Objective

2

To explore the possible mechanism of

Fuzheng Qudu Decoction

（扶正祛毒汤， FQD） in the treatment of minimal residual leukemia.

Methods

2

Twelve New Zealand white rabbits were randomly divided into normal group and low-， medium-， high-dose FQD groups， with three rabbits in each group. Rabbits in the low-， medium-， and high-dose groups of FQD were given concentrated decoction of 5， 10 and 20 g/（kg·d） by gavage for 3 days， while the normal group was given 7.5 ml of normal saline by gavage. After the last intragastric administration， blood was collected from the heart to obtain normal serum， and low-， medium- and high-dose FQD serum. After diluting the bone marrow of patients with complete remission of acute myeloid leukemia， the CD34

+

cells were isolated and purified； and the expanded CD34

+

cells were divided into blank group， cytokine group， normal serum group and FQD low-， medium- and high-dose serum groups. Except for the blank group， samples were added with cytokines to induce dendritic cells within 9 days， and the cell morphology was observed before induction and during culture. Nine days later， the expression of dendritic cell surface antigen molecules CD1a， CD83， human leukocyte DR antigen （HLA-DR）， B7-1， and B7-2 were detected， and the expression of protein and mRNA of B7-1 and B7-2 in dendritic cells was detected.

Results

2

No dendritic changes were observed in the cells of the blank group； the cell bodies were significantly enlarged， and the cell surface showed typical stellate pleomorphism or dendritic protrusions in the cytokine group， normal serum group and FQD low-， medium-， and high-dose serum groups， with medium-dose serum group as the most typical one. Compared to those in the blank group， the expressions of dendritic cell surface markers CD1a， CD83， HLA-DR， B7-1， and B7-2 in other groups all increased （

P

＜0.05）； compared to the cytokine group and normal serum group， the three FQD groups had higher expressions of dendritic cell surface antigen molecules （

P

＜0.05）. Compared to those in the blank group， cytokine group and normal serum group， the expression of B7-1 and B7-2 protein and mRNA in the low-， medium-， and high-dose FQD serum groups all increased （

P

＜0.05）. Compared to those in the medium-dose FQD serum group， the expressions of B7-1 and B7-2 protein and mRNA in the low- and high-dose serum groups all decreased （

P

＜0.05）.

Conclusion

2

FQD can promote the maturation of CD34

+

cell-derived dendritic cells， increase the expression of co-stimulatory molecules B7-1 and B7-2， and improve the ability of antigen presentation in patients with acute myeloid leukemia in complete remission， which may represent one mechanism of action in minimal residual leukemia by FQD.