Immunity Project – HIV Vaccine Development Program [pdf]

https://dl.dropboxusercontent.com/u/702869/Immunity%20Project%20White%20Paper.pdf

by humanfromearth • 12 years ago

40 44 12 years ago

dl.dropboxusercontent.com

icinnamon5• 12 years ago

Ian from the Immunity Project (YC W14) team here! Happy to answer any questions you may have.

vertis2• 12 years ago

Excuse my lack of knowledge in this area, but is this vaccine purely preventative, or is it possible to administer it to someone already infected.

I know/believe with traditional vaccines that you usually have to do it before infection. (Though could be wrong in this regard as well)

If not, why not?

rposborne2• 12 years ago

The definition of a vaccine is that it is preventative vs. a cure which is removing a disease from a previously infected patient.

"A vaccine is a biological preparation that improves immunity to a particular disease."

howiediamond• 12 years ago

Howie from the Immunity Project here. Thanks for your question! We're really just focusing on the preventive aspect of this vaccine as we head into our Phase I human clinical trials.

rgejman6• 12 years ago

Some thoughts on this white paper, with the caveat that I'm not sure how much of what is discussed they have done and how much of it is what they are planning to do. The white paper is light on details and I re-iterate my appeal for them to release their data (at least in summary form). My apologies for some of the technical language--I want to write this first and then I can clarify the hard stuff (or you can google it)

This vaccine relies on inducing immunity to an HIV peptide* (i.e. a ~9 amino acid cleavage product of an HIV protein) that is predicted to bind to HLA molecules. At first blush, this sounds like a great idea--let's immunize people to the very thing that the immune system is supposed to recognize as bad! Unfortunately, this has been tried lots of times and usually doesn't work very well, if at all. It's been tried in cancer, it's been tried in HIV, it's been tried in practically any system you can imagine. I'm not saying that peptide vaccines don't ever work (hell, my lab has worked on one)--I'm just saying that they have had lots of promise and limited successes. In fact, animals and patients have been immunized to many cleavage products of many cancer associated antigens to little, if any, effect—or effects in animals but not in humans. We can hem and haw all day about what the specific studies show, but suffice it to say that peptide vaccines are an old idea. Perhaps Immunity will get lucky here, but I'd be surprised if there isn't a lab somewhere that has tried immunizing animals to every single breakdown product of HIV proteins already.

Immunity's white paper says that their putatively immunogenic human peptide cannot be tested in animal models because it will only bind to human HLA. So they are planning to use a mouse-analog of the human peptide to do their animal testing (or have already done this?). That is, they are planning to use (or maybe have already used?) a completely different peptide (probably 1-3 amino acids different from the human version) in animal studies than what they would use in patients. This may be a significant difference... or it might not be. There's no way to tell a priori. A more classical and IMO better approach would be to identify T cell receptor clones from patients with HIV (or without HIV) that bind to these peptides (using tetramer staining, phage display or some other high-throughput technology), demonstrate that humans are capable of creating T cells that recognize their putatively immunogenic peptide followed by T cell killing assays on cells presenting their peptide of interest. There are other approaches, but that is a commonly used one in the field.

* in some places the white paper says "peptides" and in other it says "peptide" so it's not clear if we are talking about 1 peptide or multiple. I think they are mostly talking about multiple peptides, because they want to immunize people no matter their HLA type. Different HLA types bind to different peptides. So if you have HLA A02 you will bind different peptides than if you have HLA A24... and so on for all the different HLA types.

midas0072• 12 years ago

If it were possible, how long / $ would it take to make a transgenic mouse model with the human gene(s)?

rgejman6• 12 years ago

There are a lot of moving parts, so it's really hard for me to estimate the cost here. It's done somewhat routinely in some institutions (although it is very, very expensive).

You first need to make humanize mice (i.e. mice with human immune systems). Luckily we can make those by taking NOD/SCID mice (an [expensive] immunodeficient mouse line) and then colonize them with human hematopoietic stem cells from a human donor to reconstitue the immune system. Then you have to do a lot of experiments to make sure your humanized mice can mount immune responses. Then, you can test your peptide and see if your humanized mice will make CD8 T cells to your peptide... Finally, you can infect your mice with HIV (now that you have a humanized immune system) and see how your vaccinated vs. unvaccinated mice fare.

I have no idea what the downsides of this approach are because I don't work on HIV or with humanized mice--but mice ain't people. So after all that work you'd have shed limited light on what would happen in real people.

I would argue that a better approach is to see whether HIV patients have actually made CD8 T cells against these antigens. This can be done more inexpensively and would give you pretty good evidence that your peptide is immunogenic in real people.

reidrubsamen7• 12 years ago

Hi there, Reid from Immunity Project. Thanks for the great question! Would love to talk with you off line about your research, by the way.

