2023-11-06 16:15:54
When an infectious agent enters our body, the immune system responds to eliminate it. Specifically, dendritic cells, which act as sentinels in our tissues, are capable of detecting and phagocytosing or absorbing the pathogen, and degrading it into small fragments to show them on their surface to lymphocytes, effector cells of the immune system, which recognize and detect it. “They attack specifically.”
This process, called antigen presentation, involves close contact between both cell types to form a dynamic structure, called immune synapse, through which they exchange information.
A team of researchers from the National Cardiovascular Research Center (CNIC) and the Hospital de la Princesa-UAM have discovered that dendritic cells, which are a type of cells involved in the immune response to viruses, bacteria and others, are also involved in said process, but in a way unknown to date.
In this study, the group of researchers from the CNIC and the Hospital de la Princesa-UAM, led by Professor Francisco Sánchez-Madrid, reveals that after the formation of the immune synapse, not only are lymphocytes activated, as was already known, but that dendritic cells (postsynaptic) also undergo profound changes.
The research describes very relevant alterations in the content of proteins in the postsynaptic dendritic cell. Furthermore, adds Dr. Calzada Fraile, “we have identified a mechanism induced in dendritic cells, based on an increase in lipid peroxidation through which the antigens of phagocytosed pathogens are presented more efficiently to cytotoxic CD8 lymphocytes.”
Artistic recreation of the surface of a human dendritic cell. (Image: US National Cancer Institute)
The in vivo studies carried out in collaboration with the University of Padua (Italy), in a mouse model, have made it possible to follow, study and manipulate the postsynaptic dendritic cells that have interacted with T lymphocytes in vivo during an immune response, such as the one produced during vaccination with an antigen formulated in alum, the most used adjuvant in human vaccines.
We have seen, points out Francisco Sánchez-Madrid, “that these postsynaptic dendritic cells are responsible for the generation of specific CD8 lymphocytes against the vaccine.” Therefore, “we propose to intervene in these cells as a way to increase CD8 cell responses during vaccination.”
In his opinion, the importance of this finding lies in the fact “that it is of utmost importance that vaccines are capable of generating large CD8 responses, determining factors in the protection of many infections.”
With these greater capacities to activate cytotoxic CD8 T lymphocytes, the authors of the study have shown that postsynaptic dendritic cells can be administered in vivo and thus protect the body against bacterial and viral infections, acting as a vaccine against various pathogens.
Furthermore, in this case, the researchers explain, “protection does not depend on the inclusion of microorganisms as happens in traditional vaccines, so it could be used to protect against unknown pathogens that may emerge and cause new pandemics.”
El estudio se titula “Immune synapse formation promotes lipid peroxidation and MHC-I upregulation in licensed dendritic cells for efficient priming of CD8+ T cells”. Y se ha publicado en la revista académica Nature Communications. (Fuente: CNIC)
#reveal #key #role #cells #involved #immunity