Lipopolysaccharide-activated bone marrow-derived dendritic cells
suppress ovalbumin(OVA)-induced asthma by ameliorating the immune
microenvironment
Abstract
LPS produced by Gram-negative bacteria effectively stimulates the
maturation of BMDCs. Previous studies have shown that DClps might induce
tolerance in autoimmune diseases and cancer in vivo, whereas it remains
unclear whether DClps can modulate the immune microenvironment in
allergic asthma. We sought to elucidate the potential effects of DClps
on OVA-sensitized/challenged airway inflammation in a mouse model of
asthma, which may help facilitate the application of specific tolDCs in
allergic asthma patients in the future. We generated and obtained DClps
from wild-type mice to evaluate their functional characteristics by
ELISA and FACS. We also induced OVA-sensitized/challenged asthmatic mice
and intraperitoneally treated these mice with DClps to assess the
effects of these injected cells by histopathologic analysis and
performing inflammatory cell counts in BALF. Changes in memory CD4+ T
cells, Tregs and phosphorylated protein in lung digests were analyzed.
DClps exhibited lower levels of CD80 and MHCII and increased levels of
anti-inflammatory cytokines such as IL-10 and TGF-β than DCia.
Additionally, DClps treatment dramatically ameliorated airway
inflammation and diminished the infiltration of pulmonary inflammatory
cells. In addition, we prolonged the modeling time of asthmatic mice and
demonstrated that DClps treatment decreased the proliferation activity
of pulmonary memory CD4+ T cells, which further rendered the
downregulation of Th2 cytokines. However, the number of pulmonary Tregs
did not discernibly change. DClps treatment also markedly reduced the
phosphorylation level of STAT6 protein.