Loiasis, a chronic parasitic illness from the filarial worm Loa loa, has always been neglected when compared to other high profile neglected tropical diseases. As a research service provider, Protheragen is at the forefront of Loiasis vaccine and therapeutics development, leveraging cutting-edge scientific research and technological advancements.
Overview of Loiasis
Loiasis, a tropical disease also called Loa loa filariasis, stems from a neglected tropical illness caused by the Loa loa nematode filariasis. The parasite is spread through the bite of contaminated deer flies (Chrysops) or mango flies, which are the Loa loa vectors. Adult filarial worms can grow 3 to 7 cm in length and migrate through the subcutaneous tissues of their human hosts beneath the surface of the skin. They sometimes travel into the eye subconjunctival tissues where they can be readily noticed. Although suffering from Loiasis does not typically impair vision, when the parasite drags itself across the eye, it is known to hurt. It can, nevertheless, be quite uncomfortable as well if the parasite covers the bridge of a person's nose. The parasite is also responsible for the red itchy swellings beneath the skin termed Calabar swellings.
Fig.1 The spectrum of atypical manifestations of loiasis. (Dieki R., et al., 2022)
Vaccine Development for Loiasis
Antigen Discovery and Immunoprophylaxis
The current efforts directed towards the development of a vaccine for Loiasis target the identification of appropriate antigens that could foster an effective immune response. The sequencing of the Loa loa genome has been one of the major advances to date revealing in the process a number of possible vaccine targets. One of such antigens is the 15-kDa gene product which has been shown to elicit both immunogenic and allergic reactions in host responses. These putative vaccines would target not only the larval form but also the adult worm antigens in order to inhibit the development and acculturation of the parasite within the host.
Immune Response Modulation
As with other vaccines, one more feasible direction is altering the host's immune response to avert the infection from even happening or is able to set in and progress any further. It is crucial to comprehend the immune avoidance strategies perpetrated by Loa loa, in particular, the steps taken by the microfilariae which complement attack by acquiring host regulatory proteins. It may also be possible to develop vaccines that would help the immune system of the host to identify and destroy the parasite more efficiently.
Therapeutics Development for Loiasis
Antifilarial Chemotherapy
Currently, the therapeutic for Loa Loa infection is based predominantly on antifilarial drugs such as Diethylcarbamazine, DEC. The drug is perhaps the most used but it has demerits for patients with high microfilariae count because of risk factors. To treat these issues, other drugs such as albendazole are being tested for clearing Loa loa microfilaremia, with the hope that they will be much safer.
Novel Therapeutic Strategies
Further studies are being aimed at the formulation of new therapeutic modalities, such as those directed to specific developmental stages of the parasite. For instance, the application of macrocyclic lactone agents, which target and act effectively against the adult worms, is still under investigation. Other novel combination studies which could possibly reduce microfilarial density with acceptable side effects post-therapeutic are most likely to be fruitful.
Our Services
We provide development Vaccines services that include, but are not limited to, Antigen identification, Immune response evaluation, and Preclinical evaluation of vaccines. We have selective skills in genomics and proteomics to look for possible vaccine candidates and evaluate their immunogenicity.
In addition, Protheragen also offers extensive therapeutics development services with a focus in design and optimization of antifilarial drugs. Particularly, we try to improve the current therapeutics in use and new drug candidates for Loa loa infection.
Disease Models
- BALB/c Mouse Model for Loa loa Microfilariae (mf): Intravenous administration of L. loa mf isolated from human blood.
- Mongolian Gerbil Model for Loa loa Microfilariae (mf): Intraperitoneal injection of L. loa mf.
Preclinical research is a critical phase in the development of any new vaccine or therapy. Protheragen provides comprehensive preclinical research services tailored to the unique challenges of Loiasis. If you are interested in our services, please feel free to contact us.
References
- Buell Kevin G., et al. "Atypical clinical manifestations of loiasis and their relevance for endemic populations." Open Forum Infectious Diseases. Vol. 6. No. 11. US: Oxford University Press, 2019.
- Dieki Roland, Edouard Nsi-Emvo, and Jean Paul Akue. "The human filaria Loa loa: Update on diagnostics and immune response." Research and Reports in Tropical Medicine 13 (2022): 41.
All of our services and products are intended for preclinical research use
only and cannot be used to diagnose, treat or manage patients.
