Optimal protocol for total body irradiation for allogeneic bone marrow transplantation in mice

Abstract

Summary:We have previously demonstrated, using chimeric resistant MRL/lpr mice, that a fractionated total body irradiation (FTBI) (5 Gy ؋ 2 with a 4 h interval on the day before allogeneic bone marrow transplantation (BMT) ) is the best conditioning regimen for the treatment of autoimmune diseases in radiosensitive MRL/lpr mice. In the present study, using various standard strains of mice (not radiosensitive mice), we explore the best protocol for irradiation (doses and intervals) as the conditioning regimen for allogeneic BMT. Recipient mice were exposed to various irradiation regimens: a single total body irradiation (TBI) of 9.5 or 12 Gy and FTBI of (5+5) Gy to (7+7) Gy with a 1 to 24 h interval. The method generally utilized for humans ((2+2) Gy with a 4 h interval for 3 days (total 12 Gy)) was also used. One day after the last irradiation, donor BMCs from BALB/c, C3H, or C57BL/6 (B6) mice were transplanted into C3H or B6 mice. The irradiation protocol of (2+2) Gy for 3 days was found to be insufficient to enable the complete removal of recipient immunocompetent cells, since donor-reactive T cells were observed in the recipient spleens and many recipient-type NK and CD4 + cells were also detected in the recipient hematolymphoid tissues. In all the combinations, the highest survival rate was achieved in the recipients irradiated with (6+6) or (6.5+6.5) Gy with a 4 h interval. In the surviving mice, the hematolymphoid tissues had been fully reconstituted with donor cells. Bone Marrow Transplantation (2002) 30, 843-849. doi:10.1038/sj.bmt.1703766 Keywords: bone marrow transplantation; fractionated irradiation; reconstitution Irradiation has been used as an effective conditioning regimen for bone marrow transplantation (BMT), since it kills rapidly proliferating immunocompetent cells, particularly T

Permanent partial phenotypic correction and tolerance in a mouse model of hemophilia B by stem cell gene delivery of human factor IX

“…The variable level of hFIX:Ag production observed in secondary recipients can be shown by Q-PCR to be directly related to the low levels of male donor chimerism, could be the result of expansion of radioresistant recipient cells 20 and is unlikely to be due to poor lentiviral transduction or variable clonal expansion of donor cells. While 2 Â 10 4 syngeneic Lin À cells have been shown to be the lower limit for rescue of lethally irradiated mice, 21 increasing numbers of donor cells are required to successfully reconstitute recipients receiving sublethal doses of irradiation or those with increasing antigenic disparity.…”

“…While 2 Â 10 4 syngeneic Lin À cells have been shown to be the lower limit for rescue of lethally irradiated mice, 21 increasing numbers of donor cells are required to successfully reconstitute recipients receiving sublethal doses of irradiation or those with increasing antigenic disparity. 20,22,23 When investigating immunological unresponsiveness to hFIX in the two animal models, we were aware that the C57Bl/6J 24 strain has been reported to have limited immune responses to hFIX:Ag delivered by adenovirus and that the 129/Sv strain has been shown to have a limited immune repertoire. 25 Although animals may not have mounted immune responses if challenged with hFIX alone, challenge with hFIX in adjuvant raised highly significant humoral and lower cellular responses against the antigen in control groups.…”

Analyses of Very Early Hemopoietic Regeneration After Bone Marrow Transplantation: Comparison of Intravenous and Intrabone Marrow Routes

“…As shown in Figure 6A, no significant chemotactic activity was observed in the sera collected between 4 hours and 4 days after irradiation, whereas BM tissue extracts showed a significant chemotactic activity as early as 4 hours, reaching a maximum at 16 hours. In all BMT experiments performed in our laboratory, the donor BMCs are injected into the recipient mice around 16 hours after irradiation [15]. Therefore, it is conceivable that the BM stromal cells injected directly into the bones by IBM-BMT can settle at the site of injection and that only a small number of stromal cells leak and migrate anywhere.…”

Tumor Progression Locus-2 Is a Critical Regulator of Pancreatic and Lung Inflammation during Acute Pancreatitis

“…Five days later, the animals were sacrificed, and bone marrow was collected from their harvested tibias and femurs as described (10). Other wild type and Tpl2 Ϫ/Ϫ mice destined to serve as bone marrow recipients were placed in sterile cages and given sterile food and water for 1 week prior to and 1 week following bone marrow transplantation.…”