γδ T cells in malaria: a double-edged sword

Area of Science:

• Immunology
• Infectious Diseases
• Parasitology

Background:

• Malaria causes significant mortality, particularly severe malaria.
• Clinical immunity in endemic areas reduces severe malaria but increases asymptomatic infections.
• Circulating Vγ9Vδ2 T cells decrease with malaria tolerance and reduced disease severity.

Purpose of the Study:

• To explore the complex protective and pathogenic roles of gamma delta (γδ) T cells in malaria.
• To understand how γδ T cell responses influence malaria severity and pathology.
• To investigate the link between γδ T cells, pro-inflammatory cytokines, and malaria outcomes.

Main Methods:

• Analysis of Vγ9Vδ2 T cell populations in malaria patients.
• Utilizing mouse models of experimental cerebral malaria (ECM) with Plasmodium berghei ANKA infection.
• Investigating the role of γδ T cells and IFN-γ during the liver stage of Plasmodium infection in mice.

Main Results:

• Reduced Vγ9Vδ2 T cell numbers correlate with tolerance to clinical malaria.
• γδ T cells and IFN-γ are implicated in the pathogenic component of ECM.
• Liver-stage γδ T cell activity may determine blood-stage pathology in malaria.

Conclusions:

• γδ T cell responses are critical in balancing malaria protection and severe pathology.
• The same pro-inflammatory cytokines, TNF and IFN-γ, are involved in both protective and pathogenic roles of γδ T cells.
• Understanding γδ T cell functions is crucial for developing effective malaria control strategies.