Question

What are plasma cells?

Answer 1

Plasma cells:

1. Plasma cells, also known as plasma B cells, are white blood cells that start off as B lymphocytes in the lymphoid organs and secrete huge amounts of proteins called antibodies in reaction to being exposed to specific antigens.
2. These antibodies are carried to the target antigen (foreign substance) by plasma cells and the lymphatic system, where they begin neutralization or destruction. B cells mature into plasma cells, which produce antibody molecules that are extremely identical to the receptors of the precursor B cell.
3. Plasma cells, unlike their predecessors, can't switch antibody classes, can't operate as antigen-presenting cells because they don't have MHC-II, and can't take up antigen since they don't have enough immunoglobulin on the cell surface. Continued antigen exposure through low levels of immunoglobulin, on the other hand, is critical since it defines the cell's longevity in part.
4. Differentiation by antigen stimulation that does not need the presence of a T cell (stimulation of a B cell without the involvement of a T cell) can occur anyplace in the body and result in short-lived cells that release IgM antibodies.
5. The T cell-dependent processes are divided into primary and secondary responses: a primary response (meaning the T cell is present at the time the B cell first contacts the antigen) produces short-lived cells that stay in the extramedullary regions of lymph nodes; a secondary response produces longer-lived cells that produce IgG and IgA and frequently travel to the bone marrow.
6. Plasma cells can only make one type of antibody from a single immunoglobulin class. Antibodies are produced in large quantities as part of the humoral immune response.