Mar21 M2-Adaptive Immunity 1 Flashcards

1
Q

concept of biological medications and how they work in general (for Crohn’s, asthma, etc.)

A

slow or block the immune system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

main actions of T lymphocytes

A
  • coordinators of immunity and make cytokines
  • anticancer**
  • antiviral action
  • antiTB action
  • cytotoxic action
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

main actions of B cells

A
  • produce abs
  • produce cytokines
  • present antigens**
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how B and T cell change once exposed to an antigen

A

their progeny will change its Rs so that it has better affinity to the antigen (but the cell itself doesn’t do that tho)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how innate vs adaptive recognition of antigen differs

A

innate: patterns (lipopolysaccharides (LPS), viral DNA or RNA, etc.).
adaptive: specific peptides + can change recognition to make it better (the clone of B and T cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

mucosal immune responses mechanism

A
  • cold or allergy or invader destroys mucosa

- invader picked by surveillance cells (often dendritic cells) and presented to B and T cells in lymph nodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

(IMPORTANT) what T cells receptors recognize

A

peptides (broken down, native form of the protein. not the invader itself)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

MHC class 1 found on what cells and interacts with what

A

all NUCLEATED cells of the body. MHC class 1 recognized by CD8+ T cells. ALWAYS on cell surface.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

MHC class 2 found on what cells and interacts with what

A

found on APCs. present antigen to CD4+ T cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

7 APCs in the body

A

monocytes, macrophages, B cells, dendritic cells, Langerhans cells (skin), Kupffer cells (liver), astrocytes (brain)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

dendritic cells: how they recognize foreign substances and recognize what else

A
  • with TLRs 1 to 11

- also recognize antibody coated antigens and complement coated antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

dendritic cell goal

A

engulf and digest antigens to make them peptides and show them to T cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what dendritic cell does at same time as it digests antigenic peptide to present it on MHC class 2

A
  • becomes activated

- produces cytokines to help activate T cells like IL-12 and IFN-gamma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

MHC class 1 vs class 2 when they’re on cell surface

A
  • class 1 only on surface where there’s an invader

- class 2 always there. will present an antigen if there is one.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how MHC class 1 works to present an antigen

A
  • viral invaders and other pathogens degraded in PROTEASOME
  • MHC 1 + peptide complex together (assembled) in ER
  • exported together to plasma membrane in a vesicle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how MHC class 2 works to present an antigen

A
  • MHC 2 complex assembled in ER
  • exported in acidic environment in endosomic vesicle
  • pathogens degraded in same vesicle by acid + enzymes. peptide bind
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

reaction to allergen: what cell does the dendritic cell present antigen to

A

to CD4+ effector T cells in lymph nodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

WBCs distribution in the blood (%) and lymphocytes distribution

A
neutrophils 55%
lymphocytes 33% (80% is T cells. 20% is B cells)
monocytes-macrophages 5%
band neutrophils 5%
eosinophils 3%
basophils 1%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

biggest lymph node in the body + biggest collection of lymphocytes in the body

A

spleen

GIT biggest collection of lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

T lymphocytes recognition ability

A
  • we’re born with limited repertoire of antigens that T cells can recognize
  • exposure helps mature and refine the responses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

lymphocytes mostly where in body

A

neck, tonsils, groin, spleen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

lymph node vs peripheral B:T cells ratio

A

lymph node: 50-50

peripheral blood: more T cells (80%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

3 things T cells must have to recognize antigens + the one that’s a T cell marker

A
  • CD3 (signaling complex) ***T cell marker
  • CD4 OR CD8 (immature T cells have both)
  • receptor for a peptide (TCR = T cell R)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

one therapy knocking out T cells used in transplants to avoid rejection

A

anti-CD3 therapy. spleen recognizes T cells and removes them. get temporary immune deficiency that grows back

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

elements needed in T cell - APC interaction

A
  1. CD4 interaction with MHC class 2 to recognize it as self
  2. CD3 - TCR interaction with the MHC class 2 - peptide complex
    * IT’S THE TCR THAT IS SPECIFIC TO AN ANTIGEN OR PEPTIDE*
26
Q

step after T cell - APC full interaction

A

T cells picks molecule on APC and transduces intracellular signal

27
Q

costimulation molecules in the T cell - APC (dendritic cell) interaction + WHY needed

A
  • CD28 on T cells.
  • CD80,CD86 (binding partner of CD28) on dendritic cells
  • needed to make interaction closer and allow T and APC to activate each other better
28
Q

Substance released upon T - APC interaction (2 important) (TH1 type here)

A
  1. dendritic cell makes IL-12. IL-12 causes T cell to produce cytokines like IFN-gamma
  2. T cell makes IL-2
29
Q

functions of IFN gamma released by CD4+ cells in response to IL-12 from dendritic cells

A
  • IFN gamma activates dendritic cell back

- if virus or TB, IFN gamma recruits macrophages and monocytes

30
Q

function of IL-2 produced by T cells

A

IL-2 binds IL-2 R on T cells***

**T cells upregulate IL-2 Rs 6 hrs after interaction. Otherwise can’t proliferate.

31
Q

important ligand for T cells and B cells to communicate better

A

CD40

32
Q

why MHCs is what is used to recognize cells as self

A

because differs genetically from person to person. everyone has a different MHC

33
Q

3 roles for T cells (depending on T cell type)

