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1.
Front Immunol ; 14: 1305856, 2023.
Article in English | MEDLINE | ID: mdl-38146367

ABSTRACT

Introduction: We have reanalyzed the genomic data of the International Collaboration for the Genomics of HIV (ICGH), centering on HIV-1 Elite Controllers. Methods: We performed a genome-wide Association Study comparing 543 HIV Elite Controllers with 3,272 uninfected controls of European descent. Using the latest database for imputation, we analyzed 35,552 Single Nucleotide Polymorphisms (SNPs) within the Major Histocompatibility Complex (MHC) region. Results: Our analysis identified 2,626 SNPs significantly associated (p<5. 10-8) with elite control of HIV-1 infection, including well-established MHC signals such as the rs2395029-G allele which tags HLA-B*57:01. A thorough investigation of SNPs in linkage disequilibrium with rs2395029 revealed an extensive haploblock spanning 1.9 megabases in the MHC region tagging HLA-B*57:01, comprising 379 SNP alleles impacting 72 genes. This haploblock contains damaging variations in proteins like NOTCH4 and DXO and is also associated with a strong differential pattern of expression of multiple MHC genes such as HLA-B, MICB, and ZBTB12. The study was expanded to include two cohorts of seropositive African-American individuals, where a haploblock tagging the HLA-B*57:03 allele was similarly associated with control of viral load. The mRNA expression profile of this haploblock in African Americans closely mirrored that in the European cohort. Discussion: These findings suggest that additional molecular mechanisms beyond the conventional antigen-presenting role of class I HLA molecules may contribute to the observed influence of HLA-B*57:01/B*57:03 alleles on HIV-1 elite control. Overall, this study has uncovered a large haploblock associated with HLA-B*57 alleles, providing novel insights into their massive effect on HIV-1 elite control.


Subject(s)
HIV Seropositivity , HIV-1 , Humans , HIV-1/genetics , Alleles , Genome-Wide Association Study , HLA-B Antigens/genetics , Major Histocompatibility Complex , HIV Seropositivity/genetics , DNA-Binding Proteins/genetics , Transcription Factors/genetics
2.
Oncol Rep ; 49(6)2023 06.
Article in English | MEDLINE | ID: mdl-37114528

ABSTRACT

Cervical cancer (CC) is a multifactorial disease of which human papillomavirus (HPV) is the main etiological agent. Despite cervical Pap smear screening and anti­HPV vaccination, CC remains a major public health issue. Identification of specific gene expression signatures in the blood could allow better insight into the immune response of CC and could provide valuable information for the development of novel biomarkers. The present study performed a transcriptomic analysis of peripheral blood mononuclear cells (PBMCs) from Senegalese patients with CC (n=31), low­grade cervical intraepithelial neoplasia (CIN1; n=27) and from healthy control (CTR) subjects (n=29). Individuals in the CIN1 and CTR groups exhibited similar patterns in gene expression. A total of 182 genes were revealed to be differentially expressed in patients with CC compared with individuals in the CIN1 and CTR groups. The IL1R2, IL18R1, MMP9 and FKBP5 genes were the most upregulated, whereas the T­cell receptor α gene TRA was the most downregulated in the CC group compared with in the CIN1 and CTR groups. The pathway enrichment analysis of the differentially expressed genes revealed pathways directly and indirectly linked to inflammation. To the best of our knowledge, the present study is the first large transcriptomic study on CC performed using PBMCs from African women; the results revealed the involvement of genes and pathways related to inflammation, most notably the IL­1 pathway, and the involvement of downregulation of the T­cell receptor α, a key component of the immune response. Several of the stated genes have already been reported in other cancer studies as putative blood biomarkers, thus reinforcing the requirement for deeper investigation. These findings may aid in the development of innovative clinical biomarkers for CC prevention and should be further replicated in other populations.


