Shared Flashcard Set

Details

BU - Immunology, Chapter 1 - 4
Immune Response, Cells of the Immune System, Antibodies
139
Biology
Undergraduate 4
02/08/2015

Additional Biology Flashcards

 


 

Cards

Term
Define Immunology
Definition
the study of the mechanisms used to defend bodies from invasion from other organisms (pathogens, toxins, chemicals, foreign molecules)
Term
What can be used to defend against attacks on the immune system?
Definition
Immunizations (Vaccines)
Term
Define Immunization (Vaccine)
Definition
an injection given to a person with a full/portion of a disease-causing organism that gives immunity against a disease
Term
What are some oppponents to the immune system?
Definition
Pathogens, Opportunistic pathogens, Bacteria, Fungi, (unicellular) protozoans, viruses, worms
Term
Define pathogen
Definition
an organism with the potential to cause disease
Term
Define opportunistic pathogen
Definition
organism that normally colonizes in the body; may cause disease when in wrong place or if the immune system is compromised
Term
What are the two divisions of the Immune Response?
Definition

1. Innate Immune Response

2. Acquired/Adaptive Immune Response

Term
What are the basic characterisitics of the Innate Immune Response?
Definition
  • always the first to respond to an attack 
  • fast, 1st line of defense
  • primitive, never changes 

ex. mechanical and chemical barriers, phagocytes. active innate response

Term
Give some examples of mechanical barriers of the innate immune response; chemical?
Definition

MECHANICAL: tears, skin, fluids

 

CHEMICAL: stomach acids, lysosome in tears

 

NORMAL FLORA: organisms on the skin and in the mouth, urinary, genital tract, etc. that outcompete pathogens and acidify the enviornment 

Term
What are the two parts of the Active Innate Immune Response?
Definition

1. Recognition of Pathogens

2. Effector Mechanisms (responses that kill pathogens)

Term
What are the basic characteristics of the Adaptive Immune Response?
Definition
  • slower, takes days to weeks to respond
  • adapts with time to give a better response on 2nd and 3rd exposure 
  • has memory for long term immunity 
  • very specific (good and bad: no overlap between certain diseases)
Term
In basic terms, how does the adaptive immune response work?
Definition

Activation of effector cells - these cells are preexisting in the body and are equipt with receptors to identify billions of molecules; 

 

They are activated by the union of antigen (Ag) with it's receptor. If this occurs, the cell is 'selected' and the number of hte receptors increases (clonal expansion). 

Term
Define clonal selection
Definition
foreign molecule selects only those cells that can respond to or recognize it
Term
Define clonal expansion.
Definition

only selected cells replicate to create clones (always recognize the same original molecule);

 

this increases response and is the basis of memory

Term
Do the innate and adaptive immune responses interact?
Definition

Yes - both work to fight against attacking organisms; adaptive immunity becomes smarter and has memory so that after first exposure the response is faster and more specific; 

 

Both induce inflammation

Term
Define Inflammation
Definition

a localized physical condition (tissue damage or destruction) caused in response to an infection and/or damage that eliminates or walls-off the infection or damaged area

 

characterized by: redness, swelling, heat, pain

Term
By what process is inflammation induced? (begin with physical damage to body)
Definition

1. skin damaged --> bacteria enter body

2. clot forms to stop bleeding and entry of more bacteria

3. resident cells (macrophages) secrete cytokines

4. cytokines induce inflammation

Term
Define cytokine
Definition
a small molecule protein that signals to other cells to do some specific action
Term

What is the purpose of inflammation?

