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No, it's cellulair. Handy to be recognized by the cytotoxic T-cells.
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∙ 12y ago
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What are the differences between humoral immunity and cellular immunity?
ANTIBODY IMMUNITY IS BETTER TERMED AS HUMORAL IMMUNITY Humoral immunity is acquired by B-lymphocytes and T-helper lymphocytes as An antigen is engulfed by antigen processing cell (APC) e.g. , B-cells then a part of an antigen (epitope) is presented to T-helper cells in association with MHC-II (MAJOR HISTOCOMPATIBILITY COMPLEX) then T-helper cell activates B-cell to produce effector cell (plasma cell) and memory cell then plasma cell secrete antibodies which neglify harmful or toxic effects of the above antigen. CELL MEDIATED IMMUNITY Every cell of the body can show this response while in the above case only APC can show humoral response A whole foreign body/ antibody is engulfed by the cell then epitope is represented to cytotoxic T-lymphocytes(CTLs) then CTLs secrete certain chemicals which kill the cell along with foreign body.
Where are Class II molecules found?
Presented by APCs as MHC-exogenous peptide complex
Class II MHC molecules are found only on which of the following?
Presented by APCs as MHC-exogenous peptide complex
Where are major histocompatibility complex-you MHC-you molecules located?
Each individual has a unique MHC profile Clinically important MHC are HLA(human leukocyte antigens) -A, -B -DR -expression of a particular combination of MHC genes Class I - are located on all nucleated cells Class II - are located on macrophages, dendritic cells, B cells.
When an antigen is bound to a class II MHC protein it can activate what cell?
When an antigen is bound to a class II MHC protein, it can activate helper T cells. Helper T cells play a critical role in initiating and coordinating immune responses by releasing various signaling molecules and activating other immune cells.
What cells express MHC class II molecules?
There are two classes of MHC. MHC I are expressed in all cells except red blood cells (because they lack nuclei). MHC I andMHC II are expressed in professional antigen presenting cells (APC's) that include :macrophages, dendritic cells and B cells.
How does involvement of MHC 1 and MHC 2 help immune system?
MHC IMHC I is present in all cells except red blood cells (they lack nuclei). MHC I will present an intravesicular antigen to the cells surface for it to be identified as self or foreign by your adaptive immunity cells.MHC IIMHC II is present in professional antigen presenting cells which include: macrophages, B cells and dendritic cells. These cells will engulf bacteria, soluble proteins, viruses, etc. Whatever was taken into the cell becomes processed in the increasingly acidic endosome that eventually will cut the antigen into peptides. MHC II transported from the ER will meet up with this endosome and the peptides will bind to MHC II for it to eventually present on the cells surface.
What is the difference between a class I MHC mechanism vs a class II MHC mechanism?
The Class I MHC molecules process endogenous(intracellular) peptides/antigens whereas the Class II process exogenous(extracellular) peptides/antigens. The Class I molecules are assembled and located in the ER whereas the Class II are assembled in the ER but located in the endosomes. When extracellular peptides are taken into the cell via receptor mediated endocytosis or phagocytosis, they will be transported into the endosomes and get degraded. This will enable the peptide generated to be loaded onto the Class II molecules. For Class I, when a bacteria or virus infect a cell, they will replicate and produce proteins. These proteins will be ubiquitinated and degraded by the proteasome. This smaller peptides can then be transported into the ER via the TAP transporters, that are complexed with the Class I molecules, to be loaded onto the Class I molecules.
Difference between MHC class1 and MHC class2 molecules?
MHC proteins express antigens on a cell surface for T cells to identify whether the antigens presented are self or foreign. There are two classes MHC I and MHC II. They differ in which cells they require to activate depending on the pathogen present.
Major histocompatibility complex serves as the identification fingerprint for?
Well, there is not really a short answer for it: 1) there are 2 class of MHC: HLA/MHC-I: binds to CD8 T cells HLA/MHC-II: binds to CD4 T cells A physician has to check for a good match of the MHC subtypes in a transplation between graft and host. A good match reduces the risk of immune complications after the transplantation.
What role does the macrophage play in?
presents antigens of an engulfed pathogen in its class II MHC molecules to helper T cells, and releases IL-1
When MHC will be expressed?
MHC I and MHC II are always expressed. The antigen it presents on a cells surface can be foreign or it can be self. It is the T cell that determines whether what the MHC is displaying is self or not. Remember antigen can be protein, lipid, sugars, etc.
