title: Stage-specific excretory-secretory small heat shock proteins from the parasitic nematode Strongyloides ratti--putative links to host's intestinal mucosal defense system.
abstract: In a search for molecules involved in the interaction between intestinal nematodes and mammalian mucosal host cells, we performed MS to identify excretory-secretory proteins from Strongyloides ratti. In the excretory-secretory proteins of the parasitic female stage, we detected, in addition to other peptides, peptides homologous with the Caenorhabditis elegans heat shock protein (HSP)-17, named Sra-HSP-17.1 (∼ 19 kDa) and Sra-HSP-17.2 (∼ 18 kDa), with 49% amino acid identity. The full-length cDNAs (483 bp and 474 bp, respectively) were identified, and the genomic organization was analyzed. To allow further characterization, the proteins were recombinantly expressed and purified. Profiling of transcription by quantitative real-time-PCR and of protein by ELISA in various developmental stages revealed parasitic female-specific expression. Sequence analyses of both the DNA and amino acid sequences showed that the two proteins share a conserved α-crystallin domain and variable N-terminals. The Sra-HSP-17s showed the highest homology with the deduced small HSP sequence of the human pathogen Strongyloides stercoralis. We observed strong immunogenicity of both proteins, leading to strong IgG responses following infection of rats. Flow cytometric analysis indicated the binding of Sra-HSP-17s to the monocyte-macrophage lineage but not to peripheral lymphocytes or neutrophils. A rat intestinal epithelial cell line showed dose-dependent binding to Sra-HSP-17.1, but not to Sra-HSP-17.2. Exposed monocytes released interleukin-10 but not tumor necrosis factor-α in response to Sra-HSP-17s, suggesting the possible involvement of secreted female proteins in host immune responses.
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany. abssan2000@yahoo.com
authors.forename: Abuelhassan Elshazly
authors.initials: AE
authors.lastname: Younis
authors.forename: Frank
authors.initials: F
authors.lastname: Geisinger
authors.forename: Irene
authors.initials: I
authors.lastname: Ajonina-Ekoti
authors.forename: Hanns
authors.initials: H
authors.lastname: Soblik
authors.forename: Hanno
authors.initials: H
authors.lastname: Steen
authors.forename: Makedonka
authors.initials: M
authors.lastname: Mitreva
authors.forename: Klaus D
authors.initials: KD
authors.lastname: Erttmann
authors.forename: Markus
authors.initials: M
authors.lastname: Perbandt
authors.forename: Eva
authors.initials: E
authors.lastname: Liebau
authors.forename: Norbert W
authors.initials: NW
authors.lastname: Brattig
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D005260:Female; D050888:Heat-Shock Proteins, Small / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006790:Host-Parasite Interactions; D006801:Humans; D007413:Intestinal Mucosa / Q000276:immunology / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D010802:Phylogeny; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D017170:Strongyloides ratti / Q000254:growth & development / Q000276:immunology / Q000502:physiology*
chemical_list: D050888:Heat-Shock Proteins, Small; D015801:Helminth Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D011994:Recombinant Proteins