological challenges.
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