Brainscape's Knowledge GenomeTM

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


See full index

VET 411: Skin > Skin Immune System > Flashcards

Skin Immune System Flashcards

1
Q

immune functions of keratinocytes

A
  • form the epithelial barrier
  • produce antimicrobial peptides (AMPs)
  • initiate INNATE immune responses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

pilosebaceous units

A

sweat + sebaceous glands

  • produce AMPs
  • produce superficial aqueous-lipid layer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

langerhans cells

A

intra-epidermal dendritic cells

TOLEROGENIC
- promote function of regulatory T cells

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

dermal interstitial dendritic cells

A

present in the perivascular locations in the dermis

IMMUNOGENIC
- promote pro-inflammatory response

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

what are the main components of the skin’s immune function

A
  1. epithelial and keratinocyte microenvironment
  2. APCs (LCs, DCs, macrophages)
  3. skin-homing Tem cells
  4. dermal microvascular units
  5. skin draining LNs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

do keratinocytes provide innate or adaptive immune activity

A

INNATE
- act as APCs (express MHC I and II)
- release growth factors and chemokines
- express TLRs that recognize PAMPs
- express inflammasomes that recognize DAMPs (activates IL-1 –> pro inflammatory)

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

what is the skin microbiome

A

commensal bacteria and fungi that live on the skin without triggering an immune response

maintained by Treg cells

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

T regulatory cells

A

cells that recognize commensal bacteria and release anti-inflammatory cytokines to prevent an autoimmune response

  • mediated by langerhans cells
  • recognition occurs early in life
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the epithelial barrier and does it contribute to innate or adaptive immunity

A

keratinocytes + pilosebaceous units

INNATE immunity:
- produce AMPs
- produce aqueous lipid layer

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

function of the aqueous lipid layer

A

traps AMPs on the surface to create a protective barrier

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

sebaceous adenitits

A

immune mediated destruction of sebaceous glands by activated T cells and dendritic cells

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

how does sebaceous adenitis occur

A
  1. aqueous lipid layer gets compromised
  2. prevents AMPs from being trapped on surface
  3. decreased skin barrier
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

adaptive immunity in the skin

A
  1. CD1 (langerhans) cells present skin oils to Th22 T cells
  2. Th22 T cells produce IL-22
  3. IL-22 promotes keratinocyte and AMP proliferation
  4. maintains skin homeostasis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how is adaptive immune function compromised in sebaceous adenitits

A

when an endogenous lipid is presented to the Th22 T cells, they initiate an autoimmune response instead of releasing IL-22 for skin homeostasis

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

clinical signs of sebaceous adenitis

A
  1. keratinization defects: hyperkeratosis, follicular plugging, alopecia
  2. increased susceptibility to infections: folliculitis, pyoderma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the major skin histiocytes

A
  1. dermal macrophages
  2. dendritic cells (langerhans and dermal DCs)
17
Q

function of dermal macrophages

A

scavenging roles
- express adhesion molecules (integrins)
- express scavenger receptors

18
Q

function of skin dendritic cells

A

maintain skin homeostasis and respond to infection

act as APCs for T cells
- express CD1, MHC I, MHC II
- express adhesion molecules
- migratory - travel to skin draining LNs
- instruct naive T cells

19
Q

langerhans cell function

A

TOLEROGENIC
- promote anti-inflammatory response
- slow turnover
- locally renewed
- abundant adhesion molecules
- few TLRs, CRs, and inflammatory mediators

20
Q

resting langerhans cells

A

induce activation and proliferation of Treg cells to maintain tolerance in normal skin

21
Q

activated langerhans cells

A

induce activation and proliferation of memory T cells (Tem)

limit activation of Treg cells

22
Q

dermal dendritic cell function

A

IMMUNOGENIC
- promote pro-inflammatory response
- fast turnover
- renewed by bone marrow precursors
- abundant TLRs, CRs, and inflammatory mediators
- few adhesion molecules

23
Q

canine X linked SCID

A

severe combined immunodeficiency

mutations in the IL-2R submit in six yc-cytokine receptors

common in basset hounds and corgis

24
Q

function of yc-cytokine receptors

A

B, NK, T and dendritic cell function

mutation –> decreased function of most immune cells –> immunodeficiency

25
Q

function of CD8+ T cells against CPV-2 in healthy dogs

A

langerhans cells induce CD8+ memory T cells via IL-15 autocrine loop

CD8+ memory T cells regress CPV-2 lesions

26
Q

why are X-SCID dogs prone to developing CPV-2 infections

A

lack of yc-cytokine receptor –> decreased T cell function –> inability to activate CD8+ memory T cells –> increased susceptibility to CPV-2

27
Q

CPV-2

A

canine papilloma virus 2

oncogenic - often progresses to squamous cell carcinomas

suppresses innate immune function of the skin by down regulating keratinocyte release of pro-inflammatory cytokines

28
Q

are T or B cells more common on the skin surface

A

T cells (resident and migratory memory T cells, regulatory T cells)

B cells only recruited during inflammation

29
Q

can any T cell migrate to the skin surface

A

NO - requires specific effector memory T cells that have been presented antigen by LCs or DCs

T cell must have homing receptors and chemokine receptors that match chemokine ligands on the skin surface

30
Q

homing receptors

A

cutaneous lymphocyte antigen that binds to a vascular addressin (E-selectin)

31
Q

what vessel do cells use to travel from skin to lymph nodes

A

lymphatics

32
Q

what vessel do cells use to travel from lymph nodes to skin

A

blood

33
Q

steps of traveling from skin to LNs

A
  1. LCs/DCs express CCR7 to bind to CCL21 in lymphatic endothelium –> LN
  2. CCR7 binds to CC21 in lymph node paracortex
  3. LC/DCs present antigen to naive T cells by binding MHC to TCR –> induces T cell to replace CCR7 with CCR4 –> becomes memory T cell
34
Q

steps of traveling from LN to skin

A
  1. effector memory T cell traffics in blood to skin
  2. CCR4 binds to CCL17 on skin surface
  3. homing receptor binds addressin on the skin
  4. adhesion ligand binds adhesion receptor
35
Q

resident memory T cells (Trm)

A

do not leave the skin (mostly)
- generated in local immune responses
- globally protects skin
- rapid protection

inflammation: atopic dermatitis, psoriasis
malignancy: epitheliotropic cutaneous T cell lymphoma

36
Q

migrating memory T cells (Tmm)

A

migrate ONLY to skin draining lymph nodes via the lymphatics

37
Q

central memory T cells (Tcm)

A

migrate to ALL lymph nodes in the body
- generated in local immune responses
- less effective in local protection because migrates

malignancy: sezary syndrome

VET 411: Skin (16 decks)

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