3.2. Immunomodulatory effects of MQL on splenocytes from BALB/c
mice immunized by OVA
BALB/c mice were immunized twice with OVA and alum, then splenocytes
were isolated. Using this ex vivo system, we investigated whether
MQL treatment regulates allergic immune responses by suppressing cell
proliferation via increased HO-1 expression.
OVA-induced Th1- (IFN-γ) and Th2-related cytokines (IL-4, IL-5, and
IL-13) were significantly suppressed by MQL treatment (Fig.
2A-D) . Next, to investigate whether the immunomodulatory effects of MQL
were a consequence of decreased cell proliferation, we measured
proliferation and IL-2 production. Notably, MQL treatment suppressed
IL-2 production as well as splenocyte proliferation (Fig. 2F and
G) . To further characterize these T cell subsets, we analyzed Th1-
(STAT1) and Th2-associated transcriptional factor (STAT6), as well as
HO-1. Figures 2H and I show that STAT6 and STAT1
phosphorylation were reduced by MQL treatment, whereas HO-1 expression
was increased by MQL. Interestingly, however, the Th1-related cytokine
IL-12 was increased by MQL treatment (Fig. 2E) . These results
indicate that MQL treatment largely inhibits Th1- and Th2-related immune
responses via reduction of cell proliferation induced by HO-1
up-regulation.