Robin Weiss: [00:00:00] Thank you, Steve [Goff], but it was the organizers who gave me this title, but I kept to it, and it's great to be back at Cold Spring Harbor and to see so many longstanding colleagues and friends. Thank you for inviting me. Now the first thing I'd like to say is that in terms of history and archives, [00:00:30] the publications in Cold Spring Harbor Laboratory Press have it all, and there's even one book I've left out, which was the original HTLV-HIV meeting that was held here in the fall of 1983 and published in 1984. (1)  These books were the state of the art at the time, but they're very good historical archives now, to see how we were [00:01:00]—I was going to say groping towards the truth, but that's not a good word.

There are also the annual meetings of retroviruses, big fat abstracts, 400 abstracts in the books and so on. I particularly remember the main Cold Spring Harbor Symposium in 1974, which was devoted to tumor viruses, [00:01:30] and it was David Baltimore summing up at the end that clarified what was a rather murky field in terms of nomenclature. (2) He came up with gag, pol, env, and onc, and so on, and suddenly the mist cleared. We knew what we were talking about, because everyone had different terms of their different viruses. So Cold Spring Harbor has been important over the years. I think is a very [00:02:00] valuable archive for students of the history of this field. 

Of course AIDS goes far beyond science. When a new disease suddenly appears that's fatal, that’s associated with sex and drugs, it's bound to create myths and one or two scientists have contributed to them, myths of blame or denial.

The ill of AIDS also [00:02:30] coincided with the growth of the internet. So patients often knew more than their physicians. Activist groups, particularly here in the USA helped to set the agenda. We'll be hearing from Mark Harrington later in the meeting. Of course this impact of AIDS affected the arts and literature too. I've just put up a couple of poems  which I'm not going to read out to you. (3) I'll take all my 20 minutes, but Miroslav Holub’s (1923–1998, Czech immunologist and poet) is hardly longer than a haiku but it sums up Pneumocystis pretty well.

Well, back to retroviruses. If we look at the chronology of retrovirus isolation, it really spans the era of virology. (4)  It's only in 1898 that viruses were distinguished from other microbes as passing through filters: tobacco mosaic virus (TMV), and foot and mouth disease virus (FMDV) [00:03:30]. The first virus that we now know is a retrovirus as a filtrate was discovered in 1905, a lentivirus as we'd now call this. It goes on through the years of the 20th century, but the human ones came late. We did not know about them until really 1980 onwards, and that's the history we're going to [00:04:00] celebrate.

If we look at the different types of retroviruses, they're broadly divided into seven groups, there's outliers as well. The human retroviruses are marked in red, the HTLVs and the HIVs, and I've also put up a couple in realm of the 8% of the human genome that represents fossil retroviral infections. [00:04:30] A tremendous amount was learned about retroviruses from the avian alpharetroviruses and from the mammalian gammaretroviruses from the murine and feline leukemia viruses especially. We'll hear more about those later.

I chose a few landmark events in my mind about retrovirology, [00:05:00] starting with Peyton Rous (1879–1970), isolating the first solid tumor virus. (5) [Howard] Temin (1934–1994) and [Harry] Rubin's (1926–2020) cell transformation assay. Perhaps we shouldn't forget that at that time they didn't know that Rous sarcoma virus is an RNA virus. We didn't know what the nucleic acid was. That was only shown a little later by Lionel and Elizabeth Crawford. Then came the age of oncogenes, [00:05:30] the discover with reverse transcriptase, and then the human retroviruses.

Now I would like to acknowledge Howard Temin—we'll hear more about him and John Coffin—and my mentor from my first post doc, rather rudely interrupted by the arrival of the Soviet tanks in Prague was Jan Svoboda (1934–2017, Czech virologist). I should [00:06:00] say to Jim [Watson] that I'm a kind of socialist, but that kind of socialism wasn't any more successful than capitalism, I don't think, and it was hard working behind the Iron Curtain. And my second postdoctoral mentor, Peter Vogt (b. 1932), these pictures show him sitting in our kitchen with his wife, Hiroko Vogt, but that's many years later.