 

Definition

fight infection

alert person of a problem via heat, swelling, redness, and pain 

Term
Which two bioprocesses occur that cause the characteristics of inflammation to present?
Definition

1. Local Blood Vessel Dilation(Vasodilation): increases the amount of fluid that travels through an area; leads to redness

2. Vascular Permeability Increases : the area between cells fills with fluids (swelling), proteins and cells leave the blood and enter tissue (heat), increased pressure on nerve endings (pain)

Term
What causes redness during inflammatory responses?
Definition
increased blood flow in the damaged area due to local blood vessel dilation
Term
What causes swelling to present in an inflammatory response?
Definition
the area between cells fills with fluids due to increased vascular permeability
Term
What causes the heat to present in an inflammatory response?
Definition
the movement of proteins and cells from the blood to the tissue due to increased vascular permeability
Term
What causes the pain to present in an inflammatory response?
Definition
the pressure on nerve endings by fluids in the tissue due to increased vascular permeability
Term
Define antibody (Ab)
Definition

a protein produced by animals which binds specifically to a foreign chemical structure on an antigen 

 

though similar, ≠ immunoglobulin

Term
Define antigen (Ag)
Definition
a foreign molecule or particle on a portion of a larger molecule that an antibody can bind to
Term
Describe erythrocytes.
Definition

Red Blood Cells

  • structure: small, round, disk-shaped with no nucleus 
  • function: transport oxygen and aid in immunity
Term
Describe Leukocytes
Definition

aka White Blood Cells; two types: 

1. Granulocytes

2. Mast Cells

Term
Describe granulocytes
Definition

WBC's that contain granules in their cytoplasm; the granules contain toxins that kill pathogens; 

 

have polymorphic nuclei

Term
What are the three types of granulocytes?
Definition
Neutrophils, Eosinophils, Basophils
Term
Describe Neutrophils
Definition
  • short-lived
  • produced in the bone marrow
  • 50-70 percent of blood leukocytes in humans 
  • rapid mobilization: 1st leukocyte to enter site
  • professional phagocytes (bacteria) 
  • major component of pus
  • stain with neutral dyes
Term
Describe Eosinophils
Definition
  • fairly rare: 1-3 percent of blood leukocytes
  • phagocytic
  • kill parasites and worms (attach to worms and focus granuoles towards the worm to burn a hole = die)
  • stains with red eosin dye
Term
Describe basophils
Definition
  • small - about the same size as a RBC
  • non-phagocytic 
  • extremely rare: less than 1 percent of blood leukocytes
  • involved in immune response - produce histamine
  • worm and parasite defense
Term
How does histamine affect the body?
Definition

leads to: 

  • vascular permeability
  • smooth muscle contraction
Term
Describe mast cells
Definition

white blood cell NOT found in blood

  • found in tissues 
  • not a granulocyte
  • secretes histamine
  • role in inflammation, parasite defense, and allergic reactions
Term
What are Myeloid Antigen Presenting Cells (APC's)?
Definition
  • phagocytic, collect and process foreign Ag to present them to adaptive immune response 
  • three types: 
  • monocytes, macrophages, dendritic cells
Term
Describe monocytes.
Definition

Myeloid APC

  • 5-10 % of blood leukocytes, 
  • bean shaped nucleus
  • phagocytic
  • two types: 
  • inflammatory monocytes, patrolling monocytes
Term
Describe Inflammatory Monocytes
Definition
  • enter tissue quickly for inflammation 
  • produce cytokines

 

Term
Describe patroling monocytes
Definition
  • crawl along capillaries/blood vessels
  • become tissue macrophages
Term
Describe macrophages
Definition
  • Myeloid APC
  • large irregular shapes
  • have vacuoles 
  • phagocytic
  • long lived
  • role in inflammatory response by producing cytokines
  • role as an APC in the acquired response
Term
Describe dendritic cells
Definition

Myeloid APC

  • star shaped cells with long processes/projections
  • collect Ag in tissue and take it to site of immune response (lymphnodes, spleen)
  • professional APC's
  • pick up "garbage" neutrophils and monocytes leave behind
Term
Describe lymphocytes
Definition
  • usually very small
  • prominant, round nuclei 
  • when activated, cytoplasmic space increases
  • 20-40 percent of blood leukocytes
  • three types: 
  • Natural Killer Cells, B Lymphocytes, T Lymphocytes 
Term
Describe Natural Killer Cells
Definition

Lymphocyte

  • aka NKC's 
  • large, granular 
  • recognize and kill some virus infected cells
  • effector cell of innate immunity
  • must have NK1.1 protein on cell surface
Term
Describe T Lymphocytes
Definition

