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  • LIAI completes world's most comprehensive analysis on influenza virus data

    http://www.eurekalert.org/pub_releas...-lcw122606.php

    Study will help international scientific community combat seasonal and avian flu strains

    SAN DIEGO ? (January 1, 2007) Researchers from the La Jolla Institute for Allergy & Immunology (LIAI) announced today the results of a first of its kind study analyzing all published data worldwide on influenza A virus antibody and T cell epitopes. Antibody and T cell epitopes are small sites on a virus that are the targets of the immune response, and they are critical for developing therapies and vaccines to combat infectious disease.

    The study, using information from a worldwide research database funded by the National Institute of Allergy and Infectious Diseases (NIAID), one of the National Institutes of Health (NIH), provides an important tool for scientists seeking to develop vaccines and therapies against both seasonal and pandemic influenza strains, including the deadly H5N1 avian flu.

    "This study shows what is currently known about influenza A virus epitopes -- what are the areas that are well covered in the current research and where are the holes in our knowledge," said Alessandro Sette, Ph.D., director of LIAI's Center for Infectious Disease and one of the study's authors. "From this information, the scientific community can determine areas where focus is needed going forward."

    The findings are being published online this week in a paper, "Antibody and T Cell Epitopes of Influenza A Virus ? Knowledge and Opportunities" in the journal Proceedings of the National Academy of Sciences USA. LIAI researcher Huynh-Hoa Bui, Ph.D., was lead author on the paper.

    The study looked at all scientific data on influenza A virus antibody and T cell epitopes published to date worldwide, drawing from the NIAID's Immune Epitope Database, a new worldwide scientific resource that went public last summer. LIAI researchers developed the database ? which is the world's largest repository of scientific data on how the body's immune system responds to infectious agents -- under a $25 million contract awarded by the NIAID in 2004.

    The database places particular emphasis on emerging infectious diseases, such as West Nile virus, along with those diseases considered potential bioterrorist threats. The database's influenza research was analyzed first due to the continuing problem of seasonal influenza and public health concerns over the possible spread of the H5N1 avian flu.

    "The database marks the first time that all known antibody and T cell epitope information has been compiled in one place," said Sette, noting the searchable online database is freely available to scientists around the globe. "It gives researchers ways of sharing knowledge and information never available before. Previously, everyone did their own study, but would have no way of knowing if a particular epitope had been used one time, for example by a single individual responding to a single virus, or 100 different times. Now, scientists can search the database and find out all existing information on their particular topic. This will enable them to avoid unnecessary repetition and make faster progress toward new therapies and vaccines."

    The database, publicly accessible at http://immuneEPITOPE.org, includes information culled from more than 100,000 separate research articles published over several decades, with the influenza information representing only a portion of the massive data set. "The influenza data shows that people have done a lot of work that gives important information as to how we respond to influenza virus," said Stephen Wilson, Ph.D., LIAI chief technology officer and project director of the database. "It also highlights those critical areas where we need to look further. The fact that we don't have a comprehensive vaccine for flu shows we have more work to do. This study shows us where we need to focus going forward."

    For the influenza study, LIAI researchers analyzed information from 58 different influenza A virus strains, involving 600 different antibody and T cell epitopes. In particular, the LIAI scientists identified epitopes that were similar in many influenza strains. "This is important because the influenza virus continually changes requiring scientists to develop a new vaccine every year," Sette said. "If we can find shared epitopes, it may be possible to develop an influenza vaccine with greater cross protection for many different viruses." Sette said the study found hundreds of similar epitopes among the different virus strains. However, it remains to be seen whether these epitopes are similar enough to enable the successful development of a highly cross reactive influenza vaccine that would protect against many viruses. And, in fact, the study found only one epitope that has been published, which appears to be an ideal candidate for creating a multi-strain influenza vaccine.

    Regarding gaps in knowledge of the way people respond to influenza, Wilson said two significant points emerged. "One concern is that most of the current influenza research is based on strains maintained in the lab, rather than wild influenza strains. Since we know the virus mutates, research needs to be done using influenza strains currently circulating in the population, so-called 'wild' strains, rather than using strains propagated in the lab. "

    Secondly, Wilson noted that the analysis showed that most of the detailed studies were done in animal models, primarily mice, with very little data coming from studies with humans or birds. Only one of the antibody epitopes came from a human. "This is understandable given the ethical and health issues of testing a potential pathogen in humans," Wilson said.

    "However, based on this information, I think the research community will pursue data directly relevant to human immunity to influenza virus to close those critical gaps."

    Regarding the dreaded H5N1 avian flu specifically, the information showed some important H5N1 epitopes currently being investigated. However, the number represented only a few of the 600 influenza virus epitopes in the database. "Given the concerns among the worldwide health community about this virus, I think this data gives timely assistance to much needed research in this area," Wilson said. He noted that such information is extremely valuable and shows how important the database can be for all researchers in determining their future research plans. "This study focused on influenza because it is a major illness that kills 36,000 Americans each year and global concerns over the possible spread of the H5N1 avian flu. In the future, database information on other infectious diseases can also be analyzed and used to good effect."

