Adipose tissue parasite sequestration drives leptin production in mice and correlates with human cerebral malaria

Circulating levels of the adipokine leptin are linked to neuropathology in experimental cerebral malaria (ECM), but its source and regulation mechanism remain unknown. Here, we show that sequestration of infected red blood cells (iRBCs) in white adipose tissue (WAT) microvasculature increased local vascular permeability and leptin production. Mice infected with parasite strains that fail to sequester in WAT displayed reduced leptin production and protection from ECM. WAT sequestration and leptin induction were lost in CD36KO mice; however, ECM susceptibility revealed sexual dimorphism. Adipocyte leptin was regulated by the mechanistic target of rapamycin complex 1 (mTORC1) and blocked by rapamycin. In humans, although Plasmodium falciparum infection did not increase circulating leptin levels, iRBC sequestration, tissue leptin production, and mTORC1 activity were positively correlated with CM in pediatric postmortem WAT. These data identify WAT sequestration as a trigger for leptin production with potential implications for pathogenesis of malaria infection, prognosis, and treatment.

Automated summary

Levels of the adipokine leptin are associated with neuropathology in experimental cerebral malaria (ECM), with infected red blood cells (iRBCs) sequestering in white adipose tissue (WAT) microvasculature leading to increased vascular permeability and local leptin production. In mice, parasite strains that do not sequester in WAT display reduced leptin production and protection from ECM. Adipocyte leptin production is regulated by the mechanistic target of rapamycin complex 1 (mTORC1) and disrupted by rapamycin, highlighting the potential implications of WAT sequestration for malaria infection pathogenesis, prognosis, and treatment.