[03] Lymphocyte Development and Activation Flashcards
What are the two main types of lymphocytes?
- B lymphocytes (B cells)
- T lymphocytes (T cells)
Where do lymphocytes originate from?
They originate from stem cells in the bone marrow
Where do B cells mature?
B cells mature in the bone marrow
Where do T cells mature?
T cells mature in the thymus
What is the role of B cells in immunity?
They produce antibodies that are used to attack invading bacteria, viruses, and toxins
What is the role of T cells in immunity?
They are involved in cell-mediated immunity
What does it mean when a B cell or T cell is “activated”?
An activated lymphocyte has recognized its specific antigen and responds by proliferating and differentiating
What triggers B cell activation?
Interaction with an antigen and assistance from a helper T cell
What are the outcomes of B cell activation?
- Plasma cells that produce antibodies
- Memory B cells that are ready for future exposure to the antigen
What triggers T cell activation?
Interaction with an antigen presented on the surface of an antigen-presenting cell (APC)
What are the outcomes of T cell activation?
- Cytotoxic T cells that destroy infected cells
- Helper T cells that assist in B cell activation
- Memory T cells that are ready for future exposure to the antigen
What are antigen-presenting cells (APCs)?
Cells that process and present antigens to T cells
What is the role of helper T cells in lymphocyte activation?
They enhance the response of other immune cells like B cells and cytotoxic T cells
What is the role of cytotoxic T cells in lymphocyte activation?
They kill infected cells
What is the role of memory B cells and memory T cells?
They provide long-term immunity and rapid response upon re-exposure to the same antigen
