1. Horizontal DNA Transfer from Donor to Host Cells as an Alternative Mechanism of Epithelial Chimerism after Allogeneic Hematopoietic Cell Transplantation 
Miguel Waterhouse, Maria Themeli, Hartmut Bertz, Nicholas Zoumbos, Jürgen Finke, Alexandros Spyridonidis 
Biology of Blood and Marrow Transplantation 
Volume 17, Issue 3, Pages (March 2011)
DOI: /j.bbmt
Copyright © 2011 American Society for Blood and Marrow Transplantation Terms and Conditions

2. Figure 1
Apoptotic bodies can transfer DNA to cultured epithelial cells and primary BMSC. (A) Percentage of CMFDA, BrdU, or FISH-Y chromosome signals in HaCaT cells after their cocultivation for hours with apoptotic or nonapoptotic Jurkat cells (Y+, BrdU, and/or CMFDA labeled). A representative example of a HaCaT cell with engulfed CMFDA+ apoptotic bodies is shown. (B) Detection of BrdU and FISH-Y signals within the nucleus of HaCaT cells analyzed by confocal microscopy and 3D analysis. (C) Image shows a prophase of a dividing HaCaT cell stained positive for FISH-Y (above). BrdU and FISH-Y signals were found within the isolated chromosomes in metaphase spreads from HaCaT cells (below). (D) Detection of BrdU and FISH-Y signals within the nucleus of primary BMSC analysed by confocal microscopy and 3D analysis. CK: cytokeratin, DAPI: nuclear stain. Data in graphs are represented as mean + SD. Magnification 600×.
Biology of Blood and Marrow Transplantation  , DOI: ( /j.bbmt )
Copyright © 2011 American Society for Blood and Marrow Transplantation Terms and Conditions

3. Figure 2
Mechanisms of DNA transfer. Percentage of HaCaT cells with intracellular or intranuclear BrdU+ signal after their coculture for 48 hours with BrdU-labeled apoptotic bodies, apoptotic bodies separated from the HaCaT cells in a transwell system (T/W), or after pretreatment with cytochalasin or bafilomycin. Repeated exposure indicates that HaCaT cells were challenged with apoptotic bodies that were replaced every 12 hours (4 challenges). Data in graphs are represented as mean + SD.
Biology of Blood and Marrow Transplantation  , DOI: ( /j.bbmt )
Copyright © 2011 American Society for Blood and Marrow Transplantation Terms and Conditions

4. Figure 3
HaCaT cells bearing foreign DNA may express the transferred genome. (A) HaCaT cells were cocultured with apoptotic GFP+JvM-13 cells, nonapoptotic GFP+JvM-13, apoptotic GFP+JvM-13 in a transwell system (T/W), or with apoptotic GFP+JvM-13 pretreated with DNaseI. After cocultivation, cultures were washed several times in order to remove all nonadherent JvM-13 cells or JvM-13 apoptotic bodies, and only the adherent HaCaT cells were used for further analysis. GFP expression was evaluated by FACS in terms of fluorescence intensity compared to untreated cells. (B) GFP expression in HaCaT cells was also evaluated by fluorescence microscopy, and representative photos are shown (DAPI:blue, GFP:green). Magnification 600×.
Biology of Blood and Marrow Transplantation  , DOI: ( /j.bbmt )
Copyright © 2011 American Society for Blood and Marrow Transplantation Terms and Conditions

5. Figure 4
HaCaT cells bearing foreign DNA are viable and able to proliferate. (A) HaCaT cells were cocultured with BrdU-labeled apoptotic Jurkat cells and then BrdU+ and BrdU− populations were isolated by FACS sorting, assessed by FACS for percentage of Annexin+ apoptotic cells and by microsatellite analysis for the presence of foreign DNA, and then placed in culture. After 1 week in culture, BrdU+ sorted cells reached similar confluency as the BrdU− fraction. No BrdU or Y signal was any more detectable in the BrdU+ sorted population after 1 week of culture. CK: cytokeratin, DAPI: nuclear stain. Stain colors as indicated by the legends. Magnification 100×.
Biology of Blood and Marrow Transplantation  , DOI: ( /j.bbmt )
Copyright © 2011 American Society for Blood and Marrow Transplantation Terms and Conditions

6. Figure 5
Donor-derived DNA in buccal swabs after allogeneic HCT. Capillary electrophoresis of PCR for microsatellite markers. Large amount of donor-DNA was detected in buccal samples after transplantation. Two representative examples are shown (A and B). P/D: patient/donor-specific microsatellite peaks; d: day of sampling after transplantation.
Biology of Blood and Marrow Transplantation  , DOI: ( /j.bbmt )
Copyright © 2011 American Society for Blood and Marrow Transplantation Terms and Conditions

7. Figure 6
Horizontal DNA transfer from donor to host cells as an alternative new mechanism of epithelial chimerism after allogeneic hematopoietic cell transplantation. Our proposed model suggests that after allo-HCT, there is a continuous transfer and integration of donor apoptotic genomic material into host epithelium that results in emergence of epithelial cells that contain donor-derived genome.
Biology of Blood and Marrow Transplantation  , DOI: ( /j.bbmt )
Copyright © 2011 American Society for Blood and Marrow Transplantation Terms and Conditions