Lecture 1- intro

Question 1

Who is the father of vaccination and what disease did he work with?

Answer 1

Edward Jenner & smallpox

Question 2

Name 2 things the immune system is good for

Answer 2

1- Fighting infections (bacteria, viruses, parasites, fungi)

2- surveying for tumors and rejecting tumors

Question 3

What happens if the immune system goes rogue?

Answer 3

autoimmunity
allergies
transplant rejection

Question 4

Where is the immune system located?

Answer 4

circulates through the body all the time, lymphatic system- lymph nodes are where immune responses may be initiated

• spleen
• bone marrow and thymus (primary lymphoid organs)

Question 5

Who are the major players of the immune system?

Answer 5

cells- hematopoietic stem cell– myeloid, lymphoid, erythroid lineages

Question 6

name the cells in lymphoid lineage

Answer 6

B cells
T cells
NK cells

Question 7

name the cells in myeloid lineage

Answer 7

granulocytes: neutrophils, eosinophils, basophils

phagocytes/monocytes: dendritic cells, macrophages, mast cells

Question 8

name the cells in erythroid lineage

Answer 8

megakaryocyte

erythrocyte

Question 9

name 2 other components of the immune system

Answer 9

cytokines

complement

Question 10

describe cytokines

Answer 10

• “hormones” of the immune system
• secreted by cells upon exposure to a pathogen; secreted by one cells and act on another cell (autocrine or paracrine)
• interleukins- communication between leukocytes- can cause or inhibit activation
• cause fever, swelling, recruitment of cells, amplification of immune response

Question 11

name the cell types of innate immunity

Answer 11

all phagocytes, granulocytes, NK cells

Question 12

name the cell types of adaptive immunity

Answer 12

B cells

T cells

Question 13

describe innate immunity

Answer 13

• molecules and cells that distinguish host from infectious agents by recognizing conserved motifs
• rapid, activated within minutes to hours of exposure
• not significantly increased by previous exposure (constant, no memory)
• does not rearrange DNA to form highly specific receptor

Question 14

describe adaptive immunity

Answer 14

• cells with very specific receptors for an unlimited number of targets
• effective only after a delay of several days
• has immunological memory- enhanced responsiveness upon re-encounter of same pathogen
• rearrange DNA to form highly specific receptors

Question 15

Which is worse- lacking innate immunity only or lacking adaptive immunity only?

Answer 15

lacking innate immunity is worse- can kill host

Question 16

describe the receptors of B and T cells

Answer 16

B cells have highly specific antigen-binding site
T cell receptor: antigen-binding site is highly variable
T cell receptor is always at cell surface

Question 17

what is an antigen?

Answer 17

a molecule (often a protein derived from a pathogen) recognized by the immune system as foreign, you generate an immune response to it

Question 18

what is an antibody?

Answer 18

protein produced by B cells, circulate in blood and lymph, binds very specifically to a given pathogen when they come upon it
- aka immunoglobulin

Question 19

what is epitope?

Answer 19

more specific part of antigen, the part that is actually bound by the antibody

Question 20

name the primary lymphoid organs and their function

Answer 20

1. thymus- T cells
2. bone marrow- B cells

primary organs are where selection occurs (B and T cells, auto-reactive)

Question 21

name the secondary lymphoid organs and their function

Answer 21

lymph nodes

where activation of the cells occur, clonal expansion when activated

Question 22

primary lymphoid organs function in _____

secondary lymphoid organs function in ____

Answer 22

selection

activation

Question 23

what is clonal expansion?

Answer 23

the selection and expansion of a receptor specificity that makes a cell clonally expand (signal sent to nucleus of B cell for clonal expansion, every offspring of that B cell will have the same receptor)

• in the end, there is so much expansion that there has to be contraction

Question 24

describe the early events of the innate immune system when infection starts

Answer 24

1. surface wound introduces bacteria, which activate resident effector cells to secrete cytokines
2. vasodilation and increased vascular permeability allow fluid, protein, and inflammatory cells to leave blood and enter tissue
3. infected tissue becomes inflamed- redness, swelling, pain
4. large reserves of neutrophils are stored in bone marrow and are released when needed to fight infection
5. neutrophils travel to and enter infected tissue- they engulf and kill bacteria, the neutrophils die in tissue & are engulfed and degraded by macrophages

Question 25

describe the transition from innate to adaptive immune response

Answer 25

transition begins with the migration of dendritic cells to the draining lymph nodes

dendritic cells are carrying pathogens, T and B cells specific for these antigens will undergo clonal expansion in the lymphoid tissue

(lymph nodes are architectually organized into B and T cell centers)

Question 26

describe process of clonal expansion and selection

Answer 26

1- lymphocyte clones mature in generative lymphoid organs, in the absence of antigens
2- clones of mature lymphocytes specific for diverse antigens enter lymphoid tissues
3- antigen-specific clones are activated (“selected”) by antigens
4. antigen-specific immune responses occur

Question 27

describe the phases of the adaptive immune response

Answer 27

1. antigen recognition
2. lymphocyte activation (clonal expansion and differentiation)
3. antigen elimination (antibodies and effector T cells)
4. contraction, homeostasis (apoptosis)
5. memory