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Ashano E, Isewon I, Oyelade J, Adebiyi E. Cluster analysis of Plasmodium RNA-seq time-course data identifies stage-specific co-regulated biological processes and regulatory elements. F1000Res 2016; 5. [PMID: 27990252 PMCID: PMC5155496 DOI: 10.12688/f1000research.9093.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/29/2016] [Indexed: 12/26/2022] Open
Abstract
In this study, we interpreted RNA-seq time-course data of three developmental stages of Plasmodium species by clustering genes based on similarities in their expression profile without prior knowledge of the gene function. Functional enrichment of clusters of upregulated genes at specific time-points reveals potential targetable biological processes with information on their timings. We identified common consensus sequences that these clusters shared as potential points of coordinated transcriptional control. Five cluster groups showed upregulated profile patterns of biological interest. This included two clusters from the Intraerythrocytic Developmental Cycle (cluster 4 = 16 genes, and cluster 9 = 32 genes), one from the sexual development stage (cluster 2 = 851 genes), and two from the gamete-fertilization stage in the mosquito host (cluster 4 = 153 genes, and cluster 9 = 258 genes). The IDC expressed the least numbers of genes with only 1448 genes showing any significant activity of the 5020 genes (~29%) in the experiment. Gene ontology (GO) enrichment analysis of these clusters revealed a total of 671 uncharacterized genes implicated in 14 biological processes and components associated with these stages, some of which are currently being investigated as drug targets in on-going research. Five putative transcription regulatory binding motifs shared by members of each cluster were also identified, one of which was also identified in a previous study by separate researchers. Our study shows stage-specific genes and biological processes that may be important in antimalarial drug research efforts. In addition, timed-coordinated control of separate processes may explain the paucity of factors in parasites.
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Affiliation(s)
- Efejiro Ashano
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, 110001, Nigeria
| | - Itunuoluwa Isewon
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, 110001, Nigeria.,Department of Computer and Information Sciences, Covenant University, Ota, Ogun State, 110001, Nigeria
| | - Jelili Oyelade
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, 110001, Nigeria.,Department of Computer and Information Sciences, Covenant University, Ota, Ogun State, 110001, Nigeria
| | - Ezekiel Adebiyi
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, 110001, Nigeria.,Department of Computer and Information Sciences, Covenant University, Ota, Ogun State, 110001, Nigeria.,Division of Applied Bioinformatics, German Cancer Research Center (DKFZ), Heidelberg,, 69120, Germany
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Anders RF, Shi PT, Scanlon DB, Leach SJ, Coppel RL, Brown GV, Stahl HD, Kemp DJ. Antigenic repeat structures in proteins of Plasmodium falciparum. CIBA FOUNDATION SYMPOSIUM 2007; 119:164-83. [PMID: 2426051 DOI: 10.1002/9780470513286.ch10] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The majority of malaria antigens that have been cloned contain short sequence repeats which encode antigenic epitopes that are naturally immunogenic. Synthetic peptides have been used to show that natural antibody responses to a strain-specific Plasmodium falciparum S antigen are largely directed against epitopes encoded in an 11-amino acid sequence that is repeated approximately 100 times in the molecule. A 16-amino acid peptide conjugated to bovine serum albumin induced antibodies specific for the S antigen of the homologous isolate. Synthetic peptides have also been used to confirm the natural immunogenicity of epitopes encoded within two blocks of related repeats in the Ring-infected Erythrocyte Surface Antigen (RESA). A 16-amino acid peptide, comprising four repeats of the tetrameric sequence EENV, induced antibodies reactive with the native molecule. Detailed analyses of these anti-peptide antisera indicate that short sequence repeats express more than one epitope, some of which may cross-react with other repeat structures.
