Human leukocyte antigens class I and class II alleles associated with vertical human immunodeficiency virus transmission - an exploratory study from Mumbai, India.

Background Human leukocyte antigens (HLA) an important host genetic factor is responsible for influencing human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) transmission and disease progression. Contributions of HLA I and II alleles have not been reported in the Indian population with respect to vertical HIV transmission. Aim In the current study we determined the frequencies of HLA class I and class II alleles in a cohort of children exposed to HIV through their mothers. Method In this exploratory study children perinatally exposed to HIV-1 who fit the study criteria and had completed 18 month follow-up were typed for HLA class I and class II alleles using polymerase chain reaction combined with sequence-specific oligonucleotides probes (PCR-SSOP) and sequence-specific primer (SSP) method. HLA typing was done in 30 positive and 60 HIV negative children along with confounding factors such as treatment regimens, viral load and CD4 count of the mother, feeding option, etc. SPSS software was used for statistical analysis and online docking tools for in-silico analysis. Results HLA-B*40 (p = 0.018) was significantly higher in negative children and was associated with protection, whereas HLA-A*01 (p = 0.05), HLA-B*37 (p = 0.032) and HLA-DRB1*09 (p = 0.017) were associated with transmission. Known protective allele HLA-B*27 was only present in negative children. Many specific haplotypes were exclusively present in the negative children or the positive ones. In-silico analysis was performed to predict the ability of HLA-B*40 to bind to antigenic peptides obtained from HIV-1 sequences in our study group. Limitations Small sample size is a concerning limitation of the study. Nonetheless this is a comprehensive study on HLA alleles in HIV exposed Indian children Conclusion Our study highlights the contribution of HLA class I and II alleles in the Indian children and further adds to understanding the immunogenetic mechanisms. These can be developed as markers for prediction of infection transmission. The observations also contribute to the database of genetic makeup of our population and can help in designing vaccine strategies.

Distribution of killer immunoglobulin-like receptor genes in HIV infected long-term non-progressors from Mumbai, India.

BACKGROUND: Few reports suggest the association of killer immunoglobulin-like receptors of natural killer cells with human immunodeficiency virus infection. India with world's third largest population of human immunodeficiency virus / acquired immunodeficiency syndrome, offers scope to study such association. OBJECTIVE: Current study (2010-2015) was designed to evaluate if killer immunoglobulin-like receptors gene polymorphisms are associated with HIV infection outcomes specifically, with long term non progressors. METHODS: Killer immunoglobulin-like receptors genotyping was done using polymerase chain reaction - sequence-specific primer method. Viral load was measured by Cobas Taqman HIV-1 test. Estimation of CD4 counts was done using BD FACS CD4 count reagent. RESULTS: The activating gene frequencies identified were 3DS1 (53.8%), 2DS3 (69.2%), 2DS4 (76.9%), 2DS5 (69.2%), 2DS1 (76.9%) and 2DS2 (92.3%). The inhibitory gene frequencies were 2DL2 (92.3%), 2DL5 (76.9%), 2DL3 (69.5%), 3DL1 (84.6%), 3DL2 (92.3%) and 2DL1 (100%). The results highlight high frequency of 3DS1/3DL1 heterozygote and killer immunoglobulin-like receptor 2DS1, among these long term non progressors indicating their possible association with slow progression. Genotype analysis shows total 13 genotypes, of which 8 genotypes were identified for the first time from India. Two genotypes were unique/novel, which were unreported. All genotypes observed in this study were considered to be Bx genotype (100 %). LIMITATIONS: A small sample size (n=13, due to a rare cohort) and the absence of control group were the limitations of this study. CONCLUSIONS: The present study highlights the distribution of killer immunoglobulin-like receptor genes in a very rare group of human immunodeficiency virus -1 infected individuals - long term non progressors. All the long term non progressors tested show the presence of Bx haplotype and each long term non progressors has a different killer immunoglobulin-like receptor genotype.