A Short History of the Discovery of Viruses – Part 3

29 January, 2015

Phages, Cell Culture and Polio

The Phage Group and the birth of molecular biology

Some of the more fundamental discoveries in modern biology were facilitated either by the study of viruses, or by use of viruses as tools for exploring host cell mechanisms.  The foundations for this work were laid by Felix d’Hérelle and others, working after 1917 with bacterial viruses in cultured bacteria.  Indeed, Macfarlane Burnet’s first important work was in 1929, showing by use of plaque counting that a single bacterial cell infected with a single phage produced 20 – 100 progeny some 20 minutes following infection.  The fact that phages adsorbed irreversibly to their hosts as part of the infection process was shown by AP Krueger and M Schlesinger in 1930 – 1931.  Schlesinger later showed between 1934 and 1936 that the bacteriophage he worked with consisted of approximately equal amounts of protein and DNA, the first proof that viruses might be nucleoprotein in nature.

However, it took until 1939 for the former physicist Max Delbrück, working with the biologist Emory Ellis at Caltech, to elucidate the growth cycle of a sewage-isolated Escherichia coli bacteriophage in a now-classic paper simply entitled “The Growth of Bacteriophage”.  This used the simple technique of counting plaques in a bacterial lawn in a Petri dish, following infection of a standard bacterial inoculum with a dilution series of a phage preparation.

Their principal finding was that viruses multiply inside cells in one step, and not by division and exponential growth like cells.. This was determined using the so-called “one-step growth curve”, which allowed the accurate determination of the titres of viruses released from bacteria that had been synchronously infected.  This allowed calculation of not only the time of multiplication of the virus, but also the “burst size” from individual bacteria, or the number of viruses produced in one round of multiplication.  This was a fundamental discovery, and allowed the rapid progression of the field of bacterial and phage genetics

Indeed, Wolfgang Joklik wrote in 1999:

Conceptualization of the one-step growth cycle completely changed virology. From then on, populations of host cells were infected with multiplicities greater than 1 infectious unit per cell, which meant that infection was synchronous and that virus replication was amenable to biochemical and, therefore, molecular analysis. This study represents the beginning of molecular virology, molecular biology, and molecular genetics.”

One important facet of this work was that it showed that infection could be caused by single phages: the power of the plaque assay meant that even dilutions of phage preparations that contained only a single particle could produce a detectable plaque.

The Phage Group was started in the 1940s after Delbrück and Salvador Luria – also famous for inventing the Luria broth used to this day to grow bacteria –  met at a conference.  They soon began to collaborate, and in 1943 published the famous Luria–Delbrück experiment or Fluctuation Test: this showed that resistance to phage infection in bacteria could arise spontaneously and without selection pressure.  This was fundamental to understanding bacterial evolution and the development of antibiotic resistance in particular.

Also in 1943, they added Alfred Hershey to the group.  An important early result of their joint work was the proof that co-infection of one bacterium with two different bacteriophages could lead to genetic recombination, or mixing of the phage genomes. 

Hershey and his assistant Martha Chase subsequently went on in 1952 to perform the legendary Hershey-Chase experiment in order to prove whether or not DNA was the genetic material of the phage: this purportedly used a new high speed Waring blender Hershey had purchased for his wife, but which never made it to her.  This was published as “Independent Functions of Viral Protein and Nucleic Acid in Growth of Bacteriophage“, and essentially cemented the central role of DNA as the material of heredity.

The Hershey-Chase Experiment

Building on an observation by RM Herriott in 1951 that phage “ghosts”virus particles that had lost their DNA due to osmotic shock – could still attach to and lyse their target bacteria, they grew up preparations of the E coli bacteriophage T2 separately in the presence of the radioisotopes 35S and 32P, to label the protein and nucleic acid components of the phage respectively.  They confirmed the earlier observations by showing that “plasmolysed” phage ghosts retained nearly all of the 35S and the ability to bind to phage-susceptible bacteria and bind phage-specific antibodies, while the free DNA fraction retained nearly all of the 32P, which was DNAse-susceptible, unlike DNA in intact phages.  Their conclusion was that:

The ghosts represent protein coats that surround the DNA of the intact particles, react with antiserum, protect the DNA from DNase…, and carry the organ of attachment to bacteria”.

