Immunity I Flashcards
Protection against infections:
immunity
Collection of cells and molecules that are responsible for defending the body against pathogens:
immune system
Organism that causes disease:
pathogen
The goal if the immune system is to: (2)
- prevent foreign substances from entering the body
- establish immunocompetence
The ability of the body to produce a robust immune response following exposure to disease-producing agents
immunocompetence
Mediates the initial protection against infections:
innate immunity
Innate immunity is considered a ____ defense
non-specific
_____ is responsible for rapidly eliminating microbes that enter host tissues
innate immunity
Responsible for eliminating damaged and necrotic cells:
innate immunity
The non-specific defenses of innate immunity include: (3)
- physical barriers
- chemical barriers
- effector cells
The physical barriers of innate immunity include: (4)
- skin
- mucous membranes
- nasal hairs
- respiratory tract cilia
The chemical barriers of innate immunity include: (6)
- skin pH
- mucous secretions
- gastric acids
- tears
- sweat
- saliva
The effector cells of innate immunity include: (4)
- macrophages
- neutrophils
- NK cells
- dendritic cells
PAMPs:
Pathogen Associated Molecular Patterns
Recognize general microbial patterns through pattern recognition receptors:
PAMPs
DAMPs:
Damage associated molecular patterns
Recognize molecules released from damaged or necrotic host cells:
DAMPS
Neutrophils are considered ____ of innate immunity
effector cells
First cell type to respond topmost infections (bacterial and fungal)
Neutrophils
Describe the lifespan of neutrophils in innate immunity:
short-lived
function to ingest and degrade dead cells, debris, tumor cells, pathogens, and foreign material through phagocytosis:
neutrophils
Neutrophils may be activated by ____ in innate immunity
macrophages
How do neutrophils degrade dead cells, debris, tumor cells, pathogens and forge in material?
phagocytosis
Dendritic cells are considered ____ of innate immunity
effector cells
Describe the structure of dendritic cells:
thin, membranous cytoplasmic processes
What do dendritic cells do?
Present antigens to T-cells
Dendritic cells present ____ to ____
antigens; T-cells
Dendritic cells are abundant near:
epithelium & mucous membranes
Dendritic cells help to:
shape adaptive immune response
Although dendritic cells are part of the ____ immune response, they help to shape the ___ immune response
innate immune response; adaptive immune response
Dendritic cells in the epidermis are called:
langerhans cells
Macrophages are considered ____ of innate immunity
effector cells
Macrophages can survived in ____ for ___
extravascular tissue; long periods
What are the three main functions of macrophages?
- ingest and degrade dead cells, debris, tumor cells, pathogens and foreign material through phagocytosis
- may present antigens to T-cells
- release cytokines to activate other immune cells
What might macrophages present to T-cells?
antigens
Macrophages may activate ____ by ____
neutrophils; releasing cytokines
Describe the 6 steps of phagocytosis:
- attachment of the phagocyte to the pathogen
- ingestion of the pathogen
- formation of phagosome
- formation of phagolysosome
- destruction of pathogen and formation of residual body
- elimination of waste materials
Natural killer cells are considered ____ of innate immunity
effector cells
Capable of rapidly attacking and killing infected cells
natural killer cells
Natural killer cells induce:
apoptosis
Cell responsible for inducing apoptosis:
NK cells
NK may release ____ to ___
cytokines; activate other immune cells
What is responsible for the killing of virus infected cells?
NK cells
Collection of circling and membrane-associated proteins important to the defense to against microbes:
Complement system
Activated by antibodies that bind to microbes or other antigens —> component of adaptive immunity (humoral)
Classical pathway (complement system)
Activated when complement proteins are activated on microbial surfaces —> component of innate immunity
Alternate pathway (complement system)
Activated by mannose binding lectin binding to surface of glycoproteins on microbes —> component of innate immunity
Lectin pathway (complement system)
What activates the classical pathway of the complement system?
activated by antibodies that bind to microbes or other antigens
The classical pathway of the complement system is a component of:
adaptive immunity (humoral)
When is the alternate of the complement system activated?
activated when complement proteins are activated on microbial surfaces
The alternative pathway of the complement system is a component of:
innate immunity
What is the lectin pathway of the complement system activated by?
