Browsing by Author "Fellay, Jacques"

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    Common genetic variation and the control of HIV-1 in humans.
    (PLoS Genet, 2009-12) Fellay, Jacques; Ge, Dongliang; Shianna, Kevin V; Colombo, Sara; Ledergerber, Bruno; Cirulli, Elizabeth T; Urban, Thomas J; Zhang, Kunlin; Gumbs, Curtis E; Smith, Jason P; Castagna, Antonella; Cozzi-Lepri, Alessandro; De Luca, Andrea; Easterbrook, Philippa; Günthard, Huldrych F; Mallal, Simon; Mussini, Cristina; Dalmau, Judith; Martinez-Picado, Javier; Miro, José M; Obel, Niels; Wolinsky, Steven M; Martinson, Jeremy J; Detels, Roger; Margolick, Joseph B; Jacobson, Lisa P; Descombes, Patrick; Antonarakis, Stylianos E; Beckmann, Jacques S; O'Brien, Stephen J; Letvin, Norman L; McMichael, Andrew J; Haynes, Barton F; Carrington, Mary; Feng, Sheng; Telenti, Amalio; Goldstein, David B; NIAID Center for HIV/AIDS Vaccine Immunology (CHAVI)
    To extend the understanding of host genetic determinants of HIV-1 control, we performed a genome-wide association study in a cohort of 2,554 infected Caucasian subjects. The study was powered to detect common genetic variants explaining down to 1.3% of the variability in viral load at set point. We provide overwhelming confirmation of three associations previously reported in a genome-wide study and show further independent effects of both common and rare variants in the Major Histocompatibility Complex region (MHC). We also examined the polymorphisms reported in previous candidate gene studies and fail to support a role for any variant outside of the MHC or the chemokine receptor cluster on chromosome 3. In addition, we evaluated functional variants, copy-number polymorphisms, epistatic interactions, and biological pathways. This study thus represents a comprehensive assessment of common human genetic variation in HIV-1 control in Caucasians.
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    Genome-wide mRNA expression correlates of viral control in CD4+ T-cells from HIV-1-infected individuals.
    (PLoS Pathog, 2010-02-26) Rotger, Margalida; Dang, Kristen K; Fellay, Jacques; Heinzen, Erin L; Feng, Sheng; Descombes, Patrick; Shianna, Kevin V; Ge, Dongliang; Günthard, Huldrych F; Goldstein, David B; Telenti, Amalio; Swiss HIV Cohort Study; Center for HIV/AIDS Vaccine Immunology
    There is great interindividual variability in HIV-1 viral setpoint after seroconversion, some of which is known to be due to genetic differences among infected individuals. Here, our focus is on determining, genome-wide, the contribution of variable gene expression to viral control, and to relate it to genomic DNA polymorphism. RNA was extracted from purified CD4+ T-cells from 137 HIV-1 seroconverters, 16 elite controllers, and 3 healthy blood donors. Expression levels of more than 48,000 mRNA transcripts were assessed by the Human-6 v3 Expression BeadChips (Illumina). Genome-wide SNP data was generated from genomic DNA using the HumanHap550 Genotyping BeadChip (Illumina). We observed two distinct profiles with 260 genes differentially expressed depending on HIV-1 viral load. There was significant upregulation of expression of interferon stimulated genes with increasing viral load, including genes of the intrinsic antiretroviral defense. Upon successful antiretroviral treatment, the transcriptome profile of previously viremic individuals reverted to a pattern comparable to that of elite controllers and of uninfected individuals. Genome-wide evaluation of cis-acting SNPs identified genetic variants modulating expression of 190 genes. Those were compared to the genes whose expression was found associated with viral load: expression of one interferon stimulated gene, OAS1, was found to be regulated by a SNP (rs3177979, p = 4.9E-12); however, we could not detect an independent association of the SNP with viral setpoint. Thus, this study represents an attempt to integrate genome-wide SNP signals with genome-wide expression profiles in the search for biological correlates of HIV-1 control. It underscores the paradox of the association between increasing levels of viral load and greater expression of antiviral defense pathways. It also shows that elite controllers do not have a fully distinctive mRNA expression pattern in CD4+ T cells. Overall, changes in global RNA expression reflect responses to viral replication rather than a mechanism that might explain viral control.
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    Host determinants of HIV-1 control in African Americans.
