Over 6 scientists and practitioners gathered at the 15th International Congress of Immunology in Milan – one of the largest medical congresses in the world. Vaccines are the most important topic of the scientists’ presentations. Work is underway on a vaccine that allows the human immune system to fight HPV-16 – one of the most oncogenic viruses, and to stimulate T lymphocytes to eliminate cancerous tumors.
From Milan for Medonet Marek Mejssner
Held from 22 to 27 August this year. in Milan, the 15th International Congress of Immunology (ICI), is the world’s largest gathering of immunologists, virologists and bacteriologists, both scientists and practitioners.
Vaccines are an important topic at the Milan congress, especially since immunologists have decided to use them to attack diseases that are often the most difficult to treat, and therefore have a tumor origin.
How to prevent the development of cancer
Can we prevent our own immune system from developing cancer? You can, but first the cancer must be properly diagnosed, scientists have long said. This task was undertaken by a team of researchers led by prof. immunology, Ferdinand Ossendorp, of Leiden University in the Netherlands, who finally developed a therapeutic vaccine that allows the human immune system to correctly recognize and deal with HPV-16 – one of the most carcinogenic viruses.
Human Papilloma Virus (HPV) is widespread; we know over 200 types. They are transmitted mainly through sexual and skin contact, and about 40 of them cause infections in the genitourinary organs in men and women. Usually, most of these infections are of no long-term health significance and are self-limited. Others cause mild changes to the skin and mucous membranes of the reproductive organs known as genital warts or condylomas, which are fairly common in men and women. They affect up to 1 percent. human population. However, there are two extremely dangerous viruses – HPV-16 and HPV-18.
HPV-16, the most dangerous of which is responsible for cancers of the vulva, cervix, head and neck. There are prophylactic vaccines for him, but they do not treat already acquired HPV infection. The team of prof. Ossendorpa developed his vaccine through long-term experimentation and research with proteins. First, scientists created 13 long-chain, overlapping artificial peptides. They were to help the immune system recognize the so-called the oncogenic proteins E6 and E7 that facilitate the formation of cancerous tumors in the HPV16 virus. Peptides worked properly, because during the research it turned out that in over 50% of virus-infected women taking them have completely or partially resolved, strong pre-neoplastic changes, the so-called HPV-16. vulvar median neoplasia.
However, this did not make the vaccine completely effective. Scientists have added a new element to it – a ligand, i.e. the TLR1 / 2 receptor protein. The toll-like receptor (TLR for short) is a very old part of the immune mechanism, common to most multicellular organisms on Earth and found in both fruit flies and humans. These receptors are found on the surface of the cell membrane (TLR 1,2,4,5,6 and 11) and intracellularly (TLR 3,7,8 and 9). They are responsible for developmental processes and start the production of proteins that kill bacteria, fungi and viruses. They serve as the body’s alarm system – binding TLR to microbes activates T-lymphocytes and dendritic cells, which are responsible for threat recognition and immune memory (the body remembers how to deal with a threat it has already fought against). TLR1 / 2 is the most potent and its artificial receptor protein has been linked to two selected from the 13 most potent long-chain peptides.
Phase I and II clinical trials of the new vaccine’s toxicity and effects on the immune system began in the spring of 2013 at a clinic in the Netherlands. They are administered to patients with diagnosed head and neck cancer. Tests were also carried out on mouse and human cells – in vitro. They showed rapid maturation and proper functioning of dendritic cells, which means that the therapeutic vaccine activated the body’s defense system against neoplastic changes caused by HPV-16 viral proteins. The studies conducted so far, according to the researchers, provide a solid basis for the rapid determination of doses and preparation of a market version of a therapeutic vaccine for HPV-16.
Learn to fight cancer
A similar vaccine that activates the human immune system so that it can recognize and fight cancer cells was undertaken by a team consisting of Dr. Karolina Pałucka and Dr. Jacques Banchereau from the Baylor Institute for Immunology Research in the USA. The therapeutic vaccine should, as in the case of the Dutch team vaccine, create a specific receptor that works in the case of cancer cells and teach memory T lymphocytes how to deal with them.
For this, activation of the dendritic cells that induce, regulate and maintain T lymphocytes is needed. In this way, scientists hope to obtain anti-cancer CD8 + T lymphocytes. These are specific lymphocytes that recognize proteins in all nuclear cells of the body and help protect it against external pathogens (viruses, bacteria, fungi). Researchers wanted to obtain CD8 + T cells that could recognize tumor cells and memory lymphocytes, that could remember how they had been killed if they reappeared.
For the new high-sensitivity lymphocytes, an appropriate control system, which only dendritic cells can provide, was still needed. Due to the capabilities and affinity for CD8 + T cells, scientists from Baylor Institute decided to use Langerhans cells for this purpose.
Langerhans cells are immature dendritic cells. They are found mainly in the skin, and if an infection occurs, it is these cells that absorb and process the antigens of the microorganisms. Then they travel to the lymph nodes to reach the cells presenting the antigen, i.e. they serve as specific couriers of the body, delivering information from the front line to the cells of the immune system about the direction of the attack and the type and number of the enemy.
Scientists are now testing their research on inflammation, which is common in breast cancer. It usually accelerates tumor growth. The team is currently working on reprogramming dendritic cells in this inflammation so that they induce the action of tumor-specific CD8 + T cells that are cytotoxic. The production and proper functioning of such lymphocytes will mean that some forms of cancer can be combated by the body’s immune system, induced only by the appropriate vaccine.
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Held from 22 to 27 August this year. in Milan, the 15th International Congress of Immunology (ICI), is the world’s largest gathering of immunologists, virologists and bacteriologists, both scientists and practitioners. Organized every 3 years by the world federation – International Union of Immunological Societies (IUIS) – bringing together 65 national immunological associations and 4 great regional associations, the congress presents the results of the latest and most important research in the field of virology, bacteriology, clinical immunology and shows new trends in immunology . It always gathers a large number of participants – the last congress in August 2010, organized in Kobe, was attended by 6. participants; in Milan their number will probably not be less. According to the Scientific Council of the Congress, 4000 papers and abstracts were received; the number of presentations is therefore higher than three years ago at the previous Kobe Congress. This means that ICI will be the largest medical congress this year in the world.