Subject(s)
Papillomavirus Infections , Uterine Cervical Dysplasia , Uterine Cervical Neoplasms , Humans , Female , Leukocytes, Mononuclear/pathology , Papillomavirus Infections/diagnosis , Uterine Cervical Neoplasms/pathology , Uterine Cervical Dysplasia/diagnosis , Gene Expression Profiling , Biomarkers , Papillomaviridae/genetics
3.
Sci Rep ; 13(1): 782, 2023 01 16.
Article in English | MEDLINE | ID: mdl-36646780

ABSTRACT

Profiling of the antibody responses to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) proteins in African populations is scarce. Here, we performed a detailed IgM and IgG epitope mapping study against 487 peptides covering SARS-CoV-2 wild-type structural proteins. A panel of 41 pre-pandemic and 82 COVID-19 RT-PCR confirmed sera from Madagascar and Senegal were used. We found that the main 36 immunodominant linear epitopes identified were (i) similar in both countries, (ii) distributed mainly in the Spike and the Nucleocapsid proteins, (iii) located outside the RBD and NTD regions where most of the reported SARS-CoV-2 variant mutations occur, and (iv) identical to those reported in European, North American, and Asian studies. Within the severe group, antibody levels were inversely correlated with the viral load. This first antibody epitope mapping study performed in patients from two African countries may be helpful to guide rational peptide-based diagnostic assays or vaccine development.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , Epitope Mapping , Antibodies, Viral , Immunodominant Epitopes , Senegal
4.
Front Genet ; 13: 836581, 2022.
Article in English | MEDLINE | ID: mdl-35401686

ABSTRACT

Skin aging is an ineluctable process leading to the progressive loss of tissue integrity and is characterized by various outcomes such as wrinkling and sagging. Researchers have identified impacting environmental factors (sun exposure, smoking, etc.) and several molecular mechanisms leading to skin aging. We have previously performed genome-wide association studies (GWAS) in 502 very-well characterized French women, looking for associations with four major outcomes of skin aging, namely, photoaging, solar lentigines, wrinkling, and sagging, and this has led to new insights into the molecular mechanisms of skin aging. Since individual SNP associations in GWAS explain only a small fraction of the genetic impact in complex polygenic phenotypes, we have made the integration of these genotypes into the reference Kegg biological pathways and looked for associations by the gene set enrichment analysis (GSEA) approach. 106 pathways were tested for association with the four outcomes of skin aging. This biological pathway analysis revealed new relevant pathways and genes, some likely specific of skin aging such as the WNT7B and PRKCA genes in the "melanogenesis" pathway and some likely involved in global aging such as the DDB1 gene in the "nucleotide excision repair" pathway, not picked up in the previously published GWAS. Overall, our results suggest that the four outcomes of skin aging possess specific molecular mechanisms such as the "proteasome" and "mTOR signaling pathway" but may also share common molecular mechanisms such as "nucleotide excision repair."

5.
Sci Rep ; 7(1): 3424, 2017 06 13.
Article in English | MEDLINE | ID: mdl-28611375

ABSTRACT

TNFα is a homotrimeric pro-inflammatory cytokine, whose direct targeting by protein biotherapies has been an undeniable success for the treatment of chronic inflammatory diseases. Despite many efforts, no orally active drug targeting TNFα has been identified so far. In the present work, we identified through combined in silico/in vitro/in vivo approaches a TNFα direct inhibitor, compound 1, displaying nanomolar and micromolar range bindings to TNFα. Compound 1 inhibits the binding of TNFα with both its receptors TNFRI and TNFRII. Compound 1 inhibits the TNFα induced apoptosis on L929 cells and the TNFα induced NF-κB activation in HEK cells. In vivo, oral administration of compound 1 displays a significant protection in a murine TNFα-dependent hepatic shock model. This work illustrates the ability of low-cost combined in silico/in vitro/in vivo screening approaches to identify orally available small-molecules targeting challenging protein-protein interactions such as homotrimeric TNFα.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Molecular Docking Simulation , Small Molecule Libraries/pharmacology , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Administration, Oral , Allosteric Regulation/drug effects , Animals , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/chemistry , Cell Line, Tumor , Drug Evaluation, Preclinical , Female , HEK293 Cells , High-Throughput Screening Assays , Humans , Mice , Mice, Inbred BALB C , Protein Binding/drug effects , Receptors, Tumor Necrosis Factor/chemistry , Receptors, Tumor Necrosis Factor/metabolism , Small Molecule Libraries/chemistry , Tumor Necrosis Factor-alpha/chemistry , Tumor Necrosis Factor-alpha/metabolism
6.
PLoS One ; 10(9): e0136989, 2015.
Article in English | MEDLINE | ID: mdl-26367535

