During my study of the immune system, I came across 2 very contrasting explanation as to how prions work.

Firstly, scientific American pointed out this:

link here:

"A major breakthrough occurred when researchers discovered that the infectious agent consists primarily of a protein found in the membranes of normal cells, but in this case the protein has an altered shape, or conformation. Some scientists hypothesized that the distorted protein could bind to other proteins of the same type and induce them to change their conformation as well, producing a chain reaction that propagates the disease and generates new infectious material. Since then, the gene for this protein has been successfully cloned, and studies using transgenic mice have bolstered the prion hypothesis. The evidence in support of the hypothesis is now very strong, though not incontrovertible

However based on this website

The guess was that they infected cells by causing normal prions to become misshapen, too. That theory, though, has been proven false, though it is still commonly believed. (See Sanctuary: Bad Bad Prions from Discover, dated 9 January of this year for an example of the ongoing belief.) The first serious attack on the prion-as-infectious-agent theory was reported in Medical Hypotheses in 1997. The article makes the case that prions trigger an autoimmune response.(1) As becomes clear the more one looks into the issue, this makes sense and fits the facts as known.

The problem right now is that my campbell 11th edition textbook, which is the newest edition and just recently revised also points to the same explanation as the first source.

Which source is correct in showing the method in which prions cause diseases?

  • 1
    $\begingroup$ i don't see any contradiction between the two quotations. The first quotation describes the formation and expansion of prions. Note that many proteins have a potential to misfold into the so-called prions. Prions are misfolded proteins, which in their original, natural conformation have their specific biological functions or their function is unknown (which does not mean they don't have any). The second quotation speculates about the disease caused by the prions rather than the formation of the prions. By the way, what is "a normal prion"? Prion is an abnormal state of a protein. $\endgroup$
    – user37894
    Nov 14, 2017 at 21:16

1 Answer 1


I agree with commenter Martin Klvana, but there are a couple things going on here I wanted to touch on:

  1. I think that your second quote is making an error in saying that if prions cause immune responses that means they aren't "infectious" in the sense of propagating misfolding of homologous proteins. The standard understanding is that prions work biochemically by refolding prionogenic proteins to make more infection prion particles (see e.g. wikipedia), similar to your source 1 and your textbook. It's completely possible that these newly infectious prion particles lead to immune reactions in additional to the "infecting" particle. The key here is to separate the biochemical phenomenon (propagated misfolding of proteins) from the medical phenomenon (disease, immunological response).
  2. To more directly answer the question: as far as I can tell from scanning a couple of articles (here, here), immune responses are not a prominent part of the best-known prion diseases, but I'm not an expert and could be wrong. I was unable to easily locate the 1997 Medical Hypotheses paper referenced by your source 2.
  3. I haven't looked deeply into this, but that website appears to be run by an advocacy group and the "read full article" link is broken. So... I would put less stock in that source. Advocacy groups are fine and all but I don't think that their blog posts are good sources of biomedical science information.

Hope that helps.

  • 3
    $\begingroup$ it becomes really obvious the advocacy group articles is not written by a scientist as they talk about prions lacking a "life imperative" that viruses supposedly have. This lack of a metaphysical force is supposed to explain why it can't be an infectious agent instead it displays a lack of basic biological knowledge. $\endgroup$
    – John
    Nov 15, 2017 at 16:02

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