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12 Cards in this Set
- Front
- Back
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How is Leishmania transmitted? |
Sandfly vectors - Old world - Phlebotomus species New world - Lutzomyia species |
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Leishmania |
Obligate intracellular single-celled parasite Many species Can be transmitted across wide range of mammals |
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Infective and non-infective stages of leishmania |
Amastigotes Non-infective promastigotes Metacyclic, infective promastigotes |
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What cells do leishmania infect/invade? |
Cells of the macrophage lineage. |
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Morphology of amastigotes |
Rounded (loses flagellum once inside macrophages) |
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Morphology of promastigotes |
Long and slender and has one flagellum 20-25 um including flagellum Increased expression of surface molecules: GP633, LPG, GIPLS |
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Some examples of mammals in which Leishmania can live and be transmitted |
Rodents, Dogs, Sloths |
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Clinical manifestations you can see and what its caused by |
Skin sores: on ears, face, nose Proliferating mass of macrophages |
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The three types of molecules on the surface of metacyclic promastigotes and their purpose |
To prepare for host-cell invasion Lipophosphoglycan - Inositol lipid anchor of glycocalyx Family of glycoinositol phospholipids GIPLs - gkycosylphosphatidylinositol anchored proteins - surface protease |
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How promastigotes attach to macrophages |
LGP and GP63 attach directly to via mannose fucose receptor or via complement componenets : CR1 and CR3 |
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Why aren't promastigotes destroyed? (outside of cell) |
Shed and elongates LPG (parasites thicker) Increased GP63 - cleaves C3b to inactive form LPG + GP63 interact with complement receptor -> prevents macrophage from becoming a killing cell |
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How parasite survives in macrophage |
Parasitophorous vacuole -> pH4.2 - 5.2 LPG inhibits lysosomal enzymes GP63 inactivates host proteases (esp at pH4 LPG inhibits PKC (involved in generating toxic metabolites in macrophages) |
