Antigen peptides are actively transported across the endoplasmic reticulum by the transporters associated with antigen presentation (TAP). TAP genes polymorphism could influence the selection process that determines which antigen peptides play a role in the pathogenesis of allergic rhinitis. The aim of this study was to investigate the association of TAP genes polymorphism with allergic rhinitis. TAP1 and TAP2 genotyping were performed on 110 allergic rhinitis patients and 107 healthy controls. TAP1 polymorphic residues at codons 333 and 637, and TAP2 polymorphic residues at codons 379, 565, 651, and 665 were analyzed by the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Analysis of TAP1 gene polymorphism demonstrated decreased frequencies of Ile/Val genotype at codon 333, Asp/Gly genotype at codon 637, and haplotype A and B in allergic rhinitis patients when compared to controls (p<0.05). However, there was no significant difference in the genotype, phenotype, or allele frequencies at four TAP2 codons between controls and allergic rhinitis patients. In conclusion, TAP1 gene polymorphism may be an important factor contributing to the genetic susceptibility in the development of allergic rhinitis in the Korean population.
ATP-Binding Cassette Transporters/*genetics ; Adolescent ; Adult ; Aged ; Child ; Codon ; Female ; Genetic Predisposition to Disease ; Genotype ; Humans ; Hypersensitivity/*genetics ; Hypersensitivity, Immediate/*genetics ; Korea ; Male ; Middle Aged ; *Polymorphism, Genetic ; Rhinitis/*genetics

Interleukin (IL)-12 activates T helper (Th) 1 cells to produce interferon (IFN)-gamma which inhibits atopic inflammation. IL-12 acts through interaction with its receptor, especially beta2 subunit. In several studies, the low production of IFN-gamma in peripheral mononuclear cells of atopic patients on response to IL-12 stimulation has been reported. Therefore we investigated the IL-12 receptor beta2 (IL-12R beta2) mRNA expression and RNA editing, nucleotide 2451 C-to-U conversion, to find the cause of low responsiveness to IL-12 in atopy. Quantitative real time PCR for mRNA expression and sequence analysis for RNA editing were performed in 80 atopic patients and 54 healthy controls. The expression of IL-12R beta2 mRNA was significantly lower in atopic patients than healthy controls (p<0.05). In sequence analysis, RNA editing on nucleotide 2451 was not found from either atopic patients or healthy controls. In additional evaluation, there was no relationship between expression of IL-12R beta2 mRNA and serum total IgE or blood eosinophil count. Reduced IL-12R beta2 mRNA expression in atopic patients indicate the reduced capacity to respond to IL-12 which induce IFN-gamma production and this may contribute to Th2-skewed immune response in atopy.
Sensitivity and Specificity ; Risk Factors ; Risk Assessment/*methods ; Reproducibility of Results ; Receptors, Interleukin-12/*genetics/metabolism ; RNA, Messenger/*genetics/*metabolism ; RNA Editing/genetics ; Male ; Korea/epidemiology ; Hypersensitivity, Immediate/*epidemiology/*genetics/metabolism ; Humans ; Genetic Predisposition to Disease/epidemiology/genetics ; Female ; Biological Markers/metabolism ; Adult

Allergy was originally defined in 1906 in 1906 by Clemens von Pirquet as 'altered reactivity' to denote the different reaction which on second exposure to and antigen due to the formation fo antibodies, when compared to the first exposure. The term atopy decribes the clinical presentation of Type I hypersensitivity, which include asthna, eczema, hay fever and urticaria, These usually occur in subjects with a family history of these or similar conditions. The mechanism of allergy is the Type I hypersensitity reaction. contact with allergen results in its being processed by an antigen presenting cell and presented to T helper cells which then help B cells to IgE antibody. The IgE antibody is rapidly taken up via its Fc portion by mast cells and basophils, which are then senitized. Subsequent contact with same allergen will result in the cross-linking of IgE molecules by their fab portions which cause cell degranulation and mediator release. The contribution of genentic factors to the development of atopy has been an intriguing issue. The exact controlling mechanisms of the genetic factors are unknown, but there are many studies support the genetic controls of the development of atopy. Abnormally high levels of IgE synthesis and associated atopy often run in families. Althouth the full inhritance pattern is probably multigenic, family studies has shown that their is clear autosomal transmission of atopy. The ability to make specific IgE antibodies to certain antigens, e.g., ragweed pollen, is also inherited and may be linked to particular class II major histocompatibility complex alleles. Therefore, I think that the clinicians must consider the environmental and genetic factors when evaluate the atopic disease.
Alleles ; Ambrosia ; Antibodies ; B-Lymphocytes ; Basophils ; Cell Degranulation ; Eczema ; Genetics* ; Humans ; Hypersensitivity* ; Hypersensitivity, Immediate ; Immunoglobulin E ; Major Histocompatibility Complex ; Mast Cells ; Pollen ; Rhinitis, Allergic, Seasonal ; T-Lymphocytes, Helper-Inducer ; Urticaria