Association of toll-like receptor four single nucleotide polymorphisms with incidence of infectious bovine keratoconjunctivitis (IBK) in cattle

• Published in: Immunogenetics (New York) 2011-02, Vol.63 (2), p.115-119
• Main Authors: Kataria, Ranjit S, Tait, Richard G. Jr, Kumar, Dinesh, Ortega, Manuel A, Rodiguez, Jose, Reecy, James M
• Format: Article
• Language: English
• Subjects: Allergology; Animals; Bacteria; Biomedical and Life Sciences; Biomedicine; Breeding; Brief Communication; Cattle; Cattle - genetics; Cattle - immunology; Cattle Diseases - genetics; Cattle Diseases - immunology; Cell Biology; Cornea; Data processing; Disease; Gene Function; Genes; Gram-negative bacteria; Human Genetics; Immunology; Infection; Infections; Keratoconjunctivitis; Keratoconjunctivitis, Infectious - genetics; Keratoconjunctivitis, Infectious - immunology; Ligands; Mathematical models; Pasture; Pasture management; Pathogens; Phenotypic variations; Polymerase chain reaction; Polymorphism, Single Nucleotide; Restriction fragment length polymorphism; Seasons; Single nucleotide polymorphisms; Single-nucleotide polymorphism; Statistical analysis; Statistical models; TLR4 protein; Toll-like receptor 4; Toll-Like Receptor 4 - genetics; Toll-Like Receptor 4 - immunology; Toll-like receptors; Weaning
• ISSN: 0093-7711; 1432-1211
• DOI: 10.1007/s00251-010-0484-6

Toll-like receptor 4 (TLR4) is a receptor protein that binds pathogen ligands, which are mainly associated with Gram-negative bacteria. The objective of this study was to investigate the association of nucleotide polymorphisms in TLR4 with infectious bovine keratoconjunctivitis (IBK), or pinkeye, incidence in American Angus cattle. Animals with previously calculated breeding values for IBK susceptibility were used to identify two SNPs in TLR4; Int1 (A/G) in intron1 (−26 Ex2 position) and Ex3 (C/T) in exon3 (1,678 position). To investigate the possible role of these SNPs in IBK susceptibility, the disease incidence information was collected on 370 calves raised in Iowa at two time points--June or August (disease season) and October (at weaning) and genotyped using PCR-RFLP protocols. In statistical models including year, pasture management group, and SNP, the Int1 SNP had a significant effect on IBK infection rates both in-season (P < 0.05) and at weaning (P < 0.01), whereas the Ex3 SNP was not significant (P > 0.79) at either time point. Furthermore, the Int1 SNP alone could account for 2.1% of phenotypic variation in IBK infection during the disease season and 3.0% of phenotypic variation in IBK infection at the time of weaning. These data indicate that there is a relationship between Int1 genotype and the rate of IBK infection in American Angus cattle.