Activated by mannose binding lectin binding to the surface of glycoproteins on microbes
The lectin pathway of the complement system is a component of:
innate immunity
What pathways of complement are components of the innate immune system?
Alternative & Lectin Pathways
For the intimate of the complement system activation, describe what each pathway is activated by:
- Alternative pathway
- Classical pathway
- Lectin pathway
- microbe
- antibody
- mannose binding lectin
List the functions of the following complement proteins:
C3b:
C3a:
C5a:
C5b, 6,7,8,9
C3b: opsonization
C3a: histamine release from mast cells enhancing inflammation
C5a: histamine release and chemotaxis of neutrophils
C5b, 6,7,8,9: MAC
In the early steps of complement, ____ is involved in inflammation
C3a
In the early steps of complement, C3a is involved in:
inflammation
In the early steps of complement, C3b is deposited on the microbe and functions in:
opsonization and phagocytosis
In the early steps of complement ___ is deposited on the microbe and functions in opsonization and phagocytosis
C3b
In the later steps of complement, ____ is involved in inflammation
C5a
In the later steps of complement, C5a is involved in:
inflammation
In the late steps of complement, complement proteins C6-9 form:
MAC
In the later steps of complement, complement proteins C6-9 are involved in:
lysis of the microbe (MAC)
C3b coats microbes, promotes binding to phagocytes resulting in microbes being ingested and destroyed:
Opsonziation (coating & promoting) and phagocytosis (ingesting)
What complement protein functions in opsonization and phagocytosis?
C3b
C5a and C3b are chemoattractants for leukocytes and lead to the recruitment of cells to promote:
inflammation
What complement proteins function in inflammation?
C5a and C3b
What complement proteins are considered chemoattractants for leukocytes?
C5a and C3b
Complement activation concludes with the MAC leading to microbial death through the process of:
cell lysis
Complement protein activation concludes with:
MAC
The MAC of complement is responsible for:
microbial death
Soluble proteins that mediate immune and inflammatory reactions in innate immunity:
cytokines
Cytokines of innate immunity are responsible for communication between:
leukocytes and other cells
Describe the secretion of cytokines in innate immunity:
secreted in small amounts in response to external stimuli
Cytokines in innate immunity are secreted in response to:
external stimuli
Most of the cytokines in innate immunity function in ___ & ____ actions
autocrine & paracrine
The cytokines of innate immunity include: (3)
- TNF
- IL-1
- Interferon
In the innate immune reaction that responds to extracellular bacteria and fungi:
acute inflammatory response & complement
In the innate immune reaction, the intracellular bacteria are eliminated by:
phagocytosis
In the innate immune reaction, viruses are responded to by:
Type I interferon & N K Cells
Receptors of innate immunity include:
- Toll-like receptors (TLRs)
- NOD-like receptors
- C-type lectin receptors
In innate immunity, the plasma membrane and endosomal receptors that recognize LPA and viral and bacterial RNA/DNA are:
Toll-like receptors
In innate immunity, what is responsible for recognizing LPS and viral and bacterial RNA/DNA?
TLRs
- The plasma membrane and endosomal receptors of innate immunity:
- The cytosolic receptors of innate immunity:
- The plasma membrane receptors of innate immunity:
- TLRs
- NOD-like receptors
- C-type lectin receptors
NOD-like receptors of innate immunity are recognize:
- necrotic cell products
- ion disturbances
- microbial products
Innate immune receptors responsible for recognizing necrotic cell products, ion disturbances and microbial products:
NOD-like receptors
C-type lectin receptors recognize:
Fungal polysaccharides
Innate immune receptor responsible for recognizing fungal polysaccharides:
C-type lectin receptors
Primary lymphoid organs include:
- bone marrow
- thymus
____ cells develop in the bone marrow
B-cells
____ cells develop in the thymus
T-cells
Sites where adaptive immunity is initiated:
secondary lymphoid organs
Where do the lymphocytes have contact with antigens?
secondary lymphoid organs
What are the two things that occur in secondary lymphoid organs?