ABSTRACT

BACKGROUND: Many genome-wide association studies have been performed on progression towards the acquired immune deficiency syndrome (AIDS) and they mainly identified associations within the HLA loci. In this study, we demonstrate that the integration of biological information, namely gene expression data, can enhance the sensitivity of genetic studies to unravel new genetic associations relevant to AIDS. METHODS: We collated the biological information compiled from three databases of expression quantitative trait loci (eQTLs) involved in cells of the immune system. We derived a list of single nucleotide polymorphisms (SNPs) that are functional in that they correlate with differential expression of genes in at least two of the databases. We tested the association of those SNPs with AIDS progression in two cohorts, GRIV and ACS. Tests on permuted phenotypes of the GRIV and ACS cohorts or on randomised sets of equivalent SNPs allowed us to assess the statistical robustness of this method and to estimate the true positive rate. RESULTS: Eight genes were identified with high confidence (p = 0.001, rate of true positives 75%). Some of those genes had previously been linked with HIV infection. Notably, ENTPD4 belongs to the same family as CD39, whose expression has already been associated with AIDS progression; while DNAJB12 is part of the HSP90 pathway, which is involved in the control of HIV latency. Our study also drew our attention to lesser-known functions such as mitochondrial ribosomal proteins and a zinc finger protein, ZFP57, which could be central to the effectiveness of HIV infection. Interestingly, for six out of those eight genes, down-regulation is associated with non-progression, which makes them appealing targets to develop drugs against HIV.


Subject(s)
Acquired Immunodeficiency Syndrome/genetics , Gene Expression Profiling/methods , Polymorphism, Single Nucleotide , Quantitative Trait Loci , Transcriptome , Cohort Studies , DNA-Binding Proteins/genetics , Databases, Genetic , Disease Progression , Gene Expression Regulation , Genetic Association Studies , Genetic Predisposition to Disease , HSP40 Heat-Shock Proteins/genetics , Humans , Pyrophosphatases/genetics , Random Allocation , Repressor Proteins , Transcription Factors/genetics
7.
Appl Microbiol Biotechnol ; 99(10): 4471-84, 2015 May.
Article in English | MEDLINE | ID: mdl-25575888

ABSTRACT

Historically used in textile and paper industry, hemp fibres have started to find new applications in composite materials with important economic and ecological advantages. However, their applications are limited since manufacturers have some difficulties to standardise fabrication processes. This study is a first step before selection and isolation of strains that could later be used to optimise microbial retting efficiency and hence fibre quality. We studied six samples harvested on different ground types, at different dates and with different retting durations on field to obtain an exhaustive representation of the process. After DNA extraction, total bacteria and fungi associated with stems during retting were specifically quantified using real-time PCR. Then, using sequence analysis of randomly cloned 16S and 18S ribosomal RNA (rRNA) genes, a phylogenetic characterisation of the dominant microorganisms was carried out. Quantitatively, we showed that there were 8.1-9.5 log10 16S rRNA gene copies per gram of hemp straw for bacteria and 8.6-9.6 log10 18S rRNA gene copies per gram for fungi. Qualitatively, we noticed a higher bacterial diversity in comparison to fungi. This work showed that in the different samples, the same species were present but in significantly different proportions according to ground type, harvest dates and retting durations on field. The most frequent bacterial sequences were affiliated to species Escherichia coli, Pantoea agglomerans, Pseudomonas rhizosphaerae, Rhodobacter sp., Pseudomonas fulva, Rhizobium huautlense and Massilia timonae, whereas fungal sequences were principally related to the genera Cladosporium and Cryptococcus.


Subject(s)
Bacteria/isolation & purification , Bacteria/metabolism , Biodiversity , Cannabis/microbiology , Fungi/isolation & purification , Fungi/metabolism , Bacteria/classification , Bacteria/genetics , Cannabis/metabolism , Fungi/classification , Fungi/genetics , Molecular Sequence Data , Phylogeny , Plant Stems/metabolism , Plant Stems/microbiology , Real-Time Polymerase Chain Reaction
8.
J Infect Dis ; 210(12): 1946-50, 2014 Dec 15.
Article in English | MEDLINE | ID: mdl-24939907

ABSTRACT

Past genome-wide association studies (GWAS) involving individuals with AIDS have mainly identified associations in the HLA region. Using the latest software, we imputed 7 million single-nucleotide polymorphisms (SNPs)/indels of the 1000 Genomes Project from the GWAS-determined genotypes of individuals in the Genomics of Resistance to Immunodeficiency Virus AIDS nonprogression cohort and compared them with those of control cohorts. The strongest signals were in MICA, the gene encoding major histocompatibility class I polypeptide-related sequence A (P = 3.31 × 10(-12)), with a particular exonic deletion (P = 1.59 × 10(-8)) in full linkage disequilibrium with the reference HCP5 rs2395029 SNP. Haplotype analysis also revealed an additive effect between HLA-C, HLA-B, and MICA variants. These data suggest a role for MICA in progression and elite control of human immunodeficiency virus type 1 infection.


