infection

Question 1

Malaria is caused by

Answer 1

single cell protozoan parasite: Plasmodium (intracellular parasite)

Question 2

Leishmaniasis is caused by

Answer 2

protozoan parasite, Leishmania

Question 3

Filarial worms (extracellular parasite) cause diseases like

Answer 3

Elephantiasis

Question 4

Helminths (flat worms) (extracellular parasite) can cause Schistosomiasis and lead to _______

Answer 4

liver damage

Question 5

Adaptive immunity: the lymphocyte expansion helps to _______

Answer 5

keep pace with rapidly dividing microbes

Question 6

Do intracellular and extracellular pathogens require different defense mechanisms?

Answer 6

Yes, different

Question 7

lgG, lgA, lgM are important for host defense against ________

Answer 7

bacteria, fungi, viruses

Question 8

lgE is important for host defense against ________

Answer 8

parasitic worms

Question 9

lgA is important for host defense against ________

Answer 9

mucosal immunity

Question 10

Mucosal secretions, tears, saliva, breast milk, bile, are rich in _______

Answer 10

lgA

Question 11

lgA ______ microbes and prevents them from using mucosal surfaces as portals of entry for host colonisation

Answer 11

neutralises

Question 12

Difference btw lgA acting against BACTERIA vs against VIRUSES

Answer 12

BACTERIA: prevents bacterial adhesion to epithelium, a key 1st step in infection

VIRUS: blocks entry into epithelium (blocks binding to virus receptor), or directly inactivate virus

Question 13

Role of effector CD4+ T cells

Answer 13

• necessary as helpers to promote B cell antibody production
• they also help in the generation of cytotoxic and memory CD8+ T cells

Question 14

Role of CD8+ cytotoxic T cells

Answer 14

provide cell-mediated immunity by targeting and killing infected cells

Question 15

Role of CD8+ cytotoxic T cells: 1. ______ facilitates entry of granzymes into the cytosol, granzymes activate 2. ______.

Answer 15

1. perforin

2. apoptosis

Question 16

Adverse effects of anti-bacterial immunity:

1. Local
2. Systemic effects of inflammation
3. Severe cases
4. Rare late sequelae

Answer 16

1. Local: acute inflammation may cause tissue damage
2. Systemic effects of inflammation: fever & metabolic abnormalities
3. Severe cases: septic shock (hypotension)
4. Rare late sequelae: cross-reactive responses against self tissues (eg. Rheumatic heart disease aft Streptococcus pyogenes infection)

Question 17

Specialised immune responses to Helminths: what is the effector mechanism?

Answer 17

Eosinophils kill lgE-coated parasites

Question 18

Specialised immune responses to Leishmania: what is the immune response and effector mechanism?

Answer 18

T cells produce IFN-y → activates phagocytes → phagocytes kill parasites living in intracellular compartment (endosomes)

Question 19

Specialised immune responses to Malaria: what is the immune response and effector mechanism?

Answer 19

CD8+ T cells → secretion of cytokines → IFN-y, TNF activate macrophages & neutrophils to kill parasites

Question 20

Immune responses to microbes are capable of causing tissue injury (eg. _______, _______)

Answer 20

cytokine storm

uncontrolled inflammation