Neutrophils in malaria: A double-edged sword role

Area of Science:

• Immunology
• Infectious Diseases
• Hematology

Background:

• Neutrophils are abundant leukocytes and the first responders to pathogens.
• Malaria, a significant global disease caused by Plasmodium parasites, led to 627,000 deaths in 2020.
• Neutrophils combat malaria parasites via phagocytosis and reactive oxygen species (ROS), but may also contribute to pathogenesis through granule release and neutrophil extracellular traps (NETs).

Purpose of the Study:

• To review the multifaceted role of neutrophils in malaria infection.
• To discuss conflicting data from mouse models regarding neutrophil function in malaria.
• To explore neutrophil-mediated mechanisms underlying increased susceptibility to bacterial infections in malaria patients.

Main Methods:

• Literature review synthesizing current research on neutrophils and malaria.
• Analysis of studies investigating neutrophil functions (phagocytosis, ROS, NETs) in malaria.
• Examination of evidence linking neutrophil behavior to secondary bacterial infections in malaria.

Main Results:

• Neutrophils exhibit dual roles in malaria: defense and potential pathogenesis.
• Malaria parasites actively inhibit neutrophil antimicrobial functions.
• Discrepancies exist between human and mouse models of neutrophil responses in malaria.
• Impaired neutrophil function correlates with increased risk of opportunistic infections, such as Salmonella.

Conclusions:

• Neutrophils play a complex role in malaria, influencing both host defense and disease severity.
• Understanding neutrophil dysregulation is key to addressing secondary bacterial infections in malaria.
• Further research is needed to reconcile conflicting data and elucidate precise mechanisms.