Immuno uno y dos

Question 1

Immunology: what is it?

Answer 1

Immunology is the branch of biomedical science that covers the study of all aspects and components of immune system in all organisms

• innate immune response, adaptive immune response, immune memory

Question 2

what is the immune system?

Answer 2

the immune system is a network of cells, tissue and organs that work together to protect the body from infection and other harmful substances

the immune system *prevents and *limits the *entry and effect of pathogens, to maintain optimal health

Question 3

What a pathogen must do in order to cause disease?

Answer 3

1. gain access to body
2. attached to or enter host’s cell
3. while in body reproduce and avoid host’s immune system
4. induce harmful changes in the host

Question 4

what is immunity?

Answer 4

immunity is the *** abillity to ward of diseases through defence mechanisms

• ability to prevent disease caused by microbes and their products
• ability to protect against environmental agents such as allergins and toxins
• ability to protect from malignant tumour formation
  (body’s vulnerability to diseases is called “susceptibility”

Question 5

Why an understanding of immunology is essential?

what is immunotherapy?

Answer 5

• to diagnose, treat, manage and prevent diseases
  -to conduct research to optimize immune responses ranging from infections to diseases such as cancer
• immunotherapy: biologic therapy a type of cancer treatment that boosts the body’s natural defences to fight cancer.
• potential overreaction of the body’s immune system “cytokine storm”

Question 6

what are the types of responses?

which ones are/is non-specific?

which ones are/is specific?

which ones are/is retained for later use?

Answer 6

innate immune response (inherent, congenital, inborn)
- defense mechanisms present from birth
- occurs *immediately
- non-specific

adaptive immune response
- specific immune response to specific *pathogens once they have breached innate immunity

immune memory
- follows the adaptive response, when mature adaptive cells, highly specific to the original pathogen, are retained for later use.

Question 7

A battery of responses to prevent entry and invasion are which type of immune response?

Remember the previous assault and
protect when encountered again?

Answer 7

innate response

◼ Remember the previous assault and
protect when encountered again-
adaptive response

Question 8

How does the immune system prevent diseases?

Answer 8

• prevent entry of pathogens
• neutralize and remove pathogens after they enter body
• destroy own body’s cells that have modified due to pathogen/illness (cancer)

Question 9

What are the cellular components of the immune system?

Answer 9

bone marrow: contain stem cells, precursors for all

myeloid cells: eusoniphils, basophils, mast cells, monocytes, dendritic cells, and macrophages

lymphoid cells: B and T cells, natural killer (NK) cells

immune cells constantly circulate throughout the bloodstream ready to react to foreign invasion

Question 10

what is haemotopoiesis?

Answer 10

formation of the cellular components of the blood

Question 11

What are the organs of immune system?

Answer 11

1. primary lymphoid organs

• thymus,
• bone marrow

2. secondary lymphoid organs

• lymph node
• spleen
• mucosa associated lymphoid tissue (MALT) -> found in various submucosal membrane sites of body such as the GI, oral passage, nasopharyngeal tract, thyroid, breast, lung

Question 12

THYMUS GLAND

where is it located?

primary or secondary lymphoid organ of immune system?

within the thymus, what matures? which are critical to the adaptive immune system

Developing T-cells are referred to as ? and are of hematopoietic origin

Answer 12

thymus gland is located in the thoracic cavity

primary lymphoid organ of immune system

T cells or T lymphocytes which are critical to adaptive immune system

Developing T cells referred to as thymocytes and are of hematopoietic origin

Question 13

Transport of T cells

what is the lymphatic system and what is it composed of?

immune cells are carried through the ? and converge in ?

Answer 13

lymphatic system is a network of tissues and vessels composed of lymph, an ECF and lymphoid organs such as the thymus and lymph nodes.

immune celles are carried through lymphatic system and converge in lymph nodes

Question 14

first or second or third line of defence below
1. innate and non specific
2. adaptive and specific

what does 1st line of defence incorporate e.g. chemical barriers, normal microbiota?

Answer 14

innate and non specific: first and second line of defense

adaptive and specific would be 3rd line of defensse

1st line of defense incorporates:
- skin and mucous membranes, physical barriers, chemical Barr, gut microbiome, normal microbiota

Question 15

Skin: structure and properties

Epidermis: give 3 characteristics

dermis: give 6 character..

