Virology Journal - Latest Comments

HPV Vaccination

Liam Fanning — 2009-09-08T00:00:00Z

Comment on paper in Sunday Times,
http://www.timesonline.co.uk/tol/news/world/ireland/article6736296.ece

Is this original?

Edward Rybicki — 2009-09-08T00:00:00Z

Dear Dr Murata;

we were very interested to read your recent paper in Virology Journal describing h4 insertions / replacements in HPV-16 L1 protein as a means of displaying heterologous peptides - especially as you chose this region because lack of it interferes with capsid formation and presents peptides well.

We were a little surprised, though, to see this in the abstract:

"HPV L1 monomers bearing heterologous epitopes within the L1 h4 region can self-assemble into capsomeres that elicit antibody response against such non-
HPV encoded epitopes. Thus, the L1 h4 region can function as a novel antigen display site within the L1 pentamer, which in turn may serve as a potential
vaccine template. "

and this in the Discussion:

"Because papillomavirus L1 protein-based oligomers (capsomeres and VLPs) can elicit a broad array of immune responses, they have been studied as potential
vaccine platforms (reviewed in [15]). Such efforts have primarily focused on placing heterologous epitopes on surface-displayed, genetically variable loops of L1 or at the carboxy-terminus of full-length or truncated L1. Since capsomeres are also immunogenic, we tested the hypothesis that the h4 domain of the L1 monomer, which projects laterally and outwards on L1 pentamers, can be used for antigenic display of foreign epitopes. We demonstrate that: 1) such antigen presentation is feasible and does not overtly affect the formation of capsomeres; 2) such capsomeres likely exists as monomeric capsomeres with some degree of aggregation noted; and 3) mice immunized with capsomeres bearing RSV F epitopes generate antisera that recognizes the purified F protein. Thus, we conclude that foreign epitopes embedded within the h4 domain can be immunogenic when presented in the context of capsomeres."

...given that a paper from our group in 2003 [Varsani et al., J Virol 77: 8386-8393, 2003] described much the same thing. We said then:

"The most immunogenic chimera overall was ChiF-L2, where the L2 epitope [L2 108-120] was presented in place of the h4 helix: this region (aa 414 to 426) is highly exposed in the atomic structure of HPV-16 L1 proposed by Modis et al. (24) and therefore probably highly immunogenic. Chimera ChiF-L2 bound all the neutralizing MAbs and induced a strong L1 and L2 epitope response. We suspect that the h4 helix in native VLPs forms important interactions and that altering this region prevents the formation of VLPs. Chen et al. (4) showed that deletion of the region aa 408 to 431 resulted in pentamer formation only; these observations support our finding that ChiF-L2 is only seen to form capsomers." [bold = my emphases]

Do you have any comment on this? As it is, your paper appears to reinvent a wheel already well described some 6 years ago!

Differences and similarities between our work and those of Varsani, et al. (J. Virol 2003: 77; 8386-8393)

Yoshihiko Murata — 2009-09-08T00:00:00Z

We do note that Varsani, et al. (J. Virol 2003: 77; 8386-8393) have previously engineered a single 13 aa neutralizing epitope from HPV 16 L2 protein within various regions of the HPV 16L1 protein. One of their L1 derivatives (ChiΔF-L2) bore the L2 epitope as a substitution of aa 414-426, which maps to the L1 helix 4 (h4) domain. As we have found with our capsomere derivatives, ChiΔF-L2 reacts slightly more strongly with H16:V5 mAb in ELISAs as compared to intact 16L1 VLPs. When injected into laboratory mice, ChiΔF-L2 was the most immunogenic among the various L1-L2 chimeras with respect to the L2 epitope and as assayed by immunoblots to detect reactogenicity against bacterially derived L2 protein; our findings confirm their assertion that h4 region is “probably highly immunogenic” (p. 8392). There are no data reported on the HPV pseudoneutralization capacities of the resulting sera.

However, our constructions differ from that of Varsani, et al. in that: 1) using baculovirus-derived L1 derivatives, we confirm previous results from bacterially derived L1 deletions that the removal of a larger portion of L1 (aa 404-436) results in capsomere formation; and 2) we demonstrate that the replacement of such a deletion with one of two neutralizing epitopes of varying length and predicted in-solution structure (aa 255-278, which forms a helix-coil-helix, and aa 423-436, a linear epitope) of the respiratory syncytial virus (RSV) fusion (F) protein also leads to capsomeres with some degree of aggregation as confirmed by sucrose gradient ultracentrifugation. Thus, we show that the larger h4 deletion that that used to generate ChiΔF-L2 can accommodate the presence of heterologous aa sequences with minimal to moderate ultrastructural perturbations of L1 capsomeres.

