[Experimental study on immunotherapy with dendritic cell in leukemic mice model].
OBJECTIVE
To explore the feasibility and efficiency of immunotherapy with dendritic cell (DC) in leukemic mice model after allogeneic bone marrow transplantation (allo-BMT).


METHODS
Mature DC were expanded from mice bone marrow mononuclear cells (MNC) by adding mouse granulocyte-macrophage colony stimulating factor (mGM-CSF) and interleukin-4 (mIL-4). Three days later they were pulsed with frozen thawing L7212 leukemia-related antigen. Mice bearing leukemia received allo-BMT at d 0, and then were divided into control group (A), T cells group (B) and DC + T cells group (C) to receive respective immune therapy at d 14. The survival rate, survival time, occurrence of graft-versus-host disease (GVHD), cytotoxicity of spleen cells and serum cytokine level were observed. The survivors in each group were rechallenged with L7212 cells to observe the immune response to the leukemia.


RESULTS
Mature DC were successfully induced from bone marrow MNC. In groups B and C, the relapse rates were 30% and 0%, while the long term survival rates after BMT was 30% and 70% respectively. Both of the differences were statistically significant (P < 0.05). However, the incidence of GVHD in these two groups were similar. The mean survival times were (32.95 +/- 13.29) days and (41.15 +/- 13.88) days, respectively (P < 0.01). MTT assay indicated that spleen cells from group C had specific killing activity to L7212 cells. Enzyme-labeled immunosorbent assay (ELISA) showed that the serum IL-2 level in group C was (419.75 +/- 26.66) pg/ml, being significantly higher than that in the other two groups (P < 0.01). When the survivors were rechallenged with L7212 cells, there was difference between the survival rates of groups C and B (85.7% vs 33.3%, P < 0.05).


CONCLUSIONS
Immunotherapy with leukemia related antigen-pulsed DC in combination with donor lymphocyte infusions is an effective approach to reinforce GVL effect and decrease relapse after allo-BMT.
Li
Xiang-xin
XX
Department of Hematology, Qilu Hospital, Shandong University, Jinan 250012, China.
Chen
Xue-liang
XL
Ma
Dao-xin
DX
Liu
Chun-sheng
CS
He
Xiao-peng
XP
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D016026:Bone Marrow Transplantation; D019496:Cancer Vaccines / Q000276:immunology; D002454:Cell Differentiation; D003713:Dendritic Cells / Q000276:immunology*; D005260:Female; D020544:Graft vs Leukemia Effect; D007167:Immunotherapy; D007942:Leukemia, Experimental / Q000276:immunology / Q000601:surgery / Q000628:therapy*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D015996:Survival Rate; D014184:Transplantation, Homologous
D019496:Cancer Vaccines