Answer 15

epidermis:
1. dead keratin layer
2. tightly packed multiple layers of epithelium
3. dryness of the skin (not a nice env. for pathogens to enter)

dermis:
1. thick dermal collagen
2. sweat consists of salt that prevents growth of pathogen
3. antimicrobial peptides
4. lysozyme - destroys cell wall of bacteria by breaking down peptidoglycan
5. sebum secreted by sebaceous (oil) glands
6. lower pH of skin to a level inhibitory to many bacteria

Question 16

SKIN: structure and properties

Largest organ of the body in terms of ? and ?

Mucous membranes:
- line all body cavities that are?
- single layer of living ? packed tightly to prevent entry of pathogens
- continual shedding of cells removes attached ?
- produce ?, ? and ?

Answer 16

• SA and weight
• Line all body cavities open to the outside environment.
  ◼ Single layer of living epithelial cells packed tightly to prevent entry of pathogens
  ◼ Continual shedding of cells removes attached microorganisms
  ◼ Produce mucus, lysozyme, and antimicrobial peptides.

Question 17

Chemical barriers / Other factors?

Answer 17

• tears, saliva, pH, gastric acid, mucus, hairs (Ear, nose), earwax, cilia (respiratory tract), urinary and vaginal secretions, peristalsis, defecation, vomiting, diarrhea

Question 18

Normal flora (microbial antagonism)

Normal flora present in the skin and mucous membranes protect the body by?

Normal flora of the intestines improve overall health by producing ?

Answer 18

1. competing with potential pathogens by
   competing for nutrients and changing the pH of site

Normal flora of the intestines improve overall health by producing several types of vitamins and important breakdown products (short chain fatty acids), along w multiple other funci. that are only just comiing to light through recent research, gut - brain axis

Question 19

Second line of defense - innate e.g.?

which cells are involved in the innate immune system and their features?

Answer 19

phagocytes: neutrophils, eosinophils, monocytes/macrophages

inflammation, fever, antimicrobial substances

cells involved in the innate immune system: neutrophils, eosinophils, basophils, monocytes/dendritic cells, macrophages

features:
the ability to respond quickly and broadly when a problem arises typically leading to inflammatino

activate adaptive immunity

critical for host defense

disorders in innate cell function may cause chronic susceptibility to infection

Question 20

Formed elements in the blood

function of:

erythrocytes
leukocytes
platelets

Answer 20

erythrocytes - transport of O2 and CO2
leukocytes - defines and immunity
platelets - blood clotting

Question 21

ORIGIN AND DEVELOPMENT

***All immune cells come from precursors in the *? and develop into mature cells through a series of changes that can occur in diff. parts of the body

Answer 21

• All immune cells come from precursors in the bone marrow!

Question 22

Granulocytes
Contains granules in there ?

types? (4) and describe them

Answer 22

Granulocytes
Contains granules in there cytoplasm

Neutrophils
- most abundant WBC. predominant cells in pus, accounts for whitish appearance. respond quickly following tissue injury. hallmark of acute inflammation. - PHAGOCYTE***

Eosinophils
- main effector cells in allergic responses and asthma. also fight parasitic/helminth colozation. -PHAGOCYTE***

basophils - least common granulocyte. when activated, release histamine and other inflammatory chemicals.

mast cells - play a key role in inflammation allergy and anaphylaxis.

Question 23

Agranulocytes

2 types?

what are their phagocytic cells called?
tissue =
liver =
skin =
brain =
bone =

Answer 23

lymphocytes - most involved in specific immunity Tcells, B cells, natural killer cells (NK cells)

monocytes - circulate in the blood, leave the blood and ***MATURE INTO MACROPHAGES IN TISSUES - PHAGOCYTE.

tissue = histiocytes
liver = kupffer cell
skin = langerhan’s cell and dendritic cells
brain = microglia
bone = osteoclast

Question 24

Agranulocytes: lymphocytes

list 3 diff. types of lymphocytes and what they do?

what do the kupffer cell and langerhan’s cell do?

Answer 24

1. cytotoxic cells (C8) - kill virus-infected cells
2. helper T cells (CD4) - help cytotoxic T cells and B cells in their immune functions
3. B cells - produce antibodies

Langerhans cells (LC) are members of the dendritic cell family, residing in the epidermis and in the epithelia of the respiratory, digestive and urogenital tracts.