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McGarvey MJ, Goldin RD, Karayiannis P, Thomas HC. The expression of hepatitis B virus polymerase in hepatocytes during chronic HBV infection. J Viral Hepat 1996; 3:67-73. [PMID: 8811640 DOI: 10.1111/j.1365-2893.1996.tb00083.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A recombinant protein corresponding to part of the amino-terminal domain of hepatitis B virus (HBV) polymerase was expressed in Escherichia coli. Antisera raised against this protein stained hepatocytes, from human liver biopsies, predominantly in the nucleus but some cytoplasmic staining was also observed. No staining was observed in hepatocytes from uninfected patients. Liver biopsies, taken from patients who were infected with human immunodeficiency virus (HIV) as well as HBV showed more intense staining with these antisera than that seen in patients who were infected with HBV alone. The staining pattern suggests that either the whole HBV polymerase protein, or a portion encoding the amino-terminal domain, is translocated to the nucleus. This event may be an important early step in replication of the HBV genome.
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Affiliation(s)
- M J McGarvey
- Department of Medicine, Imperial College School of Medicine at St Mary's, London, UK
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Kemp DJ, Cowman AF, Walliker D. Genetic diversity in Plasmodium falciparum. ADVANCES IN PARASITOLOGY 1990; 29:75-149. [PMID: 2181830 DOI: 10.1016/s0065-308x(08)60105-0] [Citation(s) in RCA: 112] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- D J Kemp
- Walter and Eliza Hall Institute of Medical Research, Victoria, Australia
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Cheung A, Leban J, Shaw AR, Merkli B, Stocker J, Chizzolini C, Sander C, Perrin LH. Immunization with synthetic peptides of a Plasmodium falciparum surface antigen induces antimerozoite antibodies. Proc Natl Acad Sci U S A 1986; 83:8328-32. [PMID: 3534885 PMCID: PMC386921 DOI: 10.1073/pnas.83.21.8328] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Polypeptides expressed on the surface of merozoites, the invasive stage of the asexual blood cycle, are good candidates for the development of malaria vaccines. Five synthetic peptides with predetermined specificity deduced from a genomic DNA clone coding for the NH2-terminal portion of the main merozoite surface polypeptide of Plasmodium falciparum were evaluated for their capability to raise antibodies that react with the P. falciparum merozoites. Antibodies induced by two of the peptides (3 and 5) reacted with the membrane surfaces of seven of seven isolates of P. falciparum from different geographic areas. Antibodies against peptide 4, which contains a repeated amino acid sequence (Gly-Gly-Ser and Val-Ala-Ser), reacted with six of seven isolates. Structural analysis of the deduced polypeptides suggests that peptide 3 is exposed at the surface of merozoites. When it was used to immunize monkeys, three of the four animals were partially protected from a challenge infection that induced a fulminant infection in control animals.
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Kemp DJ, Coppel RL, Stahl HD, Bianco AE, Corcoran LM, McIntyre P, Langford CJ, Favaloro JM, Crewther PE, Brown GV. The Wellcome Trust lecture. Genes for antigens of Plasmodium falciparum. Parasitology 1986; 92 Suppl:S83-108. [PMID: 2423947 DOI: 10.1017/s0031182000085711] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Sporozoites ofP. falciparumand other Plasmodia appear to be fairly simple antigenically, in that there is a dominant antigen, the circumsporozoite (CS) protein that forms the sporozoite surface coat (Potocnjak, Yoshida, Nussenzweig & Nussensweig, 1980; Santoroet al.1983). Consequently, the CS protein and the gene encoding it have now been studied in considerable detail (Elliset al.1983; Godsonet al.1983; Ozakiet al.1983; Dameet al.1984; Eneaet al.1984). In contrast to sporozoites, the asexual blood stagesof P. falciparumare antigenically complex. Two-dimensional gel analyses of immunoprecipitated, biosynthetically labelled antigens indicate that repeated infection withP. falciparumresults in the synthesis of antibodies against a large number of distinct antigens (Perrin & Dayal, 1982; Brownet al.1981, 1983). In further contrast to the sporozoite, the asexual blood stages of differentP. falciparumisolates exhibit a high degree of antigenic heterogeneity (Brownet al.1983; Hallet al.1983; McBride, Walliker & Morgan, 1982). Much of this antigenic diversity is no doubt due to allelic differences but clonal populations of parasites may also have the capacity to undergo antigenic variation (Hommel, David & Oligino, 1983).