At the bottom of the slide [00:06:30] is an example of this cell transformation assay or focus assay for Rous sarcoma virus that Howard Temin and Harry Rubin developed at Caltech while working in an Renato Dulbecco’s (1914–2012) lab. You can see the little spots in the wells or petri dishes are individual colonies of transformed cells as shown on the right. They gave a nice linear dose response to the amounts of [00:07:00] virus you put in, so it was a way of titrating them, as well as a way of examining what's going on in cell transformation.

My personal entry into the field, my first paper on viruses came out in August 1967. That's 49 years ago. It seems an awful long time ago. Astonishingly a very similar paper came out at about the same time from [00:07:30] Peter Vogt. What we were both showing was that a virus that was supposed to be defective and lacking envelope was actually infectious. Now, the fact that they produce particles had already been shown by Harriet Robinson (Emory Vaccine Center), who's in the audience, by labeling particles with tritiated uridine, but suddenly we had infectious virus. And this was [00:08:00] really the beginning of the…realization that there's something inside normal cells that we call [00:08:30] endogenous retroviruses and these viruses coming out of chickens plated on quail cells, they were xenotropic so to speak. 

Now, what about human tumor viruses? Well, we know we have them, we wouldn't be having this meeting without them, but they've also been rumors that haven't always held up. The discovery of reverse transcriptase in [00:09:00] 1970, it was not only terribly important in terms of understanding the virus, but it provided a tool for looking for virus infections because it was relatively easy to detect and investigators started finding viruses everywhere. Jim's already mentioned Sol Spiegelman (1914–1983)—I've left out the L in his name, sorry—I think he was right about Qβ and wrong about human retroviruses (6) and one of the papers [00:09:30] that showed what was really going on came from Bob Gallo's lab. (7) There was the announcement with great fanfare and [Robert M.] Bob McAllister and colleagues of a human retrovirus, which turned out to be an endogenous feline retrovirus, but the human tumor being passed through fetal cat brain as a xenograft. (8) This was shortly before nude mice (an immunocompromised lab mouse) had been developed. [00:10:00]. It was a way of growing human tumors and the tumor then picked up a virus from the host. 

Many virologists who were looking for human retroviruses during the 1970s gave up and said, "They're not really there." Bob [Gallo] persisted, and was rewarded in 1980 with a genuine human retrovirus infection. (9) If you're interested, Cécile Voisset, [00:10:30] David [J.] Griffiths and I wrote up a 40-page review on "Human RNA 'Rumor' Viruses" published eight years ago. (10) We were recommended to do this after we'd owned up to one we thought was human that turned out to be an endogenous rabbit sequence. We've all been through these experiences and it's there to be read. That didn't prevent yet another xenograft contaminant coming up [00:11:00] with the big fuss four or five years ago, about XMRV (xenotropic murine leukemia virus–related virus), and Kate Bishop (Francis Crick Institute) and John Coffin and the others who helped sort this out. (11)

It still seems to be curious that there are no gammaretroviruses in humans, infectious ones, because they so readily infect human xenografts. So if I say, "Why not?" people tell me, "Oh, haven't you heard about restriction factors?" and we'll certainly hear about them at this meeting, [00:11:30] yet some gammaretroviruses have quite a broad potential host range, and they're not restricted from jumping from one species to another or adapting to new species. I'll just give one example, the gammaretroviruses in Southeast Asian mice, which have jumped into primates, into a lesser ape, the lar gibbon and into koalas. Here's a virus, that the reservoir is endogenous, [00:12:00] is passed genetically, but it's a complete genome. (12)  It can come out as an infectious virus. It can infect very, very distantly related species, a marsupial, and an ape, so it's perhaps surprising that we haven't picked up one of these as well.

Not all mammals harbor infectious retroviruses. This is also curious. There will be a poster on some endogenous [00:12:30] sequences in dogs, I noticed in the abstract book. Here we have cats, and Max Essex will be speaking about cats. They're are a chockablock with different kinds of retrovirus. "Why don't dogs have them? Might humans be like dogs?", people wondered. Of course, it turns out we weren't.

