Leishmania

Question 1

Cutaneous is caused by which strain mainly and why?

Answer 1

L. major because possibly skin is cooler and it’s not as heat resistant

Question 2

Visceral is caused by which strain?

Answer 2

L. donovani

Question 3

Mucocutaneous is caused by which strain and how?

Answer 3

L. braziliensis and is thought of as a secondary infection from primary

Question 4

Human forms

Answer 4

Promastigotes - nonreplicative
Amastigotes - replicative

Question 5

Sandfly form

Answer 5

Promastigotes

Question 6

How does it get into cell?

Answer 6

Opsonized by the alternative pathway and taken up by CR3

Question 7

How does the promastigote become an amastigote?

Answer 7

Requires Normal Human Serum (NHS)

Question 8

GP63 / Promastigote Surface Protein (PSP) / Major Surface Protein (MSP) / leishmanolysin

Answer 8

Protects from compliment lysis by inhibiting C5 binding and MAC formation
The sandfly promastigotes don’t express it

Question 9

LipoPhosphoGlycan (LPS) (6 things)

Answer 9

Specific to promastigotes
Compliment resistance
Prevents phagolysosomal fusion until susceptible promastigote differentiates into a
resistant amastigote
Prevents acidification
ROS protection by impairing the assembly of NADPH-oxidase
Decreases proinflammatory response

Question 10

Apoptotic mimicry

Answer 10

Amastigotes enter macrophage by expressing Phosphatidyl Serine (PS)

Question 11

PS

Answer 11

Triggers SHP1 which inhibits macrophage activation and thus reduces RNS

Question 12

PAMPs and PRRs

Answer 12

Promastigote =
Existing - opsonization by the alternative pathway - CR3
LPG - TLRs

Amastigotes =
PS - PSReceptor

Question 13

Host control

Answer 13

TLR - IL12 - Th1 - IFNgamma - activate macrophage - RNS