Fever, a universal host defense in infection and inflammation, paradoxically contributes to neurological complications in malaria. While febrile temperatures enhance the expression of parasite virulence proteins that mediate vascular adhesion and disease severity, its effects in the endothelium remain elusive. Here we present a 3D fever-on-a-chip model that recapitulates human brain and lung microvessels under febrile conditions. Short febrile episodes at 40 °C, common in treated cerebral malaria patients, rapidly enhanced iRBC and immune cell binding under flow. Mechanistically, we demonstrated that this phenotype was driven by endothelial glycocalyx shedding, which exposed endothelial receptors EPCR and ICAM-1. Preserving glycocalyx integrity with a broad MMP inhibitor prevented the temperature-induced rise in cytoadhesion. These findings identify fever as a host-specific amplifier of vascular pathology in malaria and highlight endothelial-protective or antipyretic interventions as important strategies to mitigate febrile microvascular pathology.

Expansion microscopy has recently emerged as an alternative technique for achieving high-resolution imaging of biological structures. Improvements in resolution are achieved by physically expanding samples through embedding in a swellable hydrogel before microscopy. However, expansion microscopy has been rarely used in the field of virology. Here, we evaluate and characterize the ultrastructure expansion microscopy (U-ExM) protocol, which facilitates approximately four-fold sample expansion, enabling the visualization of different post-entry stages of the HIV-1 life cycle, focusing on nuclear events. Our findings demonstrate that U-ExM provides robust sample expansion and preservation across different cell types, including cell-culture-adapted and primary CD4+ T-cells as well as monocyte-derived macrophages, which are known HIV-1 reservoirs. Notably, cellular targets such as nuclear bodies and the chromatin landscape remain well preserved after expansion, allowing for detailed investigation of HIV-1–cell interactions at high resolution. Our data indicate that morphologically distinct HIV-1 capsid assemblies can be differentiated within the nuclei of infected cells and that U-ExM enables detection of targets that are masked in commonly used immunofluorescence protocols. In conclusion, we advocate for U-ExM as a valuable new tool for studying virus–host interactions with enhanced spatial resolution.

Self assembly of organoids and assembloids from synthetic cells with DNA.