38 Questions
What is the main function of effector CTLs?
Recognizing and eliminating infected or abnormal cells
How do perforin and granzymes contribute to apoptosis?
Perforin forms pores allowing granzymes to enter the cytosol
Which cytokine produced by effector CTLs promotes inflammation and enhances immune responses?
Interferon-gamma (IFN-γ)
What is the main role of DCs in presenting viral or tumor antigens to naive CD8+ T cells?
Providing costimulation via B7 and other signals
What is the specificity of CD8+ TCRs in recognizing antigens?
Only recognizing cytosolic antigens presented by class I MHC molecules
What is the main function of effector CTLs during acute infection?
Secretion of cytokines
In chronic infections like HIV or HCV, what is a common characteristic of exhausted CTLs?
Reduced cytokine production
Which receptor is upregulated on exhausted CTLs in chronic infections?
PD-1
How do cytotoxic granules released by CTLs contribute to cell killing?
Produce toxins to damage cell membranes
What is the primary function of cytotoxic T lymphocytes (CTLs)?
Targeting and eliminating cells infected with intracellular pathogens
What is the primary process through which CTLs eliminate target cells?
Perforin/granzyme-mediated cell killing
How do CTLs recognize the target cells they need to eliminate?
By recognizing specific antigens presented on the surface of infected cells
What role do CTLs play in the immune response against intracellular pathogens?
Recognizing specific antigens on infected cells and inducing their apoptosis
How do cytokines like interleukin-2 (IL-2) affect CD8+ T cell responses?
Enhancing the proliferation and differentiation of CD8+ T cells
What is a key aspect of the interaction between CTLs and infected cells?
Recognition of specific antigens presented by infected cells
What is the function of perforin in cytotoxic T lymphocytes (CTLs)?
Forms pores in the target cell membrane
How do effector CTLs induce apoptosis in target cells?
Release cytotoxic molecules like perforin and granzymes
What is the primary function of granzymes released by CTLs during cytotoxic activity?
Cleave key intracellular substrates
In addition to combating intracellular pathogens, what other role do CTLs play?
Immune surveillance against cancer
What happens to target cells when CTLs release cytotoxic molecules like perforin and granzymes?
Undergo apoptosis
What is the main role of CD8+ T cells in response to antigens?
Recognizing and responding to antigens derived from infected or abnormal cells
Which signal is essential for optimizing CD8+ T cell activation and proliferation?
CD40-CD40L interactions
What happens during the differentiation of CD8+ T cells into effector cytotoxic T lymphocytes (CTLs)?
Acquisition of effector functions and changes in gene expression
How do effector CTLs combat pathogens?
By inducing apoptosis in infected or abnormal cells
What guides the migration of immune cells, including effector CTLs, to the site of infection?
Chemokines and adhesion molecules
What is the role of perforin in CTL-mediated killing of target cells?
It forms transmembrane channels in the target cell membrane, allowing for the influx of water and ions.
Which cell component is responsible for the precise delivery of cytotoxic molecules from CTLs to target cells?
Immune synapse
What is the primary function of granzymes in the process of CTL-mediated killing?
Inducing apoptosis by disrupting the integrity of the target cell membrane
What is the initial step taken by CTLs before initiating the killing of target cells?
Formation of the immune synapse
Which feature distinguishes granzymes from perforin in CTL-mediated killing?
Storage within cytotoxic granules
What is the purpose of CD8+ T cell activation?
To maintain immune homeostasis
Which cells are involved in antigen cross-presentation during CD8+ T cell activation?
Dendritic cells
What happens when naive CD8+ T cells encounter their specific antigen?
They bind to the antigen-presenting cells in lymph nodes
What is the role of CD4+ Helper T cells during CD8+ T cell activation?
Provide assistance in the activation process
Which molecule is responsible for presenting antigenic peptides on dendritic cells during CD8+ T cell activation?
Major histocompatibility complex class I (MHC-I)
What is the significance of antigen cross-presentation in CD8+ T cell activation?
It enables CD8+ T cells to respond to endogenous antigens
Which type of cells are targeted by CTLs during immune responses?
Cells containing specific microbes or antigens in their cytosol
What factor is essential for the proliferation and differentiation of CD8+ T cells into effector CTLs?
Interleukin-2 (IL-2)
Test your knowledge on agents modulating Th17 cell responses and the function of Cytotoxic T lymphocytes (CTLs) in the immune system. Learn about how these agents aim to dampen inflammation and how CTLs recognize and kill target cells containing specific microbes or antigens.
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