Strongyloidiasis is a neglected tropical disease caused by a parasite, Strongyloides stercoralis. We provide end-to-end solutions, including diagnosis development, vaccines, and therapeutics, intended to help formulate new strategies against strongyloidiasis.
Overview of Strongyloidiasis
Strongyloidiasis is a parasitic disease caused by the soil-transmitted helminth Strongyloides stercoralis which is very common in tropical and subtropical regions including an estimated 614 million people globally. This disease has a unique status because it classified as one of the most medically neglected tropical diseases (NTDs) because of its chronic nature and the serious consequences it can inflict, particularly in individuals with weakened immune systems. The S. stercoralis has a unique autoinfective lifecycle which allows the larvae to penetrate the intestinal mucosa which initiate multi-system symptoms that may progress into a severe state of hyperinfection or disseminated strongyloidiasis.
Fig.1 The life cycle of strongyloides. (Varatharajalu R., et al., 2016)
Vaccine Development for Strongyloidiasis
To develop a vaccine against strongyloidiasis, the immunogenic antigens capable of eliciting a protective immune response need to be defined. Several methods have been used to busca these antigens such as:
- Deoxycholic Acid-Soluble Antigens (DOC-Ag): These antigens that were isolated from the larvae of Strongyloides stercoralis were able to provide protective immunity in several murine models.
- Recombinant Proteins: Among these is the Ss-IR antigen which is a recombinant protein that was shown to reduce the survival of larvae in vaccinated mice by nearly 80%.
- DNA Vaccines: For instance, the Sseat-6 gene products, which caused a 35% drop in larvae survival following immunization.
Table 1. Vaccines and passive immunization approaches for Strongyloides stercoralis. (Levenhagen M. A., et al., 2016)
| Description |
Characterization |
Delivery |
Strongyloides challenge strain |
Mouse strain |
Immune Response |
Targets of Protective immunity |
DNA vaccine
DNA immunization
(Sseat-6 gene) |
Strongyloides stercoralis Na+K+ATPase, a 34 kDa antigen from DOC-Ag recognized by human IgG in Immunoblotting and Sequencing |
Plasmid containing GM-CSF (granulocytemacrophage colony-stimulating factor) sequence |
Strongyloides stercoralis L3i in diffusion chambers |
Female BALB/cJ mice 6-8 weeks of age |
Antibody can partially mediate larval killing and the role of cells in the killing process was not clear |
35% of reduction in larval survival |
| Recombinant vaccinesSs-IR (S. stercoralis immune-reactive antigen) |
Recombinant Strongyloides stercoralis antigen of ~31 kDa highly immunogenic in humans |
1:10 rehydragel (alum) in PBS |
Strongyloides stercoralis L3i in diffusion chambers |
Male BALB/cByJ mice 6-8 weeks of age |
ADCC based mechanism |
80% of reduction in larval survival |
Therapeutics Development for Strongyloidiasis
Administered as the first line treatment for strongyloidiasis with an approximate efficacy of 86%, ivermectin is a semi-synthetic derivative of avermectin. Its method of action consists of binding to glutamate-gated chloride channels on the parasitic helminths which creates a resultant paralysis and death of the parasite.
Albendazole offers less efficacy when compared to ivermectin; however, it is a second line therapeutic that is helpful in conditions where the patient cannot tolerate or take Ivermectin.
This macrocyclic lactone has demonstrated a potential effective alternative to Ivermectin with a cure rate of 94% in the Moxidectin trial against Strongyloides stercoralis.
Our Services
The task of developing vaccines and therapeutics for strongyloidiasis is achieved better by combining vaccine research and immunology, parasitology, biopharmaceuticals and other facets. Therefore, our company is uniquely positioned to offer integrated solutions in the design and developement of vaccines and therapeutics like:
Preclinical Research
- Pharmacodynamics Study Services
- Pharmacokinetics Study Services
- Drug Safety Evaluation Services
Disease Models
- hRSV Infection Models
- hRSV A2 Infection Models
- hRSV M37 Infection Models
- Macaque-adapted hRSV Infection Models
- Clinical Isolate hRSV Infection Models
In addition, we also provide the following optional services, including but not limited to:
- In Vitro Antigen Screening: Utilizing advanced bioinformatics tools to predict and analyze potential antigens.
- Molecular Cloning and Expression: Cloning and expression of potential vaccine antigens in suitable systems.
- Protein Purification and Characterization: Ensuring the quality and purity of antigens for vaccine development.
- Drug Screening and Optimization: Screening libraries of compounds for activity against Strongyloides stercoralis and optimizing lead candidates.
If you are interested in our services, please feel free to contact us.
References
- Varatharajalu Ravi, and Kakuturu V. Rao. "Strongyloides stercoralis: current perspectives." Reports in Parasitology (2016): 23-33.
- Levenhagen, Marcelo Arantes, Hélio Conte, and Julia Maria Costa-Cruz. "Current progress toward vaccine and passive immunization approaches for Strongyloides spp." Immunology Letters 180 (2016): 17-23.
- Buonfrate, Dora, et al. "Current pharmacotherapeutic strategies for Strongyloidiasis and the complications in its treatment." Expert Opinion on Pharmacotherapy 23.14 (2022): 1617-1628.
All of our services and products are intended for preclinical research use
only and cannot be used to diagnose, treat or manage patients.