1. We have successfully gotten an immune response with memory (by elispot) after a single dose of the PLGA microspheres containing one or two peptides when combined with TLR-4 (MPLA) and TLR-9 (CpG) agonists. We used H2d restricted epitopes to do the study in C57BL/6 mice – this study is done and in the PRJ review process. We are being careful about posting the results in the event we need to re-submit to a journal who would get heartburn if they saw the data posted.

2. We are raising money now to essentially repeat the experiment (on a smaller scale because we think we understand the optimal formulation configuration now) in C57BL/6 NOG mice (with human PBMCs grafted in from a donor with known HLA type). The new experiment starts off looking like the experiment in (1) above: intradermal tail injection, wait 14 days, sacrifice, get the spleen, confirm immune response to peptide target by flurospot. The next part is new: separate CD8 from CD4 cells (from the mouse spleen), infect the CD4 cells with HIV, see if the vaccination attempt was good enough to see p24 antigen suppression and/or a change in the CD4 counts (all in-vitro). We can finish this study in a couple months, assuming the crowd funding keeps going well and we start in a couple weeks. We will use a different mechanism to publish our paper around this experiment so that we can get it out right away in a fashion that will lead to peer review and open access (We just learned about peerj.com – thoughts on that?).

Looking forward to hearing your thoughts on our approach.

rgejman6• 12 years ago

#1 suffers from the critique I mentioned above. The peptide(s) you are using are designed for H2d. Do you have evidence that their human analogs* are immunogenic?

#2 I assume now you are using the human version of the peptide? I'm not sure why you're doing this in vitro when you can now do it in vivo. Why not (a) infect the mouse with HIV, (b) look at viral titers w/ and w/o pre-vaccination, (c) look for specific CD8 T cells that have developed against peptide-HLA complexes.

I'm not sure I understand your in vitro experiment. Are you planning on mixing CD4 and CD8 T cells together in vitro from vaccinated/non-vaccinated mice and looking for increased killing of the CD4 cells (as estimated by decreased p24)?

*I assume it's mostly anchor changes here

14573894• 12 years ago

The role of the TLR-4 and TLR-9 agonists; Are they essentially acting as adjuvants for your vaccine when delivered in conjunction with the peptide on the surface of the same microsphere?

Also, did you consider using nanospheres? Why PLGA?

EDIT: This is the bit I want some clarification on, from your white paper:

These microspheres make the very small targets look large and threatening to the immune system, provoking an immune response after a single dose

EDIT2: Got my answer in the white paper, yes they are adjuvants. Still would like to know why PLGA and what the mechanism of how they appear more "threatening" is.

limpon2• 12 years ago

Hi Reid, as I said before, I wish you all the best but I simply don't understand how your experiment 2 is going to work. Did I understand correctly that you will immunize mice and then isolate CD4 T cells from the spleen. Then infect those cells and see if cells from immunized mice die slower/less/not at all and don't express p24 in high levels. I'm afraid this experiment will not work this way. CD4 T cells by itself can not be immunized against HIV. The immunizing effect comes from memory B cells that produce antibodies. These antibodies bind to HIV infected CD4 T cells and as such label them as evil to be killed by other cells. CD4 T cells alone will not show any effect in regards to susceptibility to HIV no matter how well your immunization works. As rgejman pointed out, it would be way better to infect the mice with HIV and do a CD4 T cell count there every week. This would be so much easier and it might actually show you something relevant.

shiven2• 12 years ago

Wait! But what HIV protein(s) is the peptide(s) derived from?

Let's not overlook the decades of prior data! The field is littered with names like VRC01, Camelid and so many other players. I know, I know, antibodies all versus antigen in this case. But keep reading ...

HIV is a master at developing resistant forms of itself. What if it changes the epitope and evades the vaccine induced antibody(ies), again!?! (Edit: Don't forget the long-term viral reservoirs that survive against the best antiretrovirals known to us!)

This is something I care about personally: What is their strategy against resistance? (Or, like everyone else before them, they will build that bridge when the water is above their nose!?! Not being snarky, just very concerned.)

And might I also ask: Any concerns about accidentally inducing an autoimmune disorder with that antigen/epitope? Why/why not?

Added: I'd love to see these guys succeed and really want to see a rationale and approach that goes beyond what has been tried and not worked so far. Also, kudos for the open-science approach!

icinnamon5• 12 years ago

Hey shiven! Thanks for your question. This is Ian Cinnamon from the Immunity Project team.

