Vascularized bone marrow transplanted in orthotopic hind-limb stimulates hematopoietic recovery in total-body-irradiated rats.
Hematopoietic recovery after bone marrow transplantation (BMT) is reported to be slow with long-lasting immune deficiency. This may be attributable to lack of a proper microenvironment for hematopoietic cell proliferation and differentiation. We have designed a model in which complete hematopoietic reconstitution of lethally irradiated rats can be achieved by vascularized bone marrow transplantation (VBMT) in an orthotopic hind-limb graft. The aim of the study was to investigate the process of repopulation of bone marrow cavities and peripheral blood of irradiated rats after VBMT and, in particular, to follow the contribution of grafted BM cells and residual recipient BM cells in hematopoietic regeneration. Lewis hind-limbs were transplanted orthotopically to totally irradiated (8 Gy) syngeneic sex-mismatched recipients (VBMT). In the control group 8 x 10(7) BM cells in suspension were injected intravenously (BMCT). After 10 days BM and peripheral blood (PB) cells were collected from the recipient. For cell subset analysis cytomorphological evaluation of BM smears and flow cytometry of PB cells were performed. Additionally, PCR was performed using specific primers for rat Y chromosome (sex-determining region Y-Sry) to detect male (donor or recipient) cells in sex-mismatched BM graft recipients and the products were analyzed by electrophoresis. VBMT brought about much faster replenishment of nucleated cells in BM and PB than did BMCT. Cytometry analysis of PB cells revealed more lymphocytes in VBMT than in BMCT recipients. The amount of donor DNA of bands corresponding to Y-Sry was also higher in PB cells of VBMT than of BMCT recipients. The presence of host DNA was observed in PB cells of VBMT rats but was not detected in PB population of BMCT recipients. VBMT is highly effective in hematopoietic reconstitution of irradiated recipients. The fast cell maturation and repopulation may be due to the presence of stromal cells transplanted in a normal spatial relationship with donor hematopoietic cells in hind-limb graft. Self renewal of radioresistant host cells was seen after VBMT but not after BMCT.
Janczewska
S
S
Department for Surgical Research and Transplantology, Medical Research Center Institute, Polish Academy of Sciences, Warsaw.
Ziolkowska
A
A
Interewicz
B
B
Majewski
T
T
Olszewski
W L
WL
Lukomska
B
B
D000818:Animals; D016026:Bone Marrow Transplantation / Q000502:physiology*; D003037:Cobalt Radioisotopes; D005260:Female; D005720:Gamma Rays; D006410:Hematopoiesis / Q000502:physiology* / Q000528:radiation effects; D006614:Hindlimb / Q000637:transplantation*; D007165:Immunosuppression Therapy / Q000379:methods; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D051381:Rats; D011917:Rats, Inbred Lew; D014185:Transplantation, Isogeneic / Q000276:immunology* / Q000379:methods; D014916:Whole-Body Irradiation
D003037:Cobalt Radioisotopes