A
  • fight IC infections (CD8. viruses, TB, IC pathogens)
  • assist other cells (CD4+ to activate them and make them multiply and differentiate)
  • signals to inhibit or slow down immunity (T reg. CD4+ Foxp3+)
34
Q

4 CD4+ effector T cells categories

A

th1, th2, th9, th17

35
Q

characteristic of cytokines released by leukocytes in general

A

ability to turn off after they turn on

36
Q

th1 cells function + KEY cytokine

A

supply cytokines to MONOCYTES to help them fight IC organisms (viruses, IC pathogens)
**IFN-gamma (there’s also IL-12)

37
Q

th2 cells fct + key cytokines

A
  • supply cytokines for B cells to make Abs responses. (to fight parasites + slow pathogens by mucous prod for ex)
  • *IL4 and IL13
38
Q

th17 cells fct + key cytokine

A
  • supply cytokines for phagocytes and cells of innate immunity to destroy bacteria (especially staph) and fungi
  • IL-17 (part of a group of th17 cytokines)
39
Q

reg T cells fct + key cytokines (CD4+ Foxp3+)

A

-regulate all cell activities via ***IL-10, TGF-beta and also via cell-cell contact

40
Q

IL-10 and TGF-beta actions

A

turn OFF cytokines

41
Q

helper cell type and cytokine category involved in response to allergens

A

TH2 and TH2 cytokines (bc want to make Abs to the allergen)

42
Q

what happens when naive T cell is stimulated

A

changes its surface architecture, meaning:

  • upregulates IL-2 Rs
  • upregulates chemokine Rs like CCR3, CCR4, CCR5 (to leave lymph node)

-upregulates adhesion molecules like CD28

43
Q

how the response of a T cell to T cell - APC interaction is amplified

A
  • T cells multiply
  • maturing T cells that are producing cytokines are cloned
  • maturing T cells change the genetic makeup of their TCR to remember peptides better
44
Q

2 types of T cells in general

A
  • effector T cells (stimulate or attack cells, magnifies the response)
  • memory T cells: small clone of antigen recognizing cells
45
Q

Th1 function and key cytokines + key to remember

A

-fight IC organisms
-IFN gamma**
(also IL-12, IL-18)

46
Q

th2 function and key cytokines + key to remember

A
  • IL-4 and IL13** (for Ab production and parasite defense)
  • fct in allergies + prod of IgE
  • IL-5 for stimulation of eosinophils
  • IL-9 for mucous prod
47
Q

th17 function and key cytokines + key to remember

A
  • antibacterial and antifungal

- IL-17, IL-22

48
Q

Treg cells function and key cytokines + key to remember

A
  • turn off immune response (regulation)

- IL-10 and TGF-beta

49
Q

th1, th2, th17 and treg cells are part of which category

A

EFFECTOR CD4+ (helper) T cells

50
Q

where T cell-APC interaction occurs

A

in lymph node

51
Q

CD8+ cytotoxic T cells fct and how they recognize that they have to act

A
  • directly fight viral AND FUNGAL infections

- recognize viral peptides produced and expressed by all cells of our body on MHC class 1

52
Q

how CD8 cells kill other cells

A

produce perforin and granzyme causing cell to apoptose (and necrose too)

53
Q

other functions of CD8 cells

A
  • produce pro-inflam cytokines like IFN-gamma (also prod by th1 CD4+)
  • some CD8 regulatory cells exist and produce IL-10, TGF-beta
54
Q

viral infection to MHC 1 presentation

A
  • virus gets in epith cell
  • replictes
  • proteasome picks up viral protein and degrades it to peptide
  • presentation on MHC class 1
55
Q

how cytotoxic T cells operate once get through epithelium and reach virally infected cells

A

for each infected cell:

  • CD8 and TCR (specific to one antigen) recognizes MHC1+peptide
  • T cell activated and and produces perforin, granzyme, etc.
56
Q

why cells killed by CD8 cells die by apoptosis

A

so they don’t release their contents and cause massive inflammation

57
Q

most common congenital problem of T cells (low T cells number)

A

SCID of a defective cytokine receptor for IL-2. (X-linked SCID)

58
Q

causes of acquired problems of T cell function (low T cells number)

A
  • HIV

- drugs used for transplant, cancer, etc.

59
Q

examples of diseases that T cells are important in initiating and maintaining

A
  • autoimmune diseases
  • allergy
  • cancers (especially dermatologic)
60
Q

cause of immune exhaustion in cancer (and why cancer can take over immune system)

A

after some time, T cells respond to T reg cells and stop acting

61
Q

immune exhaustion: molecules involved

A

checkpoint molecules on T reg cells surface (adhesion molecules) like CD28 and PD1. They tell cells to stop acting

62
Q

downside of checkpoint inhibitors

A

25% of people get side effects of a completely uncontrolled (overwhelming) immunity. Looks like sepsis.