A New Assay for Malaria Drug and Vaccine Development
- by Team ABLE - 10 Feb, 2020
An article published in Experimental Biology and Medicine (Volume 245, Issue 1, January 2020) (https://journals.sagepub.com/doi/pdf/10.1177/1535370219897393) describes a new assay that can be used to test malaria drugs and vaccines.
- study, led by Dr. Gordon Awandare, Professor of Biochemistry, Cell and Molecular Biology at the University ofGhanain Legon,Accra, reports that Cell Trace Far-Red (CTFR), a newly developed cytoplasmic dye, can be used to study malaria parasite invasion of red blood cells.
Malaria, one of the world's most debilitating infectious diseases, claims over 400,000 lives annually. Of all parasite species capable of transmitting the disease, Plasmodium falciparum is the most devastating and accounts for over 90% of all cases globally. Despite the drastic reduction of the disease burden in recent years, global malaria elimination is still far from being a reality. Barriers to achieving elimination include the lack of an efficient vaccine and a complete understanding of the parasite's biology. Vaccine development would also benefit from standardized approaches to study parasite features that lead to disease pathogenesis. Thus, there is a need for the development of new, sensitive, reproducible assays which can be adopted by all to allow for easy comparison of data generated from different countries to help in prioritizing vaccine candidate for development.
In the current study, Dr.Awandare and colleagues optimized a flow-cytometry based invasion assay using Cell Trace Far-Red (CTFR) to distinguish different populations of red blood cells. The study showed that CTFR strongly labeled target erythrocytes, even at very low concentrations, as non-toxic to the parasite and could be combined with other nucleic acid dyes required in flow-cytometry assays.
Laty Gaye Thiam, a co-author of the study, said "An important feature of CTFR is that it is affordable, and the spectral features associated with the dye allow for its use in the vast majority of flow cytometers available in the field. Therefore, this experiment can be easily performed across various research centers in West Africa, where resources are often limited."
Dr.Awandare added "One of the challenges in using parasites obtained directly from clinical samples for invasion inhibition assays is the need to distinguish red blood cells coming from the patient from those added as targets for the parasites to invade. Therefore, we usually need combinations of dyes that can be used to achieve this differentiation while also allowing us to identify the sub-population of red cells that have been successfully invaded by the parasites during the assay. We have now added CTFR to the tool kit for preparing such invasion assays, as well as growth inhibition assays which can be applied for testing both vaccines and drugs."
Dr. Steven R. Goodman, Editor-in-Chief of Experimental Biology & Medicine, said, "Gordon Awandare and colleagues have provided a detailed analysis of the use of a newly developed cytoplasmic dye, Cell Trace Far-Red (CTFR), in flow cytometry-basedP. falciparum invasion phenotyping assays. Their studies demonstrate the value of this approach for future multiplex testing of P. falciparum invasion-blocking approaches."
The study, led by Dr. Gordon Awandare at the University of Ghana reports that Cell Trace Far-Red (CTFR), a newly developed cytoplasmic dye, can be used to study malaria parasite invasion of red blood cells.