Invasion of erythrocytes during the asexual blood stage of malaria is an area of intense research owing to its promise a target for anti-malarial treatments. Difficulties in the development of efficient therapies lie, in part, due to a fundamental lack of insight into the molecular processes and biophysical mechanisms which govern host-pathogen interactions at this stage. Invasion is a highly dynamic process involving the micron sized merozoite, numerous ligand receptor interactions and critical biomechanical forces [1, 2, 3, 4]. An important part of the invasion process is the formation of the parasitophorous vacuole membrane (PVM) at the point of entry to the host red blood cell. This membrane provides a physical barrier and an exchange surface between the parasite and the host cell. The formation of the PVM and subsequent remodelling of the host membrane during invasion are incredibly dynamic events and are very challenging to study in real time [5]. Studies using advanced microscopy techniques are often limited to fixed points in time or rely heavily on qualitative analysis. Until now a high-resolution 4D view of this complex invasion process has remained an insurmountable technical challenge.
We built a custom high-speed multi-dimensional lattice light sheet microscope to assess the molecular and biophysical formation of the PVM during invasion in 4-dimensions. Using various functional fluorescence imaging methods, we show, for the first time, temporal changes in the physical and molecular properties of the forming PVM. In addition, a computational framework to measure geometric features, such as membrane curvature, membrane surface area and volume has been developed. The combined spatial and temporal resolution of the lattice light sheet microscope offers unprecedented insights into the dynamic processes underpinning host-pathogen interactions.