Clinically Relevant T Cell Markers Cryopreservation Selectively Decreases Detection of Nine Standard Peripheral Blood Mononuclear Cell

Biobanking is an operational component of various epidemiological studies and clinical trials. Although peripheral blood is routinely acquired and stored in biobanks, the effects of specimen processing on cell composition and clinically relevant functional markers of T cells still require a systematic evaluation. In this study, we assessed 25 relevant T cell markers in human PBMCs and showed that the detection of nine membrane markers (e.g., PD-1, CTLA4, KLRG1, CD25, CD122, CD127, CCR7, and others reflecting exhaustion, senescence, and other functions) was reduced among at least one T cell subset following standard processing, although the frequency of CD4, CD8, and regulatory T cells was unaffected. Nevertheless, a 6-mo-long cryopreservation did not impair the percentages of cells expressing many other membrane and all the eight tested intracellular lineage or functional T cell markers. Our findings uncover that several clinically relevant markers are particularly affected by processing and the interpretation of those results in clinical trials and translational research should be done with caution. ImmunoHorizons, 2021, 5: 711–720. Received for publication June 1, 2021. Accepted for publication July 30, 2021. Address correspondence and reprint requests to: Dr. Feng Q. Hefeng, Department of Infection and Immunity, Luxembourg Institute of Health, 29 rue Henri Koch, Esch-sur-Alzette, 4354 Luxembourg. E-mail address: feng.he@lih.lu ORCIDs: 0000-0002-9110-9583 (C.M.C.); 0000-0003-2902-5650 (R.B.); 0000-0002-0558-4653 (F.B.); 0000-0002-8055-0103 (M.O.); 0000-0003-2657-7361 (F.Q.H.). The flow cytometry data presented in this article have been submitted to Mendeley Data under DOI 10.17632/23zbd3yrmn.1. This work was supported by Luxembourg National Research Fund CORE Programme Grant CORE/14/BM/8231540/GeDES (to F.Q.H.), National Research Fund AFRRIKEN Bilateral Programme (TregBAR) (to F.Q. H. and M.O.), PRIDE Programme Grants PRIDE/11012546/NEXTIMMUNE and PRIDE/10907093/CRITICS (to the Ph.D. student C.M.C.). The work was also partially supported through intramural funding of Luxembourg Institute of Health and Luxembourg Centre for Systems Biomedicine through Ministry of Higher Education and Research of Luxembourg. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. C.M. C. designed and performed the experiments, performed data analysis, visualization, and drafted the manuscript. S.C. and W.A. performed parts of experiments. M.K. performed parts of analyses and flow cytometry quality control. A.C. , R.B. , M.O. , and F.B. provided substantial insights and supervision into the project. F.Q. H. conceived and oversaw the whole project and wrote and revised the manuscript. Abbreviations used in this article: FDR, false discovery rate; MFI, mean fluorescence intensity; RT, room temperature; Tconv, CD4FOXP3 cell; Treg, CD4 regulatory T cell. The online version of this article contains supplemental material. This article is distributed under the terms of the CC BY 4.0 Unported license. Copyright © 2021 The Authors https://doi.org/10.4049/immunohorizons.2100049 711 ImmunoHorizons is published by The American Association of Immunologists, Inc. RESEARCH ARTICLE Clinical and Translational Immunology by gest on A uust 1, 2021 hp://w w w . im m unohzons.org/ D ow nladed from