The first genuine retrovirus infection in humans that was reported in a [00:13:00] literature was in 1971, from [Michael Anthony] Tony Epstein's (b. 1921) group—Tony Epstein of EBV [Epstein-Barr virus] fame—and he and Bert [Geoffrey] Achong (1928–1996, Trinidadian pathologist) observed this virus in culture that came out of a Kenyan patient with a carcinoma. (13) It was a foamy virus and later it was shown actually to be identical [00:13:30] to the chimpanzee [simian] foamy virus (SFV). In fact, we now know from very nice work done at CDC by Walid Heneine and colleagues that zoonoses, human infections with foamy virus of some primates occur quite commonly if humans have contact with them and that's not only Pygmies in the tropical forest in the Congo, its primate handlers here in USA, [00:14:00] but apparently, they're one stop infections. (14) They persist but they've examined infected people who happened to have been blood donors, and not found any foamy virus in the recipients. Here we have a virus that does infect humans, but it's off the radar. No one ever quotes it.

Along came HTLV. [00:14:30] The human T-cell leukemia viruses, first called, and now human T-lymphotropic virus. Bob Gallo's group found this in, the first patient is African American with aggressive cutaneous T-cell lymphoma, and you'll hear more about this from Bob, I guess. (15) Then a related virus [HTLV-II] found two years later from a patient with hairy cell leukemia, but we don't really know whether that [leukemia] was a coincidence [00:15:00] or not. (16) Incidentally, it's not really clear that HTLV-II is a pathogen, but it does immortalize CD4 cells in vitro, it has transforming properties, and it's prevalent in the West Indies, because the African West Indians had brought the virus with them from Africa. It was also found in Japan, and there was a very interesting paper three years before [00:15:30] the virus was discovered here by Bob Gallo and colleagues from [Kiyoshi] Takatsuki's group defining a new form of leukemia that looked hematologically different with these very characteristic flower cells, and in the same paper, when they mapped where these cases, adult T-cell leukemia, lymphoma, where the patients were born, they got this high density [00:16:00] in Kyushu and down the train to Okinawa, a little bit in Shikoku, but just one or two. There's one case who was born up in Hokkaido, so that looked interesting. (17)

In fact, Bob [Gallo] suggested that it may have been brought in by the Portuguese who landed and established their trading colony in Nagasaki. (18) [00:16:30] [Tsutomu] Kitamura and his colleagues in Nagasaki took this up, and they said, "Thus the HTLV of southwest Japan was probably directly brought in by Portuguese or their associated Black Africans." (19)  And I think it was Fernando de Noronha, Bob, who produced a picture like this. (20) He showed the monkey as well. You see, here's a Portuguese dignitary with his train of office—it was Ito [Yohei] was it? [00:17:00]—here's his African, the servant or slave holding the parasol above him. 

To Yorio Hinuma, this was a blow to national pride. He was extremely chauvinistic about, "HTLV is our Japanese virus." (21) Very different attitude from people in Africa who said, "Oh, [00:17:30] we didn't give rise to HIV." Beatrice [Hahn] will tell us otherwise. Science is not always politically correct, but he did produce some interesting evidence that it was quite a common infection in the hunter-gatherers in that northernmost part of Japan who are genetically more related to a people on Sakhalin Island and in the monkeys, nice furry ones that [00:18:00] live in that northern climate. Here's a nice project, this was all 30 years ago. If we really want to know, perhaps both [Yorio] Hinuma and Bob Gallo were right, but with today's sequencing we could very easily check whether this one was of the southwest Japan was an introduction, and whether this one's truly indigenous or not. It would be a good masters project also. [00:18:30] You wouldn't get a grant for it, but you could do it.

