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Kagan Ben Tikva S, Gurwitz N, Sivan E, Hirsch D, Hezroni-Barvyi H, Biram A, Moss L, Wigoda N, Egozi A, Monziani A, Golani O, Gross M, Tenenbaum A, Shulman Z. T cell help induces Myc transcriptional bursts in germinal center B cells during positive selection. Sci Immunol 2024; 9:eadj7124. [PMID: 38552029 DOI: 10.1126/sciimmunol.adj7124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 02/09/2024] [Indexed: 04/02/2024]
Abstract
Antibody affinity maturation occurs in secondary lymphoid organs within germinal centers (GCs). At these sites, B cells mutate their antibody-encoding genes in the dark zone, followed by preferential selection of the high-affinity variants in the light zone by T cells. The strength of the T cell-derived selection signals is proportional to the B cell receptor affinity and to the magnitude of subsequent Myc expression. However, because the lifetime of Myc mRNA and its corresponding protein is very short, it remains unclear how T cells induce sustained Myc levels in positively selected B cells. Here, by direct visualization of mRNA and active transcription sites in situ, we found that an increase in transcriptional bursts promotes Myc expression during B cell positive selection in GCs. Elevated T cell help signals predominantly enhance the percentage of cells expressing Myc in GCs as opposed to augmenting the quantity of Myc transcripts per individual cell. Visualization of transcription start sites in situ revealed that T cell help promotes an increase in the frequency of transcriptional bursts at the Myc locus in GC B cells located primarily in the LZ apical rim. Thus, the rise in Myc, which governs positive selection of B cells in GCs, reflects an integration of transcriptional activity over time rather than an accumulation of transcripts at a specific time point.
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Affiliation(s)
- Sharon Kagan Ben Tikva
- Department of Systems Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Neta Gurwitz
- Department of Systems Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ehud Sivan
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Dana Hirsch
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Hadas Hezroni-Barvyi
- Department of Systems Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Adi Biram
- Department of Systems Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Lihee Moss
- Department of Systems Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Noa Wigoda
- Bioinformatics unit, Life Science Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Adi Egozi
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Alan Monziani
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ofra Golani
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Menachem Gross
- Department of Otolaryngology-Head and Neck Surgery, Hadassah Medical Center, Jerusalem 9112102, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Ariel Tenenbaum
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112102, Israel
- Department of Pediatrics, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Ziv Shulman
- Department of Systems Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
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Yanowski E, Yacovzada NS, David E, Giladi A, Jaitin D, Farack L, Egozi A, Ben-Zvi D, Itzkovitz S, Amit I, Hornstein E. Physically interacting beta-delta pairs in the regenerating pancreas revealed by single-cell sequencing. Mol Metab 2022; 60:101467. [PMID: 35240340 PMCID: PMC8983436 DOI: 10.1016/j.molmet.2022.101467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 02/05/2022] [Accepted: 02/25/2022] [Indexed: 11/12/2022] Open
Abstract
Objectives Until recently, communication between neighboring cells in islets of Langerhans was overlooked by genomic technologies, which require rigorous tissue dissociation into single cells. Methods We utilize sorting of physically interacting cells (PICs) with single-cell RNA-sequencing to systematically map cellular interactions in the endocrine pancreas after pancreatectomy. Results The pancreas cellular landscape features pancreatectomy associated heterogeneity of beta-cells, including an interaction-specific program between paired beta and delta-cells. Conclusions Our analysis suggests that the particular cluster of beta-cells that pairs with delta-cells benefits from stress protection, implying that the interaction between beta- and delta-cells might safeguard against pancreatectomy associated challenges. The work encourages testing the potential relevance of physically-interacting beta-delta-cells also in diabetes mellitus. Single-cell RNA-sequencing systematically maps physically interacting endocrine cells in the pancreas. The landscape of pancreatectomy associated beta-cell heterogeneity is mapped in a single cell resolution. Interaction-specific beta - delta cellular program safeguards beta cells against pancreatectomy-associated stress. Physically interacting beta delta pairs were discovered in an injury model and may also be relevant in diabetes.
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Affiliation(s)
- Eran Yanowski
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Molecular neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Nancy-Sarah Yacovzada
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Molecular neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Eyal David
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Amir Giladi
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Diego Jaitin
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Lydia Farack
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Adi Egozi
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Danny Ben-Zvi
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, 9112102, Israel
| | - Shalev Itzkovitz
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ido Amit
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Eran Hornstein
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Molecular neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel.
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Farack L, Itzkovitz S. Protocol for Single-Molecule Fluorescence In Situ Hybridization for Intact Pancreatic Tissue. STAR Protoc 2020; 1:100007. [PMID: 33111069 PMCID: PMC7580104 DOI: 10.1016/j.xpro.2019.100007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We describe an optimized smFISH protocol for the intact pancreas. The protocol is adapted from Lyubimova et al. (2013), a generic tissue smFISH protocol that works for most tissues but not the pancreas. The main changes implemented include increasing the period of mRNA denaturation from 5 min to at least 3 h and increasing formamide concentrations from 10% to 30%. These modifications yield sensitive single mRNA visualization that is comparable to those achieved in other tissues using the standard protocol. For complete details on the use and execution of this protocol, please refer to Farack et al., 2018, Farack et al., 2019. An optimized protocol for single-molecule transcript imaging in the intact pancreas Visualization of mRNA molecules with high sensitivity while preserving spatial information Enables to interrogate intact pancreatic tissue at any metabolic and pathological state
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Affiliation(s)
- Lydia Farack
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Shalev Itzkovitz
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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Tutucci E, Singer RH. Simultaneous Detection of mRNA and Protein in S. cerevisiae by Single-Molecule FISH and Immunofluorescence. Methods Mol Biol 2020; 2166:51-69. [PMID: 32710403 DOI: 10.1007/978-1-0716-0712-1_4] [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: 04/19/2023]
Abstract
Single-molecule fluorescent in situ hybridization (smFISH) enables the detection and quantification of endogenous mRNAs within intact fixed cells. This method utilizes tens of singly labeled fluorescent DNA probes hybridized against the mRNA of interest, which can be detected by using standard wide-field fluorescence microscopy. This approach provides the means to generate absolute quantifications of gene expression within single cells, which can be used to link molecular fluctuations to phenotypes. To be able to correlate the expression of an mRNA and a protein of interest in individual cells, we combined smFISH with immunofluorescence (IF) in yeast cells. Here, we present our smFISH-IF protocol to visualize and quantify two cell cycle-controlled mRNAs (CLN2 and ASH1) and the cell cycle marker alpha-tubulin in S. cerevisiae. This protocol, which is performed over 2 days, can be used to visualize up to three colors at the time (i.e., two mRNAs, one protein). Even if the described protocol is designed for S. cerevisiae, we think that the considerations discussed here can be useful to develop and troubleshoot smFISH-IF protocols for other model organisms.
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Affiliation(s)
- Evelina Tutucci
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA.
- Systems Biology Lab, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
| | - Robert H Singer
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA.
- Janelia Research Campus of the HHMI, Ashburn, VA, USA.
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