title: A single-platform approach using flow cytometry and microbeads to evaluate immune reconstitution in mice after bone marrow transplantation.
abstract: The monitoring of immune reconstitution in murine models of HC transplantation, using accurate and automated methods, is necessary in view of the recent developments of hematopoietic cell (HC) transplantation (including reduced intensity conditioning regimens) as well as emerging immunological concepts (such as the involvement of dendritic cells or regulatory T cells). Here, we describe the use of a single-platform approach based on flow cytometry and tubes that contain a defined number of microbeads to evaluate absolute blood cell counts in mice. This method, previously used in humans to quantify CD34+ stem cells or CD4+ T cells in HIV infected patients, was adapted for mouse blood samples. A CD45 gating strategy in this "lyse no wash" protocol makes it possible to discriminate erythroblasts or red blood cell debris from CD45+ leukocytes, thus avoiding cell loss. Tubes contain a lyophilized brightly fluorescent microbead pellet permitting the acquisition of absolute counts of leukocytes after flow cytometric analysis. We compared this method to determine absolute counts of circulating cells with another method combining Unopette reservoir diluted blood samples, hemocytometer, microscopic examination and flow cytometry. The sensitivity of this single-platform approach was evaluated in different situations encountered in allogeneic HC transplantation, including immune cell depletion after different conditioning regimens, activation status of circulating cells after transplantation, evaluation of in vivo cell depletion and hematopoietic progenitor mobilization in the periphery. This single-platform flow cytometric assay can also be proposed to standardize murine (or other mammalian species) leukocyte count determination for physiological, pharmacological/toxicological and diagnostic applications in veterinary practice.
authors.affiliation: Unité Mixte EFS/Université EA2284/Inserm U645, IFR133, Laboratoire d'Immunologie, Etablissement Français du Sang Bourgogne Franche-Comté, INSERM U645, 1 Boulevard A. Fleming, BP1937, F-25020 Besançon, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Perruche
authors.forename: François
authors.initials: F
authors.lastname: Kleinclauss
authors.forename: Agnès
authors.initials: A
authors.lastname: Lienard
authors.forename: Eric
authors.initials: E
authors.lastname: Robinet
authors.forename: Pierre
authors.initials: P
authors.lastname: Tiberghien
authors.forename: Philippe
authors.initials: P
authors.lastname: Saas
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000097:blood / Q000276:immunology; D016026:Bone Marrow Transplantation; D018791:CD4 Lymphocyte Count / Q000379:methods*; D005434:Flow Cytometry / Q000379:methods* / Q000592:standards; D006678:HIV / Q000276:immunology*; D015658:HIV Infections / Q000097:blood* / Q000276:immunology / Q000821:virology; D019650:Hematopoietic Stem Cell Mobilization; D006801:Humans; D017493:Leukocyte Common Antigens / Q000097:blood* / Q000276:immunology; D008212:Lymphocyte Depletion; D051379:Mice; D008853:Microscopy; D008863:Microspheres; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D033581:Stem Cell Transplantation; D018183:Transplantation Chimera / Q000097:blood*; D019172:Transplantation Conditioning
chemical_list: D018952:Antigens, CD34; D017493:Leukocyte Common Antigens