SDF-1 gene polymorphism and CCL3L1 gene copy number and susceptibility to HIV-1 / AIDS among Indians

Background

Stromal derived factor (SDF-1) is a natural ligand for CXCR4 and chemokine (C-C) motif ligand 3-like 1 (CCL3L1) is for CCR5 HIV coreceptors. The individual role of the SNP in 3′ untranslated region of SDF-1 (SDF1-3′A) and low copy number of the CCL3L1 gene in determining susceptibility to HIV infection is well documented. The aim of the present study was to analyze the synergistic effect of the SNP in SDF-1 gene and CNV in CCL3L1 gene influencing the susceptibility to HIV-1/AIDS in Indians.

Methods

This study involved the assessment of 105 healthy control individuals and 44 HIV-1 patients for the SDF-1 gene polymorphism by PCR-restriction fragment length polymorphism (RFLP) and CCL3L1 gene copy number (CN) by real-time PCR.

Results

In order to assess the synergistic effect of the SDF1-3′A polymorphism and CCL3L1 CN, SDF1-3′A allele and CCL3L1 > 2 copies conferring a protection to HIV-1 were considered as reference combination. The odds ratio (OR) was 0.97 (95% CI - 0.30 to 3.13; p = 0.597) for SDF1-3′A, CCL3L1 < 2 copies, 0.73 (95% CI - 0.23 to 2.33; p = 0.408) for SDF1, CCL3L1 > 2 copies and 0.93 (95% CI - 0.327 to 2.703; p = 0.555) for SDF1-3′A, CCL3L1 < 2 copies combinations as compared to SDF1-3′A, CCL3L1 > 2 copies.

Conclusion

Our analyses suggest that a combination of SDF1-3′A and lower copy number of CCL3L1 do not provide any discernible synergistic protection from HIV-1 infection.