Immune System Overview Flashcards
What is the state of protection against foreign pathogens?
Immunity
What prepares the immune system to eradicate an infectious agent before it causes disease?
Vaccination
What is the term for acquiring protective immunity in a critical mass of people? (vaccination/ infection recovery)
Herd Immunity
What is the basis of herd immunity?
serves as buffer for others/ lowers rate of spread
What kind of immunity combats pathogens via antibodies?
Humoral Immunity
What cells/ lymphocytes produce antibodies?
B cells (humoral)
What is an example of passive immunity?
infection > protection/ mother breastfeed to baby
What is an example of active immunity?
Vaccination
What kind of immunity relies on T cells?
Cell-Mediated Immunity
What are passive/ active immunity both examples of?
Humoral Immunity
What is the basis of cell-mediated immunity?
T cells
How are B/T cell receptors generated?
Gene Segment Rearrangements - randomly
Why are so many random B/T cell receptors generated?
so many potential antigens
What happens when a B cell encounters an antigen?
produce an antibody specific to antigen
What do T cell receptors do?
bind antigens/ peptides presented by APCs
In the humoral response, what becomes the antibody-producing cell?
B- cell receptor
What is the outcome of the cell-mediated/ T lymphocyte response?
cytokine secretion/ killing of infected cells
What kind of immunity is the thymus associated with?
Cell-mediated (T)
What kind of immunity is bone marrow associated with?
Humoral (B)
What are the 4 major categories of pathogen?
viruses/ bacteria/ fungi/ parasites
What is the difference between microbe/ pathogen?
pathogen= microbe that causes disease
What are immune responses specific to?
organism type/ pathogen structure/ cellular location (intra/extra)
What is the interaction between foreign organisms/ recognition molecules from host cells?
Pathogen Recognition
What includes whole pathogens/ fragments/ products?
ligands
What is the outcome of ligand binding?
immune response (pathogen labelling/ destruction)
What kind of immunity is responsible to recognize/ kill/ engulf pathogens?
cellular
What kind of immunity involves soluble proteins for labelling/ destruction of invaders?
humoral - antibodies
What kind of molecules does immune system rely on?
recognition molecules
What kind of recognition molecule is encoded in genomic DNA/ always expressed?
PRRs = Pattern Recognition Receptors
What do PRRs bind to?
PAMPs = Pathogen-Associated Molecular Patterns
What are generic molecules found on many pathogens?
PAMPs = pathogen associated molecular patterns
Are PRR’s generic molecules?
no- Pattern Recognition Receptors = specific
Individual B/T cells have specificity for how many antigens?
1 single
Why do B/T cells only have specificity for 1 single antigen?
each cell has many copies of the receptor
What happens when a B/T cell interacts with its specific antigen?
Clonal Selection
What happens when a B/T cell is selected upon antigen interaction?
it is selected/ becomes activated
What is the result of B/T cell activation?
proliferation- large # of clones produced
Why is deletion important in clonal selection?
bad receptors- bind weak/ attack host ext
What is the problem with generating random receptors?
waste of energy- most unused
What ensures the immune system avoids destroying host tissues?
Tolerance
What is self/ non-self discrimination?
immune system avoids host tissues- tolerance
Why is tolerance important?
random receptors generated could be anti-self
How does tolerance help?
prevents anti-self molecules from circulating in bloodstream
What prohibits an immune response to host tissues maintained through elimination/ cell inhibition?
self- tolerance
