rion 2018 has finished, I think, successfully. On behalf of the Local Organizing Committee, and the NeuroPrion Association, I thank you for having  joined us in Santiago de Compostela for this conference. When planning Prion 2018, we aimed at putting an emphasis in structural biology, hence our subtitle: “Prion 2018: Back to basics, understanding the biology of prions”, of course without neglecting other very important aspects of human and animal prion disease. The workshop on structural biology of prions, the round table on the structure of PrPSc and a number of exciting invited and selected conferences and posters have, in my opinion, deepened our understanding of how prions in general, and PrPSc in particular, propagate, and what are the possible structural and molecular targets that we can exploit to find a therapy for prion diseases. The round table made clear that there are two main competing models of PrPSc that are not mutually exclusive –perhaps flat and solenoidal PrPSc molecules coexist in affected brains and interconvert into one other through deformed templating- but in any case, prion propagation boils down to amyloid templating. The possibility of obtaining large quantities of recombinant PrPSc through PMSA, described in a late-breaking communication, offers the possibility of elucidating the structure(s) of PrPSc at an atomic resolution within the next few years. This will, undoubtfully, continue to guide efforts to find a cure for prion diseases. The round table on therapy showed where we have failed in the recent past –and what we have learned from these failures- but also exciting ongoing avenues such as the humanized antibodies that are ready to be tested. It appears that acting on PrPC to stabilize it (despite the fact that it is not a very druggable molecule, described as a “golf ball”), might offer advantages over the alternative approach of blocking PrPSc propagation, given the issue of strain selection.

I would also like to reflect on what was presented and discussed about animal prion diseases. From the very intense animal disease workshop and whole-day session on animal disease, two headlines emerged: CWD (of a different flavor than that seen in North America) is now present in Europe, and is here to stay; and a camel prion disease exists in Northern Africa. Policy makers should take note; will they…? In the meantime, a lot of work lies ahead: how did these CWD prions, different from their North American cousins, emerge in Scandinavia…? And, what are the risks to humans associated to these epizootics? Might other camelids (llamas, vicuñas…) of great economic and ecological importance in South America, be at risk of an imminent prion disease…?

A few words about other neurodegenerative diseases in which protein misfolding, and prion or prion-like mechanisms play a central role. Besides some exciting presentations involving, among others, Parkinson´s and Alzheimer´s diseases, Multiple System Atrophy, ALS and, unexpectedly, Multiple Sclerosis (might it also be a prion disease?), the round table “Are they prions, prion-like proteins, or what?” was in my opinion one of the highlights of the conference. Defining whether Aβ, tau or α-synuclein are or are not prions is not a trivial exercise in semantics. As Sven Saupe stated, quoting a philosopher of language, we define, as a community, the world, by agreeing to give a certain name to things, and then act in consequence. Homosexuality used to be defined as a mental disturbance by the psychiatric community, and it was not completely wiped out from their Diagnostic and Statistical Manual (DSM) until 1987: a matter of mere semantics…? Discussion at the table, aptly conducted by Mathias Jucker and Hasier Eraña was very intense, and, incredibly, a consensus was reached by the panelists: Aβ, tau, -synuclein…transmit like a prion, kill like a prion, quack like a prion…so they must be…you can complete the sentence. But given the stigma associated to the term “prion” as being associated with a highly transmissible, mortal disease, extreme caution should be exercised by the scientific community when using the term, and intense efforts should be devoted to inform and educate the public. Furthermore, a nomenclature and classification committee or task force similar to those operating in the virus field might be a good idea. All very simple, isn´t it? Well, results from the on-line poll conducted during the session showed that only about half of the audience concurred with the table, with the other half considering that these agents are “prion-like”…

A more detailed discussion and summary of all these aspects of the conference will be the subject of a monographic issue of the journal Prion, that will come out within the next few months.

Finally, we would like to mention the session “Patients & families: a dialogue with scientists” in which we listened to intense testimonials and reflections from the people who suffer prion diseases. A reminder of whom we are working for.

But besides all this, we think that the meeting was fun. We all had, I think, a great time. I saw happy faces and lots of interactions and networking, and a lot of colleagues have told me that they enjoyed the conference (and there are pictures to prove it…), so from that perspective, it has been a success, too. Unless you are charitable lyars…

Those of you who did not have a chance to see the botafumeiro (was that embarrassing…), have an excuse to come back to Santiago de Compostela. Those who saw it the following day…well, you too. And to all of you, I look forward to seeing you again in Prion 2019 Edmonton.

Jesús R. Requena
Chair, Prion 2018 Organizing Committee