Immunology 1 Flashcards
Define the immune effector function.
Immune effector function = the ability to deal with infection and, if possible, eliminate it without harming our body in the process
What is immunological recognition?
Distinction of self from non-self cells/tissues.
What is the innate immune system?
Cells, barriers and molecules.
Functions = first defence to slow down pathogenic threats. recruit adaptive immune cells.
Rapid but not very specific.
What is the adaptive immune system?
Cells (T and B lymphocytes) and antibodies produced by B lymphocytes.
Functions = mount highly specific defence against pathogens / remember threat for possible future encounters.
Slower but more specific.
What are haematopoietic precursor cells?
Stem cells which are capable of differentiating into red (oxygen-carrying) and white (immune) blood cells.
Where are innate immune cells located?
In peripheral tissues - adapted to deal with pathogens that will be encountered at each given site.
Where are adaptive immune cells located?
At central lymphoid tissues (spleen and lymph nodes).
Where do B and T lymphocytes reside?
B: Mature in bone marrow and then travel to spleen/lymph nodes to wait to be activated.
T: Mature in thymus and travel to spleen/lymph nodes to wait to be activated.
Describe how the innate and adaptive immune systems work together in a positive feedback loop.
Dendritic innate cells present fragments of pathogens on cell surface and take them to the adaptive immune system.
B and T lymphocytes turn into effector cells and start killing. These also produce antibodies which enhance the innate immune cell function.
What is the timeline of immune cell life?
Haematopoietic stem cell -> differentiation -> immature/naive cell in bone marrow -> immature/naive cell in home tissue -> remain naive / activation -> effector function -> memory / switch off / die
What is the timeline of immune response?
Infection -> innate immunity (0-5 days) -> innate + adaptive immunity (5 days - weeks) -> elimination of pathogen (weeks) -> healing (weeks - months) -> immune memory (months - years)
What is the difference between Th1 and Th2 immunity?
Th1 immunity to viruses
Th2 immunity to parasites
What are cytokines?
Cytokines = small secreted proteins released by immune cells, which allow them to interact and communicate.
Tell each other what type of pathogen they are facing and what responses are needed.
Define interferons (IFNs), interleukins (ILs) and chemokines.
Interferons = cytokines that induce cells to resist viral replication.
Interleukins = Cytokines that are produce by white blood cells. Many types with specific functions.
Chemokines = cytokines that tell immune cells where to go.
