Question

Which of the following cell types would be LEAST likely to express MHC class II?

A) B cells
B) T cells
C) dendritic cells
D) thymic epithelial cells

Answer 1

T cells are the least likely to express MHC class II since MHC II molecules are only found on professional antigen-presenting cells, such as macrophages, dendritic cells, and B cells, whereas T cells interact with these presented antigens.

Step-by-step explanation:

The cell type which would be LEAST likely to express MHC class II is T cells. Class II MHC molecules are expressed only on the surface of antigen-presenting cells (APCs) such as macrophages, dendritic cells, and B cells. These cells are known as "professional" antigen-presenting cells because they present antigens to T cells to trigger an immune response. On the other hand, T cells do not typically express MHC class II; instead, they are involved in recognizing antigens presented by APCs. Specifically, helper T cells (CD4+ T cells) are the subset of T cells that interact with MHC class II on APCs, while cytotoxic T cells (CD8+ T cells) typically interact with MHC class I on infected cells.