Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

IgG antibody profiling of Leptospira interrogans serovar Copenhageni in infected and non-infected subjects using protein microarray

ABSTRACT: Leptospirosis is the most widespread zoonotic disease in the world. The lack of an adequate laboratory test is a major barrier for the diagnosis, especially during the early stages of illness, when antibiotic therapy is most effective. Therefore, there is a critical need for an efficient diagnostic test for this life threatening disease. In order to identify new targets that could be used as diagnostic makers for leptopirosis, we constructed a protein microarray chip comprising 61% of Leptospira interrogans proteome and investigated the IgG response against leptospiral antigens from 274 individuals, including 80 acute-, 80 convalescent-phase patients and 114 healthy control subjects from regions with endemic, high endemic and no endemic transmission of leptospirosis. A nitrocellulose line blot assay was performed to validate the accuracy of the protein microarray results. We found 16 antigens that can discriminate between acute cases and healthy individuals from a region with high endemic transmission of leptospirosis, and 18 antigens that distinguish convalescent cases. Some of the antigens identified in this study, such as LipL32, the non-identical domains of the Lig proteins, GroEL and Loa22 are already known to be recognized by sera from human patients, thus serving as a proof-of-concept for the serodiagnostic antigen discovery approach. Several novel antigens were identified, including the hypothetical protein LIC10215 which showed good sensitivity and specificity rates for both acute- and convalescent-phase patients. Our study is the first large-scale evaluation of immunodominant antigens associated with naturally acquired leptospiral infection and novel as well as known serodiagnostic leptospiral antigens that are recognized by antibodies in the sera of leptospirosis cases were identified. The novel antigens identified here may have potential use in both the development of new tests and the improvement of currently available assays for diagnosing this neglected tropical disease. Further research is needed to assess the accuracy of these antigens in more appropriate diagnostic platforms. Antibody profiling was peformed on sera from infected and non-infected subjects to investigate the IgG response against leptospiral antigens. These samples comprised 80 acute-, 80 convalescent-phase patients and 114 healthy control subjects, including 29 subjects from United States (non-endemic area), 35 blood donors from Salvador/Brazil (endemic area) and 50 healthy individuals from region with high endemicity of leptospirosis.

ORGANISM(S): Homo sapiens

SUBMITTER: Carolina Lessa Aquino

PROVIDER: E-GEOD-42720 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:Leptospirosis is the most widespread zoonotic disease in the world. The lack of an adequate laboratory test is a major barrier for the diagnosis, especially during the early stages of illness, when antibiotic therapy is most effective. Therefore, there is a critical need for an efficient diagnostic test for this life threatening disease. In order to identify new targets that could be used as diagnostic makers for leptopirosis, we constructed a protein microarray chip comprising 61% of Leptospira interrogans proteome and investigated the IgG response against leptospiral antigens from 274 individuals, including 80 acute-, 80 convalescent-phase patients and 114 healthy control subjects from regions with endemic, high endemic and no endemic transmission of leptospirosis. A nitrocellulose line blot assay was performed to validate the accuracy of the protein microarray results. We found 16 antigens that can discriminate between acute cases and healthy individuals from a region with high endemic transmission of leptospirosis, and 18 antigens that distinguish convalescent cases. Some of the antigens identified in this study, such as LipL32, the non-identical domains of the Lig proteins, GroEL and Loa22 are already known to be recognized by sera from human patients, thus serving as a proof-of-concept for the serodiagnostic antigen discovery approach. Several novel antigens were identified, including the hypothetical protein LIC10215 which showed good sensitivity and specificity rates for both acute- and convalescent-phase patients. Our study is the first large-scale evaluation of immunodominant antigens associated with naturally acquired leptospiral infection and novel as well as known serodiagnostic leptospiral antigens that are recognized by antibodies in the sera of leptospirosis cases were identified. The novel antigens identified here may have potential use in both the development of new tests and the improvement of currently available assays for diagnosing this neglected tropical disease. Further research is needed to assess the accuracy of these antigens in more appropriate diagnostic platforms.

Project description:Salivary gland polytene chromosomes of Drosophila melanogaster have a reproducible set of intercalary heterochromatin sites, characterized by late DNA replication, underreplicated DNA, breaks and frequent ectopic contacts. The SuUR mutation has been shown to suppress underreplication, and wild-type SUUR protein is found at late-replicating intercalary heterochromatin sites and in pericentric heterochromatin. We performed a genome-wide mapping of SUUR target genes in the non-polytenic Drosophila Kc cells by using DamID. This approach is based on the ability of a chromatin protein fused to Escherichia coli DNA adenine methyltransferase (Dam) to methylate the native binding site of the chromatin protein. Dam-fusion proteins are expressed at very low levels to avoid mistargeting. Subsequently, methylated DNA fragments are isolated, labeled (using Cy3 or Cy5) and hybridized to a microarray. Methylated DNA fragments from cells transfected with Dam alone served as reference. Genomic binding sites of the protein can then be identified based on the targeted methylation pattern. For detailed background information on DamID, see: van Steensel, B., Delrow, J. & Henikoff, S. Chromatin profiling using targeted DNA adenine methyltransferase. Nat Genet 27, 304-8 (2001); van Steensel, B. & Henikoff, S. Identification of in vivo DNA targets of chromatin proteins using tethered dam methyltransferase. Nat Biotechnol 18, 424-8 (2000). We generated both an N- and a C-terminal fusion of the full-length SuUR open reading frame with Dam (Dam-SUUR and SUUR-Dam, respectively). For each SUUR fusion protein we performed four independent replicates. We used for this study a cDNA array developed by the GeneCore facility in EMBL (Heidelberg, Germany), covering the DGC1 and DGC2 cDNA libraries from the Berkeley Drosophila Genome Project, which represents more than 70% of the coding Drosophila genome. We found that SUUR preferentially binds to genes that are transcriptionally silent and late replicated. We compared the SUUR binding profile to the binding profile of three PcG proteins, which are known to bind to many intercalary heterochromatin sites, and found that there is a significant overlap with Pc and esc, but less with Sce. A significant overlap is also detected with two markers of pericentric heterochromatin, the heterochromatin proteins HP1 and SU(VAR)3-9. Finally, we demonstrated that SUUR binding profile negatively correlates with DNA polytenization level in salivary gland polytene chromosomes. Taken together, these results suggest that SUUR modulates the level of underreplication by direct binding to intercalary and pericentric heterochromatin.

Dataset Information

IgG antibody profiling of Leptospira interrogans serovar Copenhageni in infected and non-infected subjects using protein microarray

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets