Immune System

Question 1

2 types of immune system in human body

Answer 1

1) innate, common set of response turned on by MOST pathogens. NON-SPECIFIC, FIXED
2) adaptive, individual response to SPECIFIC antigen exposure. ADAPTATION in response- faster more effective response on 2nd exposure

Question 2

4 components in innate system

Answer 2

Physical barrier - epithelial surfaces
Cellular components- phagocytes, NK cells
Complement and mediators
Cytokines

Question 3

Physical barriers- where

• what are the secretory products
• contains what other cells
• peritoneal lymphocytes secretion

Answer 3

skin, GIT, RT
Secret 
- defensins (board spectrum AB) 
- cytokines (IL1 and TNFa)
Epithelia contains 
-lymphocytes (peritoneal- antibodies against LPS)
-mast cells (mediator)

Question 4

4 types of recognition receptors (for microbes) on cell surface

Answer 4

• mannose
• opsonins
• toll- like
• 7TM a helical

Question 5

4 types of cells involved in innate system

Answer 5

• macrophages
  & neutrophils –> phagocytosis
• NK cells –> killing infected cells
• dendritic cells –> presentation to T cells by APCs

Question 6

Toll- like receptors

• on what cells
• response to what
• effect

Answer 6

Found on most cells of innate IMS
Respond to microbial markers e.g. LPS, bac peptidoglycan, ds RNA
Results in up regulation of inflammatory gene expression (TNFa, IL1,IL12,E selectin, iNOS

Question 7

Which WBC is always 1st on scene

Why

Answer 7

Neutrophils

Compose 40% of WBC

Question 8

Complement system

• what is zymogens
• 3 pathways
• result

Answer 8

Zymogen: gain enzymatic activity by cleavage
3 pathway : classical, alternative, lectin
- opsonisation, phagocytosis

Question 9

Which C is responsible for chemotaxis of neutrophils

Answer 9

C5a

Question 10

Which C cleavage is resp for opsonisation/ oxidation of microbes

Answer 10

C3b

Question 11

Role of cytokines

• TNF/IL1 -produce by ..
• effects

Answer 11

• By Macrophages that’s are challenged by LPS
• pro inflammatory cytokines
• stimulate neutrophil migration to site of infection

Question 12

The roles of cytokines

• IL12 -produced by..
• effects

Answer 12

By macrophages and dendritic cells

• promotes NK cytolysis (viral)
• stimulate INFgamma production in T,NK cells
• IFNgamma stimulates mac to kill microbes
• positive feedback loop (microbes-mac-IL12-t cells-IFNg-mac)

Question 13

What are the limitations of Innate IMS

Answer 13

• non specific
• limited recognitions of pathogens
• no memory, fixed response each time
• localised