Patients with leptospirosis are commonly treated with antibiotics. Jarisch-Herxheimer reaction caused by toxic bacterial substances massively released as a result of the antibiotic mediated-bacterial lysis occurs in some patients which may aggravate the existing severe clinical manifestations. In this study, a humanized-murine single-chain monoclonal antibody (HuScFv) was produced and tested as an alternative of antibiotics for treatment of leptospirosis. Complementary DNA was prepared from total RNA of a murine hybridoma clone secreting monoclonal antibody (MAb) specific to LipL32 of pathogenic Leptospira spp. The MAb had therapeutic efficacy in Leptospira challenged hamsters. The VH and VL coding sequences were amplified using the cDNA as a template. The sequences were linked to form a single-chain variable murine DNA fragment (muscFv). CDR sequences of the muscFv were grafted onto the best matching human VH and VL immunoglobulin frameworks. After cloning of the humanized murine DNA sequences (huscFv) into a phagemid vector and the vector was introduced into competent Escherichia coli, the HuScFv was produced. On the same weight basis, the HuScFv possessed equal neutralizing activities to the murine ScFv counterpart against heterologous Leptospira-mediated hemolysis in vitro and rescued hamsters from a heterologous Leptospira lethal challenge. The HuScFv antibody has high therapeutic potential as an alternative to antibiotics for human leptospirosis, especially for drug hypersensitive patients.

Download full-text PDF

Source
http://dx.doi.org/10.1093/protein/gzp008DOI Listing

Publication Analysis

Top Keywords

heterologous leptospira
8
monoclonal antibody
8
huscfv produced
8
alternative antibiotics
8
murine dna
8
huscfv
5
humanized-monoclonal antibody
4
antibody heterologous
4
leptospira
4
leptospira infection
4

Similar Publications

Leptospirosis is a widespread disease throughout the world, presenting in severe clinical forms in dogs. The pathogenicity of the different serovars in field infections is not fully documented, and clinical diagnosis is often limited to a combination of serological tests and molecular analyses. The latter, although a fundamental tool, cannot identify the infecting strain without further analysis.

View Article and Find Full Text PDF

Biophysical characterization and structural insights of leptospiral complement regulator-acquiring protein A.

Biochem Biophys Res Commun

December 2024

Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Prof. CR Rao Road, Gachibowli, Hyderabad, Telangana, 500046, India. Electronic address:

Many pathogens establish a successful infection by evading the host complement system, an essential arm of innate immunity. Pathogenic Leptospira is reported to escape complement-mediated killing by recruiting the host complement regulators by lipoproteins or outer surface proteins. One of the outer surface proteins, Leptospiral complement regulator-acquiring protein A (LcpA), is known to recruit complement regulators, C4b-binding protein (C4BP), and Factor H (FH) on the bacterial surface.

View Article and Find Full Text PDF
Article Synopsis
  • The TolC protein is an outer membrane efflux protein with high sequence conservation among pathogenic species, suggesting its importance in virulence.
  • * Structural modeling shows that it is composed of six β-strands and 10 α-helices, which supports its function similar to other bacterial efflux proteins.
  • * Recombinant TolC has potential as a diagnostic marker due to its ability to interact with host tissues and proteins, enhancing pathogen adhesion and immune evasion.
View Article and Find Full Text PDF

Leptospirosis is the most widespread zoonosis and a life-threatening disease in humans and animals. Licensed killed whole-cell vaccines are available for animals; however, they do not offer heterologous protection, do not induce long-term protection, or prevent renal colonization. In this study, we characterized an immunogenic Leptospira methyl-accepting chemotaxis protein (MCP) identified through a reverse vaccinology approach, predicted its structure, and tested the protective efficacy of a recombinant MCP fragment in the C3H/HeJ mice model.

View Article and Find Full Text PDF

Aims: Currently, immunoinformatic approaches have shown promise in rapidly and cost-effectively identifying new antigens from the Leptospira proteome. Chimeric multiepitope proteins offer a strategy with significant potential for implementation in diagnosis and vaccines development.

Methods And Results: In this study, we detail the immunoinformatic analyses and design of a new recombinant chimeric protein constructed with epitopes identified from the sequences of ErpY-like and LemA proteins, previously identified as potential antigens for controlling leptospirosis.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!