However, their most exciting result was achieved by investigating whether “…multiplication of virus is preceded by the alteration or removal of the protective coats of the particles”.  They did this by allowing adsorption of phages to bacteria in liquid suspension for different times, then shearing off adsorbed phage particles from the bacteria using the blender.  Pelleting the bacteria by centrifugation and assaying radioactivity allowed them to determine that over 75% of the 35S – incorporated into cysteine and methionine amino acids – remained in the liquid, or outside the bacteria, whereas over 75% of the 32P – incorporated into the phage DNA – was found inside the bacteria.  They concluded that:

“…the bulk of the phage sulfur remains at the cell surface during infection, and takes no part in the multiplication of intracellular phage. The bulk of the phage DNA, on the other hand, enters the cell soon after adsorption of phage to bacteria.”

Subsequent production of phage from the infected bacteria that contained next to no radioisotope-labelled protein, but did contain labelled DNA, showed that DNA was probably the genetic material, and that protein was not involved in phage heredity.

Aside from their ground-breaking discoveries, the main influence of the Phage Group was felt via their establishment of the yearly summer phage course at Cold Spring Harbor Laboratory. From 1945 through to the 1960s, Delbrück and colleagues taught the fundamentals of bacteriophage biology and experimentation to generations of biologists, which helped to instill a culture of rigorous mathematical and analytical techniques in attendees – many of whom went on to help establish the emerging field of molecular biology.

Indeed, not only did Delbrück, Luria and Hershey receive the 1969 Nobel Prize for Physiology or Medicine for their work on bacteriophages, but Luria’s first graduate student James Watson was also awarded the prize in 1962 for his work with Francis Crick on elucidating the structure of DNA.  It is a not particularly well known fact that Watson honed his analytical skills for 3-D reconstructions from X-ray data of DNA with data from TMV, which he helped to show had helical virions.

Animal cell culture

Possibly the most important development for the study of animal viruses since their discovery was the growing of poliovirus in cell culture: this was reported in 1949 by John Enders, Thomas Weller and Frederick Robbins from the USA, and was rewarded with a joint Nobel Prize to them in 1954.  They did this around the same time as David Bodian and Isabel Morgan identified three distinct types of poliovirus.

In the words of the Award Ceremony presentation speech,

“The use of cultures of human tissues has permitted attacks on many virus problems previously out of reach because of the lack of susceptible laboratory animals. Already at an early stage Enders, Weller and Robbins discovered agents representing a previously unknown group of viruses. Other scientists have systematically pursued this line and the answer to the question of the causes of a number of common-coldlike diseases now seems to be at hand. Weller has succeeded in cultivating the agents causing varicella and herpes zoster, Enders that of measles, viruses previously almost inaccessible for study. The method has also been successfully applied to several problems in the field of veterinary medicine.”

While both bacterial and plant viruses could be both grown and assayed in “culture” – bacterial cells for phages, and plants for viruses like TMV – it was very difficult to grow and work with animal viruses, and especially to assay them, or measure their concentration.  While the pock assay done on egg membranes for influenza virus was very useful, it was not applicable to many viruses.  Indeed, people working with animal and human viruses were envious of the advantages enjoyed by their colleagues working with bacteriophages and plant viruses, because their assay systems were far more generally useful, even if local lesion assays on leaves for plant virus were limited compared to the precision obtainable for bacteriophages using pure cultures of bacterial cells on Petri dishes.  Titration or assay of poliovirus, for example, required the injection of virus preparations into the brains of monkeys, or later, in the case of the Lansing or Type II poliovirus strain, into brains of mice.

The technological advances that led to the breakthrough were incremental, and in fact had occurred over a period of over sixty years: Wilhelm Roux is credited with creating the first “tissue culture” with animal cells, by maintaining extracts of chicken embryos in warmed saline in 1885.  Other early workers had used minced-up chick embryos as far back as the early 1900s; roller-tube cultures had been in use for some time for studying viruses; a number of human and other tissues had been used to culture viruses.  Part of the development was, however, the increased ease of making the necessary reagents, such as ultrafiltered bovine serum, and a greater understanding of the requirements of cells for successful growth in culture.  Another major enabling factor was the post-Second World War availability of antibiotics, which meant contaminating microorganisms could be killed in culture – which had been impossible previously.

