Adaptive Immune System Overview

Flashcards covering key concepts of the Adaptive Immune System as presented in the lecture.

The adaptive immune response develops the body’s most effective means to eliminate __.

invaders.

The primary immune response occurs during the first exposure to an __.

antigen.

Humoral immunity is __-mediated and involves B cells.

antibody.

Cell-mediated immunity deals with antigens residing __ a host cell.

within.

Activated lymphocytes receive confirming signals from dendritic cells expressing __ antigen.

cognate.

Memory lymphocytes are long-lived and activated more quickly to provide __ response.

secondary.

Antigens may be classified into two general categories: T-dependent and T- antigens.

independent.

Immunoglobulin classes include IgM, IgG, IgA, IgD, and __.

IgE.

The part of the antibody that binds to antigen is called the __ region.

variable.

The process by which activated B cells change to produce more effective antibodies is called __ maturation.

affinity.

The development of B cells undergoes negative selection to eliminate __-reactive cells.

self.

Naive lymphocytes have not encountered __ and cannot react until activated.

antigen.

T cells recognize antigens presented on MHC class I and MHC class __ molecules.

II.

Cytotoxic T cells recognize antigens presented on MHC class I molecules from __ cells.

infected.

Helper T cells assist in activating __ cells and macrophages.

B.

The process of changing from one antibody class to another is called __ switching.

class.

The binding of IgG to antigen facilitates __, leading to destruction of pathogens.

phagocytosis.

Dendritic cells are crucial for T cell activation in the __ immune response.

adaptive.

Natural Killer (NK) cells can induce apoptosis in infected 'self' cells lacking __.

MHC class I.

During the secondary response, memory B cells respond more __ than naive B cells.

rapidly.

T-dependent antigens require confirmation from __ cells for B cell activation.

T.

The antigen-binding site of an antibody attaches to a specific __.

epitope.

What are the main types of lymphocytes?

The main types of lymphocytes are B cells, T cells, and natural killer (NK) cells.

What is the function of B cells?

B cells are responsible for producing antibodies that help to neutralize pathogens.

What is the function of T cells?

T cells play a central role in cell-mediated immunity, including killing infected host cells and activating other immune cells.

What role do natural killer (NK) cells play?

Natural killer (NK) cells provide a rapid response to viral-infected cells and detect and control early signs of cancer.

What are the subtypes of T cells?

The subtypes of T cells include helper T cells (CD4+), cytotoxic T cells (CD8+), regulatory T cells, and memory T cells.

What is the function of helper T cells (CD4+)?

Helper T cells (CD4+) assist other immune cells by releasing cytokines and enhancing the immune response.

What is the role of cytotoxic T cells (CD8+)?

Cytotoxic T cells (CD8+) kill infected or cancerous cells directly by recognizing specific antigens on their surfaces.

What is the function of regulatory T cells?

Regulatory T cells help maintain immune tolerance by suppressing harmful immune responses.

What is the role of memory B cells?

Memory B cells provide long-term immunity by remembering past infections and producing a faster antibody response upon re-exposure to an antigen.

What is the role of plasma cells?

Plasma cells are differentiated B cells that produce large volumes of antibodies to help neutralize pathogens.

What are dendritic cells?

Dendritic cells are antigen-presenting cells that capture, process, and present antigens to T cells, initiating an immune response.

What is the function of dendritic cells in the immune system?

Dendritic cells play a crucial role in linking the innate and adaptive immune systems by activating T cells and influencing immune responses.

What are the outcomes of antibody-antigen binding?

The outcomes of antibody-antigen binding include neutralization, opsonization, activation of the complement system, and agglutination.

What is neutralization in the context of antibody-antigen binding?

Neutralization occurs when antibodies bind to pathogens or toxins, preventing them from entering or damaging host cells.

What is opsonization?

Opsonization is the process whereby antibodies coat a pathogen, marking it for easier recognition and phagocytosis by immune cells.

How does antibody-antigen binding activate the complement system?

Binding of antibodies to antigens can activate the complement system, leading to pathogen lysis and enhanced inflammatory responses.

What is agglutination?

Agglutination is the clumping together of pathogens or particles due to antibody binding, which facilitates their removal from the body by phagocytes.

What is IgM?

IgM is the largest antibody isotype and is the first antibody produced in response to an infection.

What is the structure of IgM?

IgM is a pentamer, consisting of five monomeric units joined together, allowing it to effectively agglutinate pathogens.

What are the primary functions of IgM?

IgM's primary functions include initiating the complement cascade, agglutinating pathogens, and acting as a B cell receptor (BCR).

When is IgM produced?

IgM is primarily produced during the early stages of an immune response, providing immediate defense before IgG is produced.

What role does IgM play in blood typing?

IgM is involved in blood typing as it agglutinates red blood cells with specific antigens, helping to identify blood types and incompatibilities.

What is IgG?

IgG is the most abundant antibody in serum and is crucial for long-term immunity against pathogens.

What is the structure of IgG?

IgG has a Y-shaped structure, consisting of two heavy chains and two light chains, allowing for specific binding to antigens.

How does IgG function in neutralization?

IgG neutralizes pathogens by blocking their ability to bind to host cells and preventing infections.

What role does IgG play in opsonization?

IgG enhances phagocytosis by coating pathogens, making them easier for immune cells to recognize and engulf.

Which immunological processes are triggered by IgG binding?

IgG binding to antigens can trigger complement activation and engagement of immune cells, increasing the immune response's effectiveness.

What distinguishes different IgG subclasses?

There are four subclasses of IgG (IgG1, IgG2, IgG3, and IgG4) that vary in their ability to activate complement and bind to Fc receptors, affecting their functional roles in immunity.

What is IgA?

IgA is an antibody found primarily in mucosal areas, such as the gut, respiratory tract, and saliva, playing a critical role in mucosal immunity.

What is the structure of IgA?

IgA exists mainly in two forms: monomeric IgA in serum and dimeric IgA in secretions, where it has a secretory component that protects it from degradation.

What are the primary functions of IgA?

IgA functions to prevent pathogen attachment and invasion at mucosal surfaces, neutralizing toxins, and viruses in secretions such as saliva, tears, and breast milk.

What is IgD?

IgD is an antibody isotype mostly found on the surface of B cells, playing a role in B cell activation and maturation.

What is the primary function of IgD?

IgD's main function is to serve as a B cell receptor (BCR) that helps in initiating the B cell response to antigens.

Where is IgD primarily found?

IgD is predominantly found on the surface of B cells, with low levels detectable in serum.

What is IgE?

IgE is an antibody isotype associated with allergic reactions and responses to parasitic infections.

What role does IgE play in allergic reactions?

IgE binds to allergens and triggers mast cells and basophils to release histamine and other chemicals, leading to allergic symptoms.

How does IgE protect against parasites?

IgE facilitates the immune response against parasites by binding to them, which leads to the activation of eosinophils and mast cells that attack the parasites.

What are the clinical implications of elevated IgE levels?

Elevated IgE levels are often associated with allergic conditions such as asthma, hay fever, and allergic dermatitis.