Abstract
There is evidence for an interaction of the commensal flora and development of allergic disease. Epidemiological studies and studies in murine models suggest that infection with H. pylori protects against developing allergic airway disease. Treatment with a lysate of the bacteria was also able to reduce allergic airway disease (Engler et al. PNAS 2014). The effect was mediated by IL-10 producing DC, but in contrast to live infection did not depend on the induction of regulatory T cells (Treg). In our in vitro study the effect of lysate of H. pylori on human monocyte-derived (mo-)DC was evaluated. Immature DC exposed for 48 h to H. pylori lysate in presence or absence of LPS matured and strongly increased the release of the anti-inflammatory cytokine IL-10. DCs exposed to the lysate reduced polarization from naïve T cells to Th1 cells. Instead, T cells differentiated by the lysate-exposed DCs of a subgroup of donors secreted more IL-10 compared to T cells from control DC, suggesting the induction of Treg. These Treg were able to suppress proliferation of alloreactive memory T cells in vitro. Our results suggest that H. pylori lysate has strong IL-10 inducing capacities in human mo-DC, which can induce IL-10 secreting T cells with a suppressive function.
Further studies are needed to assess if this approach can be utilized in humans to dampen unwanted immune responses.
- Copyright ©ERS 2015
