Polymorphisms in the CD14 and TLR4 genes independently predict CD4+ T-cell recovery in HIV-infected individuals on antiretroviral therapy

BACKGROUND: Chronic HIV infection leads to marked depletion of CD4+ T cells in the gastrointestinal (GI) tract and increased microbial translocation measured by an increase in circulating lipopolysaccharide (LPS) levels. Here, we hypothesised that single-nucleotide polymorphisms (SNPs) in genes encoding the Toll-like receptor 4 (TLR4) and CD14, the principal receptors for LPS, were associated with CD4+ T-cell recovery post-antiretroviral therapy (ART). 

METHODS: Prospective study of predominantly Caucasian HIV-infected subjects receiving suppressive ART for at least 12 months. We analysed the CD14 SNPs C-260T and the TLR4 SNPs A+896G, C+1196T. We also determined the levels of LPS and soluble CD14 (sCD14) in plasma samples collected pre- and post-ART initiation. CD4+ T-cell recovery was assessed by linear mixed models. 

RESULTS: Following ART, individuals with a TT genotype compared to a CT or CC genotype for CD14 C-260T SNP showed higher levels of sCD14 (p=0.008 and 0.003 respectively). The CC genotype for the CD14 C-260T SNP, compared to CT or TT and the TLR4 SNP (AC/GT) compared to the homozygous genotype (AA/CC) were both independently associated with enhanced long-term CD4+ T-cell recovery (>3 months; p < 0.001). 

CONCLUSION: Polymorphisms in CD14 and TLR4 are independently associated with long-term CD4þ T-cell recovery in HIV-infected individuals post-ART.