Association analysis of MICA gene polymorphism and MICA-129 dimorphism with inflammatory bowel disease susceptibility in a Spanish population.
MICA is located at 46 kb centromeric of HLA-B, is highly polymorphic and interactions with NKG2D, its receptor on the surface of NK, Tgammadelta, and T CD8 lymphocytes. A variation at amino acid position 129 of the alpha2-heavy chain domain seems to categorize MICA alleles into strong and weak binder of NKG2D receptor, and thereby to influence effector cell function. Our aim was to study allele polymorphism of MICA and the functionally relevant dimorphism (129val/met) of MICA gene in inflammatory bowel disease (IBD) patients in our population. DNA was obtained from IBD patients (n = 88) and unrelated healthy Murcians (n = 154) and used to MICA genotyping using polymerase chain reaction-sequence-specific oligonucleotides. We did not find statistical differences in the distribution of MICA alleles between the IBD and control groups. However, we found a higher frequency of MICA-129met/met and a lower frequency of MICA-129val/met genotypes in IBD patients (mainly in ulcerative colitis) than in controls (pc = 0.02). These preliminary data could suggest a relevant role of MICA-129-val/met SNP (weak/strong binders of NKG2D receptor) in the pathogenesis of IBD.
Immunology Service, University Hospital Virgen de la Arrixaca, Murcia, Spain.
Ruth
R
López-Hernández
Mariano
M
Valdés
Daniel
D
Lucas
Jose Antonio
JA
Campillo
Pedro
P
Martínez-Garcia
Hortensia
H
Salama
Manuela
M
López
Gema
G
Salgado
Carmen
C
Botella
Alfredo
A
Minguela
Manuel
M
Miras
Maria Rocio
MR
Alvarez-López
Fernando
F
Carballo
Manuel
M
Muro
D020022:Genetic Predisposition to Disease; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000235:genetics*; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D013030:Spain
D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A