Subject(s)
Disease Resistance , HIV Infections/immunology , HIV-1/immunology , Histocompatibility Antigens Class I/genetics , Adult , Cohort Studies , Female , Genetic Association Studies , HIV Infections/virology , Haplotypes , Humans , Linkage Disequilibrium , Major Histocompatibility Complex/genetics , Male , Middle Aged , Polymorphism, Single Nucleotide , RNA, Long Noncoding , RNA, Untranslated , Young Adult
9.
J Infect Dis ; 205(7): 1155-62, 2012 Apr 01.
Article in English | MEDLINE | ID: mdl-22362864

ABSTRACT

BACKGROUND: To date, only mutations in CCR5 have been shown to confer resistance to human immunodeficiency virus type 1 (HIV-1) infection, and these explain only a small fraction of the observed variability in HIV susceptibility. METHODS: We performed a meta-analysis between 2 independent European genomewide association studies, each comparing HIV-1 seropositive cases with normal population controls known to be HIV uninfected, to identify single-nucleotide polymorphisms (SNPs) associated with the HIV-1 acquisition phenotype. SNPs exhibiting P < 10(-5) in this first stage underwent second-stage analysis in 2 independent US cohorts of European descent. RESULTS: After the first stage, a single highly significant association was revealed for the chromosome 8 rs6996198 with HIV-1 acquisition and was replicated in both second-stage cohorts. Across the 4 groups, the rs6996198-T allele was consistently associated with a significant reduced risk of HIV-1 infection, and the global meta-analysis reached genomewide significance: P(combined) = 7.76 × 10(-8). CONCLUSIONS: We provide strong evidence of association for a common variant with HIV-1 acquisition in populations of European ancestry. This protective signal against HIV-1 infection is the first identified outside the CCR5 nexus. First clues point to a potential functional role for a nearby candidate gene, CYP7B1, but this locus warrants further investigation.


Subject(s)
Disease Resistance , HIV Infections/genetics , HIV Infections/immunology , HIV-1/immunology , Adult , Aged , Aged, 80 and over , Cohort Studies , Cytochrome P450 Family 7 , Europe , Female , Gene Frequency , Genetic Association Studies , Genetic Loci , HIV Infections/virology , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide , Steroid Hydroxylases/genetics , United States
10.
J Acquir Immune Defic Syndr ; 56(3): 279-84, 2011 Mar 01.
Article in English | MEDLINE | ID: mdl-21107268

ABSTRACT

BACKGROUND: Seven genome-wide association studies (GWAS) have been published in AIDS, and only associations in the HLA region on chromosome 6 and CXCR6 have passed genome-wide significance. METHODS: We reanalyzed the data from 3 previously published GWAS, targeting specifically low-frequency SNPs (minor allele frequency <5%). Two groups composed of 365 slow progressors and 147 rapid progressors from Europe and the United States were compared with a control group of 1394 seronegative individuals using Eigenstrat corrections. RESULTS: Of the 8584 SNPs with minor allele frequency <5% in cases and controls (Bonferroni threshold = 5.8 × 10⁻6), 4 SNPs showed statistical evidence of association with the slow progressor phenotype. The best result was for HCP5 rs2395029 [P = 8.54 × 10⁻¹5, odds ratio (OR) = 3.41] in the HLA locus, in partial linkage disequilibrium with 2 additional chromosome 6 associations in C6orf48 (P = 3.03 × 10⁻¹°, OR = 2.9) and NOTCH4 (9.08 × 10⁻°7, OR = 2.32). The fourth association corresponded to rs2072255 located in RICH2 (P = 3.30 × 10⁻°6, OR = 0.43) in chromosome 17. Using HCP5 rs2395029 as a covariate, the C6orf48 and NOTCH4 signals disappeared, but the RICH2 signal still remained significant. CONCLUSIONS: Besides the already known chromosome 6 associations, the analysis of low-frequency SNPs brought up a new association in the RICH2 gene. Interestingly, RICH2 interacts with BST-2 known to be a major restriction factor for HIV-1 infection. Our study has thus identified a new candidate gene for AIDS molecular etiology and confirms the interest of singling out low-frequency SNPs to exploit GWAS data.


