Long-term engraftment of normal and post-5-fluorouracil murine marrow into normal nonmyeloablated mice [see comments]

Abstract

We report the successful long-term engraftment of normal male donor bone marrow (BM) transfused into noncytoablated female mice, challenging the assumption that “niches” need to be created for marrow to engraft. We have used chromosomal banding and Southern blot analysis to identify transplanted male marrow cells, and shown the long-term stability of the chimeric marrows. Balb/C, BDF1, or CBA-J female hosts (no irradiation) received for 5 consecutive days 40 x 10(6) male cells (per day) of the same strain, and repopulation patterns were observed. Parallel studies were performed using tibia/femur equivalents of normal marrow or marrow from Balb/C mice pretreated 6 days previously with 150 mg/kg 5-fluorouracil (5-FU). Chromosome banding techniques showed that 5% to 46% of marrow cells were male 3 to 9 months posttransplant with normal donor marrow. Southern blot analysis, using the pY2 probe, showed continued engraftment at 21 to 25 months posttransplant, ranging from 15% to 42% male engrafted cells in marrow. Normal donor male marrow engrafted significantly better than 5-FU-pretreated male marrow as shown 1 to 12 months posttransplant in non-cytoablated female recipients. Percentages of male engrafted cells in BM ranged from 23% to 78% for recipients of normal donor marrow and from 0.1% to 39% for recipients of 5-FU marrow. Mean engraftment for 6 mice receiving normal marrow was 38%, whereas that for 6 mice receiving post-5-FU marrow was 8%, as assayed 1 to 3 months posttransplant. At 10 to 12 months, mean engraftment for the normal donor group was 46%, compared with 16% for the 5-FU group. The patterns of engraftment with normal and 5-FU marrow were similar for spleen and thymus. These results show that long-term chimerism can be established after transplantation of normal donor marrow to normal nonirradiated host mice and indicate that marrow spaces do not have to be created for successful engraftment. They suggest that transplanted marrow competes equally with host marrow for marrow space. Finally, these data show that post-5-FU Balb/C male marrow is markedly inferior in the repopulation of Balb/C female host marrow, spleen, and thymus, and suggest that this population of cells may not be the ideal population for gene transfer studies.

Lymphohematopoietic Stem Cell Engraftmenta

“…al. 6 extended these observations showing high levels of long-term multilineage engraftment in nonmyeloablated BALB/c mice. A series of studies utilizing a male/female transplantation model in nonmyeloablated BALB/c hosts has shown that engraftment is essentially quantitative and appears to be determined by competition between infused marrow cells and host cells.…”

Engraftment of hematopoietic stem cells in nonmyeloablated and myeloablated hosts

“…Previously Micklem, Saxe, Brecher and coworkers had demonstrated variable degrees of normal engraftment [ 1-31. More recently we confirmed and extended these results showing relatively high levels of stable engraftment of male BALB/c cells in nontreated female BALB/c hosts; levels of male DNA of up to 42% in female host marrow were found at 24-25 months after infusion of 40 x lo6 cells for five consecutive days (total 200 x lo6 cells) [4].…”

Optical Imaging of PKH‐Labeled Hematopoietic Cells in Recipient Bone Marrow In Vivo

“…Therefore, determination of cell division based on dilution of the membrane linkers should be carefully performed. Because some hematopoietic progenitors proliferate early after transplantation [42,44,45], PKH dyes are optimal for short-term tracking of BMCs and for detection of quiescent cells over longer periods.…”

“…A prevalent notion postulates that transplanted cells seek a vacant hematopoietic niche, and thus, the success of engraftment reflects a delicate equilibrium between the number of homing cells and availability of niches [20,42,43]. Cellular homing to the host BM is mediated by a variety of molecular interactions and is influenced by the phenotype of Askenasy, Farkas 510 the transplanted cells and their stage in the cell cycle [11-16, 19, 42-45].…”