Immunology and T Cell Function

<p>To aid in the production of antibodies. (A)</p> Signup and view all the answers

<p>Legionella pneumophila. (A)</p> Signup and view all the answers

<p>By escaping into the cytoplasm. (D)</p> Signup and view all the answers

<p>Leishmania. (C)</p> Signup and view all the answers

<p>Activation of phagocytes, killing of infected cells, and support for B cell functions. (A)</p> Signup and view all the answers

<p>To ingest and destroy microbes (D)</p> Signup and view all the answers

<p>Infected host cells (B)</p> Signup and view all the answers

<p>By detecting antigens displayed by MHC molecules (C)</p> Signup and view all the answers

<p>Antigen recognition in peripheral lymphoid organs (A)</p> Signup and view all the answers

<p>They are dependent on host cells for survival and replication. (A)</p> Signup and view all the answers

<p>To capture and present antigens to T cells (D)</p> Signup and view all the answers

<p>Amplifying the immune response through cytokines (D)</p> Signup and view all the answers

<p>They can respond more rapidly upon re-exposure to an antigen. (B)</p> Signup and view all the answers

<p>To help B cells produce antibodies (D)</p> Signup and view all the answers

<p>IL-2 (A)</p> Signup and view all the answers

<p>By binding to activated endothelial cells (D)</p> Signup and view all the answers

<p>Their primary role in killing infected cells (D)</p> Signup and view all the answers

<p>They become memory T cells and circulate indefinitely (D)</p> Signup and view all the answers

<p>Cytokines produced in response to infection (B)</p> Signup and view all the answers

<p>To provide rapid response upon re-exposure to antigens (B)</p> Signup and view all the answers

<p>They activate phagocytes (D)</p> Signup and view all the answers

<p>It activates NF-κB by phosphorylating IκB. (C)</p> Signup and view all the answers

<p>Aerobic glycolysis (C)</p> Signup and view all the answers

<p>Movement of NF-κB to the nucleus (D)</p> Signup and view all the answers

<p>Generates PIP3 needed for downstream signaling. (C)</p> Signup and view all the answers

<p>It increases significantly. (C)</p> Signup and view all the answers

<p>It stimulates expression of antiapoptotic proteins. (B)</p> Signup and view all the answers

<p>Through multiple immune receptors including CD28. (A)</p> Signup and view all the answers

<p>Transcription factors such as NF-κB. (B)</p> Signup and view all the answers

<p>Facilitating clonal expansion of T cells (D)</p> Signup and view all the answers

<p>It undergoes clonal expansion followed by contraction (C)</p> Signup and view all the answers

<p>1 in 1,000,000 (B)</p> Signup and view all the answers

<p>The elimination of excess T cells after an immune response (A)</p> Signup and view all the answers

<p>They are about 1000 times greater (A)</p> Signup and view all the answers

<p>Maintenance of regulatory T cells (C)</p> Signup and view all the answers

<p>Gradual expansion followed by a contraction phase (B)</p> Signup and view all the answers

<p>They allow for a faster response upon re-exposure to the same antigen (A)</p> Signup and view all the answers

<p>Membrane molecules (A)</p> Signup and view all the answers

<p>Light chain (A), Heavy chain (B)</p> Signup and view all the answers

<p>Binding to complement proteins (D)</p> Signup and view all the answers

<p>Composed of both heavy and light chains (B)</p> Signup and view all the answers

<p>Determining antibody specificity (A)</p> Signup and view all the answers

<p>Ig domain (D)</p> Signup and view all the answers

<p>IgM (C)</p> Signup and view all the answers

<p>Hinge region (B)</p> Signup and view all the answers

<p>Variable and constant regions (B)</p> Signup and view all the answers

<p>The end of the Fc region (A)</p> Signup and view all the answers

<p>Multiple constant regions (A)</p> Signup and view all the answers

<p>IgA - Enhancing phagocytosis, IgE - Allergic reactions (C)</p> Signup and view all the answers

<p>Determining the type of antibody (B)</p> Signup and view all the answers

<p>More efficient antigen binding (B)</p> Signup and view all the answers

Antibodies are proteins that recognize and bind to specific antigens, triggering immune responses.

A specific molecule that an antibody binds to, triggering an immune response.

The region of an antibody that binds to a specific antigen.

A group of proteins that share a common structural motif, including antibodies.

Antibodies are composed of two identical heavy chains and two identical light chains.

The variable regions of an antibody's heavy and light chains, responsible for antigen recognition. These regions are hypervariable, allowing antibodies to recognize virtually any antigen.

The constant regions of an antibody's heavy and light chains, responsible for effector functions, such as complement activation and binding to Fc receptors on immune cells.

The flexible region connecting the Fab and Fc regions of an antibody, allowing for flexibility during antigen binding.

The fragment antigen-binding region of an antibody, composed of the variable and constant regions of the heavy and light chains.

The fragment crystallizable region of an antibody, responsible for various effector functions, including complement activation, binding to Fc receptors, and signaling immune cells.

The portion of the heavy chain that is responsible for binding to specific receptors on immune cells.