- site where adaptive immunity is initiated
- lymphocytes have contact with antigen
- cervical lymph nodes
- axillary lymph nodes
- spleen
- peyer’s patches
- inguinal lymph nodes
These are all:
secondary lymphoid organs
Produces the cells of the immune system from stem cell precursors:
bone marrow
Bone marrow produces the cells of the ____ from ____
immune system; stem cell precursors
The soft spongy tissue in the medullary cavity of bones
bone marrow
Where is bone marrow located?
medullary cavity of bones
Lymphatic organ responsible for the maturation and specialization of white blood cells called t-lymphocytes
thymus
After maturation, ____ enter the bloodstream and travel to secondary lymphatic sites
T-lymphocytes
What happens to the thymus with age?
it involutes
After maturation, T-lymphocytes enter the ____ and travel to ____
bloodstream; secondary lymphatic sites
Where do white blood cells mature to become T-lymphocytes?
thymus
The components of waldeyer’s ring include:
- pharyngeal tonsil
- tubal tonsil
- palatine tonsil
- lingual tonsils
What tissue houses the most lymphocytes (top 3)
- lymph nodes
- spleen
- bone marrow and intestines (tie)
What type of immunity is considered the bodies first line of defense?
Innate immunity
Immunity that develops quickly:
innate immunity
Immunity that rapidly reacts against infectious pathogens:
Innate immunity
Immunity characterized by “no memory”
innate immunity
Immunity categorized as “specialized immunity”
adaptive immunity
Immunity that develops more slowly:
adaptive immunity
Immunity that mediates an effective defense against infections:
adaptive immunity
Immunity characterized by “memory” for future encounters:
adaptive immunity
From 0-12 hours after contact with a microbe, ____ immunity acts:
innate
From 1-3 days after contact with microbe, ____ immunity acts
adaptive
- epithelial barriers
- phagocytes
- dendritic cells
- complement
- NK cells
These are all components of:
Innate immunity
- B-lymphocytes
- Dendritic cells
- T-lymphocytes
- antibodies
- Effector T cells
These are all components of:
adaptive immunity
In ____ immunity, the distribution of receptors is “non-clonal” (identical receptors on all cells of the same lineage)
Innate
In ____ immunity, clones of lymphocytes with distinct specificities express different receptors (greater diversity)
adaptive
In what immune system might autoimmunity arise?
adaptive immunity
Recognizes diverse foreign substances:
adaptive immunity
Triggered when microbes pass through epithelial barriers, recognized by lymphocytes in lymphoid organs:
adaptive immunity
Substance that can induce an immune response:
antigen
Antigens are involved in ____ immunity
adaptive
Adaptive immunity can be divided into what two categories:
- humoral
- cell-mediated
Immunity that is mediated by antibodies produced by B-lymphocytes
humoral immunity
Immunity that is mediated by T-lymphocytes
cell-mediated immunity
Humoral immunity is mediated by:
antibodies
Proteins produced by B-cells
antibodies
What cells produce antibodies?
B-cells
In humoral immunity, antibodies are secreted into:
circulation & mucosal fluids
The antibodies of humoral immunity function to:
neutralize and eliminate microbes and microbial toxins
Prevent infections from being established:
antibodies
IF WE ARE TALKING ABOUT ANTIBODIES WE ARE DISCUSSING ____ IMMUNITY WHICH IS PART OF _____ IMMUNITY
HUMORAL; ADAPTIVE
Make up 10-20% of circulating peripheral lymphocyte population:
B-lymphocytes
B-lymphocytes make up 10-20% of ____ peripheral lymphocyte population
circulating
B-lymphocytes originate and mature in the:
bone marrow
Recognize antigens through membrane bound IgM:
B-lymphocytes
B-lymphocytes recognize antigens through membrane bound:
IgM
Recognize many chemical structures: soluble or cell-associated proteins, lipids, polysaccharides, nucleic acids, and small chemicals:
B-lymphocytes
B-lymphocytes recognize many chemical structures including: (5)
- soluble or cell-associated proteins
- lipids
- polysaccharides
- nucleic acids
- small chemicals
What happens to B-lymphocytes after they are stimulated?
differentiate into plasma cells and secrete antibodies
Mature B-lymphocyte=
plasma cell
What cells are responsible for secretion of antibodies?
