Question

On which type(s) of cells are class I MHC molecules located?a. Antigen-presenting cells onlyb. B cells onlyc. All nucleated body cellsd. Antigen-presenting cells and B cells

Accepted Answer

Step 1: Understand the role of class I MHC (Major Histocompatibility Complex) molecules. These molecules are responsible for presenting endogenous antigens (antigens originating from within the cell) to cytotoxic T cells (CD8+ T cells). This process is crucial for immune surveillance and the detection of infected or abnormal cells. Step 2: Recall the distribution of class I MHC molecules. Class I MHC molecules are expressed on the surface of all nucleated cells in the body. This includes most body cells, as opposed to class II MHC molecules, which are restricted to antigen-presenting cells (APCs) like macrophages, dendritic cells, and B cells. Step 3: Exclude incorrect options based on the distribution of class I MHC molecules. For example, option 'a' (Antigen-presenting cells only) and option 'b' (B cells only) are incorrect because class I MHC molecules are not limited to these cell types. Step 4: Consider option 'c' (All nucleated body cells). This is consistent with the fact that class I MHC molecules are found on all nucleated cells, including epithelial cells, muscle cells, and immune cells, but not on non-nucleated cells like red blood cells. Step 5: Evaluate option 'd' (Antigen-presenting cells and B cells). While APCs and B cells do express class I MHC molecules, this option is incomplete because it excludes other nucleated cells that also express class I MHC molecules. Therefore, option 'c' is the most accurate answer.

On which type(s) of cells are class I MHC molecules located?
a. Antigen-presenting cells only
b. B cells only
c. All nucleated body cells
d. Antigen-presenting cells and B cells

Risposta video verificata per un problema simile:

Concetti chiave

Class I MHC Molecules

Nucleated Cells

Antigen-Presenting Cells (APCs)