Background: Processing and incorporation of fragments of DNA and oligonucleotides by mammalian and bacterial cells is a continuing physiological process. It is strongly intensified in inflammation, cancer cells and after tissue and organ transplantation. The outcome of DNA transfer between mammalian cells remains not well understood. It has been suggested that the donor DNA may play a role in rejection or creating a partial tolerance. Aim: to study whether donor DNA may be identified in recipient's immune cells and if so, whether it is located in cytoplasm or penetrates into the nucleus.
Material/Methods: In sex-mismatched combination male rat DNA was injected i.v. into 10 female rats. Recipient blood (PBM), lymph node (LN) and spleen (SPL) mononuclear cells were examined 24 hr later for the presence of SRY gene characteristic for Y-chromosome. SRY was detected using polymerase chain reaction (PCR) method and real-time PCR. The PCR products were analyzed by electrophoresis in12.5% polyacrylamide gel (PAGE; Phast System, Amersham Pharmacia Biotech) and silver stained (Silver Staining Kit; Amersham Pharmacia Biotech).
Results: SRY gene was detected in female PBM, LN and SPL cell cytoplasm in 2 out of 10 rats. Moreover, it was detected in PBM nuclei in 4 out of 10 rats and in LN cell nuclei also in 4 out of 10 rats.
Conclusions: Detection of donor male DNA in nuclei isolated from female cells suggests its spontaneous transport into recipients' cells and their nuclei. The question remains open whether this finding may have any relevance to the rejection or tolerance process.

Keywords: Kidney Transplantation