[laughter]

Then came the AIDS virus. The recognition of AIDS we'll hear from Jim Curran. (22) I became convinced that it was a virus, not some behavioral thing or exposure to drugs when the second—It was the third report in Mortality and Morbidity Weekly Report came out [00:19:00] saying that recipients of blood transfusions, and particularly people with hemophilia were developing AIDS. (23) So what else could be transmissible in clotting factors but a virus? 

Unlike Bob [Gallo] and Françoise [Barré-Sinoussi] and Max [Myron Essex], I didn't think it would be a retrovirus. I didn't think that would survive factor VIII preparation. [00:19:30] Little did I know about how crude clotting factor preparations are. I would have put my money on something like a parvovirus, some small DNA virus that establishes a persistent infection, and I was completely wrong. Then the virus was isolated, as we well know, in Paris (24), and NIH (25) and in San Francisco. I think Jay [A.] Levy (b. 1938, one of the three independent discoverers of HIV) deserves a little more [00:20:00] recognition as he's getting these days but he made important contributions too. (26)

We were a bit slow to realize that HIV is a lentivirus. This is because lentiviruses weren't known to cause immune deficiency, whereas some oncogenic virus or their variants were known to cause immune deficiency. You'll hear more from Max [Essex] about that. Already in, I think it was April [00:20:30] 1984, Luc Montagnier said, "Well, an electron microscopist Charles Dauguet said, 'Look, these particles really resemble equine infectious anemia virus.'" (27) Then a slew of papers with the complete sequences of HIV were published in December '84, January '85. We were none the wiser but Simon Wain-Hobson and Pierre Sonigo went on to [00:21:00] sequence the lentivirus Visna. (28) That came after sequencing HIV and their genome structure and open reading frames looked almost identical, and then Matt [Matthew A.] Gonda did much nicer electron micrographs also saying they really do look like lentiviruses. (29) We thought they might be from the oncogenic virus family but in fact, they were [00:21:30] lentiviruses. (30)

That brings me on to a hero of mine, though I never met him, I know Ashley [T.] Haase has. Björn Sigurðsson (1913–1959) who sadly died young, aged 46. He studied infections of Icelandic sheep and including Visna and [00:22:00] Maedi, and he recognized that they were two different syndromes of the same virus. He first isolated the virus. That's published just after his death. (31) His uninfected cells—here's a cytopathic plaque of Maedi-Visna virus, the syncytia—and he coined the term lentivirus. He's worth remembering.

He did some beautiful epidemiology too. (32) [00:22:30] He came up with the story of the introduction of these infections from apparently healthy sheep from Germany that were [asymptomatic] carriers. He plotted with each red spot where these 13 or 14 rams were introduced and showed that this Maedi-Visna must have been a source from one of these two and these two. Scrapie by the way was already [00:23:00] endemic in Iceland, not associated with the rams and this was really a set of beautiful studies. I think he was a great man in the history of retroviruses and particularly lentiviruses.

As we think a bit more of the pathogenesis of lentiviruses, of course, with HIV, it causes AIDS and Michael [00:23:30] Gottlieb's first detailed paper on AIDS published [in the] New England Journal [of Medicine] in 1981 showed the selective depletion of CD4 cells. (33) David Klatzmann in Paris showed that  this was mimicked in culture. (34) and I think the really key paper is of Suzanne Gartner—again, this is Bob Gallo's group—saying this virus grows in macrophages as well [00:24:00] as in lymphocytes. (35–36)

To my mind Maedi-Visna syndrome is like AIDS without immune deficiency. You get a wasting disease and the sheep equivalent of dementia. The reservoir is in macrophages, not in lymphocytes, but the disease is progressive and fatal in susceptible animals. I think it will be quite a good model for looking at non-lymphocytic reservoirs and [00:24:30] virus dynamics. In fact, I just learned from the meeting in Baltimore two weeks ago from Victor Garcia's group [at University of North Carolina] that they've developed humanized mice, humanized for myeloid hematopoetic cells only which can be infected with HIV, and the infected macrophages sustain HIV replication. It would be interesting to know if they go on to [00:25:00] develop a Maedi-Visna-like syndrome. Infectious equine anemia virus is also has a tropism for monocytes and macrophages, and incidentally about 15% of horses' long-term infections recover. This is a sort of spontaneous functional cure. Now, you won't get a grant to study sheep or horses, but I think there are lessons we [00:25:30] could learn from them.

