Adaptive Immune Response Flashcards
What method of cell killing do natural killer cells utilize?
Degranulation
Where are naive t cells activated?
In a lymph node after contact with an antigen presenting cell
What are the three methods of costimulation for activation of CD8+ cells?
- APCs via B7 binding to CD28
- CD4+ helper cells via cytokines
- CD4+ helper cells increase APC activity via CD40L binding to CD40 on APC
What changes occur upon activation from naive t cell to differentiated cytotoxic T lymphocytes?
- Develop granules that are eventually released to kill cells
- Ability to secrete IFN-gamma and TNF-alpha
What is the importance of CD4+ T cells?
Although they do not directly kill infected cells they release critical cytokines
What cytokine does CD4+ t cells release that activates macrophages?
IFN-gamma
Which cytokines promote memory cells?
IL-7 and IL-15
Where do central memory t cells reside?
Lymph nodes
Where do effector memory t cells reside?
Peripheral tissue
What is the most prevalent antibody in the mouth?
IgA
How do NK cells recognize normal cells of the body so they don’t kill them?
Recognize self class I MHC (inhibited in infected cells)
What are the two important components of the granules used by Nk cells and CTLs?
- Perforin: allows for entry
2. Granzyme: induces apoptosis
How do intracellular pathogens try to evade the immune response?
Prevent cell from expressing MHC 1 properly
*NK cell will then kill it due to no MHC I inhibition
What are the two jobs of NK cells?
- Produce cytokines (IFN-gamma)
2. Naturally kill microbes
What is the process of a NK cell and macrophage working together to kill a microbe?
Macrophage phagocyticizes microbe -> produces IL-12 which stimulates NK cells -> NK cells release IFN-gamma -> macrophages kill microbes
What typically binds to the NK cells inhibitory receptor to show that it is a healthy normal cell?
MHC I with a self peptide
What is the role of CD8 and LFA-1 in CTL function?
They are accessory receptors.
CD8 binds to MHC class I LFA-1 binds to ICAM-1
What is FAS?
A molecule that can be used as an alternative killing method by CTLs
___________ are made by _________ and constitute most of the defense against extracellular pathogens.
Antibodies; B cells
T/F: Th2 immunity drives the antibody response.
TRUE
Which molecules on a B cell bind? Which will signal?
IgM = binds
Igbeta and alpha = signal
The B cell receptor can receive help from a ___________ receptor in order to activate the B cell.
Compliment
Is the activation of 1 B cell receptor enough to activate a B cell?
NO
What types of molecules can single handedly activate a B cell without T cell help?
Molecules with long repeats (can bind multiple B cell receptors). Ex. LPS
____ is a T cell independent antibody and is often found in the blood early on in an infection.
IgM
____ is a T-cell dependent antibody and is normally found several weeks after infection.
IgG
What are the three major fates of B cells helped by Helper T cells?
- IgM: antibody secretion
- IgG: isotype switching
- Memory B cells
What is necessary for T-B cell binding?
CD40 binds to CD40L
In the T and B cell relationship, what types of molecules determine the B cell fate?
Cytokines from T cell
What cytokine leads to IgG production?
IFN-gamma
What cytokine leads to IgE production?
IL-4
Various cytokines lead to production of what antibody often found in the oral mucosa?
IgA
Which antibodies can lead to complement activation?
IgM, IgG, IgA
Which antibodies can lead to the neutralization of microbes and toxins?
IgM, IgA, IgG
Which antibodies can opsonize and phagocytize microbes?
IgG
Which antibodies can create antibody-dependent cellular cytotoxicity?
IgG, IgE
T/F: Vaccination is passive immunization.
FALSE
Active immunization
What are the three types of live vaccines?
- Live Attenuated
- Heterologous
- Live recombinant
What are the pros and cons of live vaccines?
Pros: best response, inexpensive
Cons: can’t use in immunocompromised, fear of reversion to virulence
What are the pros and cons of killed vaccines?
Pros: safer; no worry of virulence
Cons: less effective immune response, expensive
T/F: Vaccines are better at activating B cells than T cells.
TRUE
