Genome scientists develop new approaches to studying a widespread form of malaria

Scientists from the Institute of Genome Sciences (IGS) of the University of Maryland's Faculty of Medicine (UMSOM) have come up with a new way to use genomic sequences to study and better understand transmission, treat and eradicate Plasmodium vivax, the most common form of malaria. P. vivax is unicellular transmitted by mosquitoes. It is the most widespread human parasite of malaria, responsible for more than 8.5 million cases of clinical malaria worldwide and threatening more than two billion people in 90 countries. contrary to Plasmodium falciparum, another species of malaria, P. vivax can not be grown in vitro and remains poorly understood and resilient to elimination efforts.

IGS researchers collaborated with researchers from the Pasteur Institute of Cambodia to badyze the gene expression profiles of the parasite of P. vivax Malaria patients enrolled in a study to determine the effectiveness of chloroquine as an antimalarial treatment. Using a combination of genomic and bioinformatic approaches, they compared parasite transcriptomes, or a set of ribonucleic acid (RNA) molecules, from different patient infections. , and badyzed the response of parasites to chloroquine, a common antimalarial, according to the research. published in Nature Communications.

"By badyzing parasite mRNAs directly from blood samples from infected patients, we found that not all infections contained the same proportion of male and female parasites needed to infect mosquitoes and spread the disease. This observation suggests that parasite transmission is more complex than we thought before and perhaps the parasite is able to alter its development to ensure optimal survival, "said David Serre, PhD, badociate professor of microbiology and immunology and member of the IGS.

Dr. Serre, who is a principal investigator, said the researchers had badyzed the changes in gene expression induced by chloroquine treatment and had demonstrated that this antimalarial drug, while effectively eliminating P. vivax parasites, acts differently from P. falciparum parasites. "This highlights the biological differences between these two human malaria parasites and the importance of specifically studying this important pathogen if we hope to eventually eliminate malaria worldwide," he said. he declares.

Genome sequencing studies have provided unique insights into this neglected human parasite, but are limited to identifying biological differences encoded in the DNA sequence. However, gene expression studies, which could provide information on parasite lifecycle regulation and its response to drugs, have been difficult to implement for this pathogen because of the heterogeneous mixture of parasitic stages present in the parasite. in every infection of the patient.

"This important research will help us better understand how to treat, prevent and eventually eliminate this species of malaria.This is particularly crucial in a context of growing concern for drug resistance to antimalarial treatments," said the Dean of Medicine. UMSOM, E. Albert Reece, MD, Ph.D., MBA, Executive Vice President of Medical Affairs of the University and Distinguished Professor John Z. and Akiko K. Bowers.

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More information:
Adam Kim et al., Plasmodium vivax transcriptomes reveal a stage-specific chloroquine response and differential regulation of male and female gametocytes. Nature Communications (2019). DOI: 10.1038 / s41467-019-08312-z