title: Prenatal vitamin D₃ supplementation suppresses LL-37 peptide expression in ex vivo activated neonatal macrophages but not their killing capacity.
abstract: Vitamin D has regulatory effects on innate immunity. In the present study, we aimed to assess the effect of prenatal vitamin D₃ (vitD₃) supplementation on neonatal innate immunity in a randomised, placebo-controlled trial by evaluating cathelicidin (LL-37) expression and the killing capacity of macrophages. Healthy pregnant women (n 129) attending a clinic in Dhaka were randomised to receive either a weekly oral dose of 0·875 mg vitD₃ or placebo starting from 26 weeks of gestation up to delivery. Serum, plasma and monocyte-derived macrophages (MDM) were obtained from the cord blood. 25-Hydroxyvitamin D (25(OH)D) concentration was measured in serum. MDM were stimulated with or without Toll-like-receptor 4 ligand (TLR4L). Innate immune function was assessed by measuring LL-37 peptide levels in the culture supernatant of MDM by ELISA, LL-37 transcript levels by quantitative PCR, and ex vivo bactericidal capacity of MDM. VitD₃ supplementation did not increase LL-37 peptide levels in plasma or in the extracellular fluid of macrophages with or without TLR4L induction. However, stimulated intracellular LL-37 expression (ratio of stimulated:unstimulated MDM) was significantly reduced in the vitamin D group v. placebo (P=0·02). Multivariate-adjusted analyses showed that intracellular LL-37 peptide concentration from stimulated MDM was inversely associated with 25(OH)D concentration in serum (P=0·03). TLR4L stimulation increased the bactericidal capacity of MDM compared with the unstimulated ones (P=0·01); however, there was no difference in killing capacity between the two groups. A weekly dose of 0·875 mg vitD₃ to healthy pregnant women suppressed the intracellular LL-37 peptide stores of activated macrophages, but did not significantly affect the ex vivo bactericidal capacity of cord blood MDM.
authors.affiliation: Nutritional Biochemistry Laboratory, Centre for Vaccine Sciences, International Centre for Diarrheal Disease Research, Bangladesh (ICDDR,B), Mohakhali,1212Dhaka,Bangladesh.
authors.forename: Rubhana
authors.initials: R
authors.lastname: Raqib
authors.affiliation: Department of Paediatrics,Hospital for Sick Children and University of Toronto, 555 University Avenue,Toronto,ON,CanadaM5G 1X8.
authors.forename: Anna
authors.initials: A
authors.lastname: Ly
authors.affiliation: Nutritional Biochemistry Laboratory, Centre for Vaccine Sciences, International Centre for Diarrheal Disease Research, Bangladesh (ICDDR,B), Mohakhali,1212Dhaka,Bangladesh.
authors.forename: Evana
authors.initials: E
authors.lastname: Akhtar
authors.affiliation: Nutritional Biochemistry Laboratory, Centre for Vaccine Sciences, International Centre for Diarrheal Disease Research, Bangladesh (ICDDR,B), Mohakhali,1212Dhaka,Bangladesh.
authors.forename: Akhirunnesa
authors.initials: A
authors.lastname: Mily
authors.affiliation: Department of Paediatrics,Hospital for Sick Children and University of Toronto, 555 University Avenue,Toronto,ON,CanadaM5G 1X8.
authors.forename: Nandita
authors.initials: N
authors.lastname: Perumal
authors.affiliation: Nutritional Biochemistry Laboratory, Centre for Vaccine Sciences, International Centre for Diarrheal Disease Research, Bangladesh (ICDDR,B), Mohakhali,1212Dhaka,Bangladesh.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Al-Mahmud
authors.affiliation: Nutritional Biochemistry Laboratory, Centre for Vaccine Sciences, International Centre for Diarrheal Disease Research, Bangladesh (ICDDR,B), Mohakhali,1212Dhaka,Bangladesh.
authors.forename: Rokeya Sultana
authors.initials: RS
authors.lastname: Rekha
authors.affiliation: Department of International Health,International Center for Maternal and Newborn Health, The Johns Hopkins Bloomberg School of Public Health,615 North Wolfe Street,Baltimore,MD21205,USA.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Hel Baqui
authors.affiliation: Department of Paediatrics,Hospital for Sick Children and University of Toronto, 555 University Avenue,Toronto,ON,CanadaM5G 1X8.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Roth
mesh_terms: D000293:Adolescent; D000328:Adult; D023181:Antimicrobial Cationic Peptides; D001459:Bangladesh; D054804:Cathelicidins / Q000037:antagonists & inhibitors* / Q000097:blood / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D002762:Cholecalciferol / Q000009:adverse effects / Q000627:therapeutic use*; D015331:Cohort Studies; D019587:Dietary Supplements / Q000009:adverse effects; D005260:Female; D005312:Fetal Blood; D006801:Humans; D007113:Immunity, Innate; D007155:Immunologic Factors / Q000009:adverse effects / Q000627:therapeutic use*; D008262:Macrophage Activation; D008264:Macrophages / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D039382:Maternal Nutritional Physiological Phenomena; D010587:Phagocytosis; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control; D011263:Pregnancy Trimester, Third; D014808:Vitamin D Deficiency / Q000097:blood / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control; D055815:Young Adult
chemical_list: D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins; D007155:Immunologic Factors; D002762:Cholecalciferol