chuka_lis (chuka_lis) wrote,

Как это работает

Интересная статья, вышла еще летом в Нэйче..
Чем интересна- подходом к вакцинации, в нем есть рациональное звено.
Не знаю, как они продвигаются в этом направлении,  особенно после того, как вакцины другого типа, можно сказать, завоевали рынок.
Но статья мне понравилась тем, что во "Введении"  кратко и хорошо изложен  механизм работы ответа иммунитета на встречу с антигеном.[Spoiler (click to open)]Потому я его сюда и процитирую.
The vaccine candidate once introduced into the body is detected by the host innate immune system by using pattern recognition receptors (PRRs) to identify the pathogen‐associated molecular patterns (PAMPs). The pathogen-associated patterns contained in vaccine antigens attract dendritic cells, monocytes, and neutrophils that patrol throughout the body18. Through the pattern-recognition receptors (among which the Toll-like receptors play an important role) the host cells sense the potential danger when they detect a pathogen and become activated18. Elicitation of sufficient “danger signals” by the vaccine antigens or adjuvants activate monocytes and dendritic cells. They modulate their surface molecule's expression, and develop pro inflammatory cytokines and chemokines resulting in the extravasation and attraction of monocytes, granulocytes, and natural killer cells. This leads to the generation of an inflammatory microenvironment where the monocytes differentiate into macrophages and immature dendritic cells are activated19. This activation alters the expression of the homing receptors at the cell surface and triggers the migration of dendritic cells towards the lymph nodes where the activation of T and B lymphocyte takes place. On contact with naïve T cells, the T cells differentiate into regulatory CD4+ cells that maintain immune tolerance20. The immature dendritic cells recognize the protein vaccine antigen and then migrate towards the lymph node. During this migration, the dendritic cells mature and their surface expression of molecules changes21. Simultaneously, processing of antigens into smaller fragments occur which is then displayed at the cell surface in the grooves of MHC (human leukocyte antigen [HLA] in humans) molecules. The peptides from the antigens that are produced in the cytosol of infected cells are presented by MHC class I molecules and phagocytised antigens are essentially displayed on MHC class II molecules22,23,24,25. The antigenic peptides displayed by class II MHC molecules are recognized by CD4+ T cells whereas, CD8+ T cells bind to class I MHC-peptide complexes26. Activated CD4+ T cells secrete cytokines and are responsible for the further activation of B cells required for proper antibody generation27

The designed multi-epitope vaccine has the capacity to trigger both humoral and cell mediated immunity. The vaccine is processed in the antigen presenting cells (APCs) and the antigenic epitopes are recognized by MHC I receptors which further stimulates cytotoxic T cell (Tc cell) development. Tc cells trigger cytokine production which causes cytotoxic T cells to divide and attack the infected cells. The activated T cells also differentiate into memory T cells. Similarly, vaccine antigen is processed and presented in context of MHC class II molecule. B cells differentiate into plasma cells and memory B cells upon activation by cytokines. Further, the activated B cell or plasma cell produces the neutralizing antibodies responsible for clearing an infection. (B) TLR signal transduction pathway: TLR 2 homodimer utilizes MyD88 and MAL as primary adapters to activate NF-κB that triggers inflammatory cytokine secretion. TLR4 uses four primary adapters namely MyD88, MAL, TRIF and TRAM for NF-κB secretion which in turn induce inflammatory cytokine secretion activating IFN pathway.
Ну и остальные пояснения там по делу.
Tags: вакцина, иммунитет, коронавирус, статьи

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