In generating our constructions, we removed the L1 Cys 428, which is involved in intercapsomeric disulfide bond formation and is retained in ChiΔF-L2. We also note that as compared to electron micrographs of our capsomere preparations, those of ChiΔF-L2 qualitatively appear to exhibit increased degree of aggregation (Figure 2, p. 8389); no assays of in-solution behavior of ChiΔF-L2 are presented. Such aggregation may be related to residual and potentially aberrant disulfide formation among L1 oligomers via Cys428 within each L1 monomer. Thus, in our current paper, we confirm and extend previous finding by Varsani, et al.

A simple but useful study

Saima Nazir — 2009-09-08T00:00:00Z

It seems a good study exploring the effects of commonly used disinfectants. Techniques looks quite simple but very effective as well. This study is also effective in mitigating the panic created by bird flu all over the world especially noticing the virucidal activity of Lifebuoy, a commonly used soap. I congratulate the authors for this useful study.

Poxvirus vectors

Bernard Moss — 2009-05-22T00:00:00Z

Okeke et al. caution against the extensive use of poxvirus vectors in general, and MVA in particular, because of the possibility of their recombining with naturally occurring poxviruses. It was well known, prior to the studies of Okeke et al., that deliberate infection of permissive cells with two orthopoxviruses could result in recombination. The important question is whether this is a significant risk in vivo. Fortunately, the experiment has already been done in a very rigorous manner with negative results. Replicating strains of vaccinia virus were given to millions of humans as the smallpox vaccine in smallpox endemic areas and no recombinants between variola (smallpox) virus and vaccinia virus have been reported; nor is there any evidence for this in the 49 variola virus isolates that have been completely sequenced. Indeed, vaccinia virus was routinely given to people who had already been infected by contact with smallpox patients. Surely, the opportunity for a non-replicating strain of vaccinia virus like MVA or another highly attenuated strain to recombine with a naturally occurring poxvirus would be far less than with the vaccine strains used in the past. If Okeke and collaborators wish to advance their hypothesis, as a worst-case scenario they should consider injecting MVA intramuscularly into a mouse and then infecting the mouse intranasally with cowpox virus.

Vaccination group different before vaccines started

Farrel Buchinsky — 2009-05-07T00:00:00Z

The papilloma sizes in the two groups (control vs. cotton tail rabbit papillomavirus virus-like particles) clearly had a very different course as depicted in Figure 1. Why was there a difference between the groups one week before vaccination (week 7) and a more stark difference at the time of commencing the vaccine (week 8). Does the difference increase the chance of the overall result being a false positive?

How does this rabbit paper relate to a similar study that was done in dogs? Kuntsi-Vaattovaara H et al. Resolution of persistent oral...[PMID: 19379331]pubmed link

Additional Information - Preventing Hepatitis C

Emma Millward — 2009-02-11T00:00:00Z

Ross (1999) reported that an estimated 8.3 million new cases of hepatitis B, 1.3 million cases of hepatitis C and 31,000 new cases of HIV have been caused by the reuse of disposable syringes.

Pointed equipment such as needles and similar instruments has been used in the medicine for thousands of years. Although uses for these types of instruments have become complicated the disposal of instruments per say has not evolved in a resultant way.

Hundreds of health-care workers are incur needle stick injury at work each day. By means of our current knowledge of how deadly and from time to time lethal infection is spread through using dirty needles, medical staff must be protected from this risk.

Please see this short article which recommends ways to prevent contracting Hepatitis B infection: and Needlestick Injuries.

Spread of avian flu by drinking water:

Dipl.-Ing. Wilfried Soddemann — 2008-05-12T00:00:00Z

Spread of avian flu by drinking water can explain small clusters in households

Proved awareness to ecology and transmission is necessary to understand the spread of avian flu. For this it is insufficient exclusive to test samples from wild birds, poultry and humans for avian flu viruses. Samples from the known abiotic vehicles also have to be analysed. There are plain links between the cold, rainy seasons as well as floods and the spread of avian flu. That is just why abiotic vehicles have to be analysed. The direct biotic transmission from birds, poultry or humans to humans can not depend on the cold, rainy seasons or floods. Water is a very efficient abiotic vehicle for the spread of viruses - in particular of fecal as well as by mouth, nose and eyes excreted viruses.

Infected birds and poultry can everywhere contaminate the drinking water. All humans have very intensive contact to drinking water. To prove viruses in water is difficult because of dilution. If you find no viruses you can not be sure that there are not any. On the other hand in water viruses remain viable for a long time. Water has to be tested for influenza viruses by cell culture and in particular by the more sensitive molecular biology method PCR.

There is a widespread link between avian flu and water, e.g. in Egypt to the Nile delta or Indonesia to residential districts of less prosperous humans with backyard flocks and without central water supply as in Vietnam: http://www.cdc.gov/ncidod/EID/vol12no12/06-0829.htm. See also the WHO web side: http://www.who.int/water_sanitation_health/emerging/h5n1background.pdf .

