immunology

Question 1

what is BALT

Answer 1

Bronchus associated lymphoid
tissue is within the sub-epithileal layer which contain immune cells

Question 2

what is the mucociliary transport

Answer 2

eipthelial cells
goblet cells in the epithelial secret mucus
+cillia that push these out n away

Question 3

name some defects in mucocilliary transport

Answer 3

smokers
bacteria and viral infections
immotile cilia
cystic fibrosis

Question 4

respiratory epithelial immune functions

Answer 4

• excess pattern recognition receptors (eg. TLRs, NLR) which respond to PAMPS
• on activation –> secrete cytokines and chemokines at basal surface, recruiting immune cells and antimicrobial compounds

Question 5

what secretes IL-22 in epithelial of lungs

Answer 5

ILC3 and Th17

Question 6

what does ILC3 and Th17 secrete in the epithelial

Answer 6

IL-22

Question 7

function of IL-22

Answer 7

epithelial cell proliferation and barrier integrity –> protect epithelial cells

Question 8

what are the two types of lung macrophages

Answer 8

alveolar macrophage

interstitial macrophage

Question 9

role of alveolar macrophage

Answer 9

well positioned to phagocyte inhaled particles

Question 10

role of intisitial macrophages

Answer 10

activates if the barrier is breached

Question 11

outline the steps in the 2nd line of immunity

Answer 11

pathogen recognised via PRR expressed by macrophages –> inflammation and leukocyte recruitment

bacteria trigger macrophages–> release cytokine+ chemokine

vasodialtion and increased vascular permeablitliy–> redness heat and swelling

inflammatory cells migrate into tissue–> release inflam mediators–> pain

Question 12

2nd line defense in healthy lung

Answer 12

neutrophils in vasculature, not in lung tissue

Question 13

2nd line defense in infected lung

Answer 13

neutrophils are recruited in vasculature–> destroy microorganism by phagocytosis

Question 14

2nd line defence in pneumonia

Answer 14

ROS+ granule contents–> cause pulmonary damage

Question 15

outline the process of Dendritic cells

Answer 15

1)Take up antigen at mucosal surface
2)Migrate to lymph nodes via lymphatics or BALT
3)present antigen as peptide to T cells
4)Activated T cells migrate to mucosal tissue
5)Cytotoxic T cells kill virus-infected host cells
6) T help cells activate B cells –> antibodies

Question 16

outline the 3 steps in Adaptive immune system

Answer 16

1)CD4+ T cells differentiate–> become Helper T (Th) cells

2)Th cells activate B cells –> B cells differentiate into plasma cells –> secrete antibodies

3) T cell cytokines –>regulate B cell production of different antibody classes

Question 17

what regulates B cell production and hence Antibody class

Answer 17

T cell cytokines

Question 18

what are the two types of the antibody IgA

Answer 18

IgA1(serum) and IgA2(secretory)

Question 19

what is IgA1 and its function

Answer 19

mainly in serum, pro-inflam,monomer serum IgA

-Binds to FcaR on innate immune cells–>leads to phagocytosis, oxidative burst,ADCC and pro-inflam cytokines

Question 20

what is IgA2 and its function

Answer 20

mainly in mucosal secretions, non-inflam, dimer

-transported across epithelium into lumen

-poly-Ig receptor cleaves –> secretory compoment remains attached to IgA2(inhibts binding to FcaR on innate immune cells).

-Moves from basolateral–> endocytosed –> apical surface –> released to gut –> binds and neutralises pathogens and toxins

-cannot activate complement or innate immune cells

Question 21

where are mast cells found and their role

Answer 21

mast cells are found in the lamina propria and express Fc receptors for IgE

activation= results in degranulation and histamine release, release of leukotrienes and prostaglandins and cytokines

Question 22

process of IgE production

Answer 22

dendritic cells present peptide on MHCII to T cellls

Th2 differentiation

IL-4 production

B cells produce IgE