05-03-2012, 01:33 PM
"D" is the correct answer.
Fragments of antigen associated with class II MHC glycoproteins are recognized by helper T cells. Activation of helper T cells is required as an early step in the immune response. For B cells to respond to most antigens, helper T cells are an absolute requirement. However, in the case of some bacterial polysaccharides, B cells respond to the antigens in the absence of helper T cells. The primary cell type for expression of class II MHC is the macrophage that serves as an antigen-presenting cell, but thymic epithelial cells and B cells can also present antigen under appropriate conditions.
Thank you all
@Maryam: You are welcome. Good to see you
Fragments of antigen associated with class II MHC glycoproteins are recognized by helper T cells. Activation of helper T cells is required as an early step in the immune response. For B cells to respond to most antigens, helper T cells are an absolute requirement. However, in the case of some bacterial polysaccharides, B cells respond to the antigens in the absence of helper T cells. The primary cell type for expression of class II MHC is the macrophage that serves as an antigen-presenting cell, but thymic epithelial cells and B cells can also present antigen under appropriate conditions.
Thank you all
@Maryam: You are welcome. Good to see you