Subject(s)
Acquired Immunodeficiency Syndrome/genetics , Alleles , GTPase-Activating Proteins/genetics , Genetic Predisposition to Disease , Genome-Wide Association Study , Polymorphism, Single Nucleotide , Adult , Disease Progression , Europe , Female , HIV Long-Term Survivors , Humans , Male , Middle Aged , United States
11.
J Chem Inf Model ; 50(6): 992-1004, 2010 Jun 28.
Article in English | MEDLINE | ID: mdl-20527883

ABSTRACT

In the early stage of drug discovery programs, when the structure of a complex involving a target and a small molecule is available, structure-based virtual ligand screening methods are generally preferred. However, ligand-based strategies like shape-similarity search methods can also be applied. Shape-similarity search methods consist in exploring a pseudo-binding-site derived from the known small molecule used as a reference. Several of these methods use conformational sampling algorithms which are also shared by corresponding docking methods: for example Surflex-dock/Surflex-sim, FlexX/FlexS, ICM, and OMEGA-FRED/OMEGA-ROCS. Using 11 systems issued from the challenging "own" subsets of the Directory of Useful Decoys (DUD-own), we evaluated and compared the performance of the above-cited programs in terms of molecular alignment accuracy, enrichment in active compounds, and enrichment in different chemotypes (scaffold-hopping). Since molecular alignment is a crucial aspect of performance for the different methods, we have assessed its impact on enrichment. We have also illustrated the paradox of retrieving active compounds with good scores even if they are inaccurately positioned. Finally, we have highlighted possible positive aspects of using shape-based approaches in drug-discovery protocols when the structure of the target in complex with a small molecule is known.


Subject(s)
Drug Evaluation, Preclinical/methods , User-Computer Interface , Databases, Factual , Ligands , Models, Molecular , Molecular Conformation
12.
J Infect Dis ; 200(8): 1194-201, 2009 Oct 15.
Article in English | MEDLINE | ID: mdl-19754311

ABSTRACT

BACKGROUND: Previous genomewide association studies (GWASs) of AIDS have targeted end points based on the control of viral load and disease nonprogression. The discovery of genetic factors that predispose individuals to rapid progression to AIDS should also reveal new insights into the molecular etiology of the pathology. METHODS: We undertook a case-control GWAS of a unique cohort of 85 human immunodeficiency virus type 1 (HIV-1)-infected patients who experienced rapid disease progression, using Illumina HumanHap300 BeadChips. The case group was compared with a control group of 1352 individuals for the 291,119 autosomal single-nucleotide polymorphisms (SNPs) passing the quality control tests, using the false-discovery rate (FDR) statistical method for multitest correction. RESULTS: Novel associations with rapid progression (FDR, < or = 25%) were identified for PRMT6 (P = 6.1 x 10(-7); odds ratio [OR], 0.24), SOX5 (P = 1.8 x 10(-6); OR, 0.45), RXRG (P = 3.9 x 10(-6); OR, 3.29), and TGFBRAP1 (P = 7 x 10(-6); OR, 0.34). The haplotype analysis identified exonic and promoter SNPs potentially important for PRMT6 and TGFBRAP1 function. CONCLUSIONS: The statistical and biological relevance of these associations and their high ORs underscore the power of extreme phenotypes for GWASs, even with a modest sample size. These genetic results emphasize the role of the transforming growth factor beta pathway in the pathogenesis of HIV-1 disease. Finally, the wealth of information provided by this study should help unravel new diagnostic and therapeutic targets.


Subject(s)
Acquired Immunodeficiency Syndrome/genetics , Genetic Predisposition to Disease , Genome, Human , Alleles , Case-Control Studies , Cohort Studies , Disease Progression , Gene Expression Regulation/physiology , Genotype , HIV Seropositivity , Humans , Linkage Disequilibrium , Phenotype , Polymorphism, Single Nucleotide
13.
J Infect Dis ; 199(3): 419-26, 2009 Feb 01.
Article in English | MEDLINE | ID: mdl-19115949

ABSTRACT

To elucidate the genetic factors predisposing to AIDS progression, we analyzed a unique cohort of 275 human immunodeficiency virus (HIV) type 1-seropositive nonprogressor patients in relation to a control group of 1352 seronegative individuals in a genomewide association study (GWAS). The strongest association was obtained for HCP5 rs2395029 (P=6.79x10(-10); odds ratio, 3.47) and was possibly linked to an effect of sex. Interestingly, this single-nucleotide polymorphism (SNP) was in high linkage disequilibrium with HLA-B, MICB, TNF, and several other HLA locus SNPs and haplotypes. A meta-analysis of our genomic data combined with data from the previously conducted Euro-CHAVI (Center for HIV/AIDS Vaccine Immunology) GWAS confirmed the HCP5 signal (P=3.02x10(-19)) and identified several new associations, all of them involving HLA genes: MICB, TNF, RDBP, BAT1-5, PSORS1C1, and HLA-C. Finally, stratification by HCP5 rs2395029 genotypes emphasized an independent role for ZNRD1, also in the HLA locus, and this finding was confirmed by experimental data. The present study, the first GWAS of HIV-1 nonprogressors, underscores the potential for some HLA genes to control disease progression soon after infection.


