Current understanding of innate immune cell dysfunction in childhood undernutrition
- 1Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom
- 2Zvitambo Institute for Maternal and Child Health Research, Zimbabwe
- 3Kennedy Institute of Rheumatology, University of Oxford, United Kingdom
- 4Department of Paediatric Gastroenterology and Nutrition, University of Oxford NHS Foundation Trust, United Kingdom
Undernutrition affects millions of children in low- and middle-income countries (LMIC) and underlies almost half of all deaths among children under 5 years old. The growth deficits that characterise childhood undernutrition (stunting and wasting) result from simultaneous underlying defects in multiple physiological processes, and current treatment regimens do not completely normalise these pathways. Most deaths among undernourished children are due to infections, indicating that their anti-pathogen immune responses are impaired. Defects in the body’s first-line-of-defence against pathogens, the innate immune system, is a plausible yet understudied pathway that could contribute to this increased infection risk. In this review, we discuss the evidence for innate immune cell dysfunction from cohort studies of childhood undernutrition in LMIC, highlighting knowledge gaps in almost all innate immune cell types. We supplement these gaps with insights from relevant experimental models and make recommendations for how human and animal studies could be improved. A better understanding of innate immune function could inform future tractable immune-targeted interventions for childhood undernutrition to reduce mortality and improve long-term health, growth and development.
Keywords: undernutrition, innate immune cells, Infections, Children, Low- and Middle- Income Countries (LMICs)
Received: 14 May 2019;
Accepted: 09 Jul 2019.
Edited by:Nancie J. MacIver, Duke University, United States
Reviewed by:Brandt D. Pence, University of Memphis, United States
Anastasia N. Vlasova, The Ohio State University, United States
Copyright: © 2019 Bourke, Jones and Prendergast. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Claire D. Bourke, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom, firstname.lastname@example.org