Innate and Adaptive Immunity

Question 1

define the immune response

Answer 1

coordinated response of cells and molecules of the immune system

• Distinguish self from non-self
• Discriminate potentially harmful agents from nonharmful
• Recall previous encounters with the same agents
• Mount an effective response
• Can produce excessive response (examples: allergies or autoimmune diseases)

Question 2

two types of immunity

Answer 2

Innate (natural): physical, chemical, molecular , and cellular defenses in place before infection and can function immediately -effective barrier to microbes

Adaptive (AKA specific/ acquired): second defense; responds less rapidly,
-recognition of each unique type of foreign agent followed in days by an amplified and effective response
- 2 types: humoral (mediated by antibodies from Bcells)
and cell-mediated ( by T cells)

Question 3

3 types of phagocyctic cells of the immune system

Answer 3

-Monocytes/Macrophages: first line of defense for innate immunity; antigen-presenting cells (APCs) for adaptive immunity
-Granulocytes: Neutrophils-most important cell in innate immunity; use enzymes to destroy microbes
also Eosinophils and Basophils
-Dendritic Cells: APC- Immature in tissue; catch foreign agent w/fingerlike processes; “activated”; brings to lymph node; activates Adaptive response by processing and presenting molc of antigens to the lymphocytes

Question 4

3 types of immune system cells and subgroups

Answer 4

phagocyctic: monocyte/macrophage, granulocyte(neutrophils, eosinophils, basophils), dendritic
lymphocytes: T and B
NK (natural killers)

Question 5

lymphocytes

Answer 5

Bcells: mediate humoral immunity, produce plasma + antibodies and have memory cell
Tcells: cell mediated immunity, need APCs
-helper T cell (mature=C4)
-cytotoxic T cell (mature=C8)
-CD - clusters of differentiation

Question 6

humoral immunity

Answer 6

aspect of immunity that is mediated by macromolecules found in extracellular fluids such as secreted antibodies, complement proteins, and certain antimicrobial peptides.

Humoral immunity is so named because it involves substances found in the humors, or body fluids.

Question 7

clusters of differentiation (CD)

Answer 7

pattern of membrane-bound molecules on cell surface: identify different T and B cells
-protect against viruses, cancer and intracellular bacteria
-

Question 8

NKs- natural killer cells

Answer 8

innate immunity

• fight viruses and bacteria
• recognize abnormal cells from infection and thos w/ intracell pathogens (but not specific antigens)
• recognize tumor cells
• activated = cell death or no response

Question 9

what cells are more important for innate immunity? what about adaptive immunity?

Answer 9

innate: phagocytic WBCs and NK
adaptive: lymphocytes (T and B)

Question 10

Lymphatic System: structure and function

Answer 10

accessory system to vascular system
-vena cava: main drainage
removes excess fluid, proteins, large particles from interstitial spaces + returns them to circulation

Question 11

Lymphoid tissues

Answer 11

home to the Immune response: connected by network of lymph channels, blood vessels and capillaries.

Central organs:
Bone marrow
Thymus

Peripheral Lymphoid tissues:
Lymph nodes
Spleen
Mucosa-associated lymphoid tissues (MALT)- non encapsulated
Respiratory system: tonsils
GI system: Peyer patches (“tonsils” of intestine) and appendix (not super necessary)
Reproductive system

Question 12

bone marrow: function in immune system

central organ

Answer 12

Produces immature T cells (T cell progenitors), send to Thymus
Produces B cells (mature here) and acquire immunoglobulin signaling molc
[checkpoint: Only B cells that are able to distinguish themselves from non-self are allowed to mature and leave the bone marrow. it not- killed off]

Question 13

thymus: structure and function

central organ

Answer 13

fully mature at birth; smaller w/ age
pre-T cells differentiate and travel from bone marrow to the thymus where it matures (under the influence of Thymic hormone and cytokines).
T-helper and T-cytotoxic cells released in 2-3 days and sent to peripheral lymph tissues

Question 14

T cells mature where? B cells mature where?

Answer 14

T- thymus

B-bone

Question 15

non-tender enlarged lymph nodes may indicate?

Answer 15

malignancy, pain means that cells are doing their job in there

Question 16

lymph nodes: structure and function

peripheral organ

Answer 16

Encapsulated lymphoid tissue attached to the lymphatic channels
Locations: axillae, groin, great vessels of the neck, thorax, and abdomen
Lymphocytes, macrophages and dendrites are in the nodes
–>Cleaning out any antigens that pass through so that it does not go into the circulation.