Plasma cells
lymphoid cell –> Pro-B cell –> Pre-B cell –> immature B-cell –> mature B-cell:
These changes occur in:
Bone marrow
Mature B-cell –> activated B-cell –> plasma Cells & memory B cells
These changes occur in the:
peripheral lymphoid organs
List the 5 antibody classes:
- IgG
- IgM
- IgA
- IgE
- IgD
Y-shaped proteins that recognize unique markers (antigens) on pathogens:
antibodies or immunoglobulins
- Secreted into mucous, saliva, tears & colostrum
- Tags pathogens for destruction
IgA
- B-cell receptor
- Stimulates release of IgM
IgD
- Binds to mast cells and basophils
- Allergy and anti-parasitic activity
IgE
- Binds to phagocytes
- Main blood antibody for secondary responses
- Crosses placenta
IgG
- Fixes complement
- Main antibody of primary responses
- B-cell receptor
- Immune system memory
IgM
Based on the structures of the antibodies, name which is which:
- IgA
2,3,4: IgD, IgE, IgG - IgM
The most abundant antibody :
IgG
Antibody found in blood and serum:
IgG
Antibody responsible for efficiency opsonizing pathogens:
IgG
Antibody that can cross the placenta:
IgG
What are the four subclasses of IgG?
IgG1, IgG2, IgG3, IgG4
Antibody that is most commonly observed in mucous membrane secretions:
IgA
Antibody that forms a dimer when secreted:
IgA
Antibody that is considered a “neutralizing antibody”
IgA
The largest antibody:
IgM
The first antibody produced in response to antigen:
IgM
The most efficient antibody to activate complement:
IgM
Antibody that functions against helminth infections:
IgE
Antibody that mediates allergic reactions (specifically type I hypersensitivity reactions):
IgE
The least common antibody:
IgE
The function of this antibody is largely unknown:
IgD
This antibody may play a role in B-cell activation:
IgD
Antibody that is NOT secreted:
IgD
Each antibody has a unique:
amino acid sequence
The rearrangement and assembly of gene segments of antibodies occurs during:
B-cell development
Initially, ___ & ___ are present as membrane bound antibodies
IgM & IgD
What may produces antibodies of other classes?
B-cells
When does antibody class switching occur?
after stimulated by antigen and CD4 (Helper) T-cell
In antibody class switching, the B- cell still maintains its antigen specificity even though:
the heavy chain switched
What is the purpose of antibody class switching?
To broaden the functional capabilities of humoral immunity
The second exposure to antigen activates:
memory B-cells
Cells generated after primary response, to respond to antigen in future:
memory B-cells
Discuss the circulation of memory B-cells:
circulate for years after infecton
The second exposure to an antigen activating memory B-cells is part of the:
secondary response
A fraction of activated B-cells become:
memory B-cells
Circulate in the blood and lymphoid organs but DO NOT actively secrete antibodies:
Memory B-cells
What happens to memory B-cells upon re-exposure to an antigen?
rapidly differentiate into antibody producing cells
The goal of vaccination is to:
stimulate protective adaptive immune responses against microbes
The goal of vaccination is to simulate protect _____ immune responses against microbes
adaptive
With vaccination, we introduce ____ forms of microbes
non-pathogenic
Some types of vaccinations include: (3)
- inactivated vaccines
- live-attenuated vaccines
- mRNA vaccines
Types of whole vaccines include:
- inactivated
- live-attenuated
This type of vaccine contains copies of the virus that have been weakened:
Live-attentuated (whole virus vaccine)
This type of vaccine contains copies of the virus that have been killed:
Inactivated vaccine (whole virus vaccine)
Component viral vaccine that contains viral genetic material packaged inside another harmless virus that CAN copy itself:
Replicating Viral Vector
Component viral vaccine that contains viral genetic material packaged inside another harmless virus that CANNOT copy itself:
non-replicating viral vector
Component viral vaccine that contains viral genetic material (such as mRNA) which provides the instructions for making viral proteins:
DNA-based or RNA-based vaccine
Component viral vaccine that contains viral proteins that mimic the structure of the virus, but no genetic material:
VLP (Virus-like Particles)
Component viral vaccine that contains isolated and purified viral proteins:
Protein subunit
antibodies are produced by a the body in response to an antigen in ____ immunity
active
Active immunity (when antibodies are produced by the body in response to an antigen) can occur via:
- naturally
- artificially
Describe active immunity that occurs naturally:
individual with infectious disease
Describe active immunity that occurs artificially:
vaccination with attenuated virus or bacteria
Active immunity provides:
long-term immunity via memory cells
Active immunity provides long-term immunity via:
memory cells
When antibodies are derived from another source, this is considered:
Passive immunity
Describe how passive immunity can occur:
Maternal antibodies transferred across placenta to fetus
When maternal antibodies are transferred across the placenta to the fetus, this creates:
passive immunity
Passive immunity provides:
short-term immunity
Are memory cells produced in passive immunity?
