Lecture 22: Cell-Mediated Immunity I: Activation of T Cells

Which of the following is the primary route by which nave T cells enter lymph nodes?

What is the role of sphingosine 1-phosphate (S1P) in T cell trafficking?

Which type of cell is primarily responsible for presenting antigen to nave T cells in the lymph node to initiate T cell activation?

What is the consequence if a T cell receives signal 1 (TCR engagement) without signal 2 (co-stimulation)?

Which of the following molecules is NOT a co-stimulatory molecule involved in T cell activation?

What is the primary function of IL-2 in T cell activation?

Which of the following describes the function of CTLA-4 in T cell responses?

Which term describes the process where activated T cells proliferate rapidly to form a large population of cells?

What distinguishes central memory T cells (TCM) from effector memory T cells (TEM)?

Which of the following is the primary function of Lck in T cell signaling?

What is the role of ZAP-70 in T cell activation?

Which of the following transcription factors is activated as a result of T cell receptor signaling?

Which enzyme is directly inhibited by cyclosporine, leading to immunosuppression?

What is the role of CD69 in T cell activation and egress from lymph nodes?

Where do tissue dendritic cells primarily encounter antigens?

What is the effect of TNF-$α$ and PRR ligation on dendritic cells?

What surface molecule on T cells binds to GlyCAM-1 and CD34 on endothelial cells during the initial rolling interaction in lymph nodes?

The homing of T cells to draining lymph nodes is enhanced at sites of acute inflammation. What primarily mediates this increased homing?

What is the role of chemokines, specifically CCL21 binding to CCR7, in T cell trafficking?

Which of the following best describes the three key signals required for full activation and differentiation of nave T cells?

Mature dendritic cells express high levels of which molecule to stimulate T cells?

A researcher is studying T cell activation and introduces a mutation that prevents the interaction between CD28 and B7 on APCs. What is the most likely outcome?

What is the direct function of the protein kinase C (PKC) in T cell signaling?

How do glucocorticoids reduce inflammation?

What is the correct order of the following events in T cell activation, starting with antigen recognition?

Following T cell activation, several surface molecules are expressed to fine-tune the immune response. Which molecule, upon binding to its ligand, delivers an inhibitory signal to reduce T cell activity?

What is the role of phosphatidylinositol 4,5-bisphosphate (PIP2) in T cell signaling?

Memory T cells arise after an adaptive immune response. Which characteristic distinguishes effector memory T cells (TEM) from central memory T cells (TCM)?

A researcher is studying the signaling events downstream of TCR activation. They observe that a particular kinase is essential for activating phospholipase C (PLC). Which kinase is most likely involved?

Following the activation of a nave T cell, what is the primary outcome of the activation of the transcription factor NFAT?

A pharmaceutical company is developing a new drug to enhance T cell activation in cancer immunotherapy. Which of the following molecules would be the MOST promising target for increasing T cell activity?

A researcher introduces a mutation in T cells, which disrupts the function of the enzyme calcineurin. What would be the expected outcome on T cell activation?

Which event is most critical for the transition from a nave T cell to an effector T cell capable of directly killing infected cells or producing cytokines?

Which of the following is the most direct consequence of phospholipase C (PLC) activation in T cells?

A researcher discovers a new molecule that selectively inhibits the function of the MAP kinase ERK in T cells. What effect would this molecule likely have on T cell function?

A patient with an autoimmune disorder is treated with a drug that inhibits the interaction between LFA-1 and ICAM-1. What is the likely mechanism by which this drug reduces autoimmune symptoms?

What is the significance of ITAMs in the T cell receptor complex?

How does the alternate route of nave T cell entry into a draining lymph node differ from the traditional High Endothelial Venule (HEV) entry?

In the intricate dance of T cell activation, after initial antigen recognition has sparked the process, which co-stimulatory player is expressed on T cells, acting as a 'brake' with approximately twentyfold higher binding affinity to B7 molecules compared to CD28?

Which signaling element is cleaved to yield a product activating protein kinase C and another enabling calcium influx to the cytosol?

Imagine a scenario where a genetic mutation renders an individual unable to produce the common gamma chain ($\gamma$c) shared by several cytokine receptors, including the IL-2 receptor. What is the most dire immunological consequence?