Two functions of lymph nodes:
1.remove foreign material from lymph before bloodstream 2.centers for proliferation and response of immune cells

Question 17

Spleen: structure and function

peripheral organ

Answer 17

Filters antigens from the blood; important in response to systemic infection

• Red pulp where dead and dying RED blood cells are removed from circulation
• White pulp contains concentrated area of B and T lymphocytes with lots of macrophages and dendritic cells.

Question 18

MALT

peripheral organ

Answer 18

Mucosa-associated lymphoid tissues (MALT)
NON-encapsulated lymphoid tissue:on membranes of respiratory, digestive, and urogenital tracts.

include: lymphocytes, macrophages + dendritic cells, and plasma cells
* Immunity at the mucosal layers helps exclude many pathogens and protects the vulnerable internal organs

Question 19

cytokines in immunity (CtKs)

Answer 19

• umbrella term for inflamm. mediators : COMMUNICATOR/INFLUENCER - aka kylie jenner of immune system
• short-acting soluble molecules, mediated axns in innate and adaptive
• local or systemic axn
• pleiotropic (act on different cells )
• redundant (basic B!tche$- doing the same thing)

subgroups:
chemokines
CSF: colony-stimulating factors

Question 20

chemokines

Answer 20

family of cytokines. stimulate migration and activation of immune and inflammatory cells

Question 21

CSF- colony stimulating factors

Answer 21

group of CtKs: upregulate cells we need to fight infection
- stimulate bone marrow pluripotent stem and progenitor cells or precursor cells to produce blood cells (platelets, neutrophils, dendritic cells, etc)

Question 22

interleukins and interferons: general functions

Answer 22

types of cytokines
IL- made by leukocytes, act on leukocytes
(can use for cancer treatment or IL2 for renal cell carcinoma- stim. Tcells and NKs)
IFNs- interfere w/ virus multiplication

Question 23

interleukin 1 (alpha and beta)

Answer 23

variety of effects

• activates endothelium and lymphocytes
• induces fever and acute phase response
• stim neutrophil production

Question 24

innate immunity: 2 functions expanded, 5 components

Answer 24

1. Cause Inflammation and to alert the Adaptive Immunity. First line of defense
2. Responds only to microbes (in the same way to all types)

Players are already in place waiting to go:

• Epithelial barriers
• Phagocytic leukocytes (mostly neutrophils+ macrophages)
• Natural killer cells ( specialized lymphocytes)
• plasma proteins (complement system +inflamm. system)
• CtKs (regulate and coordinate the system)

Question 25

innate immunity: epithelial barriers

Answer 25

skin and mucous membranes

Question 26

2 soluble mediators of innate immunity

Answer 26

opsonins and cytokines

Question 27

opsonins: function and 3 types

Answer 27

Soluble tag for microInvader; glue antigen to innate immunity cell for better phagocytosis
Important opsonins in innate immunity: 
1.acute-phase proteins
2.lectins
3.complement

Question 28

CtKs and innate immunity

7 soldiers and what they do

Answer 28

TNF alpha, IL-1, IL-6, IL-12, IFN-y, IFN-alpha, and IFN-B, and chemokines are involved in innate immunity;
-produce chemotaxis of leukocytes
-stimulate acute-phase protein production
-inhibit viral replication
Complement system

Question 29

complement cascade overview and 3 phases

innate immunity part

Answer 29

group of proteins from plasma (C1 through C9)- present but inactive normally- activate when infection is present- act as opsonins. (glue antigen to innate immune cell that needs to kill it,)
GOAL of all three phases: Activate C3 
1. initial activation
2.early-step inflamm. 
3. late-step membrane attack

Question 30

CC: initial activation

Answer 30

recognizing microbes and activating the system:

1. Alternative– activation by cell surface molecules, no antibody (innate immune response)
2. Classical– activation by antigen-antibody complexes (adaptive immune response)
3. Lectin- activates the Classical pathway in the absence of antibody

All pathways lead to the activation of a C3 convertase enzyme which cleaves C3 and starts the reaction in phase2

Question 31

CC: early-step inflammation

Answer 31

inflammation is stimulated by 3a fragment;
vasodilation, increased vascular permeability, and late-step membrane attack responses begin because of C5 fragmenting into C5a and C5b

Question 32

CC: late-step membrane attack

Answer 32

the C5b fragment initiates formation of complement proteins C6-C9 complexes and these form a membrane attack complex which will result in cell lysis

Question 33

2 types of pathogen recognition: innate immune system

Answer 33

1. pattern recognition: our body recognizes the foreign pattern of proteins on cell surface of invader. PAMPS (pathogen-assosciated molecular patterns) PRRS (pattern recognition receptors)
2. toll-like: recognize structurally conserved molecules of invader