    ###

    About LIAI Founded in 1988, the La Jolla Institute for Allergy and Immunology is a nonprofit medical research center dedicated to increasing knowledge and improving human health through studies of the immune system. Scientists at the institute carry out research searching for cures for cancer, allergy and asthma, infectious diseases, and autoimmune diseases such as diabetes, inflammatory bowel disease and arthritis. LIAI's research staff includes more than 100 Ph.Ds.

    .
    "The next major advancement in the health of American people will be determined by what the individual is willing to do for himself"-- John Knowles, Former President of the Rockefeller Foundation

  • #2
    Re: LIAI completes world's most comprehensive analysis on influenza virus data

    Have any of you scientist-types tried out the above online database?

    .
    "The next major advancement in the health of American people will be determined by what the individual is willing to do for himself"-- John Knowles, Former President of the Rockefeller Foundation

    Comment


    • #3
      Re: LIAI completes world's most comprehensive analysis on influenza virus data

      trying to download one sample kills my browser and throws me out of the internet. Also, why can't I just get the whole database as a zipped
      file for download ?
      I prefer to have a list/program where/how the epitopes are defined
      and then run my own program.

      No traffic in the forum.
      I'm interested in expert panflu damage estimates
      my current links: http://bit.ly/hFI7H ILI-charts: http://bit.ly/CcRgT

      Comment


      • #4
        Re: LIAI completes world's most comprehensive analysis on influenza virus data

        http://www.cidrap.umn.edu/cidrap/con...7epitopes.html

        <TABLE style="TABLE-LAYOUT: auto" cellSpacing=0 cellPadding=0 width="100%" summary="Main Page Table" border=0><TBODY><TR><TD vAlign=top><TABLE cellSpacing=10 cellPadding=0 summary="Main Content Table" border=0><TBODY><TR><TD vAlign=top align=left colSpan=2>Report may spur quest for more versatile flu vaccines

        Robert Roos News Editor


        Jan 3, 2007 (CIDRAP News) ? California scientists report that their analysis of the medical literature has yielded data on more than 600 molecular components of influenza A viruses that trigger immune responses, findings they hope will spur the search for vaccines offering protection against multiple flu strains.

        Scientists at the La Jolla Institute for Allergy and Immunology (LIAI) scanned more than 2,000 scientific articles in a hunt for data on influenza A molecular structures that interact with either of two major components of the immune system: T cells and antibody-producing B cells.

        Writing in the Jan 2 Proceedings of the National Academy of Sciences, the researchers report that they found information on 602 such structures, called epitopes, from 13 different influenza A subtypes. These included one particular epitope that is shared by several human flu subtypes and the H5N1 avian flu virus.

        Flu vaccines now in use target two surface proteins, hemagglutinin and neuraminidase. Because these proteins constantly mutate, vaccines must be changed every year to match the strains expected to be circulating during the flu season. But scientists have long hoped to develop a vaccine that would target a viral protein that is "conserved," or essentially the same, in different strains. Epitopes that different strains have in common could, scientists believe, be used to make a vaccine that would protect against multiple strains and could be used for years.

        "If we can find shared epitopes, it may be possible to develop an influenza vaccine with greater cross-protection for many different viruses," Alessandro Sette, PhD, senior author of the study, commented in an LIAI news release.
        The authors used the Immune Epitope Database (IEDB), described as the world's largest repository of data on immune responses to infectious agents, to search the literature for influenza A epitopes. The La Jolla institute developed the IEDB with a $25 million contract awarded by the National Institute of Allergy and Infectious Diseases (NIAID) in 2004. Sette said the IEDB collects all known antibody and T cell epitope information in one place and is available to scientists around the world (see link below).

        The researchers found 2,063 articles related to influenza A epitopes, of which 429 were deemed worthy of detailed examination. This led to the cataloging of 412 T cell epitopes and 190 antibody epitopes from 13 viral subtypes and 58 different strains. The analysis yielded important data but also revealed important information gaps, the researchers write.

        The relatively low number of antibody epitopes was surprising, the authors write, given that antibody titers are the only accepted measure of protection from flu.
        Only two H5N1 avian flu epitopes were found, both from a 2004 Vietnam strain of the virus. The lack of H5N1 epitope data is not surprising, given the recent emergence of the virus and the special biosecurity measures required for studying it, the researchers say.

        Antibody epitopes were identified from only 5 of the 10 viral proteins?most of them from hemagglutinin, neuraminidase, and M2?whereas T cell epitopes from all 10 proteins were identified. Only one antibody epitope?versus 160 T cell epitopes?was identified by studying human samples (rather than animal samples). The authors comment that interpreting epitope data from human samples is more complex because people, unlike lab animals, typically have been exposed to many flu strains over many years.

