Intro to Immunology

Question 1

what is the purpose of the immune system

Answer 1

defense against infectious microbes

Question 2

what was the origin of the first vaccine

Answer 2

pus from cowpox administered to people to protect from smallpox

Question 3

what does cross-reactivity mean in reference to the smallpox vaccine

Answer 3

A cowpox antigen was administered, host developed Ab to cowpox, which protected host from different “smallpox” antigens

Question 4

what is the only human infectious diseease to be completely eradicated

Answer 4

smallpox

Question 5

what are the 2 components of the immune system and which is considered the early phase ? which is late phase ?

Answer 5

innate - early

adaptive - late

Question 6

which immune response involves barrier defenses, and what are the barrier defenses

Answer 6

innate

• physical (skin, mucous membranes)
• chemical (sweat, saliva)
• biological (normal flora)

Question 7

what immune response it antigen specific

Answer 7

adaptive

Question 8

all leukocytes are derived from where ?

Answer 8

hematopietic stem cells in bone marrow

Question 9

hematopoetic stem cells can differentiate into 2 kinds of cells, what are they

Answer 9

myeloid progenitor cells

lymphoid progenitor cells

Question 10

what specific types of cells are derived from myeloid progenitor cells

Answer 10

• Granulocytes (basophils, eosinophils, nuetrophils)
• Monocytes
• Dendritic cells

Question 11

what types of cells are derived from lymphoid progenitor cells

Answer 11

NK cells
B cells
T cells

Question 12

cells derived from myeloid progenitor cells are all apart of _____ immunity

Answer 12

innate

Question 13

of the cells derived from lyphoid progenitor cells, which are apart of the adaptive immune response

Answer 13

B and T cells

Question 14

neutrophils are _____ in order to respond to trouble, and make up what percentage of leokocytes

Answer 14

first, 50-75 %

phagocytes

Question 15

what specific cells play a large role in allergies and only make up about 0.2 % of leukocytes

Answer 15

basophils and mast cells

Question 16

what is the main function of eosinophils, and what percentage of leukocytes do the make up

Answer 16

fight off/destroy parasites that are too large to be phagocytized
2-5 %

Question 17

what cells are especially effective against viruses and tumor cells, how do they do this

Answer 17

NK cells, dont need MHC complex to recognize antigens

important cuz virus and tumor cells downregulate MHC complexes

Question 18

what is the main role of monocytes and what percentage of leukocytes do they make up

Answer 18

phagocytes, antigen presentation, housekeeping

5-10 %

Question 19

what cells are the main link between the innate and adaptive immune system, how do they do this

Answer 19

dendritic cells (also monocytes a lil)
-do this by presenting antigens to T cells

Question 20

what are the 2 “arms” of the adaptive immmune system

Answer 20

humoral immunity

cell mediated immunity

Question 21

humoral immunity specifically targets ______ pathogens with the aid of what cells

Answer 21

extracellular

-B cells producing antibodies

Question 22

cell mediated immunity specifically targets _______ pathogens using what cells

Answer 22

intracellular

-T cells

Question 23

what are the 2 types of T cells and what is their function

Answer 23

cytotoxic t cells - kill and induce apoptosis

helper t cells - secrete cytokines which activate cytotoxic t cells

Question 24

what are the 3 Cluster of Differentiation (CD) markers for T cells

Answer 24

CD3 - T cells
CD4 - Helper t cells
CD8 - cytoxic t cells

Question 25

what are the 3 types of antigens

Answer 25

immunogen - normal Ag eliciting immune response
tolerogen - something that is immune-nonresponsive (tolerant)
allergen - Ag inducing hypersensitivity/allergic rxn

Question 26

what is the difference b/w endogenous and exogenous Ag

Answer 26

endogenous - w/in body and presented by CD8 cells

exogenous - outside body and presented by CD4

Question 27

what activates naive B and T cells to enter the lymph node from circulation

Answer 27

APC cells binding an antigen at site of infection then transporting to the lymph node

Question 28

why does adaptive immunity take about a week to actually elicit a response

Answer 28

clonal expansion, differentiation, and multiplication of B and T cells
——-> once enough of them then travel to infection site

Question 29

explain process of how an activated lymphocyte (t cell) can travel from the lymph node to site of infection

Answer 29

1 - decrease L selectin getting naive T cell in circulation
2 - increase E and P selectin cause it to slow near site
3 - integrins cause to to slow more
4 - chemokines cause it to stop at infection site

Question 30

what effect do cytokines have on E and P selectins

Answer 30

they increase (makes sense cuz increase cytokines during inflamation)

Question 31

what are the 3 “non-specific” receptors of the innate immune system that detect microbes

Answer 31

• scavenger
• mannose
• N-formyl-methionyl
• * all signal for phagocytosis***

Question 32

what does the innate immune system use to detect antigens

Answer 32

Toll like receptors - TLRs

-also known as pattern recognition receptors

Question 33

what/how do TLRs or pattern recognition receptors recognize which tells them theres an antigen

Answer 33

pathogen associated molecular patterns (PAMPS)

Question 34

In general, what does activation of a TLR cause

Answer 34

signal cascade of lots of immune cells in innate response

Question 35

what do T cells of the adaptive immune response NEED in order to detect specific antigens

Answer 35

MHC complex

Question 36

CD4 t cells (helper) use what MHC complex to recognize specific antigens, what about CD8 (cytotoxic)

Answer 36

MHC II

MHC I