Associations and interactions of genetic polymorphisms in innate immunity genes with early viral infections and susceptibility to asthma and asthma-related phenotypes.
BACKGROUND
The innate immune system is essential for host survival because of its ability to recognize invading pathogens and mount defensive responses.


OBJECTIVE
We sought to identify genetic associations of innate immunity genes with atopy and asthma and interactions with early viral infections (first 12 months of life) in a high-risk birth cohort.


METHODS
Three Canadian family-based studies and 1 Australian population-based case-control study (n = 5565) were used to investigate associations of 321 single nucleotide polymorphisms (SNPs) in 26 innate immunity genes with atopy, asthma, atopic asthma, and airway hyperresponsiveness. Interactions between innate immunity genes and early viral exposure to 3 common viruses (parainfluenza, respiratory syncytial virus, and picornavirus) were examined in the Canadian Asthma Primary Prevention Study by using both an affected-only family-based transmission disequilibrium test and case-control methods.


RESULTS
In a joint analysis of all 4 cohorts, IL-1 receptor 2 (IL1R2) and Toll-like receptor 1 (TLR1) SNPs were associated with atopy after correction for multiple comparisons. In addition, an NFKBIA SNP was associated with atopic asthma. Six SNPs (rs1519309 [TLR3], rs740044 [ILIR2], rs4543123 [TLR1], rs5741812 [LBP], rs917998 [IL18RAP], and rs3136641 [NFKBIB]) were significant (P < .05, confirmed with 30,000 permutations) in both the combined analysis of main genetic effects and SNP-virus interaction analyses in both case-control and family-based methods. The TLR1 variant (rs4543123) was associated with both multiple viruses (respiratory syncytial virus and parainfluenza virus) and multiple phenotypes.


CONCLUSIONS
We have identified novel susceptibility genes for asthma and related traits and interactions between these genes and early-life viral infections.
University of British Columbia James Hogg Research Centre, Institute for Heart and Lung Health, Vancouver, British Columbia, Canada. denise.daley@hli.ubc.ca
Denise
D
Daley
Julie E
JE
Park
Jian-Qing
JQ
He
Jin
J
Yan
Loubna
L
Akhabir
Dorota
D
Stefanowicz
Allan B
AB
Becker
Moira
M
Chan-Yeung
Yohan
Y
Bossé
Anita L
AL
Kozyrskyj
Alan L
AL
James
Arthur W
AW
Musk
Catherine
C
Laprise
Richard G
RG
Hegele
Peter D
PD
Paré
Andrew J
AJ
Sandford
D001249:Asthma / Q000235:genetics* / Q000276:immunology*; D001315:Australia; D002170:Canada; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011110:Polymorphism, Genetic; D017472:Receptors, Interleukin-1 / Q000235:genetics; D051194:Toll-Like Receptor 1 / Q000235:genetics; D014777:Virus Diseases / Q000235:genetics* / Q000276:immunology*
D017472:Receptors, Interleukin-1; D051194:Toll-Like Receptor 1