Brainscape's Knowledge GenomeTM

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


See full index

Immunology > Innate Immunity > Flashcards

Innate Immunity Flashcards

1
Q

What are the dicision centers of the Immune System?

A

Secondary Lymphoid Tissues (Lymphnodes and Spleen)

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

Why are afferent and efferent immune responses so much slower than those of the nervous system?
How long does it take?

A

Both afferent and efferent mediated by cellular migration
(delivery of information to decision center => effector cells destroy infected cells)
=> take up material and deliver it to secondary lymphoid tissues
=> ideally only very specific response

Ca. one week

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

What are DAMPS and PAMPS?

A

danger/pathogen associated molecular patterns

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

What difficulty pose pathogens to the immune systems

A

Structurally often completely unrelated, various sizes

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

The hematopoietic system

A

Immune cells develop from hematopoietic progenitor/stem cells from bone marrow

one part gives rise to lymphocytes (effector cells => antibodyproducing, killer etc) and one lineage is the myloid lineage that produces cells to react early on or communicate (macrophages, granulocytes, monocytes)

Dendritic cells from both lineages

Erythrocytes from own lineage of hematopoietic system

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

Where are secondary lymphoid tissues

A

Lymphnodes (all over body => bc slow transduction, except for limps)
Spleen for “filtering” of blood
Tonsils, directly under mucosa of side where pathogens come in

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

What is the structure of secondary lymphoid tissues?

A

Afferent lymph vessels: where dendritic cells (detect dangers) come in
T-cell areas: T-cells come from bloodstream into areas, where dendritic cells present information to them

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

What are Peyer’s Patches

A

Secondary lymphoid tissues in the gut => detect infection in gut lumen

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

What are cytokines?

A

Small Signaling proteins that interact with receptors

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

Dendritic cells

A

form net => catch pathogens with cell protrusions
have strong migratory ability, migrate at increased frequency
upregulate co-stimulation of T-cells during migration
present information on MHC molecules

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

What signals do the dendritic cells transmit?

A

• activating conditions under which it has encountered the virus
• bits and pieces of pathogen for T-cell activation

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

What molecules on the surface of dendritic cells elicit T-cell responses?

A

MHC class II (present peptide fragments), co-stimulators, cytokines (teach immune cells which response to make)

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

Where are dendriric cells set up?

A

Basically everywhere:

e.g. on skin, but also underneath in dermis and even secondary lymphoid tissues

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

Which cells can dendritic cells activate?

A

Adaptive lymphocytes like T-cells

Innate lymphocytes e.g. NK cells
(receive information back => amplification of signals)

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

The Toll-like receptor signaling pathway

A

NFkB transmits signals from TLR downstream

(in fly: Toll receptor) => conserved

System leads to activation of cytokines and leukocytes

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

Different TLRs for…

A

different PAMPS/ different pathogens

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

Where are TLRs located?

A

At cells surface (bacterial)
In vesicular particles (viral) detect DNA and RNA of visuses when exposed (after uncoating)
In cellular compartments are even more other receptors

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

Inflammasome

A

Nod-like receptor (e.g. NLRP3)
=> cell reacts strongly to recognition by ligand for these receptors?

Non-activated cells: protein completely dispersed
Activated: Aggregation to signaling platform => cleave cytokines (for cellular communication)

19
Q

DAMPS in tumors

A

DNA damage and DNA leakage from mitochondria into cytosol allows for perception by dendritic cells

DAMPS derive from intracellular structures but are mislocated

20
Q

What are Antigens?

A

Pathogen or Tumor cell fragments

21
Q

How can conditions under which antigens are acquired be sensed?

A

Molecular pattern recognition receptors on dendritic cells

E.g. by Toll-like receptors (diff receptors for diff pathogens)

22
Q

What does it mean that a dendritic cell matures?

A

That it is activated
=> upregulation of co-stimulation and cytokine production for T-cell activation in lymph node

23
Q

Which parts of the cell are monitored by PRRs?