Subject(s)
Acquired Immunodeficiency Syndrome/genetics , Genome, Human , HIV-1 , HLA Antigens/genetics , Major Histocompatibility Complex/genetics , Cohort Studies , Disease Progression , Genotype , HIV Seropositivity/genetics , Humans , Linkage Disequilibrium , Polymorphism, Single Nucleotide
14.
Biomed Pharmacother ; 62(1): 31-40, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18096355

ABSTRACT

Members of the secreted phospholipase A2 (PLA2) protein family can inhibit HIV-1 virus replication in vitro. To evaluate the impact of PLA2 gene polymorphisms on AIDS disease development, we studied 12 family members using SNPlextrade mark technology that permitted simultaneous typing of 70 tagging Single Nucleotide Polymorphisms (tagSNPs). The study utilized HIV-1 seropositive donors with slow progressor (n=168) or rapid progressor (n=54) status, plus 355 control subjects. All donors were Caucasian (total 577 individuals). Genetic associations yielded mainly 0.01

Subject(s)
Acquired Immunodeficiency Syndrome/genetics , Genetic Predisposition to Disease , Phospholipases A2/genetics , Polymorphism, Single Nucleotide , Alleles , Cohort Studies , Disease Progression , France , Genomics/methods , Haplotypes , Humans , White People
15.
BMC Bioinformatics ; 8: 205, 2007 Jun 15.
Article in English | MEDLINE | ID: mdl-17573965

ABSTRACT

BACKGROUND: We have developed a new haplotyping program based on the combination of an iterative multiallelic EM algorithm (IEM), bootstrap resampling and a pseudo Gibbs sampler. The use of the IEM-bootstrap procedure considerably reduces the space of possible haplotype configurations to be explored, greatly reducing computation time, while the adaptation of the Gibbs sampler with a recombination model on this restricted space maintains high accuracy. On large SNP datasets (>30 SNPs), we used a segmented approach based on a specific partition-ligation strategy. We compared this software, Ishape (Iterative Segmented HAPlotyping by Em), with reference programs such as Phase, Fastphase, and PL-EM. Analogously with Phase, there are 2 versions of Ishape: Ishape1 which uses a simple coalescence model for the pseudo Gibbs sampler step, and Ishape2 which uses a recombination model instead. RESULTS: We tested the program on 2 types of real SNP datasets derived from Hapmap: adjacent SNPs (high LD) and SNPs spaced by 5 Kb (lower level of LD). In both cases, we tested 100 replicates for each size: 10, 20, 30, 40, 50, 60, and 80 SNPs. For adjacent SNPs Ishape2 is superior to the other software both in terms of speed and accuracy. For SNPs spaced by 5 Kb, Ishape2 yields similar results to Phase2.1 in terms of accuracy, and both outperform the other software. In terms of speed, Ishape2 runs about 4 times faster than Phase2.1 with 10 SNPs, and about 10 times faster with 80 SNPs. For the case of 5kb-spaced SNPs, Fastphase may run faster with more than 100 SNPs. CONCLUSION: These results show that the Ishape heuristic approach for haplotyping is very competitive in terms of accuracy and speed and deserves to be evaluated extensively for possible future widespread use.


