title: Features of two new proteins with OmpA-like domains identified in the genome sequences of Leptospira interrogans.
abstract: Leptospirosis is an acute febrile disease caused by pathogenic spirochetes of the genus Leptospira. It is considered an important re-emerging infectious disease that affects humans worldwide. The knowledge about the mechanisms by which pathogenic leptospires invade and colonize the host remains limited since very few virulence factors contributing to the pathogenesis of the disease have been identified. Here, we report the identification and characterization of two new leptospiral proteins with OmpA-like domains. The recombinant proteins, which exhibit extracellular matrix-binding properties, are called Lsa46 - LIC13479 and Lsa77 - LIC10050 (Leptospiral surface adhesins of 46 and 77 kDa, respectively). Attachment of Lsa46 and Lsa77 to laminin was specific, dose dependent and saturable, with KD values of 24.3 ± 17.0 and 53.0 ± 17.5 nM, respectively. Lsa46 and Lsa77 also bind plasma fibronectin, and both adhesins are plasminogen (PLG)-interacting proteins, capable of generating plasmin (PLA) and as such, increase the proteolytic ability of leptospires. The proteins corresponding to Lsa46 and Lsa77 are present in virulent L. interrogans L1-130 and in saprophyte L. biflexa Patoc 1 strains, as detected by immunofluorescence. The adhesins are recognized by human leptospirosis serum samples at the onset and convalescent phases of the disease, suggesting that they are expressed during infection. Taken together, our data could offer valuable information to the understanding of leptospiral pathogenesis.
authors: Centro de Biotecnologia, Instituto Butantan, Sao Paulo, SP, Brazil; Programa de Pós-Graduação Interunidades em Biotecnologia,Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
authors: Aline F
authors: AF
authors: Teixeira
authors: Laboratório de Zoonoses Bacterianas, Faculdade de Medicina Veterinária e Zootecnia, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
authors: Zenaide M
authors: ZM
authors: de Morais
authors: Nucleo de Estudos em Malária, Superintendência de Controle de Endemias - Instituto de Medicina Tropical, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
authors: Karin
authors: K
authors: Kirchgatter
authors: Centro de Bacteriologia, Instituto Adolfo Lutz, Sao Paulo, Brazil.
authors: Eliete C
authors: EC
authors: Romero
authors: Laboratório de Zoonoses Bacterianas, Faculdade de Medicina Veterinária e Zootecnia, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
authors: Silvio A
authors: SA
authors: Vasconcellos
authors: Centro de Biotecnologia, Instituto Butantan, Sao Paulo, SP, Brazil; Programa de Pós-Graduação Interunidades em Biotecnologia,Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, SP, Brazil.
authors: Ana Lucia T O
authors: AL
authors: Nascimento
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D016680:Genome, Bacterial; D006801:Humans; D007921:Leptospira interrogans / Q000235:genetics* / Q000276:immunology; D007922:Leptospirosis / Q000097:blood / Q000276:immunology / Q000382:microbiology; D008807:Mice, Inbred BALB C; D010802:Phylogeny; D010958:Plasminogen / Q000737:chemistry; D011485:Protein Binding; D017434:Protein Structure, Tertiary
chemical_list: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; C078167:OMPA outer membrane proteins; D010958:Plasminogen