        Using an analysis tool developed as part of the IEDB, the authors found that a higher percentage of T cell epitopes than of antibody epitopes were shared by multiple viral strains. About 11% of T cell epitopes were 100% identical in human and avian strains, while 30% of them were 90% identical, and 50% were 80% identical. In contrast, only 2.7% of antibody epitopes were 100% identical, and less than 11% were found to be 80% identical.

        "In general, the results suggest that significant levels of interstrain cross-reactivity are likely for T cell epitopes, but much less so for Ab [antibody] epitopes," the report says.

        Because not all antibody and T cell responses are protective, the researchers sifted their data for epitopes associated with protective immune responses in the lab. They found only 9 antibody and 9 T cell epitopes that met their criterion. Most of the protective T cell epitopes are found in both human and avian flu strains, while most of the antibody epitopes are not, they report.

        "However, one protective Ab epitope from the M2 protein shows appreciable conservation among the selected human influenza strains and H5N1," the article states. "Because M2 is a relatively conserved protein, identification of protective Ab epitopes derived from this protein, as has been pointed out, holds promise for the future development of a universal influenza epitope-based vaccine."

        The authors recommend research to address the gaps their analysis revealed, including more studies on antibody epitopes and efforts to identify more avian flu virus epitopes.

        Gregory A. Poland, MD, a flu vaccine expert at the Mayo Clinic in Rochester, Minn., applauded the report, saying it should advance the search for a flu vaccine that targets a conserved viral component and offers protection against multiple strains. He directs the Mayo Vaccine Research Group and Program in Translational Immunovirology.

        "If you find a wholly conserved piece of the virus that doesn't vary much between strains and provides cross protection between [H5N1] clade 1 and clade 2 viruses, that could be very exciting and could be the basis for developing a subunit vaccine," Poland told CIDRAP News. "You could make it quickly and in huge quantity."

        He also said the report could generate some controversy, given the division of opinion among vaccine experts on whether flu vaccines should be made from whole viruses or from viral subunits. Existing evidence shows that whole-virus vaccines are more immunogenic, but there is very little experience with subunit vaccines, he said.

        "The vaccine world is divided into whole-virus and subunit type people," Poland said. "I happen to believe there's a lot of merit to the subunit and peptide approach."

        Poland also praised the LIAI researchers for collecting all the influenza A epitope data into a single database and making it possible to do types of analyses that couldn't be done before. "It does expand the database and advances the knowledge," he said.

        The NIAID, which supported the LIAI research, hailed it in a news release: "The study should help scientists who are designing new vaccines, diagnostics and immune-based therapies against seasonal and pandemic influenza because it reveals in molecular detail exactly where the immune system focuses on the viruses. . . . Information on shared protective epitopes is important for developing influenza vaccines that can provide broad protection against multiple strains of the virus."

        However, the agency cautioned that the identification of conserved epitopes doesn?t necessarily mean that broadly protective vaccines are possible. "What is less clear from the analysis is how cross-reactive an immune response would be to most of these conserved epitopes," the news release states. "Further analysis may assist scientists in identifying vaccine targets that might offer broader protection and in predicting how effective a new vaccine will be."

        Bui H-H, Peters B, Assarsson E, et al. Ab and T cell epitopes of influenza A virus, knowledge and opportunities. Proc Natl Acad Sci 2007;104(1):246-51 [Abstract]

        See also:
        Immune Epitope Database and Analysis Resource homepage
        http://www.immuneepitope.org/home.do
        Jan 1 LIAI news release via EurekAlert
        http://www.eurekalert.org/pub_releases/2007-01/ljif-lcw122606.php#
        Jan 3 NIAID news release
        http://www3.niaid.nih.gov/news/newsreleases/2007/NewDetailsImmuneSysFlu.htm
        Aug 25, 2005, CIDRAP News story "Acambis hopes to build a flu vaccine that lasts"

        .

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        "The next major advancement in the health of American people will be determined by what the individual is willing to do for himself"-- John Knowles, Former President of the Rockefeller Foundation

        Comment


        • #5
          Re: LIAI completes world's most comprehensive analysis on influenza virus data

          can we have the 2 H5N1 epitopes ?
          Can someone get them ?

          I don't understand, why/how epitopes can be "100% or 90% identical" .

          Ab-epitopes address 5 genes ? Not only HA and NA ?

          Only 9/190 or 9/492 of epitopes correspond to protective Ab,T-cells ?

          Is the report in favour of the prepandemic vaccines ?
          Last edited by gsgs; January 4, 2007, 01:33 AM.
          I'm interested in expert panflu damage estimates
          my current links: http://bit.ly/hFI7H ILI-charts: http://bit.ly/CcRgT

          Comment

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