15 Jan Children With Food Allergies May Have Overactive Immune System From Birth
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Dr. Yuxia Zhang
MedicalResearch.com Interview with:
Yuxia Zhang PhD
Population Healthy and Immunity Division
Walter + Eliza Hall Institute
Parkville VIC 3052 Australia
Medical Research: What is the background for this study?
Dr. Zhang: There has been a dramatic increase in hospital presentations due to food allergy over recent decades, most among children under five years of age. In Melbourne Australia, up to one in every 10 babies develop food allergy during the first year of life. To understand the mechanisms underlying the increased incidences of allergy and other diseases in children, Associate Professor Peter Vuillermin and colleagues established the Barwon Infant Studies (BIS), following and collecting bio-speciments from pregnant mothers and their babies. Together with my colleagues Prof. Leonard Harrison and Mr. Gaetano Naselli from the Walter and Eliza Hall Institute of Medical Research, we examined the immune cell composition and function in cord blood in babies who developed food allergy compared to allergy-free babies at one year of age.
Medical Research: What are the main findings?
Dr. Zhang: Our initial observation was that in cord blood the proportions of CD14+ monocytes and CD4+T cells were inversely associated. In infants who developed food allergy, there was a higher ratio of CD14+monoctypes/CD4+T cells and a lower ratio of naive natural regulatory T cells (nTreg). The reduced nTreg frequency was also independently discovered by Dr. Fiona Collier in the BIS fresh blood cohort. CD14+ monocytes are the foot-solders of the immune system, which immediately release inflammatory cytokines upon infection. These inflammatory cytokines then guide the unexperienced CD4+T cells down to different paths to control infection. nTreg cells police the immune system to prevent unwanted damages during the elimination of the infections. Despite this widely accepted view of how our immune system are activated, we do not know if and how these interactions may cause an allergic reaction in babies. Through a series of in vitro experiments, we found that the inflammatory cytokines- most likely in the mucosal sites where food allergy was initiated-could lead the development of both CD4+T cells and nTregs towards a Th2-type immune phenotype. These Th2-type immune cells secrete large amount of IL-4, a cytokine through which may cause allergic reactions to some foods.
Medical Research: What should clinicians and patients take away from your report?
Dr. Zhang: In our study, it is evident that some infants who develop food allergy have an over-reactive innate immune system at birth. Even though the causes of these are unclear, it does indicate that some environmental factors may act either independently or in concert with some risk genes in early life that predispose babies to food allergy. The underlying mechanism we described in the article agrees with epidemiological evidences suggesting that diets or dietary supplements that have anti-inflammatory properties may reduce the risk for food allergy in infants and children.
However, our study did not address the efficacy of any anti-inflammatory drugs on prevention or treatment of food allergy. The underlying causes of allergic reactions maybe different from individual to individual. Thus we do not recommend self-medication.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Zhang: Do environmental factors that have shown beneficiary effects on preventing food allergy development change immune cell composition and function?
Can anti-inflammatory strategies prevent or treat food allergy?
Medical Research: Is there anything else you would like to add?
Dr. Zhang: We need to examine how environmental factors interact with the genetics leading to food allergy susceptibility in individuals in early life. Armed with these knowledge early life interventions may improve the health of our next generations.
Citation:
Zhang, F. Collier, G. Naselli, R. Saffery, M. L. Tang, K. J. Allen, A.-L. Ponsonby, L. C. Harrison, P. Vuillermin. Cord blood monocyte-derived inflammatory cytokines suppress IL-2 and induce nonclassic “TH2-type” immunity associated with development of food allergy. Science Translational Medicine, 2016; 8 (321): 321ra8 DOI:10.1126/scitranslmed.aad4322
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More on Allergies on MedicalResearch.com
Yuxia Zhang PhD (2016). Children With Food Allergies Appear To Have Overactive Immune System From Birth
Last Updated on January 16, 2016 by Marie Benz MD FAAD