Transmission of avian flu by direct contact to infected poultry is an unproved assumption from the WHO. There is no evidence that influenza primarily is transmitted by saliva droplets: “Transmission of influenza A in human beings” http://www.thelancet.com/journals/laninf/article/PIIS1473309907700294/abstract?iseop=true .

Avian flu infections may increase in consequence to increase of virus circulation. In hot climates/the tropics flood-related influenza is typical after extreme weather and floods. Virulence of influenza viruses depends on temperature and time. Special in cases of local water supplies with “young” and fresh H5N1 contaminated water from low local wells, cisterns, tanks, rain barrels, ponds, rivers or rice paddies this pathway can explain small clusters in households. At 24°C e.g. in the tropics the virulence of influenza viruses in water amount to 2 days. In temperate climates for “older” water from central water supplies cold water is decisive to virulence of viruses. At 7°C the virulence of influenza viruses in water amount to 14 days.

Human to human and contact transmission of influenza occur - but are overvalued immense. In the course of influenza epidemics in Germany, recognized clusters are rare, accounting for just 9 percent of cases e.g. in the 2005 season. In temperate climates the lethal H5N1 virus will be transferred to humans via cold drinking water, as with the birds in February and March 2006, strong seasonal at the time when drinking water has its temperature minimum.

The performance to eliminate viruses from the drinking water processing plants regularly does not meet the requirements of the WHO and the USA/USEPA. Conventional disinfection procedures are poor, because microorganisms in the water are not in suspension, but embedded in particles. Even ground water used for drinking water is not free from viruses.

http://www.un.org/apps/news/story.asp?NewsID=26096&Cr=&Cr1

Ducks and rice [paddies = flooded by water] major factors in bird flu outbreaks, says UN agency

Ducks and rice fields may be a critical factor in spreading H5N1

26 March 2008 – Ducks, rice [fields, paddies = flooded by water! Farmers on work drink the water from rice paddies!] and people – and not chickens – have emerged as the most significant factors in the spread of avian influenza in Thailand and Viet Nam, according to a study carried out by a group of experts from the United Nations Food and Agriculture Organization (FAO) and associated research centres.

“Mapping H5N1 highly pathogenic avian influenza risk in Southeast Asia: ducks, rice and people” also finds that these factors are probably behind persistent outbreaks in other countries such as Cambodia and Laos.

The study, which examined a series of waves of H5N1 highly pathogenic avian influenza in Thailand and Viet Nam between early 2004 and late 2005, was initiated and coordinated by FAO senior veterinary officer Jan Slingenbergh and just published in the latest issue of the Proceedings of the National Academy of Sciences of the United States.

Through the use of satellite mapping, researchers looked at a number of different factors, including the numbers of ducks, geese and chickens, human population size, rice cultivation and geography, and found a strong link between duck grazing patterns and rice cropping intensity.

In Thailand, for example, the proportion of young ducks in flocks was found to peak in September-October; these rapidly growing young ducks can therefore benefit from the peak of the rice harvest in November-December [at the beginning of the cold: Thailand, Viet Nam, Cambodia, Laos are situated – different from Indonesia – in the northern hemisphere].

“These peaks in congregation of ducks indicate periods in which there is an increase in the chances for virus release and exposure, and rice paddies often become a temporary habitat for wild bird species,” the agency said in a news release.

“We now know much better where and when to expect H5N1 flare-ups, and this helps to target prevention and control,” said Mr. Slingenbergh. “In addition, with virus persistence becoming increasingly confined to areas with intensive rice-duck agriculture in eastern and south-eastern Asia, evolution of the H5N1 virus may become easier to predict.”

He said the findings can help better target control efforts and replace indiscriminate mass vaccination.

FAO estimates that approximately 90 per cent of the world’s more than 1 billion domestic ducks are in Asia, with about 75 per cent of that in China and Viet Nam. Thailand has about 11 million ducks.

Dipl.-Ing. Wilfried Soddemann - Epidemiologist - Free Science Journalist soddemann-aachen@t-online.de

Interesting paper for understanding emergence and reemergence of viruses

Anupam Varma — 2008-05-12T00:00:00Z

I congratulate the authors for their very nice findings. This topic is of agreat interest to a forthcoming international conference on emerging and reemerging viruses to be held in Delhi from Dec 11 to 14, 2007. It is a great pleasure for me to invite the authors of this paper to participate in the conference. The conference is being organized by the Indian Virological Society (www.icvt07delhi.org.

Anupam Varma

Conference Chair

The title is accurate and succinct

Suraiya Rasheed — 2007-04-17T00:00:00Z

The first most comprehensive analysis of an amphotropic murine leukemia virus (MuLV) from a Southern California feral mouse. These are the only naturally occurring MulV’s that can replicate well in a wide range of cells including, murine, avian and primate/ human cells in vitro.