title: The expression level of gC1qR is down regulated at the early time of infection with porcine circovirus of type 2 (PCV-2) and gC1qR interacts differently with the Cap proteins of porcine circoviruses.
abstract: Porcine circoviruses (PCV) are small, non-enveloped single-stranded DNA-viruses. Porcine circovirus type 2 (PCV-2) is the causal agent of post-weaning multisystemic wasting syndrome (PMWS) whereas porcine circovirus of type 1 (PCV-1) is non- pathogenic. gC1qR is a membrane-located receptor of the complement protein subunit C1q and interacts with PCV capsid proteins. The mechanisms associated with the triggering of PMWS are not well known and gC1qR may have a role in the life cycle and eventually in the pathogenicity of PCV. The objectives of this study were to determine the level of expression of gC1qR during early PCV-2 infection, to determine the region of PCV-2 capsid protein (Cap) required for the interaction with gC1qR and to evaluate the interaction of gC1qR with Cap proteins of different PCV strains. The results indicate that gC1qR transcripts are downregulated in the tonsils and the tracheo-bronchial lymph nodes of piglets infected by PCV-2 at the early time of the infection. The N-terminal amino acids (a.a. 1-59) of PCV-2b Cap, an arginine rich region, are involved in the interaction with gC1qR. Porcine gC1qR interacts with Cap proteins of two pathogenic viral strains, PCV-2a and PCV-2b, while interaction has been observed with only one Cap protein of two investigated strains of PCV-1. The amino acids 30 and 49 of PCV-1Cap, solely, were not responsible of the difference of interaction observed. We have also shown that gC1qR interacts strongly with PCV-2Caps and PCV-1 GER Cap. This result suggests that the different interaction of gC1qR with PCV Cap proteins may have an impact on the pathogenicity of the PCV.
authors.affiliation: Anses, Laboratory of Ploufragan/Plouzané, Unit of viral genetic and biosafety, Ploufragan, France.
authors.forename: Guy Baudry
authors.initials: GB
authors.lastname: Kouokam Fotso
authors.affiliation: Anses, Laboratory of Ploufragan/Plouzané, Unit of viral genetic and biosafety, Ploufragan, France.
authors.forename: Cécilia
authors.initials: C
authors.lastname: Bernard
authors.affiliation: Anses, Laboratory of Ploufragan/Plouzané, Unit of viral genetic and biosafety, Ploufragan, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Bigault
authors.affiliation: Anses, Laboratory of Ploufragan/Plouzané, Unit of viral genetic and biosafety, Ploufragan, France.
authors.forename: Claire
authors.initials: C
authors.lastname: de Boisséson
authors.affiliation: Robert Koch institute, Division of viral infection, Berlin, Germany.
authors.forename: Annette
authors.initials: A
authors.lastname: Mankertz
authors.affiliation: Anses, Laboratory of Ploufragan/Plouzané, Unit of viral genetic and biosafety, Ploufragan, France.
authors.forename: André
authors.initials: A
authors.lastname: Jestin
authors.affiliation: Anses, Laboratory of Ploufragan/Plouzané, Unit of viral genetic and biosafety, Ploufragan, France. Electronic address: Beatrice.GRASLAND@anses.fr.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Grasland
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D036022:Capsid Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D018173:Circoviridae Infections / Q000276:immunology* / Q000473:pathology / Q000821:virology; D017925:Circovirus / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D015870:Gene Expression; D054884:Host-Pathogen Interactions; D018960:Hyaluronan Receptors / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D008198:Lymph Nodes / Q000276:immunology / Q000821:virology; D014066:Palatine Tonsil / Q000276:immunology / Q000821:virology; D053570:Porcine Postweaning Multisystemic Wasting Syndrome / Q000276:immunology* / Q000473:pathology / Q000821:virology; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D016415:Sequence Alignment; D065288:Serogroup; D013552:Swine; D013997:Time Factors; D020798:Two-Hybrid System Techniques
chemical_list: D036022:Capsid Proteins; D018960:Hyaluronan Receptors; D012333:RNA, Messenger
keywords: Capsid; Interaction; Porcine circovirus; gC1qR