Tute quizzes & related tangents Flashcards
Affinity maturation of B cells occurs in which area of the secondary lymphoid tissue?
Germinal centres
The two mechanisms responsible for affinity maturation are?
- Antigen dose
- Somatic hypermutation
Name the three APCs.
- B cells
- Dendritic cells
- macrophages
What cell type can prime naive T cells?
Dendritic cells
Why are hybridomas useful?
They allow us to generate monoclonal antibodies (1 idiotype, 1 isotype) i.e. will recognise only 1 epitope.
What are the characteristics of myeloma cells in relation to hybridoma formation?
HGPRTase-
Ig-
Immortal
Why are plasma cells required to form hybridomas?
They are HGPRTase+, Ig+
also mortal but we don’t want that in the hybridoma cell
What are the 5 outcomes after myeloma cells are chopped up and combined with plasma cells via polyethylene glycol (hybridomas)?
- unfused plasma cell :(
- 2x fused plasma cells :(
- heterokaryon = 1x myeloma cell fusing with a plasma cell :D
- 2x fused myeloma cells :(
- unfused myeloma cell:(
Why is HAT medium used for heterokaryon selection during hybridoma formation?
(Un)fused myeloma cells:
It restricts the De novo synthesis pathway (the one that lets you make proteins etc. from AAs and mono/disaccharides), forcing use of the salvage pathway (recycle nucleotides from shitty DNA/RNA) but they still have no HPGRTase to breakdown the medium so they die anyway
(Un)fused plasma cells:
They just die after about a week
Plasma-myeloma hybrids:
Survive! HGPRTase comes from plasma cell and immortality comes from myeloma cell.
In the endogenous pathway of Ag processing and presentation, proteins from where are broken down into peptides (in proteosome)?
Cytosol!
What are the five major characteristics of cytokines?
- Pleiotropy = target many cell types and get multiple effects
- Synergy = 2+ cytokines where the combined effect is greater than the sum of the individual CK effects
- Redundancy = CKs with overlapping biological activities (just in case)
- Antagonism = one CK inhibits or reduces the effect of another
- Cascade induction = CKs whose effect is amplified through signal transduction cascade(s)
When T cells differentiate into their subtypes (eg. Th1, Th17, etc.), are they terminally differentiated?
Nope! They can change based on the surrounding environment (what different cytokines are nearby?)
Name three types of Ag receptors and what they bind to.
TCRs - Ags presented on MHC I and II (PROCESSED)
BCRs - native Ag
Fc receptors - Fc portion of Ab
FcαR = IgA
FcµR = IgM
FcγR = IgG
FcϵR = IgE
Fc𝛿R = IgDWhich cytokine promotes differentiation to a Th1 cell and what CKs does a differentiated Th1 cell secrete?
IL-12 to get to Th1, secretes IFNγ
Helps with Ag presentation
What kind of infection would you find a larger Th1 cell population?
- viral
- bacterial
Which cytokine promotes differentiation to a Th2 cell and what CKs does a differentiated Th2 cell secrete?
IL-4 encourages differentiation to Th2, then secretes IL-4, 5, 13
Th2 cells are usually present most in what kind of immune response?
Allergy, humoral immunity
Which cytokine promotes differentiation to a Th17 cell and what CKs does a differentiated Th17 cell secrete? Bonus points for cytokines that inhibit differentiation to Th17
IL-6 and TGFβ encourage Th17 differentiation. These cells secrete IL-17, 21, 22
Inhibited by IFNγ and IL-4
What kind of infection would you find a larger Th1 cell population?
- viral
- bacterial
Which cytokine promotes differentiation to a Th2 cell and what CKs does a differentiated Th2 cell secrete?
IL-4 encourages differentiation to Th2, then secretes IL-4, 5, 13
Th2 cells are usually present most in what kind of immune response?
Parasitic, allergy, humoral immunity
Which cytokine promotes differentiation to a Th17 cell and what CKs does a differentiated Th17 cell secrete?
Bonus points for cytokines that inhibit differentiation to Th17
IL-6 and TGFβ encourage Th17 differentiation. These cells secrete IL-17, 21, 22
Inhibited by IFNγ and IL-4
What does Th17 do?
Promotes tissue inflammation
WHat are the two main phagocytic cells of the IS?
- Neutrophils
- Macrophages
