Block E - Cellular Memory Flashcards
Define immune memory (1 mark)
the ability of the immune system to respond to previously encountered antigens
What is the importance of immune memory in terms of energy conservation. (1 mark)
memory cells enable the immune system to conserve energy by not having to mount a full immune response upon re-exposure to the pathogen
Which of the following cytokines is primarily involved in the survival and homeostasis of memory T cells?
a) Interleukin-2 (IL-2)
b) Interleukin-7 (IL-7)
c) Interleukin-6 (IL-6)
d) Interferon-gamma (IFN-γ)
b
- Which cytokine is critical for the differentiation and maintenance of effector memory T cells (TEM)?
a) Interleukin-15 (IL-15)
b) Interleukin-4 (IL-4)
c) Interleukin-21 (IL-21)
d) Transforming Growth Factor-beta (TGF-β)
a
- Which cytokine produced by T helper 2 cells is involved in promoting the differentiation of B cells into memory B cells?
a) Interleukin-21 (IL-21)
b) Interleukin-4 (IL-4)
c) Interleukin-6 (IL-6)
d) Interferon-gamma (IFN-γ)
b
- Which cytokine is important for the generation of memory T cells by preventing apoptosis and promoting long-term survival?
a) Interleukin-6 (IL-6)
b) Interleukin-2 (IL-2)
c) Interleukin-15 (IL-15)
d) Interleukin-7 (IL-7)
d
- Which cytokine plays a key role in promoting the formation of germinal centers and memory B cells during an immune response?
a) Interleukin-21 (IL-21)
b) Interleukin-5 (IL-5)
c) Interleukin-2 (IL-2)
d) Interferon-alpha (IFN-α)
a
- Which of the following cytokines is primarily responsible for inducing the survival of memory B cells?
a) Interleukin-10 (IL-10)
b) Interferon-gamma (IFN-γ)
c) Interleukin-15 (IL-15)
d) Transforming Growth Factor-beta (TGF-β)
a
- Which cytokine is produced by follicular helper T cells and is essential for the differentiation of B cells into memory B cells and plasma cells?
a) Interleukin-21 (IL-21)
b) Interleukin-4 (IL-4)
c) Interleukin-7 (IL-7)
d) Transforming Growth Factor-beta (TGF-β)
a
- Which cytokine is primarily involved in the differentiation of memory T cells and is produced during viral infections or immune responses?
a) Interleukin-7 (IL-7)
b) Interferon-gamma (IFN-γ)
c) Interleukin-15 (IL-15)
d) Interleukin-4 (IL-4)
b
- What is the primary role of IL-2 in the immune system during the formation of memory cells?
a) It stimulates the production of antibodies by memory B cells.
b) It drives the initial clonal expansion of T cells.
c) It supports the survival of memory B cells.
d) It helps maintain the long-term survival of memory B cells.
b
- What is the term used to describe the phenomenon where macrophages “remember” previous infections and respond more robustly to re-infection?
A) Adaptive immunity
B) Trained immunity
C) Immune tolerance
D) Immunosuppression
b
- Which of the following epigenetic changes is commonly associated with the activation of pro-inflammatory genes in trained macrophages?
A) DNA methylation
B) Histone acetylation
C) RNA splicing
D) Translation inhibition
b
- In trained immunity, epigenetic changes in macrophages primarily involve alterations in:
A) Protein synthesis
B) Chromatin structure and gene expression
C) Cell division
D) Antibody production
b
- Which of the following is a key characteristic of macrophages that have undergone trained immunity?
A) They become resistant to all forms of infection.
B) They show a slower immune response to subsequent infections.
C) They exhibit increased expression of cytokines and pattern recognition receptors.
D) They do not change their metabolic activity after re-exposure.
c
- DNA methylation in trained macrophages typically leads to:
A) Gene activation
B) Gene silencing
C) Inhibition of protein synthesis
D) Histone deacetylation
b
- Which of the following best describes the role of metabolic reprogramming in trained immunity?
A) It reduces the macrophage’s ability to produce energy.
B) It supports enhanced glycolysis to produce more energy for inflammatory responses.
C) It decreases cytokine production by limiting metabolic substrates.
D) It prevents macrophages from differentiating into different types of immune cells.
b
- Epigenetic reprogramming in trained macrophages is most likely to lead to:
A) A decrease in the macrophage’s life span.
B) A more potent immune response upon re-exposure to the same pathogen.
C) A reduced inflammatory response in future infections.
D) A complete shutdown of the macrophage’s function.
b
- One potential negative implication of epigenetic changes in trained macrophages is:
A) Increased susceptibility to infections.
B) Chronic inflammation leading to diseases like atherosclerosis or rheumatoid arthritis.
C) Impaired vaccine responses.
D) Decreased ability to mount an immune response.
b
- Which of the following epigenetic modifications is most commonly associated with gene activation in macrophages undergoing trained immunity?
A) Histone methylation
B) DNA methylation
C) Histone acetylation
D) Chromatin condensation
c
- In addition to genetic factors, which of the following external factors can influence epigenetic changes in macrophages?
A) Pathogen type
B) Environmental factors like diet and pollution
C) Sleep patterns
D) All of the above
d
Explain why epigenetic changes in trained macrophages can lead to chronic inflammation? (3 marks)
-epigenetic changes can cause macrophages to remain in a heigtened state of alert. this leads to an increased production of pro-inflammatory cytokines (IL-6, TNF-α)
-this can lead to uncontrolled inflammation and can contribute to inflammatory diseases such as atherosclerosis, rheumatoid arthiritis
-continuous inflammation driven by trained immunity can damage tissue and organs over time.
What are the key differences between unswitched and switched memory B cells in terms of their characteristics and functions? (3 marks)
-unswitched memory B cells are characterized by IgM+ and IgD+ expression, primarily secreting IgM
-swicthed memory B cells express CD80+ and PD-L2+ with IgD- and secrete IgG.
-this distinction highlights their roles in different stages of immune responses, with switches cells providing a more robust and high affinity response
How does repeated exposure to an antigen influence antibody production and affinity? (4 marks)
-increased antibody levels
-high affinity antibodies
-memory b cells are activated to produce more effective responses
-IgM levels decrease with repeated exposure as switched memory B cells take over the response
What’s the difference between affinity in B memory cells and T memory cells.
Memory B cells undergo somatic hypermutation, increasing the affinity of antibodies over time, while memory T cells do not change affinity post-activation
What are the key differences between central memory T cells and effector memory T cells in terms of their functions and characteristics? (2 marks)
-central memory T cells (Tcm) express CCR7 and reside in peripheral lymphoid tissues, allowing for a sustained response upon re-exposure to antigens
-effector memory T cells (Tem) rapidly differentiate into effector T cells upon restimulation, secreting large amounts of cytokines like IFN-γ, IL-4, and IL-5, but do not express CCR7.
Describe linear differentiation (1 mark)
The linear differentiation model suggests a straightforward progression from naive to memory T cells
Describe bifurcative differentiation? (1 mark)
bifurcative differentiation indicates that T cells can diverge into different functional subsets
In what ways do memory T cells differ from memory B cells in terms of their activation and affinity maturation? (3 marks)
Memory T cells do not undergo affinity maturation after their initial activation, maintaining the affinity of the original antigen interaction, while memory B cells continue to mutate their V-regions, enhancing their affinity with each activation. This distinction highlights the different roles these cell types play in adaptive immunity.