Kupffer Cells are phagocytic cells that form in the lining of the sinusoids of the liver and are involved in the breakdown of RBCs

Question 25

Phagocytosis

what does it mean?

phagocytic cells of the immune system are?

Stages of phagocytosis?

Answer 25

phago = eat cyto = cell
process of ingestion of microbials, cellular debris, and nutrients

phagocytic cells of the immune system
- neutrophils, eosinophils, macrophages/monocytes

stages:
1. chemotaxis
2. adherence
3. ingestion
4. digestion
5. elimination

chemotaxis: chemical attraction of phagocytes to microbials
- microbial products (peptidoglycan, LPS), damaged tissue, cytokines, complement components.

Adherence: attachment of the phagocytic membrane to microbials or foreign material

Question 26

Adherence: what happens?

what are phagocyte receptors (present in which type of immune response)?

What is opsonization and opsonin?

Answer 26

attachment of the phagocytic membrane to microbial or foreign material

phagocyte receptors - toll like receptors (TLRs): crucial pattern recognition receptors in innate immunity that are expressed in some phagocytes

+

Microbe-Pathogen/Danger (Damage) Associated Molecular Pattern Molecules (PAMP or DAMP)

PAMPs are conserved molecular structures produced by microbials and recognized as foreign by the receptors of the innate immune system e.g. LPS, peptidoglycan.

DAMPs are damage associated molecular patterns molecules, released upon host tissue injury and are regarded as endogenous Danger signals. They are related from damaged or dying cells and activate the immune system (inflammatory response).

Opsonization is the process by which a microbe is marked for destruction by phagocytosis.

Opsonin is the antibody or other substance that binds to foreign microbials or cells, making them more susceptible to phagocytosis.

Question 27

Phagocytosis step 3, 4, 5 explain

Answer 27

Ingestion - stage 3
- pseudopods engulf the organism and form a phagosome or phagocytic vehicle

Stage 4 Digestion
- in the cytoplasm the phagosome fuses w a lysosome - phagolysosome
- lysosome: organelle in cytoplasm containing enzymes.

lysosomal enzymes
- lysozyme, lipase, protease, nuclease, toxic oxygen radicals through oxidative burst, myeloperoxidase, superoxide dismutase.

phagocytosis step 5 elimination
- residual body

Question 28

Inflammation is a second, first or third line of defense?

and what can it be caused by?

*** IMP cardinal signs of inflammation are?

explain acute and chronic inflammation and effect of inflammation.

Answer 28

second line of defence - innate - it can be caused by microbes, physical presence and chemical agents.
- host response to tissue damage
- serves to destroy the infectious agent, to confine it, and repair or replace the damaged tissue

cardinal signs of inflammation
- redness, pain, heat, swelling, loss of function

acute inflammation: intense and for short period of time e.g. staphylococcus skin infection (note: Short Staphylococcus SS)

chronic inflammation: less intense and long lasting e.g. mycobacterium infection

effect of inflammaition
1. destroy or limit infection
2. repair the damaged tissue.

Question 29

FEVER

hypothalamus controls ?

During infection, products of microbes induce the release of cytokines such as ?

A fever is thought to be a response to raise the body’s temperature enough to ?

Evidence also shows that elevated body temperatures can be bad or good for certain immune cells to be more effective?

Answer 29

During infection, products of microbes induce the release of cytokines such as interleukin - 1 which is an endogenous pyrogen (a substance produced by bacterium which produces fever when introduced or released into the blood).

A fever is thought to be a response to raise the body’s temperature enough to kill certain bacteria and viruses that are sensitive to temp. changes

Evidence also shows that elevated body temperatures can be good for certain immune cells to be more effective

Question 30

what are the 4 types of antimicrobial substances

explain complement pathway, 3 complement/activation pathways

Answer 30

1. complement
2. interferons
3. iron-binding proteins
4. antimicrobial peptides

(only know complement and MAC)
Complement:
- a component of the innate immune system
- a group of >30 proteins activated as a cascade by a pathogen or by an antigen-antibody rxn
- together, the action of these proteins destroys microbes by:
a. enhanced phagocytosis
b. inflammation
c. cytolysis (MAC)

3 complement/activation pathways (CAL)

1. classical pathways - initiated by antigen-antibody complexes
2. alternate pathway: initiated by the interaction between C3, factors B, D and P and the pathogen
3. Lectin Pathway: Mannose-binding Lectin (MBL) binds to Mannose/sugars on the surface of the microbes

Question 31

1. Complement fits under which category of types of immune system (innate, adaptive or immune memory?)
2. component produced by which cells?
3. Complement’s 4 basic functions?

