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Flashcards in Immunology Deck (50)
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1

There exists an evolutionary arms race between pathogen and host. What does this mean?

Pathogen exploits flaws in the defensive barriers of its host
The host evolves to correct those flaws
Pathogen replicates and evolves to evade corrections to exploit other flaws
Pathogen has ability to replicate much faster than the host; host relies on flexible and rapid immune response to combat

2

Some features of skin that contribute to barring infection include...

Tightly packed keratinised cells undergo renewal constantly; limits colonisation
Low pH kills pathogens
Sebaceous glands secrete oils and enzymes to destroy bacterial cell walls

3

The innate immune system has a ___ response and is ____ to micro-organisms

Fast, non-specific

4

The adaptive immune system has a ___ response and is ____ to micro-organisms

Slow, specific

5

The 5 types of leukocytes (WBCs)?

Neutrophils, Monocytes, Lymphocytes, Eosinophils, Basophils + Mast cells

6

Primary lymphoid tissue?

Bone marrow, thymus

7

Secondary lymphoid tissue?

Spleen, tonsils (any sites of AIS activation)

8

List the leukocyte components of the innate immune system

Macrophages, neutrophils, dendritic cells, basophils, mast cells, eosinophils, NK cells

9

List the protein components of the innate immune system

Complement, acute phase, cytokines

10

Basophils and mast cells mature in bone marrow. True/false?

False
Basophils mature in bone marrow; mast cells mature once in tissue

11

Basophils and mast cells are mainly involved in ____. They secrete ____, leading to _____...

Allergic reactions
Secrete histamine and inflammatory mediators, leading to increased vascular permeability and smooth muscle contraction

12

The main function of phagocytes is?

"Eat" cells by ingesting them and mopping up debris
Neutrophils, macrophages and dendritic cells mainly involved in phagocytosis

13

PRRs recognise what on bacteria/viruses?

PAMPs
Not expressed by human cells

14

Opsonins enhance...

Phagocytosis
Act as a bridge between pathogen and phagocyte receptors

15

Major opsonins include...

C3b, collectins, Fc of IgG, CRP

16

Oxidative killing requires which crucial enzyme?

NADPH oxidase complex
Converts oxygen into reactive free radicals

17

Acute phase proteins are produced by...

The liver

18

CRP greater than 200mg/l indicates...

Severe bacterial/fungal infection

19

The function of cytokines is to...

Modulate the behaviour of cells, locally and systemically

20

Interferons are important in...

Limiting viral infections

21

Interleukins are important in...

Directing cells to divide/differentiate
Mainly produced by T cells (IL-2 important for T cell activation)

22

Chemokines are important in...

Establishing a concn gradient to direct movement of cells (tell leukocytes where to go)

23

Complement involves enzymatically activating proteins in a...

Biological cascade, resulting in a rapid response

24

Classical pathway is activated by...

Antibodies (so B cells need to have been activated for this)
IgG/IgM cause conformational change in C1, activating cascade

25

In the classical pathway, first C1 is activated, then...

C4, C2, C3

26

Lectin pathway is activated by...

Mannose-binding lectin binding to carbohydrates
This mimics binding of C1 to immune complexes, so there is no need for antibodies

27

Alternate pathway is activated by...

Spontaneous hydrolysis of C3 and its direct binding to bacterial cell walls

28

Membrane attack complex is assembled by which complement proteins?

C5-C9

29

Functions of C3a and C5a

Inflammatory mediators - recruit phagocytes

30

Examples of complement inhibitors

C1, Factor I, Factor H, C4 binding protein, CD59