Streptozotocin induces alpha-2u globulin nephropathy in male rats during diabetic kidney disease.

BACKGROUND: Alpha-2u globulin nephropathy mainly shows toxicological pathology only in male rats induced by certain chemicals and drugs, such as levamisole (antiparasitic and anticancer drugs). Streptozotocin (STZ) is also an anticancer-antibiotic agent that has been used for decades to induce a diabetic kidney disease model in rodents. The purpose of this study is to determine if STZ causes alpha-2u globulin nephropathy in male rats during an advanced stage of diabetic kidney disease. Alpha-2u globulin nephropathy, water absorption and filtration capacities (via aquaporin [AQP]-1, - 2, - 4 and - 5) and mitochondrial function (through haloacid dehalogenase-like hydrolase domain-containing protein [HDHD]-3 and NADH-ubiquinone oxidoreductase 75 kDa subunit [NDUFS]-1 proteins) were examined in STZ-induced diabetic Wistar rat model. RESULTS: More than 80% of severe clinical illness rats induced by STZ injection simultaneously exhibited alpha-2u globulin nephropathy with mitochondrial degeneration and filtration apparatus especially pedicels impairment. They also showed significantly upregulated AQP-1, - 2, - 4 and - 5, HDHD-3 and NDUFS-1 compared with those of the rats without alpha-2u globulin nephropathy. CONCLUSIONS: STZ-induced alpha-2u globulin nephropathy during diabetic kidney disease in association with deterioration of pedicels, renal tubular damage with adaptation and mitochondrial driven apoptosis.

Mimotope of Leptospira from phage-displayed random peptide library is reactive with both monoclonal antibodies and patients' sera.

The study aim was to use random heptapeptide library displayed by bacteriophage T7 for identifying mimotopes from 15 monoclonal antibodies (MAbs) specific to Leptospira spp., and from four leptospirosis patient sera, respectively. The bound phages, selected from fourth round of bio-panning with each antibody, were cloned by plaque isolation and the binding specificity of individual clones were confirmed by enzyme-linked immunosorbent assay, before being further amplified and checked for phage peptide sequence using PCR and DNA sequencing. All together 150 phages were selected, mimotope from 86 phages (56.6%) were found to match with protein sequences of Leptospira from GenBank database. The predominant mimotopes were mimotope with sequence LTPCD that found in 27.3%, followed by TPCSK (16%), KSKKSS (4%), KTKRXAS (4%), SSKSYR (3.3%), DPNXNSF (3.3%), KSGRC (2.6%), TLINIF (2%), TPCI (2%), 1.33% each with mimotopes PKKS, PCNTKXTA, and CTKKK, and one phage each (0.66%) with mimotopes PTFGS, TNSKRK, SKSSRC, RSKRIR, VTNNTP, and CSNXSKR. Interestingly, mimotopes LTPCD, TPCSK, and TPCI were found to react with both MAb and patient's sera. The matched proteins from GenBank namely, leptospiral putative outer membrane protein (matched with mimotope PTFGS), thermolysin precursor protein (matched with mimotope TPCIXXGSAS), and hypothetical protein LIC12228 (matched with mimotope CSNXSKR), were found to locate at outer membrane of Leptospira. These phage mimotopes and matched proteins may have potential for further use as diagnostic reagent and immunogen against leptospirosis in the future. The results demonstrate that phage display technique has potential for rapidly identifying phage mimotopes that interact with leptospiral MAbs and patient's sera.

Epitope mapping of monoclonal antibodies specific to serovar of Leptospira, using phage display technique.

Random heptapeptide library displayed by bacteriophage T7 was used to characterize epitopes of five monoclonal antibodies that were specific to L. australis, L. bangkok, and L. bratislava. Phages selected by biopanning were cloned by plaque isolation, and the binding specificity of individual clones was confirmed by enzyme-linked immunosorbent assay, before being further amplified and checked for phage peptide sequence using PCR and DNA sequencing. Almost all of the peptide epitopes were continuous or linear. Interestingly, in phages reacting with the monoclonal antibody (MAb) clones F11, F20, 2C3D4, and 8C6C4A12, the deduced amino acid sequence of the displayed peptides corresponded to a segment of hypothetical protein of the Leptospira genome (L. interrogans serovar Lai and Copenhageni). Considering the deduced amino acid sequences of phages reacting with the MAb clones F11, F20, 2C3D4, and 8C6C4A12, the consensus motif -SKSSRC-, -TLINIF-, -SSKSYR- and -CTPKKSGRC- appeared respectively. No similarity was observed among phage reacting with the MAb clone F21. The results demonstrate that T7 phage display technique has potential for epitope mapping of leptospiral MAbs, and for rapid analysis of the interactions between phage display peptides with the MAb. The finding of a phage peptide that binds to MAb with protective activity can be further tested as a candidate for leptospirosis vaccine in the future.