In utero exposure to diesel exhaust particles, but not silica, alters post-natal immune development and function

Our understanding of the impact of in utero exposure to PM on post-natal immune function and the subsequent response to PM exposure is limited. Similarly, very few studies have considered the effect of exposure to PM from different sources. Thus, the aim of this study was to examine how in utero exposure to PM from different sources effects the post-natal response to pro-inflammatory and immune stimuli. C56BL/6J pregnant mice were exposed intranasally on gestational day (E)7.5, E12.5 and E17.5-50 mu g of diesel exhaust particles (DEP), silica or saline. At 4-weeks post-natal age, sub-groups of male and female mice were exposed intranasally to 50 mu g of DEP or saline. Lung inflammatory responses were assessed 6 h later by quantifying inflammatory cells and cytokine production (MCP-1, MIP-2, IL-6). In separate groups of mice, the spleen was harvested to quantify B and T cell populations. Splenocytes were isolated and exposed to lipopolysaccharide or poly LC for assessment of cytokine production. Exposure to DEP in utero decreased %CD1d(high) CD5+ B cells in female mice and IFN-gamma production by splenocytes in both sexes. Male mice had elevations in macrophage and lymphocyte numbers in response to DEP whereas female mice only had elevated IL-6, MCP-1 and MIP-2 levels. In utero exposure to silica had no effect on these measures. These data suggest that in utero exposure to PM alters immune development and postnatal immune function. This response is dependent on the source of PM, which has implications for understanding the community health effects of exposure to air pollution. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

In utero exposure to particulate matter from different sources affects post-natal immune development and function, with the response varying depending on the PM source. Diesel exhaust particles had different effects on male and female mice, while exposure to silica had no impact on the measured immune parameters.