Brainscape's Knowledge GenomeTM

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


See full index

Haematology and Immunology > Innate Immune System > Flashcards

Innate Immune System Flashcards

1
Q

Innate Immunity

A

This is the first response, its fast, there is no specificity or memory

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

Physical barriers in innate immunity

A

Skin and epithelial mucosa: Resp/GI/GU tracts
Cilia – muco-ciliary escalator

Secretions: sweat, tears, saliva, gastric acid, sebaceous glands, mucus, breast milk
Saliva: lysozyme, IgA, IgG, lactoferrin

Normal flora
Commensal bacteria – compete for nutrients, prevent attachment, release fatty acids and antibacterial proteins, prevent invasion
Lactobacilli in vagina – cause acidic pH (4.0-4.5)

Physiological
Temperature (fever), pH, location of immune cells within the bloodstream – can readily attack when and wherever microbes invade

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

Cells of the innate immunity

A

phagocytes, eosinophils, basophils, mast cells, Natural Killer cells (NK)

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

Complement in the innate immune system

A

acute phase reactants, cytokines, chemokines, matrix metallo-
proteinases, defensins

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

Pattern-recognition receptors the innate immune system

A

recognition receptors such as toll-like receptors (TLR) binding to PAMPs
(pathogen associated molecular patterns) or DAMPs (damage associated molecular patterns to stimulate a response by cells of the innate immune system.

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

Mechanisms of the innate immune system

A

Inflammation

Recruitment of immune cells

Activation of complement

Opsonisation

Phagocytosis (and endocytosis)

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

Inflammation

A 
Vasodilation
Loosening of endothelial tight junctions
Increased cell adhesion molecules
Chemotaxis
Smooth muscle contraction

Resulting from damage to tissue (prostaglandin and leukotriene release), allergens (mast cell degranulation, histamine release), microbial infection (release of endotoxins, exotoxins, TLR’s, Interleukins, nitric oxide), complement activation (C3a, C5a), autoimmunity (immune complexes, complement, T-cell)

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

Phagocytosis

A
  1. Phagocyte moves towards the microbe
  2. Phagocyte attaches to microbe via opsonin
  3. Endocytosis of microbe with phagosome
  4. Phagosome fuses with lysosome
  5. Oxygen-dependent species result in microbe death (lyzozymes, lipases, proteases, RNAses and DNAses)
  6. Release of microbe products
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cells that carry out phagocytosis

A

Macrophages, neutrophils, eosinophils, dendritic cells

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

Chemostaxis of phagocytes

A

Chemically attracted to the site of infection

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

Opsonization

A

Coating process with opsonins that facilitates attachment.

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

Opsonins

A

Complement
Antibodies
Plasma Proteins

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

Complement System

A

Large group of serum proteins that participate in the lysis of foreign cells, inflammation and phagocytosis

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

Classical Pathway Complement System

A

Initiated by an immune reaction of antibodies

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

Alternative Pathway Complement System

A

Initiated by direct interaction of complement protiens with microbial polysaccharides

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

Consequences of Complement Activation

A

Cytolysis due to the formation of a membrane attack complex (C3b-C5-C5b) which produces lesions in microbial membranes

Inflammation due to complement components (C3a and C5a) triggering the release of histamine which increases vascular permeabilty

Opsonisation

B cell activation

Immune complex clearance

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

Membrane Attack Complex

A
  1. Antibody molecules attach to the antigens on the pathogens plasma membranes
  2. Complements proteins link two antibody molecules
  3. Activated complement proteins attach to pathogens membrane
  4. MAC pores in the membrane and causes cell lysis
18
Q

Life span neutrophils

A

Few days

19
Q

Main function neutrophils

A

Phagocytosis

Degranulation release of bacteriocidal components (peroxidase, defensins, acid and alkaline phosphatases)

20
Q

Main targets of neutrophils

A

Bacteria and fungi

21
Q

Receptors Neutrophils

A 
Toll like receptors
Complement
IgG 
Chemokine IL-8
Chemoattractant C5a
ICAM + VCAM - adhesion to endothelium
22
Q

Life span eosinophils

A

8-12 days

23
Q

Main function of eosinophils

A

Extracellular killing via degranulation of peroxidase, major basic protein (induced mast cell and basophil degranulation), IL-8 and cytokines

24
Q

Main targets of eosinophils

A

Parasites

25
Q

IL-5 and IL-3 stimulate

A

Production and release of eosinophils from basal membrane

Expression of IgE receptors on eosinophils

26
Q

Main function of basophils

A

Degranulation release of histamine, prostaglandins and leukotrienes and cytokines (IL-4, IL-13)

27
Q

Main targets of basophils

A

Parasites

28
Q

Receptors of basophils

A

Surface bound IgE
C3a, C5a anaphylatoxins
Toll-like receptors

29
Q

Mast cells are present in

A

Tissues exposed to the external environment

30
Q

Main function of mast cells

A 
Degranulatin through cross-linkage of IgE receptors
Histamine
Proteases
Reactive oxygen species
Cytokines – TNF alpha, IL-4, IL-13
Leukotrienes and prostaglandins
31
Q

Receptors on Mast cells

A 
Surface bound IgE
C3a and C5a
Damage associated molecular patterns
Toll like receptors
Complement
Others: that can bind drugs e.g. opioids / antibiotics
32
Q

Tissue based monocytes

A

Kupffer (liver), Microglial (brain), Mesangial (kidney)

33
Q

Life span of macrophages

A

Months to years

34
Q

Main function of macrophages

A

Phagocytosis
Antigen presentation to T cells
Release of TNF-alpha, IL-2, IL-6

35
Q

Receptors on macrophages

A

Toll like receptors
Fc for IgG and IgA
C3b
MHC class I and II

36
Q

Dendritic cells

A

Present in tissues exposed to the external environment. Once activates migrate to the lymphoid tissues.

37
Q

Main function of dendritic cells

A

Phagocytosis
Antigen presentation to CD4+ T cells via MHC II
Shape enhances activation
Secrete TNF alpha, IL-12, IL-23

38
Q

Follicular Dendritic Cells

A

Mesenchymal origin
Within follicles of lymphoid tissue
Do not express MHC II but interact with B cells

39
Q

Natural Killer Cells are activated by

A

IFN and macrophage derived cytokines

40
Q

Main functions of natural killer cells

A

Bind to and kill virus-infected and cancerous cells –reduced MHC I expression
Release of perforin + granzymes from granules
Perforates cell, inserts proteolytic enzymes, induces apotosis
Also induce apotosis by binding to FasL molecules on virus
Release IFN gamma and TNF alpha
Are inhibited by normal ‘self’ signal via MHC I

41
Q

Receptors present on NKC’s

A 
Killer activation receptors
Killer inhibitory receptors – recognise MHC class I
Toll-like receptors
Fc receptors
Adhesion molecules
FasL

Haematology and Immunology (20 decks)

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