Adaptive Immunity Flashcards
Develops only after exposure to an antigen.
Occurs naturally or artificially and actively or passively.
Based on recognition- interactions between receptors on immune system cells, antibodies and antigens
Comparability- of size, shape and charge
Adaptive immunity
“Learned” response that attacks specific pathogens
Complex & slow development
Cross-regulate defense network
Memory response
Recognizes small parts of a pathogen called antigens
2 branches- humoral and cell mediated immunity
Key properties of adaptive immunity
“Antibody generating”
Describes anything that can elicit an adaptive immune response.
Must be presented to B and T cells to “show” them what to look for.
Antigen
Specific binding site on an antigen.
Antigens can have more than one
Epitope
Very small molecules that, when attached to a larger carrier protein, can act as an antigen.
“Free epitope”
Not generally associated with pathogens but can cause immune response.
Hapten
“Outside”
Pathogens are in the blood and tissue.
Exogenous antigen
“Inside” an infected cell (pathogen) & putting proteins on outside.
Endogenous antigen
Proteins like an ID badge. They are supposed to be there. B and T cells should not recognize these.
Autoantigens
A measure of how well and antigen elicits immune response
Antigenicity
Amount of antigen needed to generate an optimal response.
Low dose does not activate enough B cells.
Too high of a dose lead to B cell tolerance.
Threshold dose
recognize innate immune response and interact with
Fc/constant region
Activated B cells convert to plasma cells and pump out antibodies.
Bind to surface of pathogens, bind to toxins, & coat pathogens.
Phagocytosis or pathogen destruction by complement proteins.
Antibody functions
Plasma cell start by making what kind of antibodies
IgM
“all”, located on unucleated host cells, present self antigens & also present on “non-self” antigens
MHC 1
“Special”
Located on macrophages, dendritic cells, and B cells.
Antigen presenting cells
Used for present epitopes to B and T cells to activate them.
MHC 2
APC’s present antigens to B & T cells to initiate adaptive immunity.
Dendritic, macrophages and B & T cells
After phagocytosis bits and pieces of pathogen (antigen) are present on MHC for recognition by T & B cells
Antigen presentation
Mature in the bone marrow
Result in plasma cells (release antibodies) and B memory cells involved in humoral response
B cells
Mature in the thymus
Result in :
Cytotoxic T cells- killed infected host cells
Helper T cells- assist in activating AI
T regulatory cells- prevent auto immunity
T cells
Must be one B or T cell that will recognize any infection we encounter.
Each B & T cell must be tested to avoid attacking self-antigens.
Finding B & T cells that bind with antigens take time.
Production of B and T cells
Block activation of harmful self-reactive lymphocytes.
Prevent autoimmune disease.
Regulatory T cells
Uses apoptosis immune response to intracellular pathogens (attack infected host cells).
Do not use antibodies
Main defense: T cells
“Endogenous cells”
Use cytotoxic T cells- activated by T cells and APC’s and has own T cell receptor.
Directly kills host cells infected with virus or pathogen and cancer cells.
Cell-mediated immune response
Uses antibodies to assist in phagocytosis.
Immune response centered in the blood.
Main defense : B cells
Humoral immunity
• can be antigen present or activated by APCs
• displays antigen on MHC 2
• tells B cell to make more copies/ mitosis
• memory cells or plasma cells
B cell activation w/ helper T cells
Recognize a particular antigen or pathogen by size, shape or charge
Variable region
