A1: Intro to Immune System Flashcards
Of the lymphocytes, which can recognize many molecules types and which can only recognize protein antigens?
B cells can make antibodies that recognize many molecule types, while T cells can only recognize antigens
What is the difference between active and passive immunity? What is an example of each?
Active immunity: after an infection or pathogen entry, the immune system creates memory cells that protect it against future infections by the same pathogen. Passive immunity: antibodies that protect against a particular pathogen are given to the individual despite never being exposed to that pathogen; much more short-lived immunity.
Vaccines or infection are active immunity, breastfeeding gives the infant passive immunity
What is the most effective antigen-presenting cell for B cells? For T cells?
B cells respond most strongly to follicular dendritic cells. T cells respond most strongly to dendritic cells.
What are regulatory T lymphocytes?
Regulatory T lymphocytes aid to suppress or limit an immune response
What are the generative lymphoid organs? What are the peripheral lymphoid organs?
Generative = bone marrow and thymus Peripheral = spleen, lymph nodes,and mucosal and cutaneous immune systems
Where are B cells found in the lymph nodes? What about T cells?
B cells are found in the follicles
T cells are found in the paracortex outside of the follicles
What is a germinal center?
In a recent immune response, the follicles stain lightly in the central region. This is due to the activation of B cells
How do B cells migrate to their location in the lymph nodes?
B cells migrate to the follicles via chemokines (follicular dendritic cells release molecules that bind to CXCR5 receptors on the B cells)
How do T cells migrate to their location in the lymph node?
T cells migrate to the paracortex via chemokines (chemokines act on CCR5 receptor on the T cells, guiding them towards the paracortex)
How are B and T cells brought together under scenarios of immune activation?
When activated, B and T cells change their surface receptors in order to no longer respond to chemokines that would otherwise draw them to follicles and paracortex, respectively.