COMPONENTS OF COMPLEMENT

how many C1 - C11
or C1 - C10
or C1 - C9?

for C3, activation is required for which pathways?

Opsonins (example C3b and C4b) - WHAT DOEs it do?

what does anaphylatoxins release? (complement peptides are C3A, C4A, and C5A)

Membrane attack complex includes polymerization of which Cs?

Answer 31

1. innate
2. hepatocytes
3. complement’s 4 basic functions:

 Opsonization: enhancing phagocytosis of
bacteria/antigens
 Chemotaxis: attracting macrophages and neutrophils
 Cell Lysis: rupturing membranes of foreign cells
 Agglutination: clustering and binding of pathogens together (sticking)

how many C1 - C11
or C1 - C10
or C1 - C9?
- C1 - C9

for C3, activation is required for the 2 pathways: alternate and classical

Opsonins (example C3b and C4b) - WHAT DOEs it do?
- coats microbes and enhance phagocytosis
- an antibody or other substance -> C3b, that binds to foreign microbial or cells making them more susceptible to phagocytosis.

what does anaphylatoxins release? (complement peptides are C3A, C4A, and C5A) -> induce related of histamines and result in severe allergic rxns

Membrane attack complex includes of polymerization of which Cs? C5-C9

Question 32

COMPLEMENT

membrane attack complex (MAC) is aka?

Typically results on the ? of the pathogen after activation of other pathways of the complement system

initiation part of this pathway includes which C#s?

Polymerization part of the pathway includes which part of C#s?

Answer 32

membrane attack complex (MAC) is aka terminal complement complex

MAC typically results on the surface of a pathogen after activation of other pathways of the complement system.

Initiation part of this pathway includes C5-C7
- C5 convertase complex cleaves C5 into C5a and C5b
- binding of C6 C7 follow allowing insertion into lipid bilayer membrane

Polymerization part of the pathway includes C8-C9
- hydrophobic sites on C8 and C9 are exposed when they bind to the complex so they can also be inserted into the membrane.

Question 33

what are Interferons?

3 main types of it

IRON BINDING PROTEINS
- bacteria requires ?
- what does this protein do to limit growth of bacteria

• in the body iron is bound to protein molecules such as transferrin, lactoferrin, ferritin, hemoglobin which are ?
• what does bacteria contain which makes it sequester iron from the body?

Answer 33

Interferons are a group of signalling proteins (cytokines) released by host cells in response to infection with pathogens such as viruses.

◼ Interferon alpha ◼Interferon beta
◼ Interferon gamma

IRON BINDING PROTEINS
- bacteria requires iron
- what does this protein do to limit growth of bacteria: it binds the iron tightly making it unavailable for microbial use, limiting growth.

• in the body iron is bound to protein molecules such as transferrin, lactoferrin, ferritin, hemoglobin which are iron binding proteins (Side note: ANYTHING TO DO WITH “FE” is iron related)
• what does bacteria contain which helps it sequester iron from the body? -> siderophores

Question 34

INNATE IMMUNITY

which ones does it include:
a. epithelial barriers
b. Helper T cells
c. Effector T cells
d. NK cells
e. phagocytes
f. complement
g. antibodies

does innate immunity include antibiotics?

ADAPTIVE IMMUNE RESPONSES

what are its 2 types?

3rd line of defence is non-specific or specific?

What is adaptive immunity?

what is **humoral response or immunity?
(humors = extracellular body fluid)

and they include which antibodies, proteins and peptides?

cell-mediated responses (T cells and B cells)

B cells or T cells, bearing unique receptors that recognize ?
Each receptor recognizes an antigen, which is simply any molecule that may bind to ?

