echemi logo
Product
  • Product
  • Supplier
  • Inquiry
    Home > Active Ingredient News > Infection > "Nature-Medical": A new direction for mRNA vaccines!

    "Nature-Medical": A new direction for mRNA vaccines!

    • Last Update: 2021-12-30
    • Source: Internet
    • Author: User
    Search more information of high quality chemicals, good prices and reliable suppliers, visit www.echemi.com
    ▎ WuXi AppTec's content team editing mRNA technology has achieved unprecedented success in the development of the new crown vaccine, and it has also made people interested in the development of other mRNA-based therapies
    .

    A few days ago, an mRNA-based anti-AIDS vaccine has shown good protection against viral infections in preclinical experiments
    .

    According to the latest results published by the research team in Nature Medicine, this new vaccine is not only safe, but also can induce antibodies and cellular immune responses against HIV-like viruses (SHIV) in rhesus monkeys
    .

    Compared with unvaccinated animals, the risk of infection in macaques that were vaccinated and boosted multiple times after each exposure to the virus was reduced by 79%
    .

    This mRNA anti-AIDS vaccine uses the same technology platform as the two approved mRNA new coronavirus vaccines.
    The mRNA molecules are encapsulated in lipid nanoparticles, except that the instructions provided by the mRNA are not the spike protein encoding the new coronavirus, but Two key proteins used to make HIV: Envelope protein (Env) and specific antigen protein Gag
    .

    After the animal is inoculated, the muscle cells assemble these two proteins together to produce virus-like particles (VLP) to stimulate the immune response.
    At the same time, due to the lack of a complete HIV genetic code, it will not actually cause infection or disease
    .

    Although the principles are easy to understand, the challenges facing the research team are enormous
    .

    Because the spike protein of the new coronavirus is relatively stable, and the immunodominant epitope is mainly in the receptor binding domain, in contrast, the HIV envelope protein is a complex trimeric protein complex with multiple scattered antibodies Epitopes, many of which are "protected" by glycosylation and conformation and are difficult to be attacked by antibodies
    .

    ▲Comparison between the envelope protein of HIV-1 and the spike protein of the new coronavirus (picture source: reference [2]) For this reason, the research team specially designed the mRNA sequence, including the introduction of key mutations in the envelope protein.
    The Env mRNA and Gag mRNA sequences of different clades of HIV are used in the booster needle to allow the immune system to respond better and improve the ability to induce antibody production
    .

    In the mouse experiment, 100% of the neutralizing antibodies can be induced in the animal after two injections of the vaccine
    .

    VLPs formed in the body have multiple envelope proteins on the surface, which are very similar to the envelope proteins of real viruses, so they can well mimic the immune response caused by natural infections
    .

    ▲Mice experiments show that viral particles formed by mRNAs carrying two proteins at the same time can induce a stronger neutralizing antibody response than only Env mRNA (picture source: reference [1]).
    Then, the research team The effect of the mRNA vaccine was tested in primate macaques, and a variety of optimized vaccination schemes were used to enhance the immune response and produce broadly neutralizing antibodies
    .

    The paper pointed out that despite the high dose of mRNA delivered, the animals tolerated the vaccine well, with only minor side effects (such as loss of appetite), and they were temporary
    .

    At the 58th week of testing, all the vaccinated monkeys produced measurable levels of neutralizing antibodies, and these neutralizing antibodies can target many different HIV strains
    .

    In addition, the mRNA vaccine also induces a powerful helper T cell response
    .

    Next, the researchers exposed monkeys to the SIV virus through the rectal mucosa every week (this modified chimeric virus can replicate in monkeys)
    .

    The unvaccinated control group was infected after an average of three weeks, while the infection time of the seven monkeys who received too many vaccines was delayed overall, which occurred after 8 weeks on average, and even two were not infected.

    .

    ▲The macaque experiment shows that this mRNA vaccine (light blue) can delay the infection or even completely resist the infection in the case of repeated exposure to the virus (picture source: reference [1]) Dr.
    Paolo Lusso, the corresponding author of this study, said, They are continuing to improve the vaccination process in order to enhance the quality and quantity of VLP, further improve the effectiveness of the vaccine, and reduce the number of booster immunization shots
    .

    "If it is confirmed to be safe and effective, we plan to conduct a phase 1 trial of this vaccine platform in healthy adult volunteers
    .

    " Dr.
    Lusso said
    .

    Dr.
    Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), is also a co-author of this research paper.
    He believes: "Although the world’s scientific research community has made unremitting efforts for nearly 40 years, it is necessary to develop effective A vaccine to prevent HIV is still an elusive goal, and this experimental mRNA vaccine combines a variety of features, which is expected to overcome the shortcomings of other HIV vaccines in the past, thus representing a promising method
    .

    "References: [ 1] Peng Zhang et al.
    , (2021) A multiclade env–gag VLP mRNA vaccine elicits tier-2 HIV-1-neutralizing antibodies and reduces the risk of heterologous SHIV infection in macaques.
    Nature Medicine.
    Doi: https://doi .
    org/10.
    1038/s41591-021-01574-5[2] Lynn Morris (2021) mRNA vaccines offer hope for HIV.
    Nature Medicine Doi: https://doi.
    org/10.
    1038/s41591-021-01602-4
    This article is an English version of an article which is originally in the Chinese language on echemi.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to service@echemi.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

    Contact Us

    The source of this page with content of products and services is from Internet, which doesn't represent ECHEMI's opinion. If you have any queries, please write to service@echemi.com. It will be replied within 5 days.

    Moreover, if you find any instances of plagiarism from the page, please send email to service@echemi.com with relevant evidence.