Inflammation is an opponent of immunity
A study conducted at University College London has shown that chronic inflammation, characteristic of the elderly, can interfere with the normal functioning of the immune system.
It has long been known that the immune system becomes weaker with age, older people are more susceptible to pathogens that do not affect the young.
Researchers have found that in the case of skin immunity, pro-inflammatory proteins synthesized in excess by skin cells block the immune system. They decided to try to slow down the production of inflammatory factors.
175 volunteers participated in the study (78 of them were over 65 years old, the rest were under 40 years old). They were injected with a weakened antigen to create an immune response without developing the disease. The antigen was Varicella-zoster virus, a representative of the herpesvirus family that causes chickenpox.
If a person has had chickenpox once, he forms lifelong immunity to its causative agent. But there are rare relapses in the form of shingles in old age, if T-lymphocytes are not active enough.
All participants had previously had chickenpox, which means they must have immunity to the pathogen.
Observation of the immune response after the introduction of the pathogen showed that in the group of elderly people, the strength of the immune response was lower compared to younger participants. This was manifested by a lower degree of redness and swelling of the skin at the injection site, as well as reduced infiltration of T-lymphocytes.
For control, a saline solution was injected into the other hand of each participant. Some elderly people had a local inflammatory response even to this neutral injection. Interestingly, the inflammatory response to saline was combined with a weak response to the chickenpox virus. Hence the assumption arose that excessive inflammation in the skin interferes with a specific immune response to the varicella-zoster virus.
Analyzing skin samples after injection, the researchers found that excessive inflammation was associated with activation of the enzyme mitogen-activated protein kinase (p38 MAP kinase). In order to find out exactly how this enzyme affects the degree of inflammation, eighteen participants over the age of 65 were given losmapimod, an experimental drug that selectively inhibits mitogen–activated protein kinase. Taking losmapimod reduces the level of C-reactive protein and monocytes in peripheral blood, as well as the secretion of interleukin-6 and tumor necrosis factor.
Four days after taking the drug, the injection with the chickenpox virus was repeated. The immune response to the pathogen among elderly participants after the course of losmapimod was more active compared to that of the same participants before taking the drug, the differences were statistically significant.
Thus, excessive inflammation in the skin inhibits antigen-specific immunity in the elderly. Suppressing inflammation restores the strength of the immune response.
Currently, a study is planned to find out whether the effectiveness of the flu vaccine among the elderly will increase after a short course of treatment with losmapimod. In addition, the results obtained can provide a basis for improving the effectiveness of immunotherapy for malignant neoplasms in the elderly.
Article by Milica Vukmanovic-Stejic et al. Enhancement of cutaneous immunity during aging by blocking p38 mitogen-activated protein (MAP) kinase–induced inflammation is published in The Journal of Allergy and Clinical Immunology.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on UCL News: Improving vaccines for the elderly by blocking inflammation.