title: Bacterial lipoprotein based expression vectors as tools for the characterisation of African swine fever virus (ASFV) antigens.
abstract: African swine fever virus (ASFV) is the causative agent of an important pig disease for which protective mechanisms are still poorly understood. The present work was aimed at the characterisation of ASFV antigens using previously reported vectors that allow their expression as fusion proteins with the bacterial lipoprotein OprI. Several recombinant clones induced SLA-restricted, ASFV-specific lymphoproliferation and one (A2) was demonstrated to stimulate ASFV-specific CTL activity in vitro, in opposition to the effect of UV inactivated virus. The nucleotide sequence of the fragment cloned in A2 showed 99% identity with a portion of the G1340L ORF of the BA71V isolate, and the expressed fusion lipoprotein induced specific antibodies in vivo. Blood mononuclear leukocytes from a pig immunised with outer membrane preparations from A2 showed to reduce strongly (99.6%) the ASFV yield in cultures of autologous macrophages. However, after inoculation with virulent virus the pig developed acute fatal ASF. Overall our results show that OprI based expression vectors are valuable tools to screen viral antigens in terms of their capacity to trigger immune competent cells.
authors.affiliation: Laboratório de Doenças Infecciosas, CIISA, Faculdade de Medicina Veterinária, Lisbon, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Leitão
authors.forename: A
authors.initials: A
authors.lastname: Malur
authors.forename: C
authors.initials: C
authors.lastname: Cartaxeiro
authors.forename: G
authors.initials: G
authors.lastname: Vasco
authors.forename: B
authors.initials: B
authors.lastname: Cruz
authors.forename: P
authors.initials: P
authors.lastname: Cornelis
authors.forename: C L
authors.initials: CL
authors.lastname: Martins
mesh_terms: D000357:African Swine Fever / Q000517:prevention & control / Q000821:virology; D000358:African Swine Fever Virus / Q000276:immunology* / Q000528:radiation effects; D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D000956:Antigens, Viral / Q000032:analysis / Q000235:genetics / Q000276:immunology*; D001426:Bacterial Proteins / Q000235:genetics*; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D005822:Genetic Vectors; D006649:Histocompatibility Antigens / Q000276:immunology; D008074:Lipoproteins / Q000235:genetics*; D008213:Lymphocyte Activation; D016131:Lymphocyte Subsets / Q000276:immunology; D013552:Swine; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014466:Ultraviolet Rays; D014614:Vaccines, Synthetic / Q000276:immunology; D014709:Vero Cells; D014760:Viral Fusion Proteins / Q000032:analysis / Q000235:genetics / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D001426:Bacterial Proteins; D006649:Histocompatibility Antigens; D008074:Lipoproteins; D014614:Vaccines, Synthetic; D014760:Viral Fusion Proteins; C060507:outer membrane lipoprotein I, Bacteria