Another take-home message you may not like is: I would say that human lentivirus infections are an excellent model for non-human primates, because we usually think the other way around. But in terms of history, HIV-1 was discovered first, then came the SIVs (simian immunodeficiency viruses). [00:26:00] The feline immunodeficiency virus (FIV), the lentivirus wasn't discovered until later, and the chimpanzee SIV even later. However, we can say that HIV-2 is discovered as a consequence of finding serological cross-reactions against the SIVs. I think Max will talk about that.

Now, why am I standing here? Where did I come into this story? I didn't come into it at all, actually. I left [00:26:30] avian retroviruses in 1979 and I left viruses. I thought I wasn't going to study retroviruses anymore, because of this paper from Bob Weinberg (b. 1942) that he showed that you could do a similar focus assay as Rous sarcoma virus by extracting DNA from tumor cells and inputting them on the non-transformed cell lines. (37) This [00:27:00] was rapidly developed by others, including Mike Wigler (b. 1947) here at Cold Spring Harbor. (38) I was just moving from the ICRF (Imperial Cancer Research Fund) labs in London, which has a high load of tumor virologists, or did in those days, to go through the Chester Beatty [Laboratories] at Royal Marsden Hospital which had much more of a focus on human tumors. I thought, right, we'll look for human tumors and I abandoned retrovirology [00:27:30].

I recruited two very smart people. Sadly they both died last year. Chris Marshall (1949–2015) said I propositioned him here at Cold Spring Harbor, I don't exactly remember that but I recruited him here. You know, Mila [Pollock] like you should do a history of not only romances between people at Cold Spring Harbor meetings or who work here but also [00:28:00] scientific collaborations that may have started from these meetings, it’d be an interesting—you've done it, have you? Oh, great. Chris joined my lab, and we were looking for molecular biologists and Charlie Weissmann (b. 1931, molecular biologist) said, I've got this guy, Alan Hall (1952–2015), he hasn't published anything but I think he's smart. Now, Charles Weissman didn't call people smart loosely. We brought Alan in as well [00:28:30] and we started looking for human oncogenes by transfection and found them.

Why did I leave this promising new field and go back to retroviruses? The answer is quite simple. Actually, Chris and Alan were so smart that I became entirely superfluous. So it was my grant and I organized the weekly lab meetings, but they just sailed way ahead of [00:29:00] me. (39) And the second reason was that we actually had human retroviruses now. I thought I should do what I'd always been doing, looking at pseudotypes and envelope properties with the human retroviruses, and I remember the particular day that postdoc in my lab Rachanee [Cheingsong-Popov] came back from Paris with LAV. Thank you very much, Françoise [Barré-Sinoussi], because it was a Leap Day (February 29, 1984). It stuck in my [00:29:30] mind and the virus took off like a rocket. 

Here are two early papers of ours where Rachanee actually developed a serological assay, and we first looked at British patients. (40) This was published on September 1st, 1984. It's curious looking back at it that it was just another paper saying you can find [00:30:00] antibodies, but actually the numbers of samples in our papers was more than the CDC, NIH, and Institute Pasteur added together! We went in for high throughput and, we found that AIDS patients were positive, people with what the same called persistent generalized lymphadenopathy sort of pre-AIDS were positive. About one in three men and boys with hemophilia were positive and blood donors, [00:30:30] thousands, of them were negative. We thought, here we've got high specificity and high sensitivity. 

But then we looked at this new disease in Uganda, "slim disease." This is the introduction to our paper by David Serwadda (b. 1959, Ugandan physician and public health specialist), Nelson Sewankambo (b. 1952, Ugandan physician and medical researcher) in Mulago Hospital in Kampala. (41) It had all the signature features of AIDS. People thought it's probably is AIDS. We looked at [00:31:00] the serology there, yes, 100% positive, aggressive forms of Kaposi's sarcoma, 100% positive, but then we thought, Oh, well with African sera, the specificity isn't good enough, we're getting 10% false positives. This test isn't enough good in Africa. And then the penny dropped. They weren't false positives. The 10% of our sample population were already HIV positive [00:31:30]. That was not a very good evening when we realized that. 

