Expression of multifunctional protein Lsa23 (LIC11360) from Leptospira interrogans in the surrogate saprophyte L. biflexa and gain of function validation

• Grant number: 22/12101-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2022
• End date: December 31, 2024
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Ana Lucia Tabet Oller do Nascimento
• Grantee: Fernanda Batista de Andrade
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Associated research grant: 19/17488-2 - Advancing the understanding of pathogenesis and virulence of Leptospira interrogans through proteomics, structural, mutagenesis and immunological analyses, AP.TEM

Abstract

Spirochetes bacteria of the genus Leptospira are composed by saprophyte, for example, L. biflexa and pathogenic species, for example L. interrogans, the etiological agent of leptospirosis. This disease is a global zoonosis, recently included in the list of Neglected Tropical Diseases. Rodents are the major leptospiral reservoirs in urban centers. The bacteria colonizes the proximal renal tubules of these animals, and are excreted alive in the urine. Currently, there is no effective vaccine, therefore the conserved outer membrane protein identification in pathogenic strains is the main research target for elucidating the pathogenic mechanisms. These proteins are probably involved with the external medium and leptospira interaction and also with the host immune system. The recombinant protein Lsa23 (Leptospiral surface adhesin of 23 kDa), encoded by LIC11360 of L. interrogans gene, was characterized in vitro by our group. This protein presents a broad spectrum of targets, with higher affinity by elements and regulatory of complement system. Lsa23 is exclusive of pathogenic strains, therefore the role in complement system escape is extremely important for the studies of pathogenicity of leptospirosis. In this study we propose the expression of Lsa23 encoded by the gene LIC11360, with peptide signal associated with a stronger constitutive promoter of lipl32 gene in the saprophytic L. biflexa. We expect to analyze the gain of function in binding and resistance experiments of the complement system attack.