Effects of CD14, TLR2, TLR4, LPB, and IL-6 gene polymorphisms on Chlamydia pneumoniae growth in human macrophages in vitro.

Chlamydia pneumoniae is an obligate intracellular gram-negative bacterium, which causes respiratory infections in humans. It can infect various cell types, e.g. vascular endothelial cells, smooth muscle cells and monocyte-derived macrophages in vitro. The susceptibility of macrophages from healthy individuals to C. pneumoniae infection is highly variable. In this study, we evaluated the effects of innate immunity genes CD14 -260 C>T, TLR2 Arg753Gln, TLR4 Asp299Gly, LBP Phe436Leu and IL6 -174 G>C polymorphisms on C. pneumoniae growth in human macrophages in vitro. The growth of C. pneumoniae was highest in CD14 -260 C>T TT genotype cells and the difference to CC and CT genotypes was statistically significant (P = 0.032 and 0.022 respectively). The G-allele of the IL6 -174 G>C polymorphism had a positive influence on chlamydial growth; the difference was statistically significant only between CC and GC genotypes (P = 0.018). TLR2 Arg 753Gln, TLR4 Asp299Gly, LBP Phe436Leu polymorphisms showed no effect on chlamydial growth.