We have previously found that gene polymorphisms that either inactivate the TLR2 gene product or have a dominant-negative role are associated with tuberculosis (TB) in Croatian population.
There was a significant difference between TLR2 gene Arg753Gln polymorphism and the risk of TB (additive model: P<0.01, OR=2.89, 95% CI: 2.13-3.91; GA vs. GG: P<0.01, OR=2.92, 95% CI: 2.09-4.08).
206 TB patients and 239 healthy controls from Hyderabad, India were analyzed for SNPs in the TLR1 and TLR2 genes, which were subsequently correlated to TB susceptibility.
TLR2rs5743708 subgroup analysis identified the A allele to increase susceptibility to TB in the Asian ethnic group, while conferring protection in the Hispanic group.
Single-nucleotide polymorphisms (SNPs) in the CCL1 gene and TLR2 gene may be associated with the development of different clinical forms of TB, depending on the different immune mechanisms.
Our findings indicate that TLR2 engagement on CD4(+) T cells increases MTB Ag-specific responses and may contribute to protection against MTB infection.
Material from M. tuberculosis and P. acne has been repeatedly detected in the sarcoidosis lesions, implying the involvement of the Toll-like receptor2 (TLR2) gene that responds to these intracellular pathogens.
BAL cells from patients in whom sarcoidosis was confirmed displayed increased cytokine responses to the TLR-2/1 ligand 19-kDa lipoprotein of Mycobacterium tuberculosis (LpqH) and decreased responses to the TLR-2/6 agonist fibroblast stimulating ligand-1 (FSL)-1.
Coinheritance of these polymorphisms with previously identified risk alleles in Toll-like receptor 2 and TIRAP was associated with an additive risk of tuberculosis susceptibility.
Moreover, TLR2 expression was higher in patients with opportunistic infections without HAART and up-regulation of TLR expression in HIV-1 patients coinfected with opportunistic infections was more pronounced in dendritic cells derived from individuals coinfected with Mycobacterium tuberculosis.
Our findings in three independent population samples indicate that variations in TLR2 and TLR9 might play important roles in determining susceptibility to TB.