Allogeneic T-cell apoptosis induced by interleukin-10-modified dendritic cells: a mechanism of prolongation of intestine allograft survival?
BACKGROUND
Genetic modification of donor dendritic cells (DC) is a potential therapy for allograft rejection. We hypothesized that in vitro interleukin-10 (IL)-10-transfected DC (DC-IL-10) may induce allogeneic T-cell apoptosis, resulting in prolonged allograft survival rat small intestine.


METHODS
Myeloid DC from Wistar-Furth rats (RT-1u) were propagated with rrGM-CSFand rrIL-4,then genetically modified to express the hIL-10 gene. Secretion of IL-10 was quantitated by enzyme-linked immunosorbent assay (ELISA). Allogeneic T cells from Lewis (LEW; RT-1(l)) at proliferative responses were determined by MTT assay in primary mixed leukocyte reactions. We then used a combination of DNA agarose gel electrophoresis, acridine orange staining, and Annexin V/propridium iodide assays to examine apoptosis of allogeneic T cells exposed to DC-IL-10. Then 5 x 10(6) donor-derived DC-IL-10 or untransduced DC were injected intravenously 7 days before small intestine transplantation (WF-->LEW).


RESULTS
DC-IL-10 showed pronounced impairment of T-cell allostimulatory activity. Apoptotic T cells were detected in the DC-IL-10 group. Flow cytometry counting at 72 hours showed 45.1% apoptotic T cells in response to DC-IL-10, whereas the untransduced group did not undergo significant apoptosis (P < .01). DC-IL-10 pretreated recipients showed moderate prolongation of allograft survival compared with controls (20.7 +/- 6.0 days vs 7.5 +/- 2.2 days, P < .01).


CONCLUSIONS
DC-IL-10 induced allogeneic T-cell hyporesponsiveness in vitro, possibly due to apoptosis. DC-IL-10 pretreated recipients displayed prolonged intestinal allograft survival rates.
Zhu
M
M
Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Wei
M F
MF
Liu
F
F
Shi
H F
HF
Wang
G
G
Chen
S
S
D000818:Animals; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology*; D006801:Humans; D016753:Interleukin-10 / Q000494:pharmacology*; D007421:Intestine, Small / Q000637:transplantation*; D051381:Rats; D011917:Rats, Inbred Lew; D011920:Rats, Inbred WF; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D014184:Transplantation, Homologous / Q000276:immunology*
D016753:Interleukin-10