B and T Lymphocytes
These cells are involved in adaptive immunity. Recall, that both develop in primary lymphatic organs (red bone marrow and the thymus) from pluripotent stem cells that originate in the red bone marrow. B cells complete maturation in the red bone marrow and T cells mature in the thymus (the B & T are based on where they mature). Mature B and T cells are able to make several proteins that are inserted into their plasma membranes. Some of these proteins function as Antigen Receptors , which are molecules capable of recognizing specific antigens.
There are 5 types of mature T cells that leave the thymus:
Helper T Cells (CD4 T Cells) Cytotoxic T Cells (CD8 T Cells)
T memory cells T suppressor cells Natural Killer T cells
There are 2 types of mature B cells that leave the red bone marrow:
Plasma cells
B memory cells
Types of Adaptive Immunity
2 Types both triggered by antigens:
1) Cell-Mediated (Cellular) Immunity: cytotoxic T cells directly attack invading antigens
Particularly effective against intracellular pathogens including viruses, bacteria, or fungi that are inside cells; some cancer cells; foreign tissue transplants Always involves Cells attacking Cells.
304
Made with FlippingBook Publishing Software