Breast Milk Exosomes and Mechanisms of Immunotoxicity from Perfluorinated Compounds (PFCs) and Polychlorinated Biphenyls (PCBs)

Principal Investigator: Dr. Diddier Prada, Associate Research Scientist, Department of Environmental Health Science at Columbia University

Project objective: The aim of this research project was to understand how certain chemicals that a mother is exposed to during pregnancy can affect the immune system development of her child. The researchers focused on two specific chemicals called perfluorinated compounds (PFCs) and polychlorinated biphenyls (PCBs). These chemicals can be found in various products and in the environment.

polychlorinated biphenyls Cl

Using results obtained with this pilot project, a new research project investigated the presence and characteristics of tiny particles called extracellular vesicles (EVs) and special molecules called microRNAs (miRNAs) in human breast milk. Breast milk is known to be crucial for a baby’s growth and health, particularly for their brain development and immune system. The study analyzed breast milk samples from 364 mothers and infants, identifying a total of 1523 miRNAs present in the milk. These miRNAs were organized into five clusters, with the top three clusters showing closely related miRNA levels.  Associations were found between miRNA expression and factors such as the time between childbirth and milk collection, the mother’s body mass index (BMI), and smoking status. However, no link was found between miRNA expression and the number of times the mother had given birth. The study highlights the need for further investigation into the factors influencing miRNA presence and levels in breast milk to better understand their implications for infant health and development.*

Project’s alignment with the Hoffman Program on Chemicals and Health mission: This research contributes to our understanding of how early-life exposures to chemicals can impact the immune system. By studying the role of breast milk and its components, the researchers hope to find ways to reduce the risks associated with these chemical exposures and promote healthier immune system development in children.

Some key takeaways:

  • The researchers were particularly interested in the role of breast milk in helping the baby’s immune system adapt to the effects of these chemicals. They examined small structures called exosomes that are present in breast milk. These exosomes contain important molecules called microRNAs that play a role in immune system communication. By studying samples from a group of mothers and their children in the Faroe Islands, the researchers aimed to understand if changes in these exosomes could reflect the mother’s exposure to PFCs and PCBs. They also wanted to investigate if these changes could predict how the child’s immune system develops.

Products resulting from Hoffman Program on Chemicals and Health support: Using results obtained with this pilot project, the investigators obtained a R21 from NIH (1 R21 ES027087-01, Early Exposure to Persistent Organic Pollutants, Breast Milk Extracellular Vesicles and Abnormal Cardiometabolic Programming). The publication below resulted from this work.

*Kupsco A, Prada D, Valvi D, Hu L, Petersen MS, Coull B, Grandjean P, Weihe P, Baccarelli AA. Human milk extracellular vesicle miRNA expression and associations with maternal characteristics in a population-based cohort from the Faroe Islands. Sci Rep. 2021 Mar 12;11(1):5840. doi: 10.1038/s41598-021-84809-2. PMID: 33712635; PMCID: PMC7970999.

Kupsco A, Lee JJ, Prada D, Valvi D, Hu L, Petersen MS, Coull BA, Weihe P, Grandjean P, Baccarelli AA. Marine pollutant exposures and human milk extracellular vesicle-microRNAs in a mother-infant cohort from the Faroe Islands. Environ Int. 2022 Jan;158:106986. doi: 10.1016/j.envint.2021.106986. Epub 2021 Nov 20. PMID: 34991248; PMCID: PMC8742869.