Enders, Weller and Robbins started with a suspended cell culture of human embryo skin and muscle tissue – a technique first described in 1928 – with the idea of studying varicella zoster herpesvirus.  However, in a case of chance favouring the prepared mind(s), the proximity of these tissue cultures and the Lansing strain of poliovirus in the same lab led to them using this instead, as part of an effort to determine whether all polioviruses exclusively multiplied in human nervous tissue.

Their cultures were started by inoculation with a suspension of infected mouse brains, and re-inoculation of mice with tissue culture fluids demonstrated that the virus was multiplying.  Injection of fluid into monkey brains after three passages of tissue culture resulted in typical symptoms of paralysis.  Later, Types I and III poliovirus were also successfully cultured – and suspended cell cultures of intestine, liver, kidney, adrenals, brain, heart, spleen, lung and brain derived from human embryos were also found to support growth of various polioviruses.

Renato Dulbecco in 1952 adapted the technique to primary cultures of chicken embryo fibroblasts grown as monolayers in glass flasks.  Using  Western equine encephalitis virus and Newcastle disease virus of chickens, he showed for the first time that it was possible to produce plaques due to an animal virus infection, and that these could be used to accurately assay infectious virus titres.  He and Marguerite Vogt went on in 1953 to show the technique could be used to assay poliovirus – and went on to show that the principle of “one virus, one plaque” first established with phages, and later to plant viruses, could be extended to animal viruses too.

Adaptation of the culture technique to roller-tubes allowed higher yields of virus – and the possibility of direct observation of the effects of virus multiplication on large sheets of cells, rather than in clumps and pieces of tissue from suspension cultures.  These effects were termed “cytopathogenic” (now generally cytopathic) for the direct damage and morphological changes to cells that could be seen and measured, and roller-tubes made it far easier and quicker to do this by simple staining of cultures with various reagents such as haemotoxylin and eosin.

adeno haema

The technique of looking at cells for cytopathic effects (also abbreviated as CPE) quickly found application in assays of infectivity – and therefore of concentration – of poliovirus preparations.  It was also possible to do neutralisation assays with immune human sera.  There was also the observation that passaging the Lansing strain through cell suspensions reduced its virulence in mice, and similar passage of Type I poliovirus significantly reduced virulence in rhesus macaques.  These developments together were part of the advances that led to the development of live poliovirus vaccines soon afterwards.

The development of polio vaccines

Poliomyelitis – the disease caused by polioviruses – became increasingly common as population densities grew, to the point where in the the USA in 1952, there were 58 000 cases of the disease, compared to 20 000 normally – and up to 500 000 people (mainly children) died worldwide

A failed attempt at producing a vaccine in 1936 by a Maurice Brodie involved the use of ground-up infected monkey spinal cords to produce a formaldehyde-killed vaccine: Brodie tested the vaccine on three thousand children, none of whom developed immunity.  Hilary Koprowski in 1948 tested a live type II poliovirus attenuated by passage in rat brains, on himself and a colleague – with no ill effects, but no test of immunogenicity or efficacy.  In 1950 he went on to test the vaccine on 20 children in a home for the disabled, with positive results for immunogenicity.  It is claimed that Albert Sabin’s live attenuated virus (see below) was supplied by Koprowski; however, events overtook him and the other groups supplied the viruses that have been used to largely eradicate the disease, even though Koprowski went on to do huge clinical trials in Africa.

It took the development of cell culture techniques for poliovirus, the finding that there were three distinct types of the virus, as well as the proof in 1953 that immune globulins alone could protect against infection, to enable the successful development of vaccines still used today.  This is very well documented elsewhere; this account will summarise the most important features of the development.

