Immune System Flashcards
Stimulated by structures common to groups of related microbes; cannot distinguish between fine differences of foreign substances.
Innate/Natural/Non-Specific Immunity:
Very specific response to a distinct macromolecule, also has the ability to “remember” macromolecule and respond more vigorously to the second exposure
Acquired Immunity:
What are the agranulocytes?
Monocytes and lymphocytes
What are the granulocytes?
Neutrophils, Eosinophils, and Basophils
What is the prevelence of WBCs from most to least abundant?
NLMEB
Are leukocytes larger or smaller than RBCs?
Larger
Are WBCs more or less numerous than RBCs?
Smaller
______ is protective; it neutralizes harmful agents, removes dead tissue and initiates the tissue repair process
Acute inflammation
What are the 5 signs of acute inflammation?
- Rubor (Red Discoloration)
- Calor (Heat)
- Dolor (Pain)
- Swelling
- Loss of Function
Non-self or damaged particles are engulfed by cells. •Essential part of inflammation and acquired immunity.
Phagocytosis
What are the 4 forms of innate immunity discussed?
Inflammation, Phagocytosis, Interferons (INF), and complement system
What are the 2 cells that accomplish phagocytosis primarily?
Macrophages and neutrophils
Which phagocytosizing cells are present in tissue at all times?
Macrophages
Can macrophages or neutrophils phagocytize far more & larger material?
Macrophages
____ are found on neutrophils and macrophages; help the cells know to engulf their meal; capable of recongnizing generic PAMPs and DAMPs
Toll-Like receptors (TLR)
If a target has an ________ attached to it, then it is marked for phagocytosis
immunoglobulin/antibody
Virally-infected cell secrete _____ and cause uninfected cells to produce enzymes that inhibit viral replication, which prevents spread of the virus to neighboring cells.
INF (interferons)
Consists of 30 distinct components that are in plasma in an inactive form and must be cleaved to become active. Activated by substances on the surface of microbes.
Complement system
What 3 things does the complement system activate/do?
(1) enhancement of inflammation,
(2) opsonization of pathogens,
(3) formation of a Membrane-Attack Complex (MAC) that lyses pathogens.
Very specific response to a distinct macromolecule (antigen), also has the ability to “remember” macromolecule and respond more vigorously to the second exposure. The process requires activation and lymphocytes (B and T).
Acquired immunity
Peptides or polysaccharide that are part of a molecule on an organism.
Antigen:
Molecular group on the antigen that is recognized by the immune system.
Epitope:
Each toxin or type of pathogen contains one or more specific chemical compounds in its make up that are different; are molecules capable of inducing an acquired immune response by binding to B-cell and T-cell receptors and the production of antibodies against them; are usually surface peptides or polysaccharides.
Antigen
______ present Antigens on their surface via Major Histocompatability Complex (MHC) Class II molecules.
Antigen Presenting Cells (APCs)
____ bind to and activate T helper cells (CD4).
APCs
______ cells activate the two branches of Acquired Immunity
T helper (CD4)
______ ingest the pathogen and induce an inflammatory response, if appropriate.
Macrophages
______ ingest the antigen and migrate to the nearest lymphoid organ
Dendritic cells
What are the main APCs of acquired immunity?
Macrophages, lymphocytes, and dendritic cells
Activated T cells (Natural Killer and Cytotoxic T, CD8) result in killing of infected cells and stimulation of phagocytosis of bacteria and fungi.
Cell mediated immunity
Activated B cells develop into Plasma cells that secrete Immunoglobulins. The antibodies neutralize toxins and viruses and enhancing phagocytosis of bacteria (opsinization)
Humoral immunity
After activation, _______ replicate a tremendous number of times (clones) and are secreted into the lymphatic circulation.
T and B Lymphocytes
Found on Antigen Presenting Cells (macrophages, dendritic cells, etc.); involved in presenting antigens to T Helper cells for cell mediated immunity
MHC Class II:
code for markers that display unique characteristics of self and foreign antigens when the cell is infected
MHC Class I:
Interaction of ____ and _____ causes activation of the T cell and creation of T cell clones.
MHC Class II and T helper cell membrane
Interaction of MHC Class II and T helper cells causes _____ and _______
activation of the T cell and creation of T cell clones
Interaction of _____ and _____ causes destruction of an infected cell when it presents a foreign antigen
MHC Class i and Cytotoxic T cell membrane
Interaction of MHC Class i and Cytotoxic T cell membrane causes ______
destruction of an infected cell when it presents a foreign antigen
____ Functions:
- Growth and proliferation of Cytotoxic and Suppressor T lymphocytes
- Growth and proliferation of B lymphocytes
- Stimulates activation of more T Helper Cells 4.Activation of macrophage system
a. Attract & slow/stop macrophage migration away from inflamed regions
b. Stimulate more efficient phagocytosis
T Helper cells
Which cells are activated by antigen presentation via MHC Class II?
T-helper cells
_______ Functions:
- After binding antigens, they:
a. Secrete perforin molecules that punch holes in the membrane of the target. The targeted cell will swell and lyse.
b. Release cytotoxic substances (granzymes) into the target through perforin channels that stimulate apoptosis - After secreting substances, they can unbind and move on to another cell
Cytotoxic T cells
T/F: All nucleated cells can present to Cytotoxic T cells because all cells (except RBCs) have MHC I
True
______ are Activated by Antigen Presentation via MHC Class I.
Cytotoxic T cells
- Capable of suppressing functions of both cytotoxic and helper T cells
- May be a separate type of cell, but they may not
- Many T cells may function as suppressors by secreting inhibitory cytokines - These cells are very important as they limit the immune system’s ability to attack one’s own tissues—they add to immune tolerance
Suppressor T cells
B cells and the antibodies they secrete create _____ immunity.
humoral
B Cells are activated by ____ and ______
intact antigens and activated T helper cells.