Answer 34

INNATE IMMUNITY

which ones does it include:
a. epithelial barriers
d. NK cells
e. phagocytes
f. complement

• no innate doesn’t include antibiotics

Third Line of Defense : Specific

2 types of adaptive immune response are:
1. humoral response or immunity
2. cell mediated responses (T and B cells)

adaptive immunity -
Specific immune response induced against a specific pathogen or molecule

humoral response or immunity: aspect of immunity that is mediated by macromolecules present in extracellular fluids

humoral responses or immunity include secreted antibodies, complement proteins and antimicrobial peptides.

2nd type of adaptive response are cell mediated responses
- B cells or T cells, bearing unique receptors that recognize “specific
signals” rather than general patterns.
- Each receptor recognizes an antigen, a molecule that may bind to a B cell receptor (BCR) or T cell receptor (TCR)

Question 35

Adaptive Immunity aka?

how long does it take to become active?

simple or complex ?

Foreign invaders trigger the immune response due to foreign characteristics on there ?

Antigen: what are these substances?

Epitope: ?

Destroys invaders using a carefully orchestrated ensemble of ?

Retains ? of the encounter
 Not only is there memory, there is also a ? and ? response on subsequent exposures
 The secondary reaction is called the?

Answer 35

 Also called “acquired immunity”

 Takes days to weeks to become effective

 Complex and sophisticated

 Recognizes foreign invaders

 Foreign invaders trigger the immune response due to foreign characteristics on their surface
 Antigen: any substance present on the pathogen that causes the immune system to produce antibodies against it
 Epitope: specific piece of an antigen that an antibody binds to

Destroys invaders using a carefully orchestrated ensemble of receptors and chemical signals (chemokines/cytokines)

retains memory of the encounter
- not only is there memory, there is also quicker and more intense response on subsequent exposures

• anamnestic response is the term for secondary reaction

Question 36

Natural or artificial below

Passive: maternal?
Passive: antibody transfer?

Active: immunization?
active: infection?

what are antigens in the form of?

epitopes: which immune cells bind to epitopes?

antigen receptors (present on B, T cells) only recognize specific ?

Answer 36

Passive: maternal -> natural
Passive: antibody transfer -> artificial

Active: immunization -> artificial
active: infection -> natural

 Usually proteins or large polysaccharides (sometimes lipids)
 Lipids or nucleic acids, when combined with proteins or polysaccharides
 Microbial or non-microbial

epitopes: Bcells, T cells, antibodies cells bind to epitopes

antigen receptors (present on B, T cells) only recognize specific episodes

Question 37

Hapten: is essentially an incomplete ?

what are they?

they attach to what to induce antibody response?

e.g.?

what are antibodies?
- produced during which **immune response and by which **cell?
- One antibody molecule has two identical ?
- what is the # of antigen binding sites in an antibody called? typically how many antigen binding sites?

Answer 37

hapten is an incomplete antigen

its a low molecular weight compounds which cannot induce and antibody response by itself

they attach to a carrier molecule to induce antibody response.

e.g. penicillin allergy

(many drugs that cause allergic rxns such as penicillin act as haptens. When injected or ingested penicillin reacts chemically with proteins in the body to form a hapten-carrier complex that can lead to severe response such anaphylaxis)

Antibodies are proteins called immunoglobulins (Ig)
- produced during the humoral immune response by B cell called a plasma cell
- One antibody molecule has two identical antigen binding sites
- Valence is the # of antigen binding sites in an antibody; typically 2 antigen binding sites

Question 38

ANTIBODY STRUCTURE

which letter-shaped hinged monomer?

how many identical heavy chains?how many identical light chains?

what are its 2 regions called?

what part of the constant region determines the class of antibody? and what is this region known as?
what does this region interact with?

Variable region can bind to?

Answer 38

Y shaped hinged monomer
Two identical heavy chains,
Two identical light chains
Constant region and variable regions
The stem/tail of the constant region determines the class of antibody. Known as the Fc region (Fragment crystallized), interacts with the cell surface receptors

Variable regions can bind to specific antigens
Fc region (stem/tail of Constant) can bind to complement
Fc region can bind to a cell such as macrophage/phagocyte

Question 39

Summary of Immunoglobulin Classes

IgG: most common antibody found in body

percentage of total serum antibody?
placental transfer?

IgM known functions: ?

IgA: (location) secretions: ?

IgD: location?

IgE: known functions: ?

