Comparison of neonatal T regulatory cell function in Papua New Guinean and Australian newborns.

To cite this article: Lisciandro JG, Prescott SL, Nadal-Sims MG, Devitt CJ, Pomat W, Siba PM., Holt PG, Strickland D, van den Biggelaar AHJ. Comparison of neonatal T regulatory cell function in Papua New Guinean and Australian newborns. Pediatr Allergy Immunol 2011: Doi: 10.1111/j.1399-3038.2011.01242.x. Abstract Background: Environmental changes, including declining microbial exposure, have been linked with the rising incidence of allergic and autoimmune diseases in 'western' populations. This potentially occurs by altering early development of immuno-regulatory pathways including T regulatory cells (T_reg). There is now increasing evidence that such conditioning begins in utero. Methods: We compared neonatal T_reg from children born under typical western conditions (Australia, AUS) with those of neonates born under more traditional conditions of high microbial burden (Papua New Guinea, PNG). Results: The frequency of neonatal T_reg, defined as CD4⁺ Foxp3⁺ CD127⁻ CD25^+/high was found to be higher in the cord blood of AUS compared to PNG newborns. However, cord T_reg suppressive function in a small subset of children was qualitatively similar between PNG and AUS newborns in both a T_reg depletion assay and a T_reg supplementation assay. Conclusions: These findings do not support the hypothesis that living in a 'western' versus more traditional environment leads to poor induction or suppressive function of neonatal T_reg. However, environmentally-induced immuno-regulation may potentially occur via alternative mechanisms in PNG newborns that should now be investigated further. [ABSTRACT FROM AUTHOR]