Lymphocyte

aka T Cell

  • large, granular when activated
  • small when resting (not active in blood)
  • recognize Ag through T cell receptors;
  • can only recognize Ag when it is presented 
  • two types: Helpter T's and Cytotoxic T's
Term

Describe Helper T Cells

 

Definition

(TH)

  • secrete cytokines to help other cells become effector cells
  • always have CD4 on surface
Term
Describe Cytotoxic T Cells
Definition
  • have T cell receptor
  • recognize and kill specific virus-infected cells
  • always have CD8 on cell surface
Term
How can lymphocytes be differentiated if they all look so similar?
Definition
  • Immunoforescence
  • Ab is tagged with a fluorescent molecule; cells with a matching receptor will fluoresce in the presence of the dye
Term
What is a Cluster of Differentiation?
Definition

(CD) - all surface proteins on cells that are non-polymorphic have numbers that identify them

 

standardized throughout world...about 350 CD proteins right now

Term
Describle B Lymphocytes
Definition
  • (B Cells) 
  • Small, resting in blood
  • Ig on surface
  • secrete Ab's
  • often activated by Ag with the aid of TH's --> plasma cells --> Ab factory (eccentric nucleus, extensive RER)
Term
Define hematopoeisis.
Definition

The process of producing and developing blood leukocytes; 

 

Occurs in bone marrow (usually)

Term
Describe hematopoeisis
Definition

Pleuripotent Hematopoeitic Stem Cell differentiates --> to make: Common Lymphoid Progenitor or Common Myeloid Progenitor

 

Common Lymphoid Progenitor --> NK Cells, T Cell Precursor (then T Cell) and B Cells

 

Common Myeloid Progenitor --> Granulocytes, Erythrocytes, Monocytes, Megakaryocytes

Term
What are the different types of Lymphoid Tissues?
Definition

1. Primary/Central Lymphoid Tissue - lymphocytes develop and mature here 

2. Secondary Lymphoid Tissue (Peripheral LT)

Term
Discuss the Primary Lymphoid Tissue
Definition
  • lymphoid tissues develop and mature here
  • a. bone marrow: major site of adult hematopoeisis; when B cells leave here they are essentially mature
  • b. Thymus: T cell precursor enter here early in life (around gestation); most of the T cells are produced, developed and matured here
Term
Discuss the Secondary Lymphoid Tissue
Definition

sites where mature lymphocytes go; site where lymphocytes are stimulated and respond to pathogens

 

blood leaves heart - arteries - arterioles - capillaries - fluid leaks out - interstitial fluid bathes the cell - blind ended lymphatics - draining lymph nodes - lymphatic vessels - thoracic duct - left subclavian vein 

Term
List the parts of the Lymph Node
Definition

1. Cortex

2. Paracortex

3. Medulla 

Term
Describe the Cortex of the Lymph Node
Definition

outer most layer of LN

 

B cell zone and Follicular DC's 

Term
What is a follicular DC
Definition
specialized dendritic cell that does not present antigen to T cells; interacts with B cells by holding onto Ag's
Term
Describe the paracortex region of the lymph node
Definition

middle layer of the lymph node

 

T cell zone; also houses DC's

Term
Describe the medulla region of the LN
Definition

Innermost section of the LN, 

 

collects filtered lymph, Abs, and plasma cells

Term
What occurs between the layers of the lymphnodes?
Definition
Helper T cells and helper B cells mix
Term
Define naive cells
Definition
Cells that have note encountered their antigen yet
Term
Define effector cells
Definition
Cells that have been activated by antigen; they do the "effect" of the activation
Term
Where do plasma cells come from?
Definition
B cells become activated B Cells which become Plasma Cells
Term
Describe the journey of antigen presented from a cut to it's presentation to T cells
Definition
SEE PAGE IN NOTES
Term
Draw a lymph node
Definition
Term
Where are chemokines produced?
Definition
Stromal cells
Term
How do lymphocytes get to the lymph nodes?
Definition
enter through high endothelial venuoles
Term
How do B cells become activated?
Definition

B cells enter the blood via high endothelial venuoles where they are then attracted to follicles by chemokines. If they do not find any Ag, they move to the next antigen. If they do become find their Ag, they move to the paracortex where they are activated by T cells. 