No
Combats infection by intracellular microbes:
Cell-mediated immunity
The predominate cell of cell-mediated immunity are:
T-lymphocytes
Regarding intracellular pathogens in cell-mediated immunity, what happens to the microbes?
Ingestion by phagocytes
In cell-mediated immunity, viruses are able to:
infect and replicate in the cytoplasm of host cells
In the cell mediated sequence, _____ travel to lymphoid tissues and present antigen via ____
APCs; MHC
In the cell mediated sequence APCs travels to ____ Nad present the antigen via MHC
lymphoid tissues
In the cell mediated sequence, T-cells migrate to:
the site of infection
In the cell mediated sequence, when T-cells migrate to the site of infection they:
Initiate response
What cells are involved when T- cells migrate to the site of infection and initiate the response?
CD4 and CD8
In the cell mediated sequence, some activated T cells ______ instead of migrating to the site of infection
remain in the lymph tissue
In the cell mediated sequence, the activated T-cells that remain in lymph tissue: (2)
- help B-cells produce antibodies
- Become memory T-cells
In the cell mediated sequence, the activated T- cells that become memory T-cells are ones that:
remain in the lymph tissues (do not travel to site of infection)
Locus of polymorphic genes on chromosome 6:
MHC
Human MHC:
Human leukocyte antigen (HLA)
What is the function of MHC?
Display peptide antigens for recognition by T-lymphocytes
What helps cells recognize between self and non-self?
MHC
Where are MHC class I found?
On all nucleated cells
MHC class I (found on all nucleated cells) are recognized by:
CD8 T cells
Where are MHC class II found?
On surfaces of APCs
MHC Class II (found on surfaces of APCs) are recognized by:
CD4 T-cells
Antigen presenting cells (containing MHC class II) are:
- macrophages
- dendritic cells
- b-cells
Become effector cells in response to antigen:
CD4 T-cells
CD4 T cells are also called:
helper T-cells
Recognizes MHC Class II On APCs:
CD4 T-cells
What happens when CD4 T-cells recognize MHC class II on APCs?
- will release cytokines to activate other cells
- clonal expansion of CD4 T cells
Defining cytokine: IFN gamma
Target cell: macrophages
Host defense: intracellular pathogens
Role in disease: autoimmunity ; chronic inflammation
Th1`
What is the defining cytokine and target cell for Th1?
IFN gamma; macrophages
Defining cytokine: IL-4,5,13
Target cell: eosinophils
Host defense: parasites (helminths)
Role in disease: allergy
Th2
What is the defining cytokines and target cells for Th2?
IL4, IL5, IL13; Eosinophils
Defining cytokine: IL-17 & IL-22
Target cell: Neutrophils
Host defense: Extracellular pathogens
Role in disease: Autoimmunity
Th17
What is Th1 role in disease?
autoimmunity & chronic inflammation
What are the defining cytokines and target cells of Th17?
IL-17 and IL-22; neutrophils
What is Th2 role in disease?
allergy
What is Th17 role in disease?
autoimmunity
CD8 T-cells may also be called:
cytotoxic T-cells
CD8 T cells recognize _____ on ____
MHC I on APCs
Become effector cells in response to antigen:
CD8 T-cells
CD8 T- cells will release ____ to ___
enzymes to kill infected cells
A fraction of antigen-activated T-cells differentiate into:
memory cells
The fraction of antigen-activated T-cells that differentiate into memory cells are found in:
- lymphoid organs
- mucosal tissue
- circulation
Central memory cells (from T-cells) are involved in ____ after re-exposure
rapid clonal expansion
