Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Micro unit 2 > L11 > Flashcards

L11 Flashcards

1
Q

Defense against pathogens is the

A

principal physiologic function of the immune system

Involves both the innate and adaptive immune response

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

Different pathogens trigger

A

distinct immune responses and effector mechanisms

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

Pathogens have mechanisms to

A

evade the immune response

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

INNATE IMMUNITY

A

MACROPHAGES
NEUTROPHILS
COMPLEMENT SYSTEM

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

ADAPTIVE IMMUNITY

A 
B cells and Antibody (IgG)
T cells (indirect help by helper CD4+ T cells)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Neutrophils and Macrophages will

A

remove particulate antigen by phagocytosis

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

HIGH AFFINITY RECEPTORS: Mannose receptor

A
  • binds mannose on microbial cell wall mediating cell-microbe binding and initiating phagocytosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

HIGH AFFINITY RECEPTORS: Mac-1 Integrin-

A

Binds microbes opsonized with complement proteins

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

HIGH AFFINITY RECEPTORS: Scavenger receptor-

A

binds microbes in a non-mannose specific manner

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

Opsonin –

A

derived from a Greek word meaning “to prepare for eating”.
Antibodies
Complement Proteins
Lectin

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

OPSONIZATION of a microbe occurs when it is

A

coated/bound by an opsonin to target it for phagocytosis (mediates binding to phagocyte receptors).
More efficient than mannose receptor mediated phagocytosis
Enhances inflammation and antimicrobicidal activity

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

RNI=

A 
REACTIVE NITROGEN INTERMEDIATES
Nitric Oxide (NO)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Exaggerated/strong activation of macrophages and neutrophils can

A

injure normal host tissue by release of lysosomal enzymes ROS and NO
Microbicidal products do not distinguish between self tissue and microbes or normal tissue and infected tissue

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

CD8 +T cell role in

A

immunity against intracellular microbes

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

CD8+T Recognize

A

antigen in a MHC I restricted manner

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

CD8+T called

A

CALLED CYTOTOXIC T CELLS as they secrete perforin and granzymes which will directly lyse/kill infected cells
Very important for anti-viral immunity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

CD8+T Secrete

A

cytokines such as IFN-g and TNF-a

18
Q

CD8+ T cells also

A

kill phagocytes which have engulfed microbes

19
Q

Macrophage: Remove

A

particulate Antigen by phagocytosis

Followed by production of ROS and RNI

20
Q

Macrophage: Take up soluble antigen, process and present antigen to

A

T cells

21
Q

Macrophage secrete

A

pro-inflammatory cytokines (IL-1, IL-6, TNF-a) and chemokines (CCL2, CXCL1, etc) that induce inflammation and immune chemotaxis
Induced through the recognition of microbial byproducts by Toll-like receptors (TLRs) and Nod-like receptors (NLRs)

22
Q

Which Th cell would be needed against intracellular infections?

A

Th 1

23
Q

Neutrophil: Migrate toward the site of

A

inflammation within an hour of tissue injury in response to chemotactic factors
IL-8
IFN-g
C5a

24
Q

Neutrophil Effectively phagocytose

A

microbes

Can eliminate microbes via ROS and RNI

25
Q

Neutrophils Can also kill microbes by

A 
oxygen independent mechanisms
DEGRANULATION (release of granuoles)
Defensins
Myeloperoxidase
Neutrophil extracellular traps (NETs)
26
Q

Role of COMPLEMENT in Immunity against Extracellular Microbes:

A

Serves as an opsonin and enhances phagocytosis by phagocytes

Serves as a chemokine and recruits and activates leukocytes to the site of inflammation

Forms the membrane attack complex (MAC) and mediates lysis of the microbe

27
Q

B cells produce

A

antibody
Neutralization
Opsonization
Memory

28
Q

B cells express

A

MHC II and can present antigen to T cells

29
Q

Bacterial products can directly

A

activate B cells in a T cell independent manner

30
Q

CD4+ T cells can also make

A

inflammatory cytokines (IFN-g and TNF-a)

These cytokines activate macrophages and promote phagocytosis, bacterial killing and inflammation

Called Th1 cells when they make these inflammatory cytokines

31
Q

CD4+ T cells (helper T cells) produce

A

cytokines (IL-4, IL-5 and IL-10)
These cytokines are B cell growth factors which activate B cells and promote antibody production

Called Th2 cells when they make these B cell promoting cytokines

32
Q

Which Th response is more important during extracellular defense?

A

Th 2

33
Q

Mechanisms of Immune Evasion by extracellular bacteria

A

Antigenic variation

Inhibition of complement activation (many bacteria)

Resistance to phagocytosis (e.g. Pneumococcus)

Scavenging of ROS (e.g. catalase-positive Staphylococci

34
Q

Facultative intracellular pathogen can

A

survive inside host cells to evade the immune system

35
Q

Obligate intracellular pathogen MUST

A

INFECT HOST to survive

36
Q

Injury caused by

A

host immune response

Deleterious effects on host immune system

37
Q

IMMUNITY TO INTRACELLULAR PATHOGENS

A

Both innate and adaptive immune response are involved

Cell mediated immune response is dominant rather than antibody response

Pathogens have mechanisms in place to survive and replicate within host cells (e.g. phagocytes)

Disease and resulting pathology are a consequence of the host’s immune response to the infectious agent

38
Q

INNATE

A 
Dendritic Cells (APC)
Natural Killer (NK) cells
Macrophage/Neutrophils
39
Q

ADAPTIVE

A

CD4+ T cells (helper T cells)

CD8+ T cells (cytotoxic T cells)

40
Q

DENDRITIC CELL

A

Professional APCs that present Ag to T cells

Carry Ag from site of infection to lymph node where they will present Ag to naïve T cells

Produce cytokines such as IL-12 that regulate the differentiation of CD4+ T cells (promote either Th1 generation or Th2 generation)

41
Q

NK CELL

A

Main function is to kill virus infected cells (and tumor cells)

Secrete cytokines (IFN-g) required for macrophage and Th1 development

Activation of NK is regulated between signals from activating and inhibitory receptors

42
Q

CD4 +T cell role in immunity against intracellular microbes

A

Recognize Antigen in a MHC II restricted manner

CALLED HELPER T CELLS as their main role is to help coordinate the responses of other immune cells

Differentiate into Th1 or Th2 subsets producing distinct cytokines with distinct biological activity

Th1 CD4+ T cells produce IFN-g and TNF-a and promote cell mediated immunity
PROVIDE HELP TO CD8+ T CELLS AND MACROPHAGES

Th2 CD4+ T cells produce IL-4 and promote antibody mediated immunity
PROVIDE HELP TO B CELLS

Micro unit 2 (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions