Basic Immunology

Front 1

On which type of cell is the CD8 co-receptor predominantly expressed?

Back 1

Cytotoxic T cells (also natural killer cells and dendritic cells)

Front 2

What is the function of CD8?

Back 2

A co-receptor for the T cell receptor
Binds to class I MHC protein

Front 3

What is a healthy/normal CD4:CD8 ratio?

Back 3

2:1

Front 4

What is the role of CD4+ T cells and how do they carry it out?

Back 4

"Helper" T cells, they secrete cytokines that influence virtually all other cells of the immune system.

Front 5

What is the role of CD8+ T cells?

Back 5

"Cytotoxic" - Important in directly killing virus infected or tumor cells.

Front 6

To what to CD4+ helper T cells respond?

Back 6

Peptide antigens when presented by class II MHC molecules.

Front 7

To what to CD8+ T cells respond?

Back 7

Antigens associated with class I MHC

Front 8

What is the role of NK cells?

Back 8

Able to lyse a variety of tumor cells, virally infected cells and some normal cells without previous sensitization.

Front 9

To what part of the immune system to NK cells belong?

Back 9

Innate

Front 10

Where are NK cells produced?

Back 10

In the bone marrow

Front 11

What are the main types of receptors expressed by NK cells?

Back 11

Fc receptors for IgG
KARS - killer activation receptors
KIRS - killer inhibitory receptors

Front 12

What do KIRS on NK cells do?

Back 12

Killer inhibitory receptors recognise MHC class I leader peptides presented in an MHC like molecule HLA-E

Front 13

How do NK cells detect virus infected cells?

Back 13

Reduced MHC class I detected by Killer Inhibitors Receptors allowing activation of killer activation receptors.

Front 14

How do NK cells mediate killing?

Back 14

Release of granule contents (perforins and granzymes) onto the surface of the infected cell.

Front 15

What is perforin?

Back 15

A protein released by NK cells and cytotoxic T cells which can create pores in the cell membrane.

Front 16

Name three types of denritic cells and their location?

Back 16

Langerhans cell - skin
Interdigitating cells - lymph node T cell areas
Follicular dendritic cells - B cell follicles of the lymphoid tissues

Front 17

What type of MHC do dendritic cells use?

Back 17

Class II

Front 18

What is the main function of neutrophils?

Back 18

Patrol bloodstream in search of invading microbes

Front 19

How is the alternative complement pathway activated?

Back 19

Interaction of C3 with certain types of molecules on microbes or by self molecules which react with these molecules.

Front 20

What are the four major functions of the complement system?

Back 20

Initiation of infammation by direct activation of mast cells.
Attraction of neutrophils
Enhancement of attachment of the microbe to the phagocyte
Killing of the microbe by the membrane attack complex

Front 21

What is the role of C reactive protein? (Both in general and how)

Back 21

Acute-phase protein.
Binds phosphocholine on dead or dying cells and some bacteria in order to activate the complement system.

Front 22

What do toll-like receptors recognise?

Back 22

Structurally conserved molecules derived from microbes.

Front 23

What is the most abundant immunoglobulin in the blood?

Back 23

IgG

Front 24

What is the only antibody to cross the placenta?

Back 24

IgG

Front 25

What is the major immunoglobulin present in external secretions such as colostrum, milk and saliva?

Back 25

IgA

Front 26

What does humoral immunity mean?

Back 26

Antibody-mediated

Front 27

What are the components of the membrane attack complex?

Back 27

C5b, C6, C7, C8, C9

Front 28

What is an opsonin?

Back 28

A substance that acts as a binding enhancer for the process of phagocytosis.

Front 29

What are the attributes of the peptidoglycan layer of gram positive bacteria?

Back 29

Thicker, multilayer

Front 30

What are the attributes of the peptidoglycan layer of gram negative bacteria?

Back 30

Thinner, single layer

Front 31

Do gram positive or gram negative bacteria have teichoic acid in their membranes?

Back 31

Gram positive

Front 32

Do gram positive or gram negative bacteria have lipopolysaccharide (endotoxin) in their cell walls?

Back 32

Gram negative

Front 33

What is the approximate diameter of bacteria?

Back 33

1-5um

Front 34

What is the approximate diameter of a virus?

Back 34

0.02-0.2um

Front 35

What are the components of the carbohydrate backbone of peptidoglycan?

Back 35

N-acetylmuramic acid and N acetylglucosamine

Front 36

What is the only bacteria without a cell wall composed of peptidoglycan?

Back 36

Mycoplasma

Front 37

What is the first stain in Gram staining and what does it do?

Back 37

Crystal violet stains all cells blue/purple

Front 38

What colour to Gram positive colours stain in the gram stain?

Back 38

Blue

Front 39

What colour do gram negative bacteria stain in the gram stain?

Back 39

Red/Pink

Front 40

How would you classify streptoccus?

Back 40

Gram positive cocci

Front 41

How would you classify staphylococcus?

Back 41

Gram positive cocci

Front 42

How would you classify neisseria?

Back 42

Gram-negative cocci

Front 43

How would you classify escherichia?

Back 43

Gram negative, facultative, rod

Front 44

What do interferons do?

Back 44

Inhibit virus replication by blocking the production of viral proteins, primarily by degrading viral mRNA via induction of the synthesis of a ribonuclease which cleaves viral mRBA but not cell mRNA

Front 45

What are the most potent inducers of interferons?

Back 45

Viruses and double-stranded RNA