An HIV-1 resistance polymorphism in TRIM5α gene among Chinese intravenous drug users.
ABSTRACT TRIM5α has species-specific restriction activity against replication of many retroviruses, including HIV-1. Though human also express TRIM5α protein, it is less potent in suppressing infection of HIV-1 than most orthologs of other nonhuman primates. Previous association studies suggested that polymorphisms in TRIM5α gene might protect against HIV-1 infection. However, the exact variation accounting for this protective effect was not certain.
One thousand two hundred ninety-four Chinese intravenous drug users (IDUs), including 1011 Hans and 283 Dai subjects, were investigated for sequence variations in TRIM5α and association with HIV-1 resistance. Resequencing of the putative functional domains in exon2 and exon8 was carried out in 1151 subjects, along with exon2 resequencing in a further 143 HIV-1-infected IDUs.
We identified 14 different nucleotide variants, including 4 with minor allele frequency >0.05. We observed that the frequency of 43Y homozygote in seronegative IDUs was significantly higher than that in the HIV-1-infected IDUs, suggesting a protective effect among the homozygote subjects [odds ratio (95% confidence interval) = 0.46 (0.22 to 0.94), P = 0.033, Mantel-Haenszel test].
we concluded that H43Y might account for the HIV-1 resistance due to TRIM5α gene in Chinese IDUs.
- SourceAvailable from: Lisa A Chakrabarti[Show abstract] [Hide abstract]
ABSTRACT: The expression of certain HLA class I alleles, including HLA-B*27 and HLA-B*57, is associated with better control of HIV-1 infection, but the mechanisms responsible are not fully understood. We sought evidence that pressure from the human restriction factor TRIM5α (hTRIM5α) could contribute to viral control. The hTRIM5α sensitivity of viruses from both HLA-B*57+ and HLA-B*27+ patients who spontaneously controlled viral replication, but not viruses from viremic patients expressing these alleles, was significantly greater than that of viruses from patients not expressing these protective HLA-B alleles. Overall, a significant negative correlation between hTRIM5α sensitivity and viral load was observed. In HLA-B*57+ patients, the T242N mutation in the HLA-B*57-restricted TW10 CTL epitope was strongly associated with hTRIM5α sensitivity. In HLA-B*27+ controllers, hTRIM5α sensitivity was associated with a significant reduction in emergence of key CTL mutations. In several patients, viral evolution to avoid hTRIM5α sensitivity was observed, but could be associated with reduced viral replicative capacity. Thus, in individuals expressing protective HLA-B alleles, the combined pressures exerted by CTL, hTRIM5α and capsid structural constraints can prevent viral escape both by impeding the selection of necessary resistance/compensatory mutations, and forcing the selection of escape mutations that increase hTRIM5α sensitivity or impair viral replicative capacity.Journal of Virology 07/2013; · 4.65 Impact Factor
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ABSTRACT: HIV and human defense mechanisms have co-evolved to counteract each other. In the process of infection, HIV takes advantage of cellular machinery and blocks the action of the host restriction factors (RF). A small subset of HIV+ individuals control HIV infection and progression to AIDS in the absence of treatment. These individuals known as long-term non-progressors (LNTPs) exhibit genetic and immunological characteristics that confer upon them an efficient resistance to infection and/or disease progression. The identification of some of these host factors led to the development of therapeutic approaches that attempted to mimic the natural control of HIV infection. Some of these approaches are currently being tested in clinical trials. While there are many genes which carry mutations and polymorphisms associated with non-progression, this review will be specifically focused on HIV host RF including both the main chemokine receptors and chemokines as well as intracellular RF including, APOBEC, TRIM, tetherin, and SAMHD1. The understanding of molecular profiles and mechanisms present in LTNPs should provide new insights to control HIV infection and contribute to the development of novel therapies against AIDS.Frontiers in Immunology 01/2013; 4:343.
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ABSTRACT: Type I interferon (IFN-I) play a critical role in the innate immune response against viral infections. They actively participate in antiviral immunity by inducing molecular mechanisms of viral restriction and by limiting the spread of the infection, but they also orchestrate the initial phases of the adaptive immune response and influence the quality of T cell immunity. During infection with the human immunodeficiency virus type 1 (HIV-1), the production of and response to IFN-I may be severely altered by the lymphotropic nature of the virus. In this review I consider the different aspects of virus sensing, IFN-I production, signalling, and effects on target cells, with a particular focus on the alterations observed following HIV-1 infection.Scientifica. 01/2013; 2013:580968.