Hello students from all over the world. Welcome to the first massive open online course on extracellular vesicles. This is a collaboration between University of Gothenburg in Sweden, Postech in Pohang, South Korea, University of California Irvine, as well as, the International Society for Extracellular Vesicles. My name is Jan Lotvall, I'm the immediate past president of the International Society for Extracellular Vesicles. And I'm a professor at Krefting Research Center in University of Gothenburg, Sweden. We have a history working with extracellular vesicles for more than ten years, beyond our other research area, which is asthma and allergy. So the International Society for Extracellular Vesicles is a very young, non-profit international academic association, that basically was created, or was born, in 2011 during an exosome meeting held in Paris, in January. It was a cold January, but we had a very friendly atmosphere, and we're discussing how to help this field to grow, and to get organized. And basically we decided then and there to start the society, and that was established during 2011 and the first society meeting was held in Gothenburg in Sweden in 2012. In the 2012 meeting we had approximately 480 participants, and now 2016 we had almost 900 participant. In next year's meeting we'll actually be held in Toronto in Canada between 18 and 21st of May. And if you're at all involve in Extracellular Vesicles Research, I really hope that you will join us there. So, the aim of this presentation is to give a little bit of an introduction to the field about extracellular vesicles. And when I say extracellular vesicles, other terms are exosomes, or micro vesicles. These are very difficult to distinguish from each other, but basically, they are both lipid bilayer membrane extracellular structures and they are usually spherical in shape. So they're extracellular structures that are present in many parts of the body. They carry different surface molecules and then can carry different functional proteins, both on the surface, and as cargo, but also nucleotides, such as RNA. So membrane proteins can be transmembrane proteins and are used to identify extracellular vesicles in a secretome. So if you think about these extracellular vesicles being released by all kinds of cells in the human body, we could consider them, and call them, a vesicular secretome, and that is present in the different tissues. So the aim of this course, and what I will touch on a little bit during my introduction, is where are they? What can they do? What does it mean? And hopefully after following the whole course, you will realize they're hugely important for the future field research in biology. And for education in biology, to understand biology. So where are they? The answer is that they are, when you think about the human body, absolutely everywhere. So if you think about the different body fluids, and they have been described over the last, I would say almost four decades, they were described. In prostate secretion in the late 1970s already. But here is an example of a publication in 1983. They're also present in urine. That was described more than ten years ago now. Breast milk, less than ten years ago. And there's also RNA in the breast milk described by Cecil Lessar in 2011. And presently in blood and plasma that's been known For more than 60 years now, I would say, actually 70 years. So when you look at electron microscopy, and this is an example for prostate secretion, Published by Johanna. In journal in 2015. And you can see here, a number of different examples of which all are spherical, but actually sometimes you can find to be multi-vesiculated. So there's a, sometimes the vesicle inside of another vesicles. And here the lower middle, you have a very happy Extracellular Vesicle present in prostate secretion. And we should remember that extracellular vesicles are present in all body fluids. Also, for example, in fetal bovine serum, often used in in vitro culture experiments to help ourselves to grow and to flourish in vitro. But there are plenty of extracellular vesicles there, exosomes, in the fetal bovine serum that can be very influential on the cellular phenotype and the function of the cell that you're actually studying. So that is something to really be aware of and consider. So if you look historically extracellular vesicles were present in plasma already in the 1940's as pro-coagulants. In '67 they were described as platelet dust. Dust, but also matrix vesicles during bone calcification. In the 70s they were described more in the prostate fluid and there are very prominent in the prostate excretions, for example in ejaculates. So they're very easy to find in that body fluid. In 1983 maybe that's the birth date of the modern face of extracellular vesicles research, specifically exosomes research. When two publications showed the release of the transferrin receptors as part of maturation of red blood cells. And these vesicles were referred to as exosomes. So if you look at the nomenclature of extracellular vesicles it's really confusing I would say. There are many different names out there and what is on the screen right now is only a few examples that can be found in the publication. There are three terms that are quite important to consider as functional Extracellular Vesicles. And these are exosomes that are released through intracellular pathways and then we have ectosomes and microvesicles which probably are the same types of vesicles they're actually budding from the surface of the cell. So, it's actually the cell membrane that folds out and creates an So, if you look at the way exosomes have producer, first they in word budding of the cell membrane and that's an early endosome And when you look closely at this endosome it can bud again and create what we call a multi-vesicular body, and those are spherical organelles with a number of different vesicles inside of the. So, if you think about the topology, the outside of the cell membrane is on the inside of the endosome, but of the vesicles inside of the multiple circular body, they are all also pointing outwards. So, when this multivesicular endosomes then fuse with the cell membranes the extra cellular vesicles leave or these vesicles leave the multivesicular body and they're then called Exosomes. So those vesicles that produce this were this way, have that nomenclature traditionally. So that's how exosomes are considered to be produced. This is a simplified example and there are probably other pathways that are important as well. Now if you think about the ectosomes, or microvesicles, they're actually budding from the surface of the cell membrane. So that's a direct excretion of cell membranes to the outside of the cell. And that's probably very important part of extracellular vesicle production as well. Now if you look at the number of publications in this area and this is from a publication that we had in Journal of Extracellular Vesicles, in December On 14 you can see a very rapid growth of the number of publications from the early 2000s, maybe from 2003 or 2004, and there has been a steady and very strong growth both in the field since then. So many people are getting into the research and biology of extracellular vesicles currently, which is of course why we find it very timely to run this massive open online course. There's also a lot of efforts going into understanding the nomenclature and this is a publication that just recently came out in Journal of Biomedical Semantics, published in April of 2016. And this paper is discussing extracellular RNA but also vesicles and vesicle nomenclature. And there are a number of different examples here that can be considered for these vesicles that anybody's studying in research. So, if you look into this center part of the nomenclature you can see the nomenclature apoptotic blebs and apoptotic vesicle or apoptotic body, you can see the nomenclature of extracellular exosome or exosomes they're often used As plural exosomes because we usually study the cloud of exosomes not the single exosome or [INAUDIBLE] that are considered to be budding directly from the plasma membrane. But there is other nomenclature out there as well. They could be called ectosomes. So where are these vesicles? Obviously they are everywhere. What they can do? They can do very many things and that will be further discussed in this massive open online course. It will also be discussed what it means, how they can be used in different ways. And it will explain how we need to understand these very carefully to understand biology. So this is a five week course. In principle there is a welcome and introduction presentation block which is mine is the first talk, then another four. Nomenclature, biogenesis and cargo, six different presentations. Collection and processing, five. Isolation of extracellular vesicles, six. And characterization and quantification, five. And when you're discussing the vesicular secretome you will learn that vesicles are not one thing, they are a cloud of messaging that the cell is sending out to its environment and influencing other cells. And different vesicles have different morphology, different structure, different messages, and different function In the recipient cell. So I hope you enjoy this massive open online course, and I welcome you to be enthused and enjoy the feel of Extracellular Vesicles. Thank you very much for your attention. And also thank you very much to Cecilia Lasser who's coordinated this course. Yong Song Gho at POSTECH who was the executive chair of education that I served when this course was initiated. And Weian Zhao at University of California Irvine that has really helped us initiate this course. Again, thank you very much for your attention.