The targets we are trying to immunize with are believed to be beneficial by a statistical analysis similar to what is described here: Mothe B, Anuska L, Ibarrondo J, Daniels M, Miranda C, Zamarreno J, et al. Definition of the viral targets of protective HIV-1-specific T cell responses. Journal of Translational Medicine 2011;9(208):20.

The guys who generated the peptides we are using have specifically asked us not to talk about the sequences because they are trying to publish now. We hope that these targets will be conserved to the point that resistance is limited (as may be the case in some HIV controllers) - won't know without clinical data.

midas0072• 12 years ago

Interesting. Would Gates and a couple others be willing to cut a few large checks to just make it happen? This is something that should be fast-tracked. As in right now, please.

icinnamon5• 12 years ago

Ian from Immunity Project here. We've actually chatted with a few of these large foundations and they are very interested. They want to see some Phase I data first, so that's why we went ahead with the crowdfunding campaign to help us get to that point! Check it out: http://pledge.immunityproject.org

rposborne2• 12 years ago

Have any of them giving you all benchmarks to hit to secure funding?

lvryc• 12 years ago

They're also running a kickstarter-style crowdfunding attempt at https://pledge.immunityproject.org/the-free-hiv-aids-vaccine .

icinnamon5• 12 years ago

We are indeed!

rgejman6• 12 years ago

Another thing I want to point out is that your home page touts safety as a design point. The text under "SAFE" says "Our vaccine does not contain killed viruses, live viruses, or genetically-modified viruses." I STRONGLY object to this language as it implies that inactivated (killed) and live* viruses are unsafe in general. This is simply not true. I believe most clinically used vaccines are either inactivated or attenuated.

I understand that you're trying to make sure people understand that your vaccine is safe. However, implying that other vaccines are unsafe because they are inactivated or attenuated does a disservice to the entire vaccine industry.

*I think you mean 'attenuated' here, not live

reidrubsamen7• 12 years ago

Thanks for the comment! We did not mean to imply that existing vaccines were dangerous and will modify the language on the site to clarify.

kayhi• 12 years ago

Is there more basic research supporting this interaction (crystallographic or otherwise) between the peptide and T cell? The paper feels like to jumps right into animal models.

"specific points identified by a data-driven analysis of actual individuals’ immune systems" pg1

What is the data in this case?

What is the sequence of the peptide(s) that are incorporated into the PLGA?

Side note: our start up works on helping biotech companies source reagents, supplies and equipment, we should be able to save you about ~15% on the ~475k part of the budget

naveenspark2• 12 years ago

Naveen here from Immunity Project. Thanks for the question. We have not done receptor analysis. We are using animal models as our starting point - we are looking for an immune response with memory to the administered peptides - if we get that response in Phase I we should be in good shape!

We received the peptides from researchers who have a manuscript in publication and would like us to keep the sequences confidential until they publish. Please see below for similar statistical research looking for targets to beneficial regions on HIV:

Mothe B, Anuska L, Ibarrondo J, Daniels M, Miranda C, Zamarreno J, et al. Definition of the viral targets of protective HIV-1-specific T cell responses. Journal of Translational Medicine 2011;9(208):20.

re: your startup / cost savings on reagents, supplies and equipment, we would love to talk to you about that. Please email us at team@immunityproject.org. Thanks!

ciokan2• 12 years ago

I would be very curious to know if the team received any kind of pressure to stop what they're doing or if they will communicate if such thing would happen. Don't want to sound cynical, I just watched a lot on the subject recently and it seems there's a huge industry behind having a lot more benefits (material ones) from the actual sick people and their life-long expensive treatments compared to a vaccine.

Even if it doesn't work God bless to you all for trying this. It's a wonderful thing to get you up in the morning.

naveenspark2• 12 years ago

Thank you for the kind words and support! We are very focused on our stated goal which is ending HIV/AIDS with a free vaccine. We haven't received any pressure to stop our work yet. If we do we will definitely let you know so we can get your help in fighting back!

limpon2• 12 years ago

I've heard lots of people speculating that the big pharma companies would be better of if there would always be HIV and they can sell their ART pills for live. But on the other hand if one of them is the first one to create a HIV immunization, this alone will make them so extremely rich. An effective HIV immunization will become standard immunization for all people in the western world and the WHO and UN will take all in their power to immunize as many people worldwide as possible. Just imagine the amount of doses that will have to be produced. And you would be the only one company having this product. This has way more financial gain that being one of the dozens of companies that produce ART therapies. On top of that a few people working in high positions of big pharma companies are still "nice" people who would actually be proud of curing a disease. Not everyone just counts their dollars every day and hopes that more people get sick.

ciokan2• 12 years ago

yes but op website says they will release it for free, thats why i'm asking in the first place.

Immunity Project – HIV Vaccine Development Program [pdf]

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