Vector-Host-Parasite immune interactions Flashcards Preview

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Flashcards in Vector-Host-Parasite immune interactions Deck (9)
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1
Q

What are the main host immune responses to ticks?

A

APCs pick up tick immunogens in draining lymph.
Basophils, eosinophils and T cells go to bite site.
Antibodies bind basophils producing histamine.

2
Q

How does tick saliva modulate the host immune response?

A

Inflammation inhibitors bind to histamine.
Cytokine modulation by changing Th1 to Th2 cells as Th1 are more protective -so down-regulated.
Anti-coagulation, vasodilation and binding wound healing growth factors.

3
Q

Why is the midgut a good target for the anti-tick vaccine?

A

It doesn’t show variability and reduces tick attachment, fecundity and egg production.

4
Q

How do African trypanosomes affect the tsetse fly ability to efficiently feed?

A

Tsetse can no longer inhibit haemostatic reactions as the parasite down regulates salivary gland gene transcription which reduces platelet aggregation and anti-coagulate activity making feeding more difficult and therefore improving chances of transmission.

5
Q

How does the salivary gland peptide, erythema help the sandfly to feed?

A

It is a vasodilator.

6
Q

How does leishmania affect the sandflies biting and feeding behaviour?

A

It increases the sandfly biting persistence, and feeding on multiple hosts by producing a gel plug with PSG.
PSG recruits macrophages and increases synthesis of polyamines for intracellular parasite growth.

7
Q

How do mosquito salivary proteins in Aedes aegypti affect dengue transmission?

A

MSPs disrupt haemostatic and immune responses to facilitate efficient blood feeding.

8
Q

How saliva effect malaria infection?

A

Increases sporozoite infectivity, and repeated prior exposure to saliva reduces infectivity in host.

9
Q

How does parasite presence affect vector feeding?

A

Parasite decrease mosquito feeding during pre-infectious stage but increase during infectious stage.
Sporozoites increase likelihood of mosquito taking multiple blood feeds.
May change the time of the night that the mosquito feeds?