Inactivated polio vaccines

The 1952-1953 polio epidemics in the US led to major public concern, and national efforts to develop vaccines.  Jonas Salk and his team at the University of Pittsburgh.  They produced virulent poliovirus types 1, 2 and 3 in culture in monkey kidney-derived Vero cells, and then used formaldehyde to inactivate the viruses to create an injectable vaccine.   After trials in animals proved that the “Inactivated Poliovirus Vaccine” or IPV was safely killed, it was trialled from 1954 in what was possibly the biggest medical experiment in history, involving 1.8 million children in the US.  By 1955 it was possible to announce that IPV was 60–70% effective against poliovirus type 1, and over 90% effective against types 2 and 3.  The vaccine was licenced in 1955, and immediately used in campaigns for vaccination of at-risk children.  

See heat map showing the number of cases of polio per 100 000 people across the USA.  Copyright Wall St Journal, 2015.

While the vaccine did not in fact prevent infection by the virus – which infects the gastrointestinal tract via the oral route – it prevented disease by means of eliciting a largely IgG-dependent circulating antibody response, which neutralised any virus entering the circulatory system and thus prevented viraemia and subsequent involvement of the nervous system.  This means that it is an excellent vaccine to use as an end-stage weapon in the fight against polio, as unlike the live attenuated vaccine, there is no “shedding” of live virus.

Attenuated live polio vaccines

While others (including Koprowski) were involved in attempting to develop attenuated live vaccines, it was Albert Sabin’s trivalent live attenuated vaccine that was eventually successful.  This was developed by repeated passage in animal and then cell culture, that resulted in the effective abolition of neurovirulence of all three poliovirus types – accompanied by a significant number of mutations in the viral genomes.  After a successful safety trial in institutionalised children in the US in 1954, Sabin worked closely with scientists and the authorities in the former USSR, and in particular Mikhail Chumakov, to first manufacture the vaccine, then to perform large-scale clinical trials between “…1955 and 1961, [when] the oral vaccine was tested on at least 100 million people in the USSR, parts of Eastern Europe, Singapore, Mexico, and the Netherlands”.  While the US was initially reluctant to use the vaccine, the Russian-made product was distributed worldwide, and rapidly usurped the dominance of IPV.  By 1963, however, the trivalent product was licenced in the US, and from 1962-1965 about 100 million doses were used.

Advantages of the “Oral Polio Vaccine” or OPV were that it could be given much more easily – as droplets, into the mouth – that it multiplied efficiently in the gut, meaning doses could be small, but not in nervous tissue so that it caused no disease, and that it elicited mucosal immunity that could prevent infection as well as disease.

Disadvantages of the live vaccine are that it requires a cold chain for transport, otherwise it loses infectivity; that it can be shed in stools by vaccinees, meaning that uncontrolled community spread is possible.  This can result in vaccine-associated paralytic poliomyelitis, either due to reversion of the vaccines to virulence by mutation, or more rarely because of immune deficiencies  in those exposed.  Because of this, and the possibility of persistence of vaccine strains in populations even in the absence of overt disease, the final stages of poliovirus eradication probably require use of IPV in areas where there is no longer any endemic wild-type poliovirus.

While there have been serious concerns about contamination of poliovirus vaccines with live SV40 virus – a known tumour-causing agent – the consensus opinion appears to be that there is no danger.

The rapid development of human virology

These observations also quickly found application with a wide variety of other human and animal viruses, which triggered an explosion in these fields that led to them rapidly overtaking plant and bacterial virology in terms of understanding how the viruses replicated, and developing assays and vaccines for them.  Indeed, the poliovirus work was rapidly followed in the same lab by the isolation of herpes zoster and herpes simplex viruses; the agent of measles was characterised by Thomas Peebles and Enders via tissue culture by 1954; adenoviruses were discovered in 1953 by Wallace Rowe and Robert Huebner and shown to be associated with acute respiratory disease soon afterwards, by Maurice Hilleman and others.

Click here for Part 1: Filters and Discovery

here for Part 2: The Ultracentrifuge, Eggs and Flu

and here for Part 4: RNA Genomes and Modern Virology

Copyright Edward P Rybicki and Russell Kightley, February 2015, except where otherwise noted.

