[The phagocytosis of apoptotic allogeneic lymphocytes by recipient liver antigen-presenting cells].
OBJECTIVE
To track the location of the transfused apoptotic allogeneic lymphocytes and asses the process of their accumulation and phagocytosis removal as consequences on allograft tolerance in recipient mice.


METHODS
Donor spleen lymphocytes were labeled by CFSE and induced to apoptosis by dexamethasone incubation. After purification by anti-annexin V-conjugated magnetic beads isolation, apoptotic lymphocytes were transfused into recipient mice through the tail veins. Tissue samples from various organs were taken at various time points to analyze the fates of the apoptotic allogeneic lymphocytes and the phagocytosis of them by organ resident APCs.


RESULTS
Using fluorescent microscopy and flow cytometry, after the apoptotic cells were recognized and uptaken, the largest amount of labeled cells were accumulated in the livers and disappeared within not more than 12 hours. Recipient liver APCs were highly efficacious in phagocytosis of apoptotic allogeneic lymphocytes; the removal was completed within 15 minutes after incubation. LSEC, KC and LDC all phagocytosized the apoptotic allogeneic lymphocytes but with significantly different rates. Considering the numbers of those cells in a normal liver, it could be calculated that LSEC and KC had greater effects in this activity.


CONCLUSIONS
The liver deserves foremost attention for study of the mechanism of allografts tolerance induced by pre-transfusion of apoptotic donor spleen lymphocytes. LSEC and KC are the main functional APCs to the alloantigens.
Wang
Yan
Y
Department of General Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China.
Gao
Yi
Y
Sun
Er-wei
EW
Chen
Zhong-hua
ZH
D000818:Animals; D000938:Antigen-Presenting Cells / Q000166:cytology / Q000276:immunology*; D017209:Apoptosis / Q000502:physiology*; D008099:Liver / Q000166:cytology* / Q000276:immunology; D017710:Lymphocyte Transfusion; D008214:Lymphocytes / Q000166:cytology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010587:Phagocytosis / Q000502:physiology*; D013154:Spleen / Q000166:cytology; D014184:Transplantation, Homologous