 

Then they either reenter the follicles or the medulla as plasma cells. 

Term
What physical changes occur in the B cell when it becomes activated?
Definition
more cytoplasm
Term
What is the function of the spleen?
Definition

The spleen is an organ that assists in immunity by: 

- filtering the blood

- removing old and damaged RBC's 

 

Term
Discuss the structure of the spleen.
Definition

The spleen has two parts: 

- Red pulp and 

- white pulp

Term
Discuss the red pulp.
Definition

Red pulp is an area of the spleen that is the site of destruction of RBC's. 

 

It contains many Macrophages that filter out antigen and pathogen. 

 

Has large sinusoids where exchange of cells occurs

Term
Discuss the white pulp.
Definition

A region of the spleen that contains T cells, B cells, macrophages, and DC's. 

 

Made up of several zones - periarteriolar lymphoid sheath (PALs) which contains a central arteriole; follicles (B cell zone) that contain germinal centers; and the marginal zones where B cells and macrophages are found

Term
Discuss the results of a spleenectomy.
Definition

A removal of the spleen due to trauma or injury is okay for adults because there have already been other lymphoid tissues developed than can take over filtration. 

 

In children, it leads to problems because bacteria with capsules and other certain pathogens are difficult or impossible to filter. 

Term
What is PALs?
Definition
Periarteriolar lymphoid sheath is a region in the white pulp of the spleen where the central arteriole passes through.
Term
Discuss the Mucosa Associated Lymphoid Tissue.
Definition

MALT includes any moist surface (mouth, nasal area, intestinal tract, urogenital tract, etc.)

 

Bronchus associated lymphoid tissue (BALT) - lungs, bronchioles, etc. 

Nasal associated lymphoid tissue (NALT) 

Gut associated LT (GALT) - tonsils, adenoids, appendix, peyer's patches

Term
Describe the basic structure of an antibody.
Definition

Y shaped structure contains two identical heavy (H) chains and two identical light (L) chians;the binding sites on both ends are identical 

 

Held together by disulfide bonds

Term
What enzyme cuts Ab's at the hinge region
Definition
Papain
Term
Which enzyme cuts an antibody into a F(ab)2 region and AA's?
Definition
Pepsin
Term
What are the types of light chains?
Definition

Kappa and Lambda 

 

An Ab from a single B cell can be either kappa or lambda, NOT both

Term
Discuss the regions of the light chains
Definition

Constant region: all kappa have the same; all lambda have the same

 

Variable region: AA varies with different Ab specificity

Term
Discuss the heavy chain.
Definition
long constant region; shorter variable region (binding sites)
Term
What is an isotype in terms of antibodies?
Definition

the varying (5) types of heavy chain constant regions

 

Ig G A M D and E

Term
Which of the isotypes of antibodies can have kappa or lambda L chains?
Definition
IgG and IgA
Term
Which isotype has an alpha heavy chain?
Definition
IgA
Term
Which antibody isotype has an epsilon heavy chain?
Definition
IgE
Term
Which antibody isotype has a mu heavy chain?
Definition
IgM
Term
How many subclasses of alpha havy chains are there in Ig A isotype antibodies?
Definition
2
Term
How many subclasses of gamma heavy chains are there in the Ig G isotype antibodies?
Definition
4 in humans
Term
Discuss the V region and C region of L chains in Ab's
Definition
They are fairly similar and known as domains - the L chain has 2 domains (C and V)
Term
Discuss Ig M
Definition
  • pentamer (flower shaped)
  • 5-10% of the blood's Ig
  • held together by disulfide bond and J chain protein
  • on B cells as B cell Receptors 
  • 1st Ig secreted in response to Ag 
  • 1st Ig produced by naive B cells 
  • no hinge region
  • generally only binds 5 regions at a time

 

