The role of Lsa23 to mediate the interaction of Leptospira interrogans with the terminal complement components pathway

Author(s)

Siqueira, Gabriela H. ^{[1, 2]} ; de Souza, Gisele O. ^[3] ; Heinemann, Marcos B. ^[3] ; Vasconcellos, Silvio A. ^[3] ; Nascimento, Ana L. T. O. ^[1]

Affiliation

^[1] Inst Butantan, Ctr Biotecnol, BR-05503900 Sao Paulo, SP - Brazil

^[2] FMUSP, Hosp Clin, Labs Invest Med, Sao Paulo, SP - Brazil

^[3] Univ Sao Paulo, Fac Med Vet & Zootecnia, Lab Zoonoses Bacterianas VPS, Ave Prof Dr Orlando Marques de Paiva 87, BR-05508270 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Microbial Pathogenesis; v. 112, p. 182-189, NOV 2017.
• Web of Science Citations: 3

Abstract

Leptospirosis is a severe worldwide zoonotic disease caused by pathogenic Leptospira spp. It has been demonstrated that pathogenic leptospires are resistant to the bactericidal activity of normal human serum while saprophytic strains are susceptible. Pathogenic strains have the ability to bind soluble complement regulators and these activities are thought to contribute to bacterial immune evasion. One strategy used by some pathogens to evade the complement cascade, which is not well explored, is to block the terminal pathway. We have, thus, examined whether leptospires are able to interact with components of the terminal complement pathway. ELISA screening using anti-leptospires serum has shown that the pathogenic, virulent strain L. interrogans L1-130 can bind to immobilized human C8 (1 kg). However, virulent and saprophyte L biflexa strains showed the ability to interact with C8 and C9, when these components were employed at physiological concentration (50 mu g/mL), but the virulent strain seemed more competent. Lsa23, a putative leptospiral adhesin only present in pathogenic strains, interacts with C8 and C9 in a dose-dependent mode, suggesting that this protein could mediate the binding of virulent Leptospira with these components. To our knowledge, this is the first work reporting the binding of Leptospira to C8 and C9 terminal complement components, suggesting that the inhibition of this pathway is part of the strategy used by leptospires to evade the innate immunity. (C) 2017 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 14/50981-0 - Search for surface proteins among the genome sequences of Leptospira interrogans: functional and immunological characterization to understanding mechanisms involved in the bacterial pathogenesis
• Grantee: Ana Lucia Tabet Oller do Nascimento
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 14/03792-8 - "Evaluation of the immune evasion by pathogenic Leptospira interrogans at the terminal complement system pathway level"
• Grantee: Gabriela Hase Siqueira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral