Recombinant Leptospira borgpetersenii serovar Hardjo-bovis 30S ribosomal protein S15 (rpsO)
Description
Diagnostic Development
Recombinant rpsO could serve as a candidate antigen for enzyme-linked immunosorbent assays (ELISAs) or lateral flow tests. For instance:
-
Cross-Reactivity: In bovine leptospirosis, L. borgpetersenii serovar Hardjo-bovis is a predominant pathogen. Recombinant proteins like rpsO may help differentiate serovar-specific immune responses, as seen with other OMPs (e.g., LipL32) .
-
Comparative Studies: Research on L. santarosai and L. interrogans highlights species-specific antigenic variation in ribosomal and OMPs, underscoring the need for tailored diagnostic tools .
Vaccine Design
Though no direct vaccine studies on rpsO exist, parallel work on Leptospira OMPs demonstrates that recombinant proteins can be evaluated for protective immunity. For example:
-
Adhesin Proteins: Recombinant adhesins like rLBL2618 from L. borgpetersenii bind host extracellular matrix components (e.g., fibronectin), suggesting ribosomal proteins could similarly mediate host-pathogen interactions .
-
Immune Reactivity: Milk IgG from Leptospira-infected cows reacts strongly with recombinant OMPs, indicating potential for rpsO to be included in multi-antigen vaccines .
Technical Considerations
-
Reconstitution: Optimal solubility is achieved at 0.1–1.0 mg/mL in sterile water. Avoid repeated freeze-thaw cycles; aliquot with glycerol for stability .
-
Storage: Lyophilized protein retains activity for 12 months at -80°C, while reconstituted aliquots are stable for one week at 4°C .
Research Gaps and Future Directions
-
Functional Assays: The role of rpsO in Leptospira ribosome assembly or pathogenesis remains uncharacterized.
-
Immunogenicity Profiling: Comparative studies with other ribosomal proteins (e.g., S19 or L1) could clarify its diagnostic utility .
-
Structural Analysis: Cryo-EM or X-ray crystallography would resolve its 3D conformation and ligand-binding sites.
Product Specs
Target Background
KEGG: lbj:LBJ_0949
Q&A
Basic Research Questions
-
What is the functional role of rpsO in Leptospira borgpetersenii?
The 30S ribosomal protein S15 (rpsO) is essential for ribosome assembly and translation fidelity. In L. borgpetersenii, genomic studies reveal that ribosomal genes like rpsO remain conserved despite genome reduction, suggesting critical roles in bacterial survival even in host-adapted strains . Methodologically, knock-out mutants or ribosome profiling can validate its necessity for in vitro growth. -
How is recombinant rpsO expressed and purified for structural studies?
-
Expression system: Typically expressed in E. coli or yeast systems (e.g., Pichia pastoris) due to high yield and solubility .
-
Purification: Affinity chromatography (e.g., His-tag purification) followed by size-exclusion chromatography to ensure monodispersity .
-
Validation: SDS-PAGE, Western blotting, and mass spectrometry confirm purity and identity .
-
-
Does rpsO exhibit immunogenic potential in vaccine development?
While rpsO is not directly linked to protective immunity in current studies, ribosomal proteins from Leptospira spp. may act as adjuvants or minor antigens. ELISA assays using sera from infected cattle show variable IgG reactivity to ribosomal proteins, but their protective efficacy remains unproven .
Methodological Challenges
-
How to resolve insolubility issues during recombinant rpsO production?
-
What computational tools are used to predict rpsO interactions in Leptospira?
Data Interpretation
-
Why do ribosomal proteins show low immunogenicity despite strong antibody responses?
Immunodominant epitopes on surface-exposed proteins (e.g., adhesins like LBL0972) overshadow intracellular targets like rpsO. Flow cytometry or immunofluorescence can localize rpsO accessibility during infection . -
How to reconcile conserved rpsO sequences with phenotypic variability in L. borgpetersenii subtypes?
Phenotypic differences (e.g., host tropism) are driven by regulatory mutations (e.g., promoter regions) or modifier genes rather than rpsO itself. RNA-seq or ribosome profiling can identify translational efficiency variations .
Key Research Gaps
-
Role of ribosomal proteins in Leptospira persistence during chronic infection.
-
Structural basis of rpsO-rRNA interactions in host-adapted strains.
-
Cross-reactivity of anti-rpsO antibodies with other bacterial ribosomes.
