One in nine pregnant women report drinking during pregnancy. Prenatal alcohol exposure (PAE) increases the risk of infection in the newborn by altering development with resultant changes in immune function including cytokine expression. Toll-like receptors are expressed on multiple types of cells and play a vital role in modulation of the innate immune system and the release of inflammatory mediators. Therefore, we predicted that PAE would result in alterations in the pattern of cytokine expression following stimulation with toll-like receptor agonists, in umbilical cord blood samples.
Cord blood samples were obtained from a subset of infants born to the prospective ENRICH-2 cohort study participants. This study includes two prenatal visits, a comprehensive assessment at birth/first month of life, and a 6-month follow-up assessment. Pregnancy alcohol use was ascertained by four Timeline Follow-Back interviews and comprehensive ethanol biomarker panels. Women were grouped into PAE and Control (no exposure) groups. Peripheral blood mononuclear cells (PBMCs) were isolated from cord blood by Ficoll-isopaque density gradient centrifugation. Cells were plated and stimulated with lipopolysaccharide (LPS, TLR4 agonist), Pam3CSK4 (TLR2 agonist), CpG ODN (TLR9 agonist) and Poly I:C (TLR3 agonist). Electrochemiluminescence assay was completed, and cytokine expressions of IFN-γ, IL-10, IL-12p70, IL-13, IL-1β, IL-2, IL-4, IL-6, IL-8 and TNF-α were measured. The cytokine expressions were compared by Student’s t-test.
To date, samples from 14 infants were evaluated (Control=7, PAE=7). Alcohol use was moderate (AA/day[SD]=0.4[0.2]). No differences in maternal age or education were observed. Significant increases in PAE compared to baseline in IFN-γ, IL-10, IL-12p70, IL-13, IL-1β, IL-2, IL-4, IL-8 and TNF-α expression following stimulation with LPS were observed (p<0.05), with PAE having more significant increases. Additionally, significant increases were observed following stimulation with Pam3CSK4, CpG ODN and Poly I:C. Interestingly, PAE resulted in a more robust increase in expression (control p values: 0.01 – 0.07; PAE p values: 0.001 – 0.05) following stimulation with Pam3CSK4 compared to the control group.
These results support that even moderate PAE may alter the developing immune system, with alterations in cytokine expression that have the potential to impact lifelong immunological reactions.
Maxwell, Jessie R.; Shahani Noor; Nathaniel Pavlik; Dominique Rodriguez; Lidia Enriquez Marquez; Jared DiDomenico; and Ludmila N. Bakhireva. "Moderate Prenatal Alcohol Exposure Increases Toll-Like Receptors Activity Detectable in Umbilical Cord Blood at Birth." (2021). https://digitalrepository.unm.edu/hsc_2021_pediatric_research/11