Genetic polymorphisms in Toll-like receptors 1, 2 and 4 in feline upper respiratory tract aspergillosis
Description
Fungal species in the genus Aspergillus are environmental saprophytes that can act as opportunistic pathogens of the nasal cavity and paranasal sinuses in humans, cats and other species. Upper respiratory tract aspergillosis (URTA) presents as non-invasive and invasive forms with the latter occurring almost exclusively in immunocompromised hosts. However, in domestic cats, invasive URTA affects apparently immunocompetent patients. A defect in innate immunity has been proposed as a predisposing factor in invasive feline URTA. Single nucleotide polymorphisms (SNPs) in pattern recognition receptor genes have been implicated in the pathogenesis of aspergillosis in humans. The aims of this study were to identify non-synonymous SNPs in the coding regions of toll-like receptors involved in the immune response to Aspergillus spp. and to compare the frequency of these SNPs between affected and control cats. The coding and flanking regions of TLR1, TLR2 and TLR4 were sequenced in 14 cats with invasive URTA and the sequences were compared with those in 20 control cats without aspergillosis.