Ch 7 Immunology: T-Cell-Mediated Adaptive Immunity

This set of 75 flashcards covers key concepts in T-cell-mediated adaptive immunity, including cell types, signaling mechanisms, and the roles of various cytokines.

T-cell priming

The process by which naive T cells circulate and interact with antigen presenting cells in secondary lymphoid tissues.

MHC

Major Histocompatibility Complex, molecules that present peptide fragments to T cells.

Dendritic cells

Professional antigen presenting cells that phagocytose pathogens and migrate to secondary lymphoid tissues.

PAMPs

Pathogen-associated molecular patterns recognized by dendritic cells.

TLRs

Toll-like receptors that recognize PAMPs on pathogens.

CCR7 receptor

A receptor on dendritic cells that binds chemokine CCL21, aiding in T-cell activation.

Costimulation

The secondary signal required for T-cell activation, often provided by B7 on APCs.

IL-2

A cytokine critical for T-cell growth and differentiation, produced upon T-cell activation.

Effector T-cells

Differentiated T cells that perform immune functions such as destroying infected cells.

APC

Antigen presenting cell, which includes dendritic cells, macrophages, and B cells.

Chemokines

Signaling proteins that direct the movement of immune cells to sites of infection.

B7

A costimulatory molecule expressed by mature dendritic cells for T-cell activation.

CD28

A receptor on T-cells that binds to B7 on APCs for costimulatory signaling.

Synapse

An immunological synapse formed between a T-cell and an APC during activation.

ITAMs

Immunoreceptor tyrosine activation motifs found in CD3 proteins crucial for signal transduction.

ZAP70

A protein that is recruited and activated in T-cells after synapse formation to initiate signaling pathways.

NFAT

Nuclear factor of activated T-cells, a transcription factor that activates T-cell expansion and differentiation.

JAKs

Janus kinases, enzymes that become activated upon cytokine receptor engagement.

Stat proteins

Signal transducers and activators of transcription that mediate gene expression changes.

TH1 helper T-cells

A subset of CD4 T-cells that promote macrophage activation and release cytokines like IFN-γ.

TH2 helper T-cells

CD4 T-cells that activate B-cells to produce IgE against allergens and multicellular parasites.

TFH cells

Follicular helper T-cells that assist in B-cell activation and differentiation.

CD8 T-cells

Cytotoxic T-cells that require stronger signals for activation compared to CD4 T-cells.

Cytotoxic T-cells

T-cells that eliminate infected or damaged cells via cytotoxic mechanisms.

Perforin

A protein released by cytotoxic T-cells that forms pores in target cell membranes.

Granzymes

Serine proteases that induce apoptosis in target cells by entering through pores.

Fas ligand

A protein expressed by cytotoxic T-cells that triggers apoptosis in target cells via Fas receptor.

Tregs

Regulatory T-cells that help maintain tolerance to self antigens and prevent autoimmunity.

Foxp3

A transcription factor found in Tregs that helps suppress immune responses.

NKT cells

Natural killer T-cells that recognize lipid antigens and play roles in immune responses.

γδ T-cells

A subset of T-cells that can recognize antigens without MHC presentation.

IL-17

Cytokine produced by TH17 cells that activates neutrophils and promotes inflammation.

L selectin

An adhesion molecule on T-cells that facilitates attachment to high endothelial venules.

CD34

An adhesion molecule on endothelial cells that interacts with L selectin on T-cells.

ICAM-1 & ICAM-2

Intercellular adhesion molecules on endothelial cells that bind to LFA-1 on T-cells.

Efferent lymphatic vessel

The vessel through which activated T-cells exit the lymph node.

Sphingosine-1-phosphate

A lipid signaling molecule that mediates the movement of T-cells back into circulation.

Immunological synapse

A structured interface between T-cells and APCs, enabling effective cell signaling.

Costimulatory signaling

A necessary signal in addition to TCR/MHC interaction for complete T-cell activation.

AP-1

A transcription factor that is activated downstream of the DAG signaling pathway.

PKC-θ

Protein kinase C theta, involved in T-cell receptor signaling and activation of NFkB.

TH17 cells

A subset of CD4 T-cells that contribute to inflammation and autoimmunity.

Lytic granules

Cytoplasmic secretory vesicles in cytotoxic T-cells containing cytotoxins.

IFN-γ

A cytokine produced by TH1 cells that activates macrophages and enhances their pathogen-fighting ability.

IL-4

A cytokine involved in B-cell activation and differentiation, particularly in response to allergens.

IL-10

An anti-inflammatory cytokine produced by Tregs that helps maintain immune homeostasis.

CD1d

A molecule that presents lipid antigens to NKT cells.

Calcium signaling

A crucial pathway activated by IP3 that leads to T-cell activation.

Cytokine receptors

Receptors on T-cells that bind cytokines and initiate signaling cascades.

Gene expression changes

Alterations in gene transcription that result from T-cell signaling pathways.

Memory T-cells

Long-lived T-cells that arise after initial activation and can respond rapidly to subsequent exposures.

Peripheral tolerance

The mechanism by which Tregs prevent autoimmunity and maintain self-tolerance.

Cytokine production

The release of signaling molecules by T-cells that modulate immune responses.

B-cell activation

The process by which B-cells are stimulated by T-cells to produce antibodies.

Clonal expansion

The proliferation of B-cells or T-cells in response to antigen recognition.

Vasodilation

The widening of blood vessels that occurs during inflammation, allowing increased immune cell access.

Neutrophil activation

Stimulation of neutrophils to enhance their ability to fight infections.