Protection conferred by immunization with rLigB(131–645) against lethal challenge in the hamster model of leptospirosis.

<p>Protection conferred by immunization with rLigB(131–645) against lethal challenge in the hamster model of leptospirosis.</p

Schematic of the Lig proteins, expression and purification of rLigB(131–645).

<p>A) The full length amino acid sequences for LigA (1224 amino acids, 128.1 kDa) and LigB (1890 amino acids, 200.8 kDa) are indicated (black line), the square boxes indicate the BIDs and the LigB C-terminal domain is shown (rectangle). The recombinant proteins used as vaccine candidates are indicated: LigB(131–645) (green boxes) includes amino acids 131–645 (53.5 kDa) and is highly identical (97.9% pairwise identity) to the same region in LigA; the LigA(631–1224), also known as LigANI, (red boxes, amino acids 631–1224, 62.8 kDa) and LigB(625–1259), also known as LigBNI, (blues boxes, amino acids 625–1259, 66.2 kDa) fragments are not highly conserved (38.1% pairwise identity). B) Expression and purification of rLigB(131–645) analysed by 10% SDS-PAGE and Coomassie staining. Lanes 1: molecular mass marker (kDa); Expression of rLigB(131–645) in an <i>E</i>. <i>coli</i>(pLigB(131–645)) clone, lane 2: supernatant (soluble) fraction and lane 3: insoluble fraction; lane 4: IMAC purified rLigB(131–645), expected molecular mass of 57.2 kDa. C) Immunoblot analysis of rLigB(131–645), following transfer the nitrocellulose membrane was probed with an anti-His-HRP antibody, lane 1: molecular mass marker (kDa); lane 2: purified rLigB(131–645).</p

Pathological findings in the hamster model.

<p>Animals vaccinated with rLigB(131–645) (A, C, E and G) or the PBS control group (B, D, F and H) were euthanized 10 days PC and tissue samples were collected. Vaccinated animals showed no gross pulmonary lesions (A) or microscopic pulmonary lesions (C). Liver (E) and kidney samples (G) showed no evidence of microscopic abnormalities. Unvaccinated animals showed gross pulmonary haemorrhaging (B) and they were confirmed to be alveolar haemorrhages by microscopic analysis (D). Dystrabeculaton (loss of cohesion) of hepatocytes (F) and swelling of kidney tubular epithelial cells (H) were prominent features. (C-F, haematoxylin-eosin, 100× magnification and G-H, haematoxylin-eosin, 200× magnification).</p