SIMPLE DETERMINATION OF DONOR HOST ORIGIN AND DONOR LEUKOCYTE SUBSETSIN RAT-MOUSE CHIMERAS/

In lethally irradiated mice, mixed lymphohaemopoietic chimerism can be established after their reconstitution with adult or embryonic rat ha emopoietic stem cells. In this report we describe a simple fluorescent staining protocol for the determination of origin and type of various leukocyte cell subpopulations (rat or mouse, and rat T, B and myeloid cells, respectively) using whole blood samples from such animals. The se data were comparable to those obtained in peripheral lymphoid tissu es. Exploiting the slightly heterogeneous reactivity of the mouse mono clonal anti-rat CD45 antibody (MRC OX-1) revealed by the application o f a PE-labelled monoclonal anti-mouse IgG1 secondary reagent together with a FITC-labelled rat anti-mouse CD45 mAb (IBL-5/25), we could dete rmine the donor-derived T, B and myeloid cells from one sample in a tw o-step procedure. Further advantages to this easy staining procedure a re that PBLs as test cells are readily available and the typing can be repeated, thus offering the opportunity for continuous monitoring of the degree of chimerism. (C) 1998 Elsevier Science B.V. All rights res erved.