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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.
Do T cells express MHC II?
No, T cells do not express MHC II. MHC II molecules are primarily found on antigen-presenting cells, such as dendritic cells, macrophages, and B cells, and are involved in presenting antigens to T cells for immune responses. T cells, on the other hand, express MHC I molecules, which present antigens to other immune cells.
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.
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
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 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.
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.
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
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.
What type of membrane protein responsible for rejection in tissue transplants?
Major histocompatibility complex (MHC) proteins, specifically MHC class I and II, are responsible for initiating an immune response against foreign tissues in tissue transplants. These proteins present antigens to T cells, triggering the immune system to recognize and reject the transplant as a foreign entity.
What membrane surface molecules bind to proteins and serve as molecular identification tags?
molecular identification tags such as phosphate group added to the Golgi prouducts aid in sorting by acting like ZIP codes on mailing labels. BIOLOGY 8TH EDITHION ( CAMPBELL ET. AL 2008)