Protective mechanism of binding antibodies to antigens
- agglutination:
- opsonization:
- neutralization:
- activation of complement
- antibody-dependent cell-mediated cytotoxicity

Answer 39

Summary of Immunoglobulin Classes

IgG: most common antibody found in body

percentage of total serum antibody = 80%
placental transfer = YES!

IgM known functions: esp. effective against microbial and agglutinating antigens; first antibodies produced in response to initial infection

IgA: (location) secretions: tears, saliva, mucus, intestine, milk), blood, lymph

IgD: location = B cell surface, blood, lymph

IgE: known functions: allergic rxns; possibly lysis of parasitic worms

Protective mechanism of binding antibodies to antigens
- agglutination: reduces # of infections units to be dealt w/

• opsonization: coating antigen w antibody enhances phagocytosis
• neutralization: blocks adhesion of bacteria and viruses to mucosa
• activation of complement: causes inflammation and cell lysis
• antibody-dependent cell-mediated cytotoxicity: antibodies attached to target cell cause destruction by macrophages, eosinophils and NK cells

Question 40

Humoral (humor means body fluid) response- extracellular (outside cell) pathogens

B-cells with a specific receptor encounters ?

B-cells work in collaboration with ? which secrete chemicals called cytokines

Leads to the proliferation and differentiation of ? into ?

? produce large quantities of antibodies against that particular antigen

Steps involved in humoral response
5 steps

MEMORY
- secondary immune response occurs as a result of ?
- memory of ? response

Answer 40

B-cells with a specific receptor encounters extracellular antigen

B-cells work in collaboration with helpter T cells which secrete chemicals called cytokines

This leads to the proliferation and differentiation of b cells into plasma cells

plasma cells produce large quantities of antibodies against that particular antigen

Steps involved in humoral response
5 steps

1. B cells encounter and bind ot antigen
2. b cell responds to antigen by proliferating
3. some b cells differentiate into long-lived memory cells
4. other b cells differentiate into plasma cells
5. plasma cells secrete antibodies into circulation (in cardiovascular system).

MEMORY
- secondary immune response occurs as a result of memory
- memory of anamnestic response

Question 41

Cell-mediated immune response Intracellular pathogens

Intracellular antigens are expressed on the ? of cell of an antigen presenting cell or infected cell

T-cell binds to ? antigen complexes on the surface

Release of cytokines that activate ? (TH1 cells and TH2 cells)

Cytokines activate ? or they might

activate Cytotoxic T-cells to ? the target cell containing the pathogen

Answer 41

Cell-mediated immune response Intracellular pathogens

Intracellular antigens are expressed on the surface of cell of an antigen presenting cell or infected cell

T-cell binds to major histocompatibility complex (MHC) antigen complexes on the surface

Release of cytokines that activate T-helper cells (TH1 cells and TH2 cells)

Cytokines activate macrophages or they might

activate Cytotoxic T-cells to lyse the target cell containing the pathogen

Question 42

Principle cells that function in cell-mediated immunity

T Helper (T H 1) Cell: ?
T Helper (T H 2) Cell:
Cytotoxic T lymphocyte (CTL):
T Regulatory (Treg) cell:
Activated Macrophage:
Natural Killer (NK) cell:

MHC (major histocompatibility complex)

• Cell surface molecules that play a major role in ?

 They bind to ? and present them to ?

 Determines compatibility for ?
 In humans also known as ?

Two separate properties of the MHC make it difficult for pathogens to evade immune responses

1.? & 2.? : MHC genes are, in fact, the most ? genes known

 ?- Multiple genes are involved
 expression is **? (equally expressed from both sets of inherited alleles)
 Polymorphic (multiple ? of each, vary from organism to organism, within a species)

 *Class I MHC- Present in all **? cells

( Class II MHC- Present only on **?
presenting cells

 Class III MHC- highest ? density but some of the genes are not involved in the immune system

MHC molecules present ? (peptide fragments), of non-self, from within the cell to ? via the cell membrane

Answer 42

Principle cells that function in cell-mediated immunity

T Helper (T H 1) Cell: activates cells related to cell-mediated immunity: macrophages, Tc cells, and natural killer cells

T Helper (T H 2) Cell: stimulates the production of eosinophils, igM, and igE

Cytotoxic T lymphocyte (CTL): destroys target cells on contact: generated from T cytotoxic (Tc) cell

