Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

We searched for new cell surface markers that allow a positive identification of thymus-repopulating cells in the bone marrow (BM) of the mouse. Recently we raised two rat monoclonal antibodies (ER-MP12 and ER-MP20) that recognize cell surface antigens expressed by mouse haematopoietic progenitor cells, among which are progenitor cells of the macrophage lineage. Here we show that the ER-MP12 antigen, but not the ER-MP20 antigen, is also expressed by BM cells with thymus-repopulating ability. Using ER-MP12 and ER-MP20 in two-colour immunofluorescence analysis six subpopulations of BM cells can be identified. The thymus-repopulating ability of each BM subpopulation was assessed after fluorescence-activated cell sorting and subsequent intrathymic injection into sublethally irradiated Thy-1 congenic recipient mice. Thymus-repopulating activity appeared to be exclusively confined to two subsets of BM cells expressing either high or intermediate levels of the ER-MP12 antigen, but lacking ER-MP20 antigen expression. These BM subsets comprised 1-2% and 30% of total nucleated BM cells respectively. The frequency of thymus-repopulating cells was maximal in the minor BM subpopulation with the highest level of ER-MP12 antigen expression. We conclude that ER-MP12 detects a hitherto unknown cell surface marker expressed by BM cells with thymus-repopulating ability.

Original publication




Journal article


Int Immunol

Publication Date





1093 - 1098


Animals, Antibodies, Monoclonal, Antigens, Surface, Biomarkers, Bone Marrow, Bone Marrow Cells, Female, Flow Cytometry, Fluorescent Antibody Technique, Hematopoietic Stem Cells, Immunophenotyping, Immunotherapy, Adoptive, Male, Mice, Mice, Inbred C57BL, Rats, T-Lymphocytes, Thymus Gland