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Heidrich HG. Plasmodium falciparum antigens as target molecules for a protective immunization against malaria: an up-to-date review. ZEITSCHRIFT FUR PARASITENKUNDE (BERLIN, GERMANY) 1986; 72:1-11. [PMID: 3515789 DOI: 10.1007/bf00927730] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Langsley G, Scherf A, Mercereau-Puijalon O, Koenen M, Kahane B, Mattei D, Guillotte M, Sibilli L, Garner I, Müller-Hill B. Characterisation of P. falciparum antigenic determinants isolated from a genomic expression library by differential antibody screening. Nucleic Acids Res 1985; 13:4191-202. [PMID: 2409532 PMCID: PMC341305 DOI: 10.1093/nar/13.11.4191] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A genomic expression library of P.falciparum has been differentially screened with a number of immune sera. The response of 9 clones to the various sera is presented, together with the DNA sequence encoding the epitopes. All but one clone are extremely A+T rich and unlike the other P.falciparum epitopes described, are not composed of amino acid repeats. One clone, which responds specifically with a protective serum, has been analysed in detail. The epitope is carried on a 160kd antigen which is transcribed from a single gene to give a protein expressed in all of the erythrocytic forms. DNA sequence of this clone reveals it to have more than one open reading frame, only one of which is transcribed in the blood stages. The possible significance of the other open readings frames is discussed.
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Perrin LH, Merkli B, Gabra MS, Stocker JW, Chizzolini C, Richle R. Immunization with a Plasmodium falciparum merozoite surface antigen induces a partial immunity in monkeys. J Clin Invest 1985; 75:1718-21. [PMID: 3889058 PMCID: PMC425516 DOI: 10.1172/jci111881] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Saimiri monkeys immunized with a Plasmodium falciparum merozoite polypeptide of 41 kD mol wt are resistant to a blood challenge infection that induces a fulminant infection in control monkeys. The sera of the immunized monkeys reacted, as shown by the indirect immunofluorescence technique, with the apical part of the merozoites from five isolates or clones of P. falciparum. Whether the immunogen was dissolved in nonionic detergent (NP-40) or in sodium dodecyl sulfate (SDS) had a marked influence on the level of protection in immunized monkeys. Thus, monkeys immunized with the antigen solubilized in a nonionic detergent developed much lower parasitemia than monkeys immunized with denatured antigen (antigen eluted from SDS polyacrylamide gel electrophoresis).
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Ardeshir F, Flint JE, Reese RT. Expression of Plasmodium falciparum surface antigens in Escherichia coli. Proc Natl Acad Sci U S A 1985; 82:2518-22. [PMID: 3887406 PMCID: PMC397590 DOI: 10.1073/pnas.82.8.2518] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The asexual blood stages of the human malarial parasite Plasmodium falciparum produce many antigens, only some of which are important for protective immunity. Most of the putative protective antigens are believed to be expressed in schizonts and merozoites, the late stages of the asexual cycle. With the aim of cloning and characterizing genes for important parasite antigens, we used late-stage P. falciparum mRNA to construct a library of cDNA sequences inserted in the Escherichia coli expression vector pUC8. Nine thousand clones from the expression library were immunologically screened in situ with serum from Aotus monkeys immune to P. falciparum, and 95 clones expressing parasite antigens were identified. Mice were immunized with lysates from 49 of the bacterial clones that reacted with Aotus sera, and the mouse sera were tested for their reactivity with parasite antigens by indirect immunofluorescence, immunoprecipitation, and immunoblotting assays. Several different P. falciparum antigens were identified by these assays. Indirect immunofluorescence studies of extracellular merozoites showed that three of these antigens appear to be located on the merozoite surface. Thus, we have identified cDNA clones to three different P. falciparum antigens that may be important in protective immunity.
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Perrin L, Perez A, Chizzolini C. Malaria: immunity, vaccination and immunodiagnosis. EXPERIENTIA 1984; 40:1343-50. [PMID: 6391948 DOI: 10.1007/bf01951887] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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