    (J Infect Dis, 2010-04-15) Pelak, Kimberly; Goldstein, David B; Walley, Nicole M; Fellay, Jacques; Ge, Dongliang; Shianna, Kevin V; Gumbs, Curtis; Gao, Xiaojiang; Maia, Jessica M; Cronin, Kenneth D; Hussain, Shehnaz K; Carrington, Mary; Michael, Nelson L; Weintrob, Amy C; Infectious Disease Clinical Research Program HIV Working Group; National Institute of Allergy and Infectious Diseases Center for HIV/AIDS Vaccine Immunology (CHAVI)
    We performed a whole-genome association study of human immunodeficiency virus type 1 (HIV-1) set point among a cohort of African Americans (n = 515), and an intronic single-nucleotide polymorphism (SNP) in the HLA-B gene showed one of the strongest associations. We use a subset of patients to demonstrate that this SNP reflects the effect of the HLA-B*5703 allele, which shows a genome-wide statistically significant association with viral load set point (P = 5.6 x 10(-10)). These analyses therefore confirm a member of the HLA-B*57 group of alleles as the most important common variant that influences viral load variation in African Americans, which is consistent with what has been observed for individuals of European ancestry, among whom the most important common variant is HLA-B*5701.
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    Host genetics and HIV-1: the final phase?
    (PLoS Pathog, 2010-10-14) Fellay, Jacques; Shianna, Kevin V; Telenti, Amalio; Goldstein, David B
    This is a crucial transition time for human genetics in general, and for HIV host genetics in particular. After years of equivocal results from candidate gene analyses, several genome-wide association studies have been published that looked at plasma viral load or disease progression. Results from other studies that used various large-scale approaches (siRNA screens, transcriptome or proteome analysis, comparative genomics) have also shed new light on retroviral pathogenesis. However, most of the inter-individual variability in response to HIV-1 infection remains to be explained: genome resequencing and systems biology approaches are now required to progress toward a better understanding of the complex interactions between HIV-1 and its human host.
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    Influence of HLA-C expression level on HIV control.
    (Science, 2013-04-05) Apps, Richard; Qi, Ying; Carlson, Jonathan M; Chen, Haoyan; Gao, Xiaojiang; Thomas, Rasmi; Yuki, Yuko; Del Prete, Greg Q; Goulder, Philip; Brumme, Zabrina L; Brumme, Chanson J; John, Mina; Mallal, Simon; Nelson, George; Bosch, Ronald; Heckerman, David; Stein, Judy L; Soderberg, Kelly A; Moody, M Anthony; Denny, Thomas N; Zeng, Xue; Fang, Jingyuan; Moffett, Ashley; Lifson, Jeffrey D; Goedert, James J; Buchbinder, Susan; Kirk, Gregory D; Fellay, Jacques; McLaren, Paul; Deeks, Steven G; Pereyra, Florencia; Walker, Bruce; Michael, Nelson L; Weintrob, Amy; Wolinsky, Steven; Liao, Wilson; Carrington, Mary
    A variant upstream of human leukocyte antigen C (HLA-C) shows the most significant genome-wide effect on HIV control in European Americans and is also associated with the level of HLA-C expression. We characterized the differential cell surface expression levels of all common HLA-C allotypes and tested directly for effects of HLA-C expression on outcomes of HIV infection in 5243 individuals. Increasing HLA-C expression was associated with protection against multiple outcomes independently of individual HLA allelic effects in both African and European Americans, regardless of their distinct HLA-C frequencies and linkage relationships with HLA-B and HLA-A. Higher HLA-C expression was correlated with increased likelihood of cytotoxic T lymphocyte responses and frequency of viral escape mutation. In contrast, high HLA-C expression had a deleterious effect in Crohn's disease, suggesting a broader influence of HLA expression levels in human disease.
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    The characterization of twenty sequenced human genomes.
    (PLoS Genet, 2010-09-09) Pelak, Kimberly; Shianna, Kevin V; Ge, Dongliang; Maia, Jessica M; Zhu, Mingfu; Smith, Jason P; Cirulli, Elizabeth T; Fellay, Jacques; Dickson, Samuel P; Gumbs, Curtis E; Heinzen, Erin L; Need, Anna C; Ruzzo, Elizabeth K; Singh, Abanish; Campbell, C Ryan; Hong, Linda K; Lornsen, Katharina A; McKenzie, Alexander M; Sobreira, Nara LM; Hoover-Fong, Julie E; Milner, Joshua D; Ottman, Ruth; Haynes, Barton F; Goedert, James J; Goldstein, David B
    We present the analysis of twenty human genomes to evaluate the prospects for identifying rare functional variants that contribute to a phenotype of interest. We sequenced at high coverage ten "case" genomes from individuals with severe hemophilia A and ten "control" genomes. We summarize the number of genetic variants emerging from a study of this magnitude, and provide a proof of concept for the identification of rare and highly-penetrant functional variants by confirming that the cause of hemophilia A is easily recognizable in this data set. We also show that the number of novel single nucleotide variants (SNVs) discovered per genome seems to stabilize at about 144,000 new variants per genome, after the first 15 individuals have been sequenced. Finally, we find that, on average, each genome carries 165 homozygous protein-truncating or stop loss variants in genes representing a diverse set of pathways.