Imaging technique reveals 3D forces exerted by tiny cell clusters — ScienceDaily

A team of researchers has developed a new technique to map the three-dimensional forces that clusters of human cells exert on their surrounding environment. The method could potentially help scientists better understand how tissue forms, how wounds heal or how tumors spread. “We know that the way groups of cells interact with their extracellular matrix is important, and we want to understand the instructions that tell these clusters to become organized into tissue-like architecture, or alternatively to become disorganized like an invasive tumor,” said Ian Y. Wong, an assistant professor in Brown University’s School of Engineering and corresponding author of a paper describing the work in the Proceedings of the National Academy of Sciences. “This technique gives us a way to profile these mechanical interactions between cells and matrix in a way that we couldn’t before.” The new technique makes use of traction force microscopy (TFM), an imaging method that has been widely used to study the forces exerted by single cells. To make TFM measurements, researchers place cells within biomaterials that mimic an extracellular matrix and contain thousands...

Plasmodium gametocytes display homing and vascular transmigration in the host bone marrow

Transmission of Plasmodium parasites to the mosquito requires the formation and development of gametocytes. Studies in infected humans have shown that only the most mature forms of Plasmodium falciparum gametocytes are present in circulation, whereas immature forms accumulate in the hematopoietic environment of the bone marrow. We used the rodent model Plasmodium berghei to study gametocyte behavior through time under physiological conditions. Intravital microscopy demonstrated preferential homing of early gametocyte forms across the intact vascular barrier of the bone marrow and the spleen early during infection and subsequent development in the extravascular environment. During the acute phase of infection, we observed vascular leakage resulting in further parasite accumulation in this environment. Mature gametocytes showed high deformability and were found entering and exiting the intact vascular barrier. We suggest that extravascular gametocyte localization and mobility are essential for gametocytogenesis and transmission of Plasmodium to the mosquito. Transmission to mosquitoes is an essential part of the Plasmodium parasite’s life cycle and a target of current intervention...