Study the Effect of Air Pollution on the Number، Expansion and Suppressory Function of Cord Blood Regulatory T cells

Air pollution is one of the main causes of escalating allergies, especially in children. Genetic factors, along with environmental factors, affect the development and maturity of the immune system during the fetal period in the uterus and the early stages of life. Regulatory T cells play an essential role in maintaining the balance for the immune system when exposed to environmental pollutants.

Cord blood sampling was performed on 10 neonates born from mothers living in pollutant areas of Tehran and 10 neonates born from mothers living in Damavand city. Cord Blood Monomorphonuclear Cells were separated via density gradient centrifugation. Flow cytometric staining of CD4, CD25, CD127, and FoxP3 cell markers, as well as intracellular staining of regulatory T cell cytokines IL-10 and TGF-β1 were performed. Isolation and purification of CD4 +, CD25 + Tcells with MACS were done and culture of regulatory T cells in the presence of anti-CD3/CD28 coated beads in 1/1 bead-to-cell ratio were performed. T-cell suppression assay was evaluated through Measurement of Teff proliferation.

In the present study, the percentages of T-regulatory IL-10 + and TGF-b1 + in infants born in clean air regions were higher than those in contaminated air. The T-cell suppressory function in in vitro Teff / Treg ratio (1. 1) was significantly lower in infants born in airborne contamination than in newborns born in clean air. The rate of proliferation of Treg cells in the presence of IL-2 and anti-CD3 / CD28 mice was higher in two-week cultures in newborns born in clean air than those born in contaminated air.

The results of the present study showed that the contractile function of T cells in umbilical cord blood in newborns born of mothers living in infected areas of Tehran was lower than those born to mothers living in Damavand. Overall, the chronic exposure of mothers to airborne particulate matter before pregnancy and during pregnancy may reduce the function of the regulatory T cells and increase the risk of an increased allergy to newborns throughout life.