Ebola virus mutating, scientists say

29 January, 2015

Scientists at the Institut Pasteur in France who are tracking the Ebola outbreak in Guinea say the virus has mutated.

Source: www.bbc.com

I would be surprised it there weren’t evidence by now of adaptation to humans: never in any previous outbreak of EHD [Ebola haemorrhagic disease] has the person-person chain of transmission been sustained for so long, meaning never before has there been the opportunity for human-specific adaptations to become established.

The article points out that on consequence of mutation may be that the virus becomes less virulent, leading to a greater incidence of asymptomatic infection – of which there is already evidence from previous outbreaks, and which has been implicated in the lessening incidence of transmission because of increasing herd immunity.

However, this same property might lead to increased transmission to the non-exposed, because of a lack of signs that contacts with the infected person(s) should be avoided – and for a disease as lethal as EHD, even a reduced mortality rate still means you should avoid it at all costs.

The idea of developing a modified live measles virus vaccine as an Ebola virus vaccine vector, which is what the Institut Pasteur is apparently doing, seems to be a very good one.  Measles is still a major potential problem in that part of the world, necessitating regular infant immunisations, and coupling anti-measles with an anti-Ebola vaccine in those countries is probably very good use of both a proven vaccine and existing EPI infrastructure.

 

See on Scoop.itVirology News

First Ebola case linked to bat play – really?

30 December, 2014

The Ebola victim who is believed to have triggered the current outbreak – a two-year-old boy called Emile Ouamouno from Guinea – may have been infected by playing in a hollow tree housing a colony of bats, say scientists.

They made the connection on an expedition to the boy’s village, Meliandou.

They took samples and chatted to locals to find out more about Ebola’s source.

The team’s findings are published in EMBO Molecular Medicine.

Source: www.bbc.co.uk

Really??  Kids played in a hollow tree where bats USED to be – and the bats in which no-one can find Ebola, are the source of the epidemic? Really??

Now even for one who is prepared to believe the worst of bats – which I am; I am on record as calling them fabulous furry flying cockroaches – the evidence here is VERY thin.

Consider the facts in evidence: 

"Villagers reported that children used to play frequently in the hollow tree"

"Emile – who died of Ebola in December 2013 – used to play there, according to his friends."

"The villagers said that the tree burned on March 24, 2014 and that once the tree caught fire, there issued a "rain of bats""

"A large number of these insectivorous free-tailed bats …were collected by the villagers for food, but disposed of the next day after a government-led ban on bushmeat consumption was announced."

"{While] The scientists …were unable to test any of the bushmeat that the villagers had disposed of, they captured and tested any living bats they could find in and around Meliandou."

"No Ebola could be detected in any of these hundred or so animals, however."

"But previous tests show this species of bat can carry Ebola."

So – the chain of logic goes: 

– Kids played in a tree

– One kid got Ebola

– Bats lived in the tree

– Those bats can be infected with Ebola

– Therefore the one kid was infected by those bats.

Really??  You would convict a whole community of bats for that, IN THE ABSENCE OF ANY EVIDENCE they ACTUALLY carried Ebola??

This is thin – very, very thin.  I am also quite happy to believe the Ebola outbreak started with bats, BUT this proves nothing.  More evidence, less hype!!

See on Scoop.itVirology News

2014 in review: ViroBlogy

30 December, 2014

The WordPress.com stats helper monkeys prepared a 2014 annual report for this blog.

Here’s an excerpt:

The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 31,000 times in 2014. If it were a concert at Sydney Opera House, it would take about 11 sold-out performances for that many people to see it.

Click here to see the complete report.
SO we’re doing alright, then?? Thanks for reading – here’s to a great 2015!

More Surprises in the Development of an HIV Vaccine

14 November, 2014

More Surprises in the Development of an HIV Vaccine

In the current issue of Frontiers in Immunology, Jean-Marie Andrieu and collaborators, report results from non-human primate experiments designed to explore a new vaccine concept aimed at inducing tolerance to the simian immunodeficiency virus (SIV) (1). This approach, which is significantly different from other vaccine concepts tested to date, resulted in a surprisingly high level of protection. If the results are confirmed and extended to the human immunodeficiency virus (HIV), this approach may represent a game changing strategy, which should be welcomed by a field that has been marred by mostly disappointing results.