In a scenario where a developing thymocyte expresses a T cell receptor (TCR) with high affinity for self-antigens presented on MHC molecules in the thymus, which of the following outcomes is MOST likely, considering the mechanisms of central tolerance?

Consider a genetically modified mouse model in which thymocytes are unable to express the co-receptor CD4. Which of the following outcomes related to T cell development and repertoire selection would be MOST likely?

A researcher is investigating a novel immunotherapeutic strategy involving the adoptive transfer of ex vivo-activated T cells. To enhance the in vivo persistence and anti-tumor activity of these transferred T cells, which of the following interventions targeting T cell metabolism would be MOST rational?

In the context of chronic viral infections, such as HIV, T cell exhaustion is a significant barrier to effective immune control. Which of the following interventions, based on a deep understanding of the molecular underpinnings of T cell exhaustion, would MOST likely reinvigorate exhausted T cells and restore their effector function?

A researcher is investigating the impact of chronic exposure to low-dose ionizing radiation on T cell function. Transcriptomic analysis reveals significant downregulation of genes involved in DNA repair pathways and upregulation of genes associated with cellular senescence. Which of the following functional consequences is MOST likely to be observed in these irradiated T cells?

A patient with a rare genetic defect exhibits impaired production of phosphatidylinositol 4,5-bisphosphate (PIP2) in T cells. Which of the following downstream signaling events would be MOST directly affected in these T cells following T cell receptor (TCR) stimulation?

An immunotherapy drug aims to enhance T cell activation by modifying co-stimulatory signals. Which of the following strategies, targeting the CD28-B7 interaction, would MOST effectively achieve this goal without inducing excessive systemic inflammation?

A research team is investigating novel strategies to overcome T cell tolerance to tumor-associated antigens. Which of the following interventions, designed to modulate the interaction between T cells and antigen-presenting cells (APCs), would be MOST effective in breaking tolerance and inducing a robust anti-tumor T cell response?

A researcher is studying the effects of a novel immunosuppressive drug on T cell signaling. The drug selectively inhibits the activity of phospholipase C (PLC). Which of the following downstream events would be MOST directly impaired by this drug?

A research team aims to develop a strategy to enhance the in vivo survival and function of adoptively transferred T cells for cancer immunotherapy. Based on current understanding of T cell metabolism, which approach would be MOST effective in achieving this goal?

Consider a scenario where a genetic mutation leads to the constitutive activation of Protein Kinase C (PKC) in T cells. Which of the following would be the MOST likely consequence of this mutation on T cell function and activity?

Which of the following mechanisms is MOST critical for enabling activated T cells to migrate out of the lymph node and into peripheral tissues to exert their effector functions?

In the context of T cell development in the thymus, what is the MOST critical function of the AIRE (Autoimmune Regulator) protein?

A researcher is investigating the role of CD69 in T cell trafficking during an acute viral infection. Which of the following experimental observations would BEST support the conclusion that CD69 is essential for retaining activated T cells within the infected tissue?

A patient presents with a novel immunodeficiency characterized by a complete absence of ZAP-70 expression in T cells. Which of the following signaling events would be MOST directly affected in these ZAP-70 deficient T cells following T cell receptor (TCR) stimulation?

A researcher is investigating the role of specific kinases in regulating T cell activation. They discover a novel kinase, Kinase X, that is activated downstream of ZAP-70 and is essential for the activation of NFAT. Which of the following is the MOST likely mechanism by which Kinase X promotes NFAT activation?

A pharmaceutical company is developing a new drug to selectively inhibit the function of the MAP kinase ERK in T cells. What effect would this molecule likely have on T cell function?

Which of the following best describes the mechanism by which cyclosporine exerts its immunosuppressive effects?

Following T cell activation, CTLA-4 is expressed and binds to B7 molecules on antigen-presenting cells (APCs). What is the PRIMARY mechanism by which CTLA-4 regulates T cell responses?

What is the MOST direct effect of phospholipase C (PLC) activation in T cells?

Which outcome is MOST likely to occur if a T cell receives signal 1 (TCR engagement) without signal 2 (co-stimulation)?

What is the primary function of Lck in T cell signaling?

During T cell activation, what is the role of phosphatidylinositol 4,5-bisphosphate (PIP2)?