A

All cellular compartments

24
Q

What function do cytokines have in dendritic cells besides activation of T-cells

A

Prevent dendritic cells from getting infected before they reach lymphnodes to activate lymphocytes
=> there they die => memory of the encounter by activation of lymphocyte

25
Q

How is the innate immunity characterized?

A

Fast reaction, cannot clear infection, buys time for adaptive immunity, non-variable receptors, works broadly on many cell types, recognizes broad classes of pathogens

26
Q

Who discovered phagocytosis?

A

Elie Metchnikoff (1908 Nobel Prize for Medicine) => father of cell mediated immunology (direct effector functions)

Innate Lymphocytes
Granulocytes (Makrophages, Neutrophils), Phagocytes take pathogens up and destroy them in endosomes

27
Q

What is the prototypic phagocyte? And how does it work?

A

Makrophage

Number of receptors on surf. to detect pathogens (TLR and others)
Uses receptors to take up pathogen into endosomal compartments (degradation through hydrolysis)

Activation leads to production of soluble factors (cytokines and chemokines => attract other cells)

28
Q

What are endosomal killing mechanisms?

A

• acidification (pH of 3.4-4)
• ROS
• antimicrobial proteins
• enzymes (hydrolases)
• substances compete for nutritional factors of bacteria

29
Q

Neutrophils

A

Throw out DNA as net with antimicrobial substances attached to capture extracellular pathogens

And substances on DNA attract other cells and make bacteria easier to digest

=> Neutrophil extracellular traps
=> Neutrophils don’t live long

30
Q

Type 1 Interferon (IFN)

A

Cytokines (proteins)
Trigger cells to produce antiviral factors by binding to surface receptors

31
Q

What types of IFN exist?

A

IFN alpha and beta (produced first)

32
Q

What are the functions of IFN?

A

• bind to cells and trigger antiviral mechanisms
=> directly make it difficult for viruses to infect
• increase antigen presentation to other cells
• activate dendritic cells and lymphocytes
• induce chemokines to attract more immune cells

33
Q

Which cells can express IFN?
Which cells does IFN alarm?

A

Any infected cell, but Plasmacytoid DCs are main source of IFN 1 (more virus detecting receptors => TLRs)
Neigboring cells

34
Q

Autocrine/paracrine

A

Self cell, neighbouring cells

35
Q

Why do all species have slightly different TLRs?

A

They are encoded in the germ-line => fix but under evolutionary pressure for respective species

36
Q

What are Innate Lymphoid cells?

A

E.g. NK cells

37
Q

How do NKs act?

A

Cytotoxic proteins delivered through tight interaction btw cytoskeletons (actin) of NK and infected cell induces apoptosis (“Kiss of death”)

38
Q

How do NKs decide to kill a cell?

A

By germ-line encoded receptors
Inhibitory and activating receptors

Healthy: no activating signal or surplus oh inhibitory signal
Infected: more activating or no inhibitory at all

39
Q

NK cell repertoire

A

Inhibitory receptors can be diff. from individual to individual: cell ( virus) that can avoid presentation by MHC molecules to immune syst through downregulating one of MHCs can be easy or difficult to detect depending on the set of NK cells

40
Q

Where do NK cells originate from?

A

Bone marrow
=> secondary lymphoid tissues (as T-cells)
=> dendritic cells activate NK cells through cytokines
=> upregulate cytotoxic machinery and antiviral cytokines

41
Q

How do tumor cells upregulate NKs?

A

Activating structures (upregulated by cell stress mechanisms and leakage of damaged DNA) that are recognized by activating receptors

42
Q

NK cell cytotoxicity

A

=> NK cells make synapse (tight interaction with target cell)
=> bring cytotoxic granules (Granzyme & Perforin) to interface
=> Perforin enables Granzyme to enter cytosol
=> cleaves (pro- and) antiapoptotic components
=> directly cleave caspases
=> apoptosis

43
Q

What are ILC1s? ILC2s and 3s?

A

Interferon-producing cells (target intracellular pathogens like NKCs)
fight extracellular pathogens

Immunology (4 decks)

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