 

HIV Graphic from Russell Kightley Media

 

Source: journal.frontiersin.org

This is a commentary by two well-respected friends of mine on a very surprising result published by the Andrieu group recently, which seems to have been ignored by the mainstream HIV vaccine world.

This is not surprising, in that Andrieu is an outsider in this field – he is a cancer researcher – but is typical of the disappointing tendency in science to ignore contributions from outside the various "Golden Circles" that exist for various specialties.

Something that should elicit interest, though, is that this group has shown that a previously obscure 

"…population of non-cytolytic MHCIb/E-restricted CD8+ T regulatory cells [that] suppressed the activation of SIV positive CD4+ T-lymphocytes".

This is interesting because Louis Picker’s groups’ recent findings, announced at the recent HIVR4P conference in Cape Town, highlighted the involvement of MHC-E proteins in what amounted to a cure of SIV infection in macaques by a modified Rhesus cytomegalovirus (RhCMV) HIV vaccine vector (see here: http://www.iavireport.org/Blog/archive/2013/09/13/cmv-based-vaccine-can-clear-siv-infection-in-macaques.aspx). 

I tweeted at the time:

"Universal MHC-E-restricted CD8+ T cells – break all the rules for epitope recognition"

Could this be a link between the two mechanisms – both from way outside the orthodoxy, I will point out?

It will be interesting to see.

See on Scoop.itVirology News

Ethical dilemma for Ebola drug trials

13 November, 2014

Public-health officials split on use of control groups in tests of experimental treatments.

With clinical trials of experimental Ebola treatments set to begin in December, public-health officials face a major ethical quandary: should some participants be placed in a control group that receives only standard symptomatic treatment, despite a mortality rate of around 70% for Ebola in West Africa?

Two groups planning trials in Guinea and Liberia are diverging on this point, and key decisions for both are likely to come this week. US researchers meet on 11 November at the National Institutes of Health (NIH) in Bethesda, Maryland, to discuss US-government sponsored trials. A separate group is gathering at the World Health Organization (WHO) in Geneva, Switzerland, on 11 and 12 November to confer on both the US effort and trials organized by the WHO with help from African and European researchers and funded by the Wellcome Trust and the European Union.

Source: www.nature.com

I have to say – faced with a deadly disease, I think it is UNethical to have control / placebo arms of any trial.

Seriously: what about comparing ZMapp and immune serum, for example, with historical records of previous standard of care outcomes rather than directly?

I know if I were an Ebola patient, and I saw someone else getting the experimental therapy and I didn’t, that I would have a few things to say.

It’s not as if these therapies have not been tested in primates, after all – in fact, both the ChAd3 and MVA-based vaccines and ZMapp have been thoroughly tested in macaques, as have the other therapeutics, with no adverse events there.

I say if people say clearly that they want an experimental intervention, that they should get one: after all, the first use of immune serum was not done in a clinical trial, but rather as a last-ditch let’s-see-if-this-works intervention – yet its use does not seem controversial?

See on Scoop.itVirology News

Genetic Data Clarify Insect Evolution

13 November, 2014

Researchers create a phylogenetic tree of insects by comparing the sequences of 1,478 protein-coding genes among species.

Using an unprecedented quantity of genetic sequence information from insects, researchers have assembled a new phylogenetic tree showing when these invertebrates evolved and how they are related to each other. The tree suggests that insects evolved approximately 479 million years ago, around the time when plants colonized land, and that insects are most closely related to cave-dwelling crustaceans. The new study, published today (November 6) in Science, also confirms some previously suspected family groupings.

 

Source:

This bolsters my contention that it was the coevolution of insects and plants – because what else were insects going to eat? – that has driven much of viral evolution as well.

Because what else was there to infect? Basically, the only terrestrial organisms around some 450 million years ago were primitive green plants, insects, fungi and bacteria. So insects ate plants, fungi infected plants, viruses in insects entered plants and vice-versa; fungi got involved as well, and possibly even bacteria.

