[The influence of antigen loading on the immunological characteristics of dendritic cells induced by low concentrations of granulocyte macrophage colony stimulating factor].
OBJECTIVE
To investigate the influence of low doses of granulocyte macrophage colony stimulating factor on the allogeneic antigen (Ag) ingestion capacity of immature dendritic cells (GM low DC), and subsequently the changes in the cellular phenotype and function.


METHODS
Mononuclear cells from C57BL/6 mice was labelled with 3H-Leu to make Ag supernatant. The Ag supernatant was cocultured with GM low DC or mature DC for 30,60 and 90 mins, then cpm value were determined. The changes in I(A)/I(E) and CD80 on cell surface after antigen ingestion were determined with flow cytometry (FCM). By using mixed lymphocyte reaction (MLR), the cells were divided into control (non-sensitized T lymphocyte), GM low DC, GM low DC and allogeneic antigen, GM low DC and allogeneic antigen and CTLA-4 Ig groups. The cpm value in each group was recorded and the stimulation index (SI) was calculated.


RESULTS
Upon 30, 60 and 90 mins of allogeneic Ag stimulation, the cpm value of GM low DC was obviously higher than that of mature DC (P < 0.05 or 0.01). In addition, the expression of I(A)/I(E) and CD80 before allogeneic Ag ingestion were significantly higher than those after Ag ingestion (I(A)/I(E): 32 +/- 8% vs. 54 +/- 10, P < 0.05; CD80: 25 +/- 10% vs. 71 +/- 18%, P < 0.01). MLR: Compared with control group, the cpm value in GM low DC with allogeneic Ag group was increased markedly (P < 0.05), with SI higher than 2.0, while no difference was found among control, GM low DC group, GM low DC and allogeneic Ag and CTLA-4Ig groups (P > 0.05), with SI lower than 2.0


CONCLUSIONS
Though GM low DC exhibits powerful antigen ingestion capacity, the cell phenotype and function will get mature gradually. Immune tolerance can be established by incubating GM low DC with CTLA-4Ig.
Wang
Qiang
Q
Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burns and Combined Injury, The Third Military Medical University, Chongqing 400038, PR China.
Peng
Yi-zhi
YZ
Wang
Yi-tao
YT
Wang
Yong-quan
YQ
You
Bo
B
D000069594:Abatacept; D000818:Animals; D000941:Antigens / Q000276:immunology*; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000008:administration & dosage / Q000494:pharmacology*; D007108:Immune Tolerance / Q000187:drug effects; D018796:Immunoconjugates / Q000494:pharmacology; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL
D000941:Antigens; D018796:Immunoconjugates; D000069594:Abatacept; D016178:Granulocyte-Macrophage Colony-Stimulating Factor