T Regulatory (Treg) cell: regulates immune response and helps maintain tolerance

Activated Macrophage: enhanced phagocytic activity; attacks cancer cells

Natural Killer (NK) cell: attacks and destroys target cells; participates in antibody-dependent cell-mediated cytotoxicity

MHC (major histocompatibility complex)

• Cell surface molecules that play a major role in cell-mediated immune responses

 They bind to foreign antigens and present them to T cells

 Determines compatibility for organ transplant

 In humans also known as human leukocyte antigen (HLA)

Two separate properties of the MHC make it difficult for pathogens to evade immune responses

1. polygenic & 2. polymorphic: MHC genes are, in fact, the most polymorphic genes known

 polygenic- Multiple genes are involved
 expression is **CODOMINANT (equally expressed from both sets of inherited alleles)
 Polymorphic (multiple variants of each, vary from organism to organism, within a species)

 *Class I MHC- Present in all **nucleated cells and in antigen-presenting cells

 Class II MHC- Present only on **antigen
presenting cells

 Class III MHC- highest gene density but some of the genes are not involved in the immune system

MHC molecules present antigens (peptide fragments), of non-self, from within the cell to cytotoxic T cells via the cell membrane

Question 43

T lymphocytes

1. T helper cells (CD#?+)
   - Th1, Th2, Th?, T?
   - bind to MHC class ? molecules
2. T-cytotoxic cells (CD#?+)
   - bind to MHC class I molecules (present in all nucleated cells)
   - processing and presenting ? and ? antigens

CD4 and CD8 are membrane-associated glycoproteins that serve as a ? for the T cell receptor.
CD = cluster of differentiation

Answer 43

T lymphocytes

1. T helper cells (CD4+)
   - Th1, Th2, Th17, Tfh (interleukin sitmulates Th cells)
   - bind to MHC class II molecules
2. T-cytotoxic cells (CD8+)
   - bind to MHC class I molecules (present in all nucleated cells)
   - processing and presenting endogenous and cytosolic antigens

CD4 and CD8 are membrane-associated glycoproteins that serve as a co-receptor for the T cell receptor.
CD = cluster of differentiation

Question 44

Antigen presenting cells (APCs)

Cells that process and present antigens for recognition to?

These APCs include: 4 things?

Answer 44

Cells that process and present antigens for recognition to T cells

These APCs include: 4 things
1. macrophages
2. b cells
3. dendritic cells
4. Langerhans cells

Question 45

T-helper cells (CD4+)

step 1
- An APC encounters and ingests a microbial. The antigen is enzymatically processed into ?, which combine with ? and are displayed on the ? of the APC

step 2
- A receptor on the surface of the ? binds to the ? complex, if this includes a Toll like receptor, the APC is stimulated to secrete a ? molecule. These two signals activate the Th cells, which produces ?.

step 3
- (a T cell that recognizes a ? that is producing costimulatory molecules becomes activated, allowing proliferation and development of effector functions.)

• The cytokines cause the ? to proliferate and to develop its effector functions.

Answer 45

T-helper cells (CD4+)

step 1
- An APC encounters and ingests a microbial. The antigen is enzymatically processed into short peptide, which combine with MHC class II molecules and are displayed on the surface of the APC

step 2
- A receptor on the surface of the CD4+ helper cell (Th cell) binds to the MHC-antigen complex, if this includes a Toll like receptor, the APC is stimulated to secrete a costimulatory molecule. These two signals activate the Th cells, which produces cytokines.

step 3
- (a T cell that recognizes a dendritic cell that is producing costimulatory molecules becomes activated, allowing proliferation and development of effector functions.)

• The cytokines cause the Th cells to proliferate and to develop its effector functions.

Question 46

ACTIVATION AND ACTION OF “CYTOTOXIC T-CELLS”

(Dr. Freeman finds them cool so might come on exam!!)

• cytotoxic T- cell work w/ which MHC I or II?

1.so firstly, the cytotoxic T cell are going to produce “ ? “ (a cytolytic protein) and “ ? “ (they are granules in the cytotoxic T-cell which apparently are “agranulocytes”- lil confusing) and they ? the membrane of the virus

2. then it also produces “ ? “

(cytokines are cell - ? molecules)

3. cytolytic pore formation occurs with the help of ? and ?
4. lastly, ? and ? occurs (cell could. be somatic)

-> when cytotoxic cells don’t do their job then that’s when ? occurs.

