ANALYSIS OF TLRS GENES EXPRESSION AND DEFB1 POLYMORPHISMS ASSOCIATION IN CHILDREN WITH BRONCHIAL ASTHMA

Bronchial asthma (BA) is one of the most common respiratory system diseases. The role of innate immunity components in the pathogenesis of bronchial asthma is studied widely, with particular focus on the antimicrobial peptides. Those include beta defensins that prevent pathogen intrusion into the respiratory tract mucosa, the most active of such pathogens being beta-defensin-1 (human beta defensin-1, HBD-1) encoded by the DEFB1 gene. We studied the association of three single nucleotide polymorphisms in the 5'-untranslated region of the gene, namely, rs11362, rs1799946 and rs1200972, with bronchial asthma in children. We also evaluated gene expression of toll-like receptors TLR2, TLR4 and TLR9. The experimental group included 48 patients of 3 to 7 years of age with BA and 70 healthy children. The.. genotype of the rs11362 polymorphism and the.. genotype of the rs1799946 polymorphism were reliably associated with the disease, while the GG genotype of the rs1799946 polymorphism and the.. genotype of the rs120097 polymorphism were found protective. Also, the.. genotype of the rs11362 polymorphism was associated with the reduced expression of DEFB1, the human beta defensin-1 encoding gene, while the AG genotype was associated with its increased expression. In children with BA, TLR2 expression increased 19.5 times in comparison with the controls; TLR9 expression increased 9.5 times, while TLR4 expression increased 8.3 times.