To investigate the immunological effect of the traditional Japanese herbal medicine (kampo), Hochu-ekki-to (HOT), on dendritic cells (DC), we examined in vitro if HOT would stimulate the maturation process of human monocyte-derived DC as do TNF-α and LPS. Monocytes from a healthy volunteer were cultured in the presence of IL-4 and GM-CSF, and the generated immature DC were stimulated with HOT, TNF-α, or LPS (HOT-DC, TNF-DC, and LPS-DC, respectively) for 2 days. Flow cytometric analysis showed that HOT stimulated DC to express the surface maturation markers CD80, CD83, and CD86 dose-dependently and that the up-regulation level was identical to TNF-α and LPS. The antigen-uptake capacity of HOT-DC was determined by FITC-labeled albumin uptake. HOT-DC lost albumin uptake capacity comparable to LPS-DC, indicating DC maturity. IL-12 (p70) production by HOT-DC and TNF-DC was not increased in comparison with LPS-DC. The antigen-presenting capacity of HOT-DC as analyzed by allogeneic T cell proliferation was significantly increased in comparison with immature DC and was identical to LPS-DC. These results demonstrate that HOT stimulates DC maturation as well as the other known maturation factors, despite low IL-12 production, and suggests the possibility that DC maturation by HOT can play an important role in the improvement of the immunoregulatory function in patients with impaired host defense.
All Science Journal Classification (ASJC) codes
- Immunology and Allergy