Scientists at the Rajiv Gandhi Centre for Biotechnology (BRIC-RGCB) have uncovered a previously unknown mechanism that enables malaria parasites to survive treatment with artemisinin, the world’s most widely used and most effective anti-malarial drug.
The findings, published as an Editor’s Choice article in The Journal of Infectious Diseases by Christeen Davis and colleagues, reveal that young red blood cells, known as reticulocytes, create a protective biochemical environment that helps malaria parasites withstand drug-induced stress.
Host Cells Play a Critical Role
The study challenges the long-held belief that artemisinin resistance is driven mainly by genetic changes within the parasite. Instead, the researchers found that the host cell itself can significantly influence treatment outcomes.
Scientists from BRIC-RGCB conducted the study in collaboration with researchers from IISER Thiruvananthapuram, Cosmopolitan Hospital, Thiruvananthapuram, and CSIR–National Chemical Laboratory (NCL), Pune.
“Our findings demonstrate that the biology of the host cell can significantly influence how malaria parasites respond to treatment,” said Dr. Rajesh Chandramohanadas, Principal Investigator at BRIC-RGCB and senior author of the study.
“The parasite is not acting alone. It exploits the natural antioxidant defences present in young blood cells to protect itself from drug-induced stress,” he added.
Findings Have Important Clinical Implications
The research is particularly relevant for children, anaemic patients, and individuals recovering from blood loss or infection, as these groups often have elevated levels of reticulocytes in their bloodstream. Consequently, such conditions may create a more favourable environment for parasite survival during treatment.
As per a press release, malaria parasites live and multiply inside human red blood cells. While previous studies largely focused on parasite genetics as the primary driver of drug resistance, the new findings highlight the significant role played by host cells in determining treatment success.
How Reticulocytes Protect Malaria Parasites
Using highly purified human reticulocytes and advanced analytical techniques, the BRIC-RGCB team discovered that immature blood cells contain abundant nutrients, antioxidants and protective enzymes. As a result, malaria parasites that infect these cells gain access to a highly protective environment.
This advantage allows the parasites to grow faster and better withstand the oxidative damage caused by artemisinin treatment.
Furthermore, the researchers observed that parasites developing inside reticulocytes were significantly less susceptible to artemisinin and related compounds than those growing in mature red blood cells. Importantly, this protective effect disappeared when the parasites were transferred back into mature blood cells. This finding confirmed that the phenomenon is driven by the host cell environment rather than permanent genetic changes within the parasite.
Potential Explanation for Treatment Failures
According to Dr. Beena Pillai, Director of BRIC-RGCB, the findings could help explain why some malaria infections persist or clear more slowly despite treatment, even when known genetic markers of drug resistance are absent.
“The significant findings will help explain why some malaria infections show delayed clearance or persistence despite treatment, even when known genetic markers of drug resistance are absent,” she said.
Broader Implications for Infectious Disease Research
Beyond malaria, the study highlights a broader principle in infectious disease biology. The success of a pathogen may depend not only on its genetic makeup but also on the physiological condition of the host cells it infects.
The researchers believe future malaria therapies could become more effective by targeting host-parasite interactions alongside the parasite itself. In particular, understanding how parasites exploit antioxidant pathways within reticulocytes may open new avenues for improving existing anti-malarial drugs and reducing treatment failures.
A New Perspective on Malaria Treatment
Malaria continues to affect hundreds of millions of people worldwide and remains a major public health challenge across many tropical regions. By demonstrating how host blood cells influence parasite survival, the BRIC-RGCB study offers an important new perspective on the disease and could help shape future treatment strategies.