T cells lecture 4

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Which ligand is expressed on the surface of effector CD8+ cells and TH1 cells to exert cytotoxic effects?

CD80 Ligand

CD28 Ligand

Fas Ligand (correct)

CD40 Ligand

What is the role of CD40 Ligand in T cell activation?

Promote differentiation into TH2 cells

Activate B cells and innate immune cells (correct)

Exert cytotoxic effect

Induce proliferation of T cells

Which ligand binds Fas on the surface of infected or stressed cells in the periphery?

TNF Ligand

Fas Ligand (correct)

CD40 Ligand

CD28 Ligand

What provides Signal 3 for CD8+ T cell activation into Cytotoxic T lymphocytes (CTL)?

Interleukin-2 (IL-2) Signup and view all the answers

In T cell activation, what role does the interaction between CD28 and B7 play?

Inducing T cell proliferation Signup and view all the answers

Which type of T cells don't express CD40 Ligand ?

CD8+ T cells Signup and view all the answers

What is a key part of licensing for both CD4+ and CD8+ T cells?

Signal through CD40 signaling Signup and view all the answers

Which process occurs in a simultaneous fashion during CD8+ T cell activation?

IL-2 secretion and CD40L expression Signup and view all the answers

What leads to increased expression of costimulatory molecules like CD80 and CD86 on APCs?

CD40 binding with activated CD4+ T cells Signup and view all the answers

Which molecule helps in directing the immune response upon CTL activation?

Cytokine secretion Signup and view all the answers

What is the first step in CTL-mediated killing of infected cells?

Recognition of nonspecific adhesion molecules Signup and view all the answers

Which molecule is responsible for inducing apoptosis in infected cells during Fas-FasL mediated killing?

FasL (Fas ligand) Signup and view all the answers

What triggers the release of granules by CTLs during granule-mediated killing?

Specific recognition via TCR:pMHC Signup and view all the answers

Which process involves reorganizing the cytoskeleton and cytoplasmic contents by CTLs?

Granule-mediated killing Signup and view all the answers

What is a critical action that APCs must take to present antigen to both CD4+ and CD8+ T cells?

Cross-presentation to MHC Class I for CD8+ T cell Signup and view all the answers

What is an essential requirement for CD8+ T cell activation to occur?

Licensing through CD40 binding Signup and view all the answers

What is the main function of Perforin in CTLs?

Forms pores in the cell membrane Signup and view all the answers

Which proteins are found in the granules of CTLs?

Perforin and Granzyme B Signup and view all the answers

What is the consequence of Granzyme B entering the cytoplasm of the target cell?

It disrupts the mitochondrial outer membrane Signup and view all the answers

Which pathway converges on caspase-3 activation, ultimately leading to apoptosis?

Fas/FasL pathway Signup and view all the answers

What is the function of CTLs in recognizing infected or tumor cells?

Killing the target cell through various pathways Signup and view all the answers

How do CD8+ T cells induce apoptosis in infected target cells?

Through pMHC:TCR interaction causing apoptosis Signup and view all the answers

What is a classic sign of apoptosis observed in the text after 40 minutes of CTL interaction with a target cell?

Membrane blebbing Signup and view all the answers

What is the role of Granules in CTLs during effector responses?

Direct killing of infected or tumor cells Signup and view all the answers

What happens when TCR on CTL binds pMHC?

Intracellular structure reorganization & granule release Signup and view all the answers

How are Fas Ligand and CD40 Ligand classified based on their location in the cell?

Transmembrane ligands Signup and view all the answers

Which cells express Fas Ligand on their surface to exert cytotoxic effects?

Effector CD8+ T cells Signup and view all the answers

Which ligand binds to CD40 on B cells and innate immune cells for activation?

CD40 Ligand Signup and view all the answers

What type of cells require more co-stimulation through B7/CD28 interaction?