Polymorphisms of transporter associated with antigen processing genes in atopic dermatitis

Area of Science:

• Immunogenetics
• Molecular Biology

Background:

• Atopic dermatitis is a complex inflammatory skin disease.
• Transporter associated with antigen processing (TAP) genes play a role in immune responses.
• Understanding genetic factors influencing atopic dermatitis is crucial.

Purpose of the Study:

• To investigate the association of transporter associated with antigen processing (TAP) gene polymorphisms with atopic dermatitis in a Japanese population.
• To develop and apply a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for TAP allele discrimination.

Main Methods:

• Genomic DNA was extracted from 29 Japanese patients with atopic dermatitis and 35 healthy controls.
• Specific regions of TAP1 and TAP2 genes were amplified using PCR.
• Amplified DNA fragments were digested with restriction enzymes (Sau3A1, AccI, EcoRII) to identify TAP alleles.

Main Results:

• Four alleles were identified for TAP1, and dimorphism was observed for TAP2 codon 687.
• A TAP1 allele (TAP1 D) rare in Caucasians was found in 6 of 35 controls.
• The TAP1 637Asp allele frequency showed a tendency to increase in atopic dermatitis patients.
• TAP1 637Asp and TAP1 A alleles formed estimated haplotypes with specific HLA-DRB1-DQB1 combinations.

Conclusions:

• TAP gene polymorphisms may be associated with atopic dermatitis susceptibility in the Japanese population.
• TAP1 637Asp allele warrants further investigation for its role in atopic dermatitis.
• Analyzing TAP gene polymorphisms can aid in understanding susceptibility loci in HLA class II-associated diseases.