Subject(s)
Algorithms , DNA Mutational Analysis/methods , Haplotypes/genetics , Polymorphism, Single Nucleotide/genetics , Sequence Analysis, DNA/methods , Software , Base Sequence , Molecular Sequence Data , Reproducibility of Results , Sensitivity and Specificity
16.
J Infect Dis ; 194(11): 1492-504, 2006 Dec 01.
Article in English | MEDLINE | ID: mdl-17083033

ABSTRACT

Interleukin (IL)-1 family members are key players in inflammatory processes but have been the subject of few studies of acquired immunodeficiency syndrome (AIDS). To better evaluate the impact of the IL-1 family on AIDS development, we genotyped the IL1 alpha , IL1 beta , IL1Ra, and IL1R1 genes in 245 slow progressor (SP) and 82 rapid progressor (RP) human immunodeficiency virus type 1-seropositive patients as well as in 446 control subjects, all of whom were of white ethnicity. One hundred sixteen frequent polymorphisms were identified, of which 23 were newly characterized by our study. Many putative associations were found between single-nucleotide polymorphism (SNP) or haplotype alleles and the extreme profiles of progression. Most of them corresponded to weak associations (.01

Subject(s)
Acquired Immunodeficiency Syndrome/genetics , Genetic Predisposition to Disease , Interleukin 1 Receptor Antagonist Protein/genetics , Interleukin-1alpha/genetics , Interleukin-1beta/genetics , Polymorphism, Genetic , Receptors, Interleukin-1 Type I/genetics , Acquired Immunodeficiency Syndrome/immunology , Cohort Studies , Disease Progression , France , Haplotypes , Humans , Statistics as Topic , White People
17.
BMC Genet ; 7: 50, 2006 Oct 26.
Article in English | MEDLINE | ID: mdl-17067372

ABSTRACT

BACKGROUND: Genetic association studies aim at finding correlations between a disease state and genetic variations such as SNPs or combinations of SNPs, termed haplotypes. Some haplotypes have a particular biological meaning such as the ones derived from SNPs located in the promoters, or the ones derived from non synonymous SNPs. All these haplotypes are "subhaplotypes" because they refer only to a part of the SNPs found in the gene. Until now, subhaplotypes were directly computed from the very SNPs chosen to constitute them, without taking into account the rest of the information corresponding to the other SNPs located in the gene. In the present work, we describe an alternative approach, called the "global method", which takes into account all the SNPs known in the region and compare the efficacy of the two "direct" and "global" methods. RESULTS: We used empirical haplotypes data sets from the GH1 promoter and the APOE gene, and 10 simulated datasets, and randomly introduced in them missing information (from 0% up to 20%) to compare the 2 methods. For each method, we used the PHASE haplotyping software since it was described to be the best. We showed that the use of the "global method" for subhaplotyping leads always to a better error rate than the classical direct haplotyping. The advantage provided by this alternative method increases with the percentage of missing genotyping data (diminution of the average error rate from 25% to less than 10%). We applied the global method software on the GRIV cohort for AIDS genetic associations and some associations previously identified through direct subhaplotyping were found to be erroneous. CONCLUSION: The global method for subhaplotyping can reduce, sometimes dramatically, the error rate on patient resolutions and haplotypes frequencies. One should thus use this method in order to minimise the risk of a false interpretation in genetic studies involving subhaplotypes. In practice the global method is always more efficient than the direct method, but a combination method taking into account the level of missing information in each subject appears to be even more interesting when the level of missing information becomes larger (>10%).


Subject(s)
Computational Biology/methods , Haplotypes , Polymorphism, Single Nucleotide , Software , Apolipoproteins E/genetics , HIV Infections/genetics , HIV Infections/immunology , HIV Seropositivity/genetics , HIV Seropositivity/immunology , HIV-1/immunology , Human Growth Hormone/genetics , Humans , Interleukin-6/genetics , Receptors, Interleukin-10/genetics , Receptors, Interleukin-4/genetics
18.
Immunogenetics ; 58(2-3): 89-98, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16491350

ABSTRACT

We have performed an extensive analysis of Th1/Th2 cytokine receptors IL2Ralpha, IL4Ralpha, IL10Ralpha, and IFNgammaR1 gene polymorphisms to evaluate their impact on AIDS progression. The coding regions and promoters of these genes were sequenced in the genetics of resistance to immunodeficiency virus cohort, composed of 327 HIV-1-positive patients with extreme progression phenotypes, slow and rapid progressors, and of 446 healthy control subjects, all of them of Caucasian descent. Overall, 104 single nucleotide polymorphisms and four insertions/deletions with a minor allelic frequency higher than 1% were identified, 21 of them being newly characterized. We observed weak associations for 13 polymorphisms of IL2Ralpha, IL4Ralpha, IL10Ralpha, and IFNgammaR1, and 11 haplotypes of IL2Ralpha, IL4Ralpha, and IFNgammaR1. However, we could not relate these positive signals to any relevant biological information on the gene function. To affirm these putative associations in AIDS, further confirmation on other AIDS cohorts will be needed. This complete catalog of polymorphisms in IL2Ralpha, IL4Ralpha, IL10Ralpha, and IFNgammaR1 cytokine receptor genes should also be useful for investigating associations in other immune-related diseases.


