Hyun‐Dong Chang

Compelling evidence suggests that the transcription factor Foxp3 acts as a master switch governing the development and function of CD4(+) regulatory T cells (Tregs). However, whether transcriptional control of Foxp3 expression itself contributes to the development of a stable Treg lineage has thus far not been investigated. We here identified an evolutionarily conserved region within the foxp3 locus upstream of exon-1 possessing transcriptional activity. Bisulphite sequencing and chromatin immunoprecipitation revealed complete demethylation of CpG motifs as well as histone modifications within the conserved region in ex vivo isolated Foxp3(+)CD25(+)CD4(+) Tregs, but not in naïve CD25(-)CD4(+) T cells. Partial DNA demethylation is already found within developing Foxp3(+) thymocytes; however, Tregs induced by TGF-beta in vitro display only incomplete demethylation despite high Foxp3 expression. In contrast to natural Tregs, these TGF-beta-induced Foxp3(+) Tregs lose both Foxp3 expression and suppressive activity upon restimulation in the absence of TGF-beta. Our data suggest that expression of Foxp3 must be stabilized by epigenetic modification to allow the development of a permanent suppressor cell lineage, a finding of significant importance for therapeutic applications involving induction or transfer of Tregs and for the understanding of long-term cell lineage decisions.

These guidelines are a consensus work of a considerable number of members of the immunology and flow cytometry community. They provide the theory and key practical aspects of flow cytometry enabling immunologists to avoid the common errors that often undermine immunological data. Notably, there are comprehensive sections of all major immune cell types with helpful Tables detailing phenotypes in murine and human cells. The latest flow cytometry techniques and applications are also described, featuring examples of the data that can be generated and, importantly, how the data can be analysed. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid, all written and peer-reviewed by leading experts in the field, making this an essential research companion.

Funding Information: Mairi Mc Grath and Regina Stark thank Francesco Siracusa and Patrick Maschmeyer for providing data and Klaas van Gisbergen for helpful discussions. Philip E. Boulais and Paul S. Frenette are grateful to Dr. Sandra Pinho for helpful comments and suggestions. They thank the National Institutes of Health for their support (R01 grants DK056638, HL116340, HL097819 to P.S.F). They also thank the New York State Department of Health (NYSTEM Program) for shared facility (C029154) and research support (N13G-262) and the Leukemia and Lymphoma Society’s Translational Research Program. Funding Information: Acknowledgements: Enrico Lugli and Pratip K. Chattopadhyay were supported by grants from the Fondazione Cariplo (Grant Ricerca Biomedica 2012/0683), the Italian Ministry of Health (Bando Giovani Ricercatori GR-2011-02347324) and the European Union Marie Curie Career Integration Grant 322093 (all to E.L.). E.L. and P.K.C. are International Society for the Advancement of Cytometry (ISAC) Marylou Ingram scholars. Alice Yue and Ryan R. Brinkman were funded by Genome BC and NSERC. Klaus Warnatz received funding from the German Federal Ministry of Education and Research (BMBF 01EO1303) and the Deutsche Forschungsgemeinschaft (DECIDE, DFG WA 1597/4-1 and the TRR130). The Jung laboratory is supported by funds of the ERC and ISF. Henrik Mei is a 2017-2021 ISAC scholar. Antonio Cosma is supported by the French government program: “Investissement d’avenir: Equipements d’Excellence” (EQUIPEX)-2010 FlowCyTech, Grant number: ANR-10-EQPX-02-01. Henrik Mei is supported by the Deutsche Forschungsgemeinschaft (DFG; grants Me3644/5-1 and TRR130/TP24). Funding Information: The Immunology Database and Analysis Portal (ImmPort) system provides an archive of immunology research data generated by investigators mainly funded through the National Institutes of Health (NIH), National Institute of Allergy and Infectious Diseases (NIAID), Division of Allergy, Immunology, and Transplantation (DAIT). It is an extensive data warehouse containing an integration of experimental and clinical trial data generated by dozens of assay types, including 63 flow cytometry and 5 CyTOF data sets. In addition, the ImmPort system also provides data analysis tools and it contains implicit knowledge and ‘‘best practices’’ for clinical and genomic studies in the form of nearly 50 templates for data deposition, management, and dissemination. ImmPort has been developed under the Bioinformatics Integration Support Contract (BISC) by the Northrop Grumman Information Technology Health

The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical samples with examples of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer-reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state-of-the-art handbook for basic and clinical researchers.