Relationship between clinical status of leukemic patients and virus-like particles in their plasma

The Discovery of Extracellular Vesicles and Their Emergence as a Next-Generation Therapy

From their humble discovery as cellular debris to cementing their natural capacity to transfer functional molecules between cells, the long-winded journey of extracellular vesicles (EVs) now stands at the precipice as a next-generation cell-free therapeutic tool to revolutionize modern-day medicine. This perspective provides a snapshot of the discovery of EVs to their emergence as a vibrant field of biology and the renaissance they usher in the field of biomedical sciences as therapeutic agents for cardiovascular pathologies. Rapid development of bioengineered EVs is providing innovative opportunities to overcome biological challenges of natural EVs such as potency, cargo loading and enhanced secretion, targeting and circulation half-life, localized and sustained delivery strategies, approaches to enhance systemic circulation, uptake and lysosomal escape, and logistical hurdles encompassing scalability, cost, and time. A multidisciplinary collaboration beyond the field of biology now extends to chemistry, physics, biomaterials, and nanotechnology, allowing rapid development of designer therapeutic EVs that are now entering late-stage human clinical trials.

A brief history of nearly EV-erything - The rise and rise of extracellular vesicles

Extracellular vesicles (EVs) are small cargo-bearing vesicles released by cells into the extracellular space. The field of EVs has grown exponentially over the past two decades; this growth follows the realisation that EVs are not simply a waste disposal system as had originally been suggested by some, but also a complex cell-to-cell communication mechanism. Indeed, EVs have been shown to transfer functional cargo between cells and can influence several biological processes. These small biological particles are also deregulated in disease. As we approach the 75th anniversary of the first experiments in which EVs were unknowingly isolated, it seems right to take stock and look back on how the field started, and has since exploded into its current state. Here we review the early experiments, summarise key findings that have propelled the field, describe the growth of an organised EV community, discuss the current state of the field, and identify key challenges that need to be addressed.

Factor VIII, HIV and AIDS in haemophiliacs: an analysis of their relationship

In this review, the association between the Acquired Immune Deficiency Syndrome (AIDS) and haemophilia has been carefully examined, especially the data that have been interpreted as indicating transmission of the human immunodeficiency virus (HIV) to the recipients of purportedly contaminated factor VIII preparations. In our view, the published data do not prove the hypothesis that such transmission occurs, and therefore HIV cannot account for AIDS in haemophiliacs.

Morphologic study of virus-like particles in a case of acute leukemia

Virus-like particles, grouped in clusters not bound by a membraine, were seen in electron micrographs of fresh leucoblasts of an acute leukemic patient. They consisted of large (100-nm diameter), round particles apparently composed of subunits. Tubular structures (30-50-nm diameter) were also seen in leucoblasts of the same patient. The two types of structures were never seen simultaneously in the same cell. The authors review the literature pertaining to the morphology of virus-like particles associated with malignant hematologic disease.

Viral etiology of leukemias. Electron-microscope observation of virus-like particles

The injection of human leukemic blood in chicken embryos before incubation determines a characteristic reticuloendotheliosis, which may be transmitted from embryo to embryo and even to the adult fowl. The viral agent responsible for this reticuloendotheliosis is filtrable and inactivated by heat. Intradermal injection of affected-embryo homogenates in leukemic patients determines a local allergic reaction. Electron microscopy has shown the existence of virus-like particles in the cells of inoculated embryos.