Term
Discuss Ig G
Definition
  • the most commonly found Ab in blood (about 73%)
  • also in lymph and interstitial fluid
  • protects the inside of the body 
  • 4 sub groups (gamma 1 2 3 4)
  • longest lasting - half life of 21 days in blood
Term
What is the difference between the subclasses of Ig G?
Definition

the number of disulfide bonds, 

difference in AA sequence, 

function

Term
Discuss Ig A
Definition
  • dimer with J chain 
  • 10-18% of Ig in blood 
  • major isotype in external secretions
  • protects external surfaces and mucosal surfaces
  • monomeric in blood, dimeric in secretions (J chain)
Term
Discuss Ig D
Definition

very rare - 0.16% of blood Ig

major purpose: B cell receptor on naive B cells

helps in activation of naive B cells

Term
Discuss Ig E
Definition
  • extremely rare in blood
  • monomeric when produced
  • immediately binds to mast cells and receptors on basophils
  • IgE arms are non specific in mast cells and basophils with a specific Ig E receptor 
  • important in anti parasite and worm immunity 
  • important to the allergic reaction
Term
Are mast cells specific to certain antigen?
Definition
No they are not specific to anything - they couple IgE becayse IgE is extremely specific.
Term
What was determined by the experiment on immunoglobulins and the AA residue positions?
Definition
  • there are only 3 regions where there is variability known as Complementarity Determining Region (CDR) - there are what bind to Ag = binding sites
  • the rest is known as "framework"
  • there are 3 CDR's in the L chain and 3 in the H chain
Term
Define epitope.
Definition
site where an Ab binds to an Ag. Can be continuous or discontinuous (3D)
Term
What kinds of valency can antigens have?
Definition
  • Monovalent (1 epitope)
  • Multivalent (2+ epitope); can be: 
  • more than one type of epitope or multiple of the same epitope
  •  
Term
If an epitope is denatured, what are the consequences?
Definition
Antibodies may not bind.
Term
Discuss the Ab binding to Ag epitope
Definition

multiple weak interactions: 

  • van der Waals
  • hydrophobic interactions
  • hydrogen bonding
  • ionic bonds/electrostatic forces

combine to form a very strong bond

Term
Define affinity
Definition
the measure of the strength with which the ab binding site binds to the antigen eiptope
Term
Define avidity
Definition
overall strength with which a multivalent Ab binds to a multivalent antigen
Term
Is avidity or affinity stronger? Why?
Definition
Avidity is greater than sum of affinities because multivalent Ags have more multivalent epitopes; both will always bond so the proximity is greater and the bond is stonger
Term
Describe the affinity and avidity of IgM
Definition
IgM has 10 binding sites - high avidity with low affinity
Term
Discuss the avidity and affinity for IgG
Definition
IgG has 2 binding sites - low avidity and high affinity
Term
What is a B cell receptor? Draw a signaling complex on a B cell
Definition

B cell receptor: Ig as an integral membrane protein

 

BCR + Ig alpha and Ig beta make up signaling complex

Term
What can bind to native Ag?
Definition
BCR and Ig
Term
Describe and draw a T Cell Receptor
Definition

alpha and beta portions 

 

variable region with binding site (Valpha, Vbeta which have CDRs), constant region, disulfide bond, transmembrane portion and short cytoplasmic tail (too short for signaling)

Term
What percentage of cells are alpha/beta TCR's found on?
Definition
95 - 99
Term
What percentage of cells are gamma-delta TCR's found on?
Definition

1 - 5 (high numbers in epithelial tissue; recognize specific bacterial compounds (lipids, glycolipids, phosphorylated antigen)

 

can recognize native Ag

Term
What are the TCR Signaling Co-Receptors?
Definition

CD4 for helper T cells: contain 4 Ig-like domains, bind to MHCR Class II

 

CD8 for cytotoxic T cells: alpha-beta chains held together by disulfide bonds; binds to MHCR Class I

Term
What are the two types of MHC's and how are they differentiated?
Definition

MHC I: for Ag from within cell -- "processing" and loading of Ag or bacteria to MHC I protein then taken outside of cell. Only TCR's and CD8 can recognize MHCI + Ag. Produced by most cells. 