Answer 46

ACTIVATION AND ACTION OF “CYTOTOXIC T-CELLS”

• cytotoxic T- cell work w/ which MHC I

1.so firstly, the cytotoxic T cell are going to produce “perforin” (a cytolytic protein) and lymphotoxin, a proteolytic enzyme -> granzymes (they are granules in the cytotoxic T-cell which apparently are “agranulocytes”- lil confusing) and they puncture the membrane of the virus

2. then it also produces “gamma-interferon”

(cytokines are cell - signalling molecules)

3. cytolytic pore formation occurs with the help of perforin
4. Cytolysis and cell death (cell could. be somatic)

-> when cytotoxic cells don’t do their job then thats when mutation occurs.

Question 47

CYTOTOXIC T CELLS

After interacting with a target cell, an activated cytotoxic T-cell releases perforins and a ? that kill the target cell

? is a transmembrane glycoprotein that serves as a ? for the T cell receptor (TCR). Like the TCR, ? binds to a major histocompatibility complex (MHC) molecule, but is specific for the class #? MHC protein

which two specific immune cells fall under both innate and adaptive immune response?

cytotoxic T cells either declogs the cancer cells or lets CD8 go back to and do its job

Answer 47

After interacting with a target cell, an activated cytotoxic T-cell releases perforins and a proteolytic enzyme (granzymes) cell that kill the target cell

CD8 is a transmembrane glycoprotein that serves as a co-receptor for the T cell receptor (TCR). Like the TCR, CD8 binds to a major histocompatibility complex (MHC) molecule, but is specific for the class I MHC protein

NK cells and Gamma-delta (γδ) T cells
NK cells have an important role in innate immune responses, particularly in anti-viral immunity

Gamma-delta (γδ) T cells link innate and adaptive immune responses

Question 48

immunotherapy called “Car T-cell therapy” for cancer treatment

• here u can remove ? and insert a gene into a T cell (insert a gene for “ ? “; thus v specific)
• can grow ? of CAR T cells in the lab and then put them back in the patient
• only works when there’s ? though

Antibody Dependent Cell mediated Cytotoxicity
(ADCC) is the killing of an ? by a cytotoxic effector cell through a non-phagocytic process, characterized by the release of the content of **?

1. Antibodies bind antigens on the ? of target cells
2. ? receptors recognise cell-bound antibodies
3. ? triggers degranulation into a lytic synpase
4. tumour cells die by ?

Answer 48

immunotherapy called “Car T-cell therapy” for cancer treatment

• here u can remove blood and insert a gene into a T cell (insert a gene for “CAR”; thus v specific)
• can grow millions of CAR T cells in the lab and then put them back in the patient
• only work when there’s comtability though

1. Antibodies bind antigens on the surface of target cells
2. NK cell CD16 Fc receptors recognise cell-bound antibodies
3. cross-linking of CD16 triggers degranulation into a lytic synpase
4. tumour cells die by apoptosis

Question 49

Cytokines

 Chemical messengers are produced during the ? by the cells of the immune system
 > than ? cytokines

Chemokines - Small cytokines involved in ?

Cytokines are ? molecules that aid cell to cell communication in immune responses and stimulate the movement of cells towards sites of ?, ? and ?

 Interleukins
Eg: IL-1, IL-12, IL-17
 ?
 IFN-a, IFN-b, IFN-g
 Tumor necrosis factor (TNF-a)

Answer 49

Cytokines

 Chemical messengers are produced during the immune response by the cells of the immune system
 > than 200 cytokines

Chemokines - Small cytokines involved in chemotaxis

Cytokines are cell signalling molecules that aid cell-to-cell communication in immune responses and stimulate the movement of cells towards sites of inflammation, infection and trauma

 Interleukins
Eg: IL-1, IL-12, IL-17

 Interferons
 IFN-a, IFN-b, IFN-g

 Tumor necrosis factor (TNF-a)

Question 50

which cytokines stimulate the immune system? give an e.g.

which cytokines suppress the immune system?

Answer 50

pro-inflammatory cytokines (Th1) stimulate the immune system. e.g. IL-2

anti-inflammatory cytokines suppress the immune system.