Journal article
Seasonal Antimicrobial Activity of the Airway: Post-Hoc Analysis of a Randomized Placebo-Controlled Double-Blind Trial
Nutrients, Vol.12(9), p.2602
08/27/2020
DOI: 10.3390/nu12092602
PMCID: PMC7551279
PMID: 32867053
Abstract
It is widely unknown why respiratory infections follow a seasonal pattern. Variations in ultraviolet B (UVB) light during seasons affects cutaneous synthesis of vitamin D
. Serum vitamin D concentration influences the expression of airway surface liquid (ASL) antimicrobial peptides such as LL-37.
We sought to determine the effect of seasons on serum vitamin D levels and ASL antimicrobial activity.
Forty participants, 18-60 years old, were randomized 1:1 to receive 90 days of 1000 IU vitamin D
or placebo. We collected ASL via bronchoscopy and measured serum 25(OH) vitamin D from participants before and after intervention across seasons. We measured ASL antimicrobial activity by challenging samples with bioluminescent
and measured relative light units (RLUs) after four minutes. We also investigated the role of LL-37 using a monoclonal neutralizing antibody.
We found that participants, prior to any intervention, during summer-fall (
= 20) compared to winter-spring (
= 20) had (1) decreased live bacteria after challenge (5542 ± 175.2 vs. 6585 ± 279 RLU,
= 0.003) and (2) higher serum vitamin D (88.25 ± 24.25 vs. 67.5 ± 45.25 nmol/L,
= 0.026). Supplementation with vitamin D
increased vitamin D levels and restored ASL antimicrobial activity only during the winter-spring. The increased ASL antimicrobial activity seen during the summer-fall was abrogated by adding the LL-37 neutralizing antibody.
ASL kills bacteria more effectively during the summer-fall compared to the winter-spring. Supplementation of vitamin D during winter-spring restores ASL antimicrobial activity by increasing the expression of antimicrobial peptides including LL-37.
Details
- Title: Subtitle
- Seasonal Antimicrobial Activity of the Airway: Post-Hoc Analysis of a Randomized Placebo-Controlled Double-Blind Trial
- Creators
- Luis G Vargas Buonfiglio - Department of Internal Medicine, Carver College of Medicine Iowa City, University of Iowa, Iowa City, IA 52242, USAOriana G Vanegas Calderon - Department of Pediatrics, Carver College of Medicine Iowa City, University of Iowa, Iowa City, IA 52242, USAMarlene Cano - Department of Internal Medicine, Carver College of Medicine Iowa City, University of Iowa, Iowa City, IA 52242, USAJacob E Simmering - Department of Internal Medicine, Carver College of Medicine Iowa City, University of Iowa, Iowa City, IA 52242, USAPhilip M Polgreen - Department of Internal Medicine, Carver College of Medicine Iowa City, University of Iowa, Iowa City, IA 52242, USAJoseph Zabner - Department of Internal Medicine, Carver College of Medicine Iowa City, University of Iowa, Iowa City, IA 52242, USAAlicia K Gerke - Department of Internal Medicine, Carver College of Medicine Iowa City, University of Iowa, Iowa City, IA 52242, USAAlejandro P Comellas - Department of Internal Medicine, Carver College of Medicine Iowa City, University of Iowa, Iowa City, IA 52242, USA
- Resource Type
- Journal article
- Publication Details
- Nutrients, Vol.12(9), p.2602
- DOI
- 10.3390/nu12092602
- PMID
- 32867053
- PMCID
- PMC7551279
- NLM abbreviation
- Nutrients
- ISSN
- 2072-6643
- eISSN
- 2072-6643
- Publisher
- Switzerland
- Grant note
- KO1HL080966 / NIH HHS P30 ES005605 / NIEHS NIH HHS P30 ES005605 / NIH HHS P30 DK054759 / NIDDK NIH HHS NO1-AI- 30040-01 / NIH HHS UL1RR024979 / NIH HHS
- Language
- English
- Date published
- 08/27/2020
- Academic Unit
- Pulmonary, Critical Care, and Occupational Medicine; Infectious Diseases; Health Management and Policy; ICTS; Epidemiology; Pharmacy Practice and Science; Injury Prevention Research Center; Internal Medicine
- Record Identifier
- 9984066110302771
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