 

MHC II: for viruses, bacteria, toxins from outside cell; phagocytized by M0 or DC then processed and loaded to MHC II protein then to membrane. Only CD4 can recognize MHCII + Ag. APC's (M0, DC, B Cells) have.

Term
INTERNALLY originating Ag are loaded to what MHC class and bind to what T cell?
Definition
MHC II, CTC w/ CD8
Term
EXTERNAL Ag load to which MHC class and bind with with T cells?
Definition
MHCR II, Helper T's with CD4
Term
Where is the fibroblast reticular cell conduit system found?
Definition

LN paracortex; helps T cells to find DC where Ag may be presented

 

Also found in the PALs in the spleen, the folliclesan cell areas to help B cells and follicular DC interact

Term
The PALs of the spleen is analagous to what part of the LN
Definition

the paracortex - 

 

follicles, germinal centers are found in spleen, LN, and all lymphoid tissue

Term

What is the follicle of the lymphoid tissue? What is a germinal center?

 

 

Definition

large accumulation of B cells; mostly made up of resting B cells 

 

if Bcells activated by Ag, clonal selection and expansion occur -> more cytoplasm so spread out nuclei = germinal center (active immune response occuring)

Term
Define interleukin
Definition

A cytokine produced by leukocyte that affects the growth and differentiation of immune and hematopoetic cells

 

Interleukins are specific cytokines identified as IL-#

 

Chemokines are a subset of interleukins

Term
Describe the difference between endocrine, paracrine, and autocrine factors.
Definition

Endocrine - cytokines released from cell and move to blood stream to act on other cells over great distance

 

Paracrine - cytokines released from one cell act on cell nearby

 

Autocrine - cytokines released from cell act on itself

Term
What are the 8 properties of cytokines.
Definition

1. Bind to Specific Receptors

2. Are Pleiotrophic 

3. Bind with High Affinity

4. Are Redundant

5. Synergistic

6. Are Antagonistic 

7. Cascade Induction 

8. Induce Receptor Expression on Other Cells

Term
Discuss cytokines bind to specific receptors.
Definition
Only the cells with the receptors can be affected by the cytokine
Term
Discuss the cytokinic property of high affinity
Definition
Cytokine receptors bind with high affinity so high concentrations are not required for efficacy which is important in autocrine and paracrine responses
Term
Discuss the pleiotrophic property of cytokines.
Definition
Cytokines can have different effects on a given cell depending on the nature of the target cells
Term
Discuss the redundancy property of cytokines.
Definition
Multiple cytokines can induce the same effect on one cell (i.e. proliferation of B cells by IL2, IL 4, and IL5)
Term
Discuss the synergystic property of cytokines.
Definition
The effect of multiple cytokines is greater than the sum of the individual effects of cytokines.
Term
DIscuss the antagonistic property of cytokines.
Definition
Some cytokines have opposite or inhibiting effects of other cytokines
Term
DIsucss the cascade induction property of cytokines.
Definition

the effect of one cytokine can induced the effects of other cytokines - snowball effect 

 

(i.e. IL 12 activates T cells which induces the secretion of IFN8, IL2, TRF, and others)

Term
Discuss the Induction of Receptor Expression by cytokines.
Definition
Cytokines can induce the expression of a given receptor on other cells.
Term
Describe the Interleukin-1 Family.
Definition
  • secreted early on in an immune response
  • produced by monocytes, M0, DC
  • generally pro-inflammatory
  • many subclasses
Term
Discuss IL-1
Definition
  • alpha and beta forms
  • activated B and T cells that have been activated previously by Ag
  • increases capillary permeability
  • induces cytokine/chemokine production
  • systemic effects once enters blood - from liver, induces production of acute phase proteins - from hypothalamus, induces fever to inhibit bacteria 
Term
Discuss IL-18.
Definition
Similar to IL-1
Term
Discuss the IL-1 Receptor Antagonist
Definition
  • blocks IL1 from binding to receptor to prevent the signaling for inflammation, capillary permeability and cytokine production 
  • anti-inflammatory
Supporting users have an ad free experience!