And there was one more paper. (42) This is my second last, Julie [Overbaugh]. We published alongside a paper from Bob Gallo's lab, Marjorie Robert-Guroff (43) the first two reports of neutralizing antibodies to HIV. We compared neutralization of a [00:32:00] small set of HTLV infected patients against their virus and of HIV infected patients, and compare them to surface immunofluorescence and a competitive radio-immunoassay for gp120. You can see that both sets of patients with high titers of virus measured by these means, but whereas the HTLV patients have very high titers of neutralizing antibodies. It's barely there [00:32:30] in the AIDS patients.

Now, 30 years later, despite the exquisitely potent and broadly neutralizing monoclonal antibodies, envelope emissions still don't show much improvement over natural selection. Maybe I'll be persuaded to the contrary later in this meeting, but some as far as I'm concerned, in this field, I’m a “long-term non-progressor” [00:33:00] and [I’m] still in the same place as I was 31 years ago. Now, no research would be possible without funding and I'll stop there. Thank you.

[applause]

Steve Goff (moderator): Don't go away. Robin, thank you. We have time for just a few questions and then we'll get on, anyone, not many [00:33:30]. Maybe none. I haven't sign us the whole audience's questions. If not, we should-

Robin Weiss: Well, Alexander Fleming (1881–1955) gave his first talk on what he later called Penicillin before it was published, and there were no questions afterwards. He sat down and said, "Well, everything must have been crystal [00:34:00] clear.”

[laughter]

Steve: Fair enough.

[applause]

Steve: Robin, thank you.

[00:34:13] [END OF AUDIO]

