Lecture 14: Lymphocyte Subsets Flashcards
Where does CD4/CD8 T cell differentiation occur?
Occurs during development in the thymus.
What leads to commitment to the CD4 lineage?
The expression of transcription factor ThPOK which represses Runx3.
Which transcription factor is associated with commitment to the CD8 lineage?
Runx3, which silences CD4 expression
True or false:
NK cells do not develop in the thymus and express rearranging antigen receptors.
False. They do not develop in the thymus, however they also do NOT express rearranging antigen receptors.
NK cells are important for
Viral and tumour immunity.
B1 B cells are also called…
Innate-like B cells
Development and renewal of B1 cells occurs in the
Development occurs during the perinatal period and self-renewal occurs in the periphery.
Which antibody do B1 cells spontaneously secrete?
IgM and to a much lesser extent IgG.
True or false:
B1 cells are directed against carbohydrates, proteins and lipids.
False, B1 cells are not directed against proteins.
True or false:
B1 cells are found in high numbers in the lymph nodes and spleen.
False, they are predominantly found in pleural and peritoneal cavities. Relatively absent from spleen and lymph nodes.
True or false:
Marginal Zone B cells are derived from B1 cells
False. They are believed to be derived from B2 cells.
True or false:
B1 cells develop into memory B cells.
False, they are do not develop into memory B cells and thus are not deemed to be part of the adaptive immunity.
True or false:
In contrast to follicular B cells, Marginal zone B cells are largely non-recirculating
True.
γδ T cell specificities
Phospholipids
MHC-I like molecules
Heat shock proteins
Natural Killer T cells (NKT) specificities
Lipid/glycolipid antigens bound to CD1 proteins
Mucosal-Associated Invariant T (MAIT) cells specificities
Vitamin B (riboflavin) metabolites covalently bound to MR1
Recognition of MHC-II induces a) ____ which also represses b) ____ expression
a) ThPOK
b) Runx3
NKT cell recognition of lipid-loaded MHC class I-like molecules is driven by the a) ___ chain more than the b) ___ chain.
a) alpha
b) beta
Selection/expansion of MAIT cells is dependent on _____
commensal gut flora
Th1 produces which cytokines and effector proteins?
IL-2, IL-3, IFN-gamma, lymphotoxin
Th2 produces which cytokines and effector proteins?
IL-3, IL-4 and IL-5
Th1 cells are biased towards immunity against _______
Intracellular pathogens
Th2 cells are biased towards immunity against __________
Parasites
Regulatory T cells secrete _____ which dampen many aspects of immunity
IL-10 and (TGF-β)
Th17 cells produce
IL-17 - a strong pro-inflammatory cytokine
The main transcription factor for Th17 cells is
RORgammaT
The main transcription factor for regulatory T cells is
FOXP3
Helper T cell subsets:
Th1, Th2, Th9, Th17, Tfh, T Reg, (nTreg/iTreg)
Role and function of CXCR5
A g protein coupled receptor responsible for drawing the Tfh cell towards the B cell area of lymph node
Key transcription factor expressed by Tfh cells is
BCL-6
Key cytokine produced by Tfh cells is
IL-21
Lymphoid Tissue Inducer Cells (LTi) are dependent on the transcription factor _____
RORgammaT
ILC1 produce
IFN-gamma, TNFalpha,
ILC2 produce
type II cytokines e.g. IL-5, IL-9, IL-13
ILC3 produce
IL-22 and IL-17
An IKAROS KO fails to produce
B cells
Role of CD4 cells with macrophage help
Help macrophages eliminate pathogens that the macrophages themselves are infected with. An important molecule in this process is IFN-γ.
Role of CD4 cells with Killer T cells
CD4 T cells license dendritic cells for optimal activation of CD8 T cells.
CD40L is upregulated on the CD4 T cell which stimulates the CD40 on the dendritic cell which enables the dendritic cell to provide signals 2 and 3 to the CD8 cell
Function of LTi cells
Induce formation of lymph nodes and Peyer’s patches
