Increased immunogenicity to LipL32 of Leptospira interrogans when expressed as a fusion protein with the cholera toxin B subunit.
Leptospirosis is one of the most widespread zoonosis in the world. The development of a recombinant leptospira vaccine remains a challenge. In this study, we cloned the Leptospira interrogans open reading frame (ORF) coding the external membrane protein LipL32, an immunodominant antigen found in all pathogenic leptospira, downstream of the highly immunogenic cholera toxin B subunit (CTB) ORF. Expression and assembly of the CTB-LipL32 fusion protein into oligomeric structures of pentameric size were observed in soluble fractions by Western blot analysis. The CTB-LipL32 protein demonstrated strong affinity for monosialotetrahexosylgaglioside (GM1-ganglioside) in an enzyme-linked immunosorbent assay (ELISA), suggesting that the antigenic sites for binding and proper folding of the pentameric CTB structure were conserved. Furthermore, antisera against LipL32 also recognized the CTB-LipL32 fusion protein, suggesting that LipL32 also conserved its antigenic sites, a fact confirmed by an ELISA assay showing soluble CTB-LipL32 recognition by sera from convalescent patients. In addition, soluble CTB-LipL32 generated higher specific titers in mice immunized without external adjuvant than co-administration of CTB with LipL32. The data presented here provide support for CTB-LipL32 as a promising antigen for use in the control and study of leptospirosis.
Habarta
Alejandra
A
Instituto de Biotecnología y Biología Molecular, Centro Científico Tecnológico CONICET La Plata, La Plata, Argentina.
Abreu
Patricia A E
PA
Olivera
Noelia
N
Hauk
Pricila
P
Cédola
Maia T
MT
Ferrer
María F
MF
Ho
Paulo L
PL
Gomez
Ricardo M
RM
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000276:immunology*; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology*; D015153:Blotting, Western; D002772:Cholera Toxin / Q000235:genetics / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005677:G(M1) Ganglioside / Q000378:metabolism; D007921:Leptospira interrogans / Q000235:genetics / Q000276:immunology*; D008074:Lipoproteins / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011485:Protein Binding; D055503:Protein Multimerization; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology
D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; C406589:LipL32 protein, Leptospira; D008074:Lipoproteins; D011993:Recombinant Fusion Proteins; D014614:Vaccines, Synthetic; D005677:G(M1) Ganglioside; D002772:Cholera Toxin