Factors for differentiation affecting of neonatal regulatory T cells

Abstract

Objective To investigate the possible factors for differentiation affecting of neonatal regulatory T cells (Treg). Methods Umbilical cord blood was collected from 200 newborns.Treg number was detected by DNA demethylation in the Foxp3 of Treg-cell-specific demethylatedregion (TSDR) based on high resolution melting analysis (HRMA), concentrations of 7, 8 -dihydroxy -9, 10-epoxy -benzo (a) pyrene(BPDE-DNA) adducts and interleukin-4(IL-4)in the supernatants of cord blood by enzyme-linked immunosorbent assay(ELISA), and follow-up questionnaires were carried out till 1.0-1.5 years, for recurrent wheezing or stubborn eczema in infants and related information on parental history of atopic diseases. Results (1) In wheezing group [(0.48±0.05)%]and eczema group[(0.76±0.05)%], the number of Tregs was significantly lower compared with that of the asymptomatic group [(1.14±0.08) %](t=2.62, 2.83, all P<0.05); the number of Treg in parental history of atopic group was significantly lower than that of the non-atopic group (P<0.05); but the Treg numbers in the non-atopic group was still lower than that of the asymptomatic group (P<0.05). (2)The concentrations of BPDE-DNA adducts in the wheezing group [(236.30±6.59) ng/L]and the eczema group [(173.40±7.38) ng/L]were higher than those of the asymptomatic group [(111.01±3.36) ng/L](t=10.35, 6.53, all P<0.05), while BPDE-DNA adduct concentrations in the atopic group with parental history of wheezing or eczema in infants were lower than those of the non-atopic group(P<0.05). (3) The concentrations of IL-4 in the wheezing or eczema group in the supernatants of cord blood was higher than the asymptomatic group (P<0.05). Conclusions Neonatal genetic factors and BPDE-DNA adducts could affect Treg differentiation, which are probably the reasons for the formation of allergic diseases. Key words: Regulatory T cells; Atopic; Polycyclic aromatic hydrocarbon; DNA adducts; Cell differentiation