Some B cells differentiate into plasmablasts which later become ______
plasma cells
A mature plasma cell can produce _____ immunoglobulins/second
2000
Immunoglobulins are secreted into the _____ and carried into the blood for circulation.
lymph
_____ region of antibody structure has antigen specificity; where the antigen binds
Fab Region (Variable Portion)
_____ region of antibody structure determines diffusivity through membranes & tissue, complement attachment, & other biological properties. The heavy chain also determines Ig classification.
Fc Region (Constant Portion)
Phagocytes have ________, so antibody binding to an antigen can lead to enhances phagocytosis (OPSONIZATION).
Fc receptors
Ig
–Most abundant Ig in blood; crosses the placenta
–Complement activation
–Opsonizes bacteria
–Neutralizes bacterial toxins and viruses
–Antibody-dependent cell-mediated cytotoxicity mediated by NK cells & macrophages
–Primary antibody in the secondary response
–Mediates Type II (ex. blood transfusion reaction) and III (ex. Grave’s Disease, Myasthenia Gravis, Lupus) Hypersensitivity Reactions
IgG
Ig
–Mediates immediate (type I) hypersensitivity reactions (asthma, hay fever, anaphalysis, food allergies, drug sensitivity, etc.)
–Defends against parasitic infections
–Activates basophils, mast cells, and eosinophils
IgE
Ig
–Secretory Ig; synthesized by plasma cells in exocrine glands (saliva, tears, saliva, etc.)
–Most abundant Ig in the body (mucosal sites)
–Mucosal immunity and neonatal immunity (transfer via breast milk)
IgA
Ig
–Most potent activator of complement
–Largest of the immunoglobulins
–The first type produced in response to an antigen
–Membrane bound on B (monomer) but can also be secreted as a pentamer
IgM
Ig
–Membrane bound; Receptor on B lymphocytes surface and aids in antigen recognition by B lymphocytes
IgD
B cells begin to express what 2 Igs when they reach maturity? Expression of these antibodies on their membrane surface allows the B cell to be able to respond to antigens.
IgM and IgD
Which Ig produces the initial response to an antigen?
IgM
Which Ig produces the larger response to an antigen expecially in secondary immune response?
IgG
Which Ig is the main activator of the complement system?
IgM
What are the 3 mechanisms of Ig action dealing with the binding of antigen-binding site of an antibody?
- Neutralization
- Agglutination
- Precipitation
What are the 3 mechanisms of Ig action dealing with the exposed Fc portion following antigen binding by antibody?
- Complement Fixation
- Opsonization
- Activation of NK Cells
(immunologic unresponsiveness to self antigens)is vital for life and develops during preprocessing of T & B lymphocytes; protects against autoimmune disorders
TOLERANCE
____% of autoimmune diseases occur in women
90%
The following are theories for why _____ fails
- Failure of regulation of self-reactive lymphocytes
- Molecular mimicry by invading pathogens.
a. Invading antigens have a similarity to self-antigens
b. Occurs in Rheumatic Fever: Streptococcal M protein resembles a portion of cardiac myosin
Immune tolerance
Which hypersensitivity reactions are antibody dependent?
1, 2, and 3
Which hypersensitivity reactions are cell dependent?
4
Which Ig is associated with hypersensitivity type 1 rxn?
IgE
Which Ig is associated with hypersensitivity type 2 and 3 rxns?
IgG
What cells are associated with Type 4 hypersensitivity rxn?
Cytotoxic and helper t cells
a.One of the most powerful immune reactions
b.Occurs when IgE stimulates mast cells and basophils
Release of secretory products from mast cell granules (ex. Histamine) causes:
•Increases vascular permeability, vasodilation, bronchial and visceral smooth muscle contraction, salivary and bronchial secretions, and inflammation
•INCREASES respiratory resistance, DECREASES BP ALLERGIC REACTIONS
Immediate Hypersensitivity Reactions, Type I
Can be life threatening if severe due to bronchoconstriction and vasodilation (histamine)
Immediate Hypersensitivity Reactions, Type I
____ causes bronchoconstriction and vasodilation
Histamine
The following are treatments for ______
- Avoid the allergen
- Take drugs that block the action of lymphocytes, mast cells, or chemical mediators
- Undergo desensitization therapy
Immediate Hypersensitivity Reactions, Type I
_______ treatment of Immediate Hypersensitivity Reactions, Type I includes the following:
–Controlled injections of the antigen
–Works by producing IgG antibodies rather than IgE
–IgG considered to be “blocking antibodies”
Desensitization therapy
If you are allergic to something, what antibodies are produced?
IgE
_______ Hypersensitivity rxn
a. The pathogen does not cause much damage to the tissue
b. Instead, helper and cytotoxic T Cells are activated (increasingly so on repeat exposures)
c. Produce a cell-mediated immune reaction, stimulating macrophage recruitment and inflammation
d. Damage is delayed 1-2 days
Delayed –Type Hypersensitivity Reactions. Type IV Hypersensitivity