I have speculated on the possibilities here (http://www.mcb.uct.ac.za/tutorial/virorig.html), but it is pleasing to see new science that reinforces some of what I have been spreading about for some years now B-)

See on Scoop.itVirology and Bioinformatics from Virology.ca

Virology Africa 2015: consider yourselves notified!

7 November, 2014

Dear ViroBlogy and Virology News followers:

Anna-Lise Williamson and I plan to have another in our irregular series of “Virology Africa” conferences in November-December 2015, in Cape Town.

As previously, the conference will run over 3 days or so, possibly with associated workshops, and while the venue is not decided, we would like to base it at least partially in the Victoria & Alfred Waterfront.

We also intend to cover the whole spectrum of virology, from human through animal to plant; clinical aspects and biotechnology.

We intend to make it as cheap as possible so that students can come. We will also not be inviting a slate of international speakers, as we have found that we always get quite an impressive slate without having to fund them fully.

It is also the intention to have a Plant Molecular Farming workshop – concentrating on plant-made vaccines – concurrently with the conference, in order to leverage existing bilateral travel grants with international partners. If anyone else has such grants that could be similarly leveraged, it would be greatly appreciated.

See you in Cape Town in 2015!

Ed + Anna-Lise

The virus as art: Linda Stannard’s electron micrographs made colourful

3 November, 2014

Dr Linda Stannard was a virologist and electron micrsocopist of some repute, here at the University of Cape Town, when she retired some years back. She worked on a lot of interesting viruses, thanks to the diagnostic Virology lab at UCT’s Medical School as well as an eclectic mix of colleagues, and managed to create some stunning images of everything from TMV to poxviruses, herpesviruses, poliovirus, rotavirus, hepatitis B and adenoviruses.
IMG_0731.PNG
Then she retired – and took her image collection with her, to be recycled as imaginative colorised versions for commercial purposes.
So Anna-Lise Williamson commissioned her to beautify the rather sterile environs of the Institute of Infectious Disease and Molecular Medicine (IDM), with the results that you see below. Her corridor and offices now look rather nice!

IMG_0725.JPG

IMG_0728.JPG

IMG_0726.JPG

IMG_0727.JPG

IMG_0679.JPG

We are opening a competition to name each virus: winner to get the satisfaction of knowing they’re smart.

ZMapp in an HIV context

30 October, 2014

It was truly a pleasure to run into Kevin Whaley of Mapp BioPharmaceutical today, here at the HIVR4P inernational conferrence in Cape Town – so I made him come and have coffee with me and Anna-Lise, so we could chat about molecular farming.
Of course, it is the ZMapp plant-made therapeutic antibody that has set the molecular farming world alight, that was the main topic. Apparently Mapp is looking at a January 2015 date for a clinical trial in the affected West African countries, alongside the adenovirus and RSV-vectored vaccines. The plants for the production of the thousands of doses that will be needed – and recall, that’s a couple of grams per dose at 50 mg/kg – are already growing at Kentucky Bioprocessing in Louisville, so one imagines that a pile of work will be coming their way in the near future.
It’s also sobering to realise that even though plants ARE a more scalable and POTENTIALLY cheaper means of production of biologics, that therapeutic antibody production in particular, MAY be better suited right now to conventional technologies, such as CHO cell or even fungal production.
This is because large quantities of MAbs will be needed, and there is established capacity for production of hundreds of thousands of litres of cell culture right now, and yields and production costs have been driven right down to US$10 / gram for MAbs already, according to Kevin.
This partly answers a question I had during the HIVR4P sessions: if one is to use 20-50 mg/kg dosages for anti-HIV neutralising MAbs such as VRC01, how would it be remotely possible to make the amounts required for use in a developing country setting, where the patient can almost definitely NOT pay?
I still think there is a role for plants – but maybe this will be in the area of prophylactic use of MAbs, where much lower doses may be effective because there is not nearly as much virus to neutralise or inactivate.
And of course, Mapp is involved here too, with plant-made VRC01 in particular being incorporated into microbicides.
A great bunch of people, with really noble aims.


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