Subject(s)
Acquired Immunodeficiency Syndrome/genetics , Polymorphism, Single Nucleotide , Receptors, Interferon/genetics , Receptors, Interleukin/genetics , Acquired Immunodeficiency Syndrome/immunology , Cohort Studies , Disease Progression , France , Humans , Interleukin-2 Receptor alpha Subunit , Interleukin-4 Receptor alpha Subunit , Receptors, Interleukin-10 , Receptors, Interleukin-2/genetics , Receptors, Interleukin-4/genetics , Th1 Cells/immunology , Th2 Cells/immunology , Interferon gamma Receptor
19.
Biomed Pharmacother ; 59(8): 474-80, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16153798

ABSTRACT

Large-scale genomic studies in cohorts have been made possible for the last few years thanks to the progress of molecular biology and bioinformatics. This systematic approach allows a better understanding of the molecular mechanisms of disease development and as a consequence can contribute to the rational design of new diagnostic and therapeutic tools. We present here the exhaustive genotyping of a candidate gene, tumor necrosis factor receptor 1 (TNFR1), in the genetic of resistance to immunodeficiency virus (GRIV) AIDS cohort. This gene was chosen because it is likely to be involved in the apoptosis pathways of CD4+ and CD8+ T-cells during human immunodeficiency virus 1 (HIV-1) infection. Seven frequent polymorphisms were characterized in 319 HIV-1 seropositive patients from the GRIV cohort with extreme disease progression phenotypes, slow progression or rapid progression, and in 427 healthy controls. The TNFR1 gene locus does not appear to be part of any haploblock and contains only a small haploblock of two successive SNPs. One promoter SNP (TNFR1_17444594, position -581) and one intronic SNP (TNFR1_27223241, position +11511) gave weak positive signals of association (resp. P=0.03 and P=0.04) as well as two haplotypes. To our knowledge, this is the first genetic association study dealing with the TNFR1 gene in AIDS and the putative associations identified will need to be validated through other AIDS cohort analyses or by further biological experimentation.


Subject(s)
Acquired Immunodeficiency Syndrome/genetics , HIV-1 , Receptors, Tumor Necrosis Factor, Type I/genetics , Acquired Immunodeficiency Syndrome/pathology , Cohort Studies , Disease Progression , Disease Susceptibility , France , Gene Frequency , Genomics , Genotype , HIV Seropositivity , Humans , Phenotype , Polymorphism, Single Nucleotide , White People
20.
Vaccine ; 23(33): 4228-35, 2005 Jul 21.
Article in English | MEDLINE | ID: mdl-16005738

ABSTRACT

Interleukin-1beta (IL-1beta) is a crucial cytokine in inflammation processes and has been implicated in the pathogenesis of several chronic inflammatory diseases. Strategies designed to blocking IL-1beta by passive administration of inhibitors (mAbs, IL-1 receptor antagonist) have previously demonstrated efficacy in rheumatoid arthritis (RA). Using molecular modelling, we have defined three murine IL-1beta peptide regions characterized by their close proximity to the receptor. Synthetic peptides corresponding to these regions, in cyclic and linear form, were delivered as immunogens in Swiss mice, resulting in significant levels of autoantibodies directed against the native murine IL-1beta cytokine as determined by ELISA and by an assay for neutralization of IL-1beta biological activity. More importantly, one of the cyclic peptides showed a protective effect against inflammation and articular destruction in DBA/1 mouse collagen-induced arthritis, a model of RA. The high rate of success observed for active immunization against cytokine peptides in vivo suggests that the in silico approach to autoantigen design may be a promising avenue for the development of anti-cytokine immunotherapeutics.


Subject(s)
Arthritis, Experimental/drug therapy , Bone and Bones/drug effects , Collagen , Interleukin-1/administration & dosage , Animals , Arthritis, Experimental/chemically induced , Arthritis, Experimental/pathology , Bone and Bones/pathology , Disease Models, Animal , Dose-Response Relationship, Drug , Drug Therapy, Combination , Interleukin 1 Receptor Antagonist Protein , Interleukin-1/chemistry , Joints/drug effects , Joints/pathology , Mice , Mice, Inbred DBA , Models, Molecular , Peptides/administration & dosage , Peptides/chemistry , Sialoglycoproteins/pharmacology
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