Micro host parasite 3 (immunity)

Question 2

Dendritic cells

Answer 2

fixed phagocytes located in layers of skin; they have dendrites or arms that grab bacteria that enter. Aka professional antigen presentive cell

Question 3

3 lines of defense

Answer 3

Physical: skin and mucous membranes; adaptive response; innate response

Question 4

Autoantigens

Answer 4

Antigens that are detected by the body that belong to itself

Question 5

Primary function of immune system

Answer 5

differentiate between self and non self; destroy that which in non-self

Question 6

Nonspecific and specific immunity

Answer 6

physical and chemical: skin and mucous membranes, inflammation, phagocytosis; adaptive response: need to be activated

Question 7

Enzymes in protection

Answer 7

enzymes in mucous membranes; digestive system; Lysosyme in eye, targets petidoglycan

Question 8

Opsonizing

Answer 8

Complement and antibodies bind to the antigen which is then more easily recognized by the phagocytes

Question 9

Nonspecific immunity

Answer 9

innate immunity is non-inducible, doesn’t need previous exposure; phagocytes immediately attempt to break down

Question 10

Describe phagocytosis in immunity

Answer 10

Binds, phagocytosed, lead to phagolysome, eliminated from body

Question 11

Escaping initial immune response

Answer 11

Destroy phagosome membrane. Inhibit lysosome/phgosome fusion. Inhibit acidification of phagosome (enzymes can’t be active) -> become intracellular pathogens

Question 12

Inflammatory response

Answer 12

Phagocyte and pathogen interact; secretes cytokines; capillaries dilated which increases immune cells present (granulocytes, phagocytes), vascular permeability increases so cells can get into wound

Question 13

Diapedesis

Answer 13

cells crawl out of permeable blood vessels to attack wound etc

Question 14

Lymphatic system parallels the blood stream

Answer 14

We get swollen lymph nodes when we are ill; monocytes etc take bacteria to lymph; lymph node is where many immune cells are; contains the infection

Question 15

What is the goal of a localized inflammatory response?

Answer 15

To isolate and contain an infection

Question 16

T cells

Answer 16

mature in thymus, become T helpers and cytotoxic T cells; aid in production of antibodies, involved in cell mediated immunity; each contains many of specific receptor

Question 17

Epitope

Answer 17

small regions of a.a. (<10) recognized by antibodies on T cell or B cell; can be many per antigen; can be linear or conformational (more common)

Question 18

B lymphocyte activation

Answer 18

binds an epitope at antibody (many copies), gets activated and become plasma cell and secretes millions of antibodies into blood

Question 19

T cell activation

Answer 19

binds an epitope at T cell receptor (not antibody!) (many copies), gets activated and makes many copies of itself

Question 20

B lymphocyte

Answer 20

can differentiate in liver and lymph areas in intestine; migrate to lymphoid tissue and produce circulatory

Question 21

Triggering immune response

Answer 21

something with antigens (cell wall, pili, etc) gets into the body (breaks in skin, injection, organ transplant)

Question 22

Humoral immunity

Answer 22

Active: Antibodies actively produced; passive, where we get antibodies from another person (anti-venoms, or mother-child via breast milk). Develops resistance to re-infection due to stimulated B lymphocytes

Question 23

Stimulants - antigens

Answer 23

need to be large enough - one epitope is not large enough

Question 24

Antigenic determinant

Answer 24

Same thing as an epitope - small part of an antigen (a few a.a.) that is recognized by antibody

Question 25

Importance of type of epitope

Answer 25

linear or conformational - important in cloning because we want it to look like the natural epitope to generate response - we only usually clone part of gene (epitope)

Question 26

Types of antigens

Answer 26

Exogenous: in bloodstream, stimulates B cell response; endogenous: virus/bac inside, antigens left on outside, generates B and T cell response; Autoantigens: self

Question 27

3 roles of antibodies**

Answer 27

Agglutination: …; neutralization: bind so toxin can affect body; opsonization: helps macrophages internalize bacteria, “targets for destruction”

Question 28

Antibody process (slide 16-17)**

Answer 28

Produced by B lymphocytes; specific, found in lymph, blood, mucus, saliva; initial delay as it is processed (10-14 days); B cells become plasma cells and make antibodies

Question 29

T cell dependent B cell response**

Answer 29

antigen presenting cell see and internalize bac to contain; present many antigens on surface; T helper cell sees antigen (recognize only one) and becomes T helper 1 or 2; TH2 releases cytokines to get B cell primed and goes flat out - clonal proliferation = self replicates and secretes antibodies

Question 30

B cell recpetor

Answer 30

B cell receptor is actually a antibody, has many of the same

Question 31

Memory B cell

Answer 31

Recognizes antigens, reacts quickly and skip the rest of T and B cells and being secreting antibodies

Question 32

Why does attenuated vaccine produce better immune response?

Answer 32

Many many epitopes!

Question 33

Memory cells

Answer 33

B lymphocyte: waits in lymph tissue; T lymphocyte: same, makes cytotoxic T cells when it gets activated again

Question 34

Goal of vaccination

Answer 34

To create memory cells; Not to generate antibodies

Question 35

T cell dependent T cell response

Answer 35

For endogenous antigens; Dendritic cells have MHC II and secretes IL-12 to stimulate TH1, and MHC I plus epitope to stimulate cytotoxic T cell; TH1 stimulates cytotoxic t cell with IL-2; cytotoxic T cell clones and self stimulates and becomes active; kills cell with certain epitope

Question 36

What cells can generate antigens?

Answer 36

Cells with nucleus - present normal antigens and viral ones

Question 37

Killing of virally infected cell

Answer 37

T cell releases Perforin which causes a hole in membrane, and releases granzyme which activates apoptosis