0
What else can I help you with?
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 molecule displays an antigen on the surface of the cells?
Major histocompatibility complex (MHC) molecules display antigens on the surface of cells. There are two main classes: MHC class I, which presents antigens to CD8+ cytotoxic T cells, and MHC class II, which presents antigens to CD4+ helper T cells. These molecules play a crucial role in the immune response by enabling the recognition of foreign substances by T cells.
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.
What structure on the macrophage activates the t cell?
The structure on the macrophage that activates T cells is the Major Histocompatibility Complex (MHC) molecule, specifically MHC class II. Macrophages present processed antigens on these MHC class II molecules to CD4+ T helper cells, initiating T cell activation. This interaction is crucial for the adaptive immune response, as it helps T cells recognize and respond to specific pathogens. Additionally, co-stimulatory signals from other surface proteins on the macrophage are necessary for full T cell activation.
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.