Citations 

Index

• 1.5 John Coffin — The Origin of Molecular Retrovirology
• 1.7 Max Essex — From Feline Leukemia Virus to AIDS in Africa
• 2.2 James Curran — Deciphering the Epidemiology of AIDS
• 2.3 Mark Harrington — The Importance of Activism to the US Response 
• 2.4 Robert Gallo — Discoveries of Human Retrovirus, Their Linkage to Disease as Causative Agents & Preparation for the Future
• 2.5 Françoise Barré-Sinoussi — Discovery of HIV
• 4.3 Beatrice Hahn — Apes to Humans: The Origin of HIV
• 8.6 David Baltimore — Bringing it to an End (And Where Are We Going?)
• Achong, Bert Geoffrey (1928–1996)
• activism, civil rights, protests, and social movements
• Africa, sub-Saharan Africa
• analogy
• antibody test, antigen test, serological test, serology
• antibody, immunoglobulin (Ig)
• avian leukosis virus (ALV)
• Baltimore
• Bishop, Kate
• blood — banks, donors, plasma, screening, transfusions, clotting factors (factor VIII), PBMCs
• Caltech (California Institute of Technology)
• Caribbean and West Indies
• carrier, asymptomatic carrier
• cats
• CDC (Centers for Disease Control and Prevention, US)
• cell culture, tissue culture, immortalized cell line
• Cheingsong-Popov, Rachanee
• Chester Beatty Laboratories, Royal Marsden Hospital, London
• chicken
• chimpanzee (Pan troglodytes)
• classification, nomenclature, taxonomy
• Cold Spring Harbor Laboratory (CSHL)
• Cold Spring Harbor Laboratory Press
• Crawford, Lionel V. (b. 1932) and Elizabeth M.
• dogs
• dose response
• Dulbecco, Renato (1914–2012)
• early names for AIDS — gay cancer, gay pneumonia, GRID, 4H, KSOI, slim disease, etc.
• endogenous retrovirus (ERV)
• env
• epidemiology
• Epstein-Barr virus (EBV)
• Epstein, Michael Anthony "Tony" (b. 1921)
• equine infectious anemia virus (EIAV)
• feline immunodeficiency virus (FIV)
• feline leukemia virus (FeLV)
• Fleming, Alexander (1881–1955)
• fluorescent tag (fluorophore, fluorescent label, fluorescent probe, immunofluorescence)
• focus assay for Rous sarcoma virus
• foot and mouth disease virus (FMDV)
• funding and grants
• gag
• Garcia-Martinez, J. Victor
• Gartner, Suzanne
• gp120
• Griffiths, David J.
• Hall, Alan (1952–2015)
• hemophilia
• Heneine, Walid
• Hinuma, Yorio
• Holub, Miroslav (1923–1998)
• horse
• HTLV (human T-lymphotropic virus)
• humanized mouse
• Imperial Cancer Research Fund (ICRF)
• in vitro vs. in vivo
• internet
• Iron Curtain
• Japan
• Kampala
• Kenya
• Kitamura, Tsutomu
• Klatzmann, David
• koala
• lar gibbon (Hylobates lar)
• leukemia and lymphoma
• Levy, Jay A. (b. 1938)
• lymphadenopathy
• macrophage
• Marshall, Chris (1949–2015)
• McAllister, Robert M.
• memory
• mentoring
• microscope — electron and optical
• MMWR Morbidity and Mortality Weekly Report
• models (model systems, model organisms, modeling)
• monoclonal antibody
• monocyte
• Montagnier, Luc (b. 1932)
• Mulago National Specialised Hospital (Mulago Hospital)
• murine leukemia virus (MLV)
• Nanban trade (viagem do Japão)
• National Institutes of Health (NIH)
• natural selection, evolutionary selection, evolutionary fitness
• New England Journal of Medicine (NEJM)
• non-human primates
• nude mouse
• observation
• oncogene (onc)
• Paris
• parvovirus
• Pasteur Institute (Institut Pasteur)
• petri dish
• Pneumocystis pneumonia (PCP)
• pol
• political correctness
• Pollock, Ludmilla "Mila"
• poppers (amyl nitrate)
• Portugal
• Prague Spring, 1968
• pseudotyping, pseudovirus
• quail
• rabbit
• radionuclide, radiolabeling, radioactive tracer
• reading frame, open reading frame
• restriction factor
• retrovirus classification, subfamilies, and genera
• reverse transcriptase
• Rous sarcoma virus (RSV)
• Rous, Francis Peyton (1879–1970)
• Rubin, Harry (1926–2020)
• San Francisco
• scientific competition and collaboration
• scientific controversy and consensus
• scientific errors and mistakes
• scrapie
• sensitivity and specificity; false positive, false negative; biological specificity
• sequencing
• Serwadda, David M. (b. 1959)
• Session 1: The Story of Animal Retroviruses
• Session 6: Immunology and Prevention
• Session 8: Pathogenesis and Prospects
• Sewankambo, Nelson (b. 1952)
• sheep
• Sigurðsson, Björn (1913–1959)
• simian foamy virus (SFV)
• simian immunodeficiency virus (SIV)
• slavery
• Sonigo, Pierre
• Spiegelman, Sol (1914–1983)
• spillover, zoonotic disease, xenotropic virus
• Svoboda, Jan (1934–2017, Czech virologist)
• Takatsuki, Kiyoshi
• Temin, Howard M. (1934–1994)
• tobacco mosaic virus (TMV)
• transfection, transduction, viral vector
• tropism
• Uganda
• United Kingdom, Great Britain
• viral load
• viral reservoir, viral latency, disease reservoir
• Visna-maedi virus (VMV)
• Vogt, Peter K. (b. 1932)
• Voisset, Cécile
• Wain-Hobson, Simon
• Weinberg, Robert Allan "Bob" (b. 1942)
• Weissmann, Charles (b. 1931)
• Wigler, Michael H. (b. 1947)
• xenograft, xenotransplantation, heterologous transplant
• XMRV xenotropic murine leukemia virus–related virus
• Yohei, Ito