Perspective - Journal of Cell Biology and Metabolism (2021) Volume 3, Issue 2
Concept of antigen processing and presentation.
Department of Life Sciences, Graphic Era deemed to be university, Dehradun, India
- Corresponding Author:
- Srashti Choudhary
Department of Life Sciences Journal of Cell Biology and Metabolism, India
Accepted date: June 28, 2021
Citation: Choudhary S. Concept of antigen processing and presentation. J Cell Biol Metab. 2021;3(2):1-2.
Antigen is a substance that enters the body and starts a cycle that can cause illness. The body then, at that point for the most part creates substances (antibodies) to fight against the antigens. Antigen presenting cells (APCs) are specialized cells which include macrophages, B lymphocytes, and dendritic cells. Apart from it the MHC group of proteins, antigen show depends on other particular flagging atoms on the surfaces of the two APCs and T cells.
Antigen is a substance that enters the body and starts a cycle that can cause illness. The body then, at that point for the most part creates substances (antibodies) to fight against the antigens. Antigen presenting cells (APCs) are specialized cells which include macrophages, B lymphocytes, and dendritic cells. Apart from it the MHC group of proteins, antigen show depends on other particular flagging atoms on the surfaces of the two APCs and T cells. Antigen-introducing cells are indispensable for compelling versatile insusceptible reaction, as the working of both cytotoxic and assistant T cells is reliant upon APCs. Antigen show takes into account explicitness of versatile insusceptibility and can add to invulnerable reactions against both intracellular and extracellular microbes. It is additionally associated with protection against tumors. Malignant growth treatments have included treating the patient with expanded quantities of dendritic cells or disease explicit T cells. These specialized cells are distinguished by two properties:
• They express class 2 MHC molecules on their membranes • They are able to deliver a co-stimulatory signal that is necessary for TH-cell activation
Unfamiliar protein antigens are broken down into little antigenic peptides that structure complexes with class I or class II MHC particles. This change of proteins into Major Histocompatibility Complexes (MHC) related peptide parts is called antigen processing and presentation. While commensal microscopic organisms straightforwardly or by implication (through APCs) impact the separation of T cells, APCs use TLRs to perceive explicit microbial markers change the capacity of T cells to battle bacterial microorganisms. Cell surface Toll Like Receptors (TLRs) help in the phagocytosis of microbial microorganisms by DCs and macrophages. The APC engaged with initiating T cells is normally a dendritic cell. White blood cells can't perceive (and in this way can't react to) "free" or solvent antigens. They can just perceive and react to antigen that has been prepared and introduced by cells through transporter particles like MHC atoms. Helper T cells can perceive exogenous antigen introduced on MHC class II; cytotoxic T cells can perceive endogenous antigen introduced on MHC class I. Most cells in the body can introduce antigen to CD8+ cytotoxic T cells through MHC class I; in any case, the expression "antigen-introducing cell" is frequently utilized explicitly to depict proficient APCs. Such cells express MHC class I and MHC class II atoms and can invigorate CD4+ partner T cells just as cytotoxic T cells.
Steps involved in antigen presentation
• Fragmentation of pathogens into proteins and then into peptides • Association of peptides with an MHC complex • Transport to cell surface for expression • Different cellulose pathways exist for association of peptides with either MHC class I and class II molecules.
Major Histocompability Complexes (MHCs)
The significant histocompatibility complex (MHC) is a huge locus on vertebrate DNA containing a bunch of firmly connected polymorphic qualities that code for cell surface proteins fundamental for the versatile invulnerable framework. These cell surface proteins are called MHC particles. The MHC loci encode two major classes of membrane-bound glycoproteins: class I and class II MHC molecules.
These MHCs work as antigen-recognition molecules and MH cells recognize antigen combined with class II molecule, whereas TC cells generally recognize antigen combined with class I molecules.
Difference between MHC and APC
Lymphocytes perceive the introduced antigens and are in this way enacted. MHC II particles are just found on the outside of APCs. APCs don't present all potential epitopes to T cells; just a choice of the most antigenic or immunodominant epitopes are introduced.
Microbes are antigens that should be partially corrupted into peptides before they bind MHC particles and are introduced on the outside of an APC. APCs normally play an important role in battling tumors, through incitement of B and cytotoxic T cells to separately deliver antibodies against tumor-related antigen and kill threatening cells. Dendritic cells, introducing tumor-explicit antigen to T cells, are critical to this interaction. Notwithstanding, more up to date treatments have gone to hereditarily designed fake antigen-introducing cells intended to make preparations framework to assault dangerous cells.