The portion of the heavy chain that is responsible for activating the complement system, a series of proteins that help clear pathogens from the body.

Highly variable regions within the variable regions (VH and VL) of an antibody, responsible for the specific antigen recognition. These loops are located at the tips of the antigen-binding sites and are extremely diverse.

A form of antibody that is secreted into the bloodstream and is the most abundant antibody in the body.

A form of antibody that is membrane-bound and is expressed on the surface of B cells.

T cells that stimulate macrophages to kill ingested microbes. They are crucial for fighting intracellular bacteria, fungi, and protozoa by enhancing the phagocytic activity of macrophages.

Special proteins that help B cells produce antibodies. These antibodies target and neutralize pathogens in the humoral immune response.

T cells that directly kill infected cells. They are essential for controlling viral infections and other intracellular pathogens.

These are microbes that can live and multiply inside host cells, evading normal immune defenses. Examples include some bacteria, fungi, viruses, and protozoa.

These are specialized immune cells that engulf and destroy microbes. They are a key part of the innate immune system.

These are cells that are not phagocytic. They can be infected by certain microbes, such as viruses.

The process by which a pathogen or other foreign substance is enclosed within a phagocytic cell.

These are specialized compartments within phagocytes where engulfed microbes are broken down and destroyed.

T lymphocytes get activated when they recognize specific antigens displayed on other cells, such as infected cells, by specialized molecules called major histocompatibility complex (MHC).

The process where naive T cells are exposed to an antigen in secondary lymphoid organs, leading to their proliferation and differentiation into effector and memory cells.

The stage where effector T cells are activated by the same specific antigen in various tissues or organs, enabling them to perform their specialized functions to fight infections.

Macrophages, B lymphocytes, and other leukocytes exchange signals with T lymphocytes, allowing them to communicate and coordinate the immune response.

Specialized cells that capture foreign antigens, process them, and present them on their surface to T cells in lymphoid organs.

Molecules displayed on the surface of cells, responsible for recognizing and binding to specific antigens. They are crucial for T cell recognition and activation.

T lymphocytes require specific signals to become activated. These signals include recognition of antigens presented by MHC, interaction with co-stimulatory molecules, and release of cytokines.

Receptors expressed by T cells that bind to specific antigens and co-stimulatory molecules, triggering the activation pathway for T cell proliferation and differentiation.

Helper T cells (CD4+) activate macrophages to destroy microbes and promote antibody production by B cells. They orchestrate immune responses by releasing signals that prompt other immune cells to action.

Cytotoxic T lymphocytes (CD8+) directly kill infected cells by releasing toxic substances that destroy the infected cell's membrane.

Naive T cells, upon encountering their specific antigen presented by an antigen-presenting cell (APC), undergo activation and differentiation into effector T cells.

Effector T cells leave lymphoid organs, enter the circulation, and migrate to sites of infection, where they encounter antigens and exert their effector functions.

Cytokines, signaling molecules produced by immune cells, attract effector T cells and other leukocytes to the site of infection through their interaction with endothelial cells.

Activated CD4+ T cells can migrate to lymph nodes and assist B cells in producing antibodies, contributing to the humoral immune response.

During activation, naive T cells express receptors (IL-2R) that bind to the cytokine IL-2, promoting their proliferation and differentiation into effector T cells.

After encountering their specific antigen, effector T cells can develop into memory T cells, which provide long-lasting immunity against the same pathogen.

A molecule that activates Protein Kinase C (PKC), which is involved in T cell signaling.

A protein complex that exists in the cytoplasm of resting T cells in an inactive form, bound to an inhibitor called IκB. When activated, it translocates to the nucleus and promotes gene transcription.

Adaptors are proteins that bind to and link different components together, facilitating signaling pathways. They play a crucial role in T cell activation.

A lipid kinase that phosphorylates the membrane phospholipid PIP2 to generate PIP3, which is essential for the activation of various signaling molecules, including Akt.

A serine-threonine kinase that is activated by PIP3 and plays a crucial role in promoting T cell survival, by stimulating the expression of anti-apoptotic proteins.

A process that involves the uptake of glucose and its conversion to energy, primarily by mitochondria.

A metabolic pathway that allows cells to generate energy in the form of ATP, but also provides building blocks for cell growth and proliferation.

The ability of T cells to differentiate into different effector cells, each with a specific function in the immune response, after encountering antigen.

The process of T cells multiplying rapidly in response to antigen, leading to a large number of antigen-specific T cells.

The process of T cells dying off after an infection is cleared, returning the immune system to a normal state.

The T cells that remain after an infection, providing long-term immunity. They are primed to respond quickly to the same pathogen in the future.

The increase in the number of T cells that can recognize a specific antigen due to clonal expansion.

A potent cytokine that stimulates the growth and differentiation of T cells, crucial for immune responses.

IL-2 is crucial for the maintenance of regulatory T cells, which help control immune responses and prevent overreactions.

The number of antigen-specific T cells increases dramatically during an infection, reflecting the clonal expansion of these cells.

The magnitude of clonal expansion is impressive, particularly for CD8+ T cells, which increase significantly in response to infection.