Immune evasion and subversion

Question 1

What is antigen varation

Answer 1

Aleration of surface antigens, phase varitation

Question 2

Trypanosomes like T. brucei constantly vary their surface antigens via what?

Answer 2

Gene conversion by varying the VSG gene expressed

Question 3

Plasmodium facliparum invaded what cells and why

Answer 3

RBCs as they lack nearly all immune receptors

Question 4

Whar protein does P. Falciparum use to sequester RBCs in post venule cappilaries

Answer 4

PfEMP1

Question 5

Where does Anaplasma phagocytophilum reside

Answer 5

Neutrophil intracellular vaculoes

Question 6

Where does M. tuberculosis reside

Answer 6

MAcrophage phagasome

Question 7

Where does L. monoctogenes escape into

Answer 7

cytoplasm

Question 8

A. phagocytophilium prevents phagosome maturation?

Answer 8

Yes

Question 9

What is the WASP protein function?

Answer 9

Controls actin dynamics

Question 10

How does molecular mimicry wvasion work

Answer 10

Many pathogens especially viruses encode host homologues to subvert immune response.

Question 11

What do superanitgens cause

Answer 11

Polyclonal T cell activation and subsequent apoptosis

Question 12

What viruses pose superantigens

Answer 12

MMTV and CMV

Question 13

B. anthracis toxin is a m____protease specigic to M___ k___ k____

Answer 13

Metalloprotease specific to MAP kinase kinase

Question 14

What does anthrax lead to in infected cells

Answer 14

Apoptosis of infected macrophages and dysfunction DC maturation

Question 15

What type of skew of immune response leads to tuberculoid leprosy

Answer 15

Controlled Th1

Question 16

What type of skew of immune response leads to lepomatous leprosy

Answer 16

Normally fatal Th2

Question 17

Evoltution and counter-evolution of the struggle for Fe2+

Answer 17

All organism need iron to grow. MAcrophages reduce iron conc. Lactoferrin sequesters iron, IFN-gamma decrease transferring receptor, Mn2+-Fe2+ transporter. Bacteria evolve siderophores. Macrophage evolves lipocalin

Question 18

Fv1 mimics what protein

Answer 18

Gag protein

Question 19

How did the placenta develop based on viruses

Answer 19

Synctins are retrovirus derived

Question 20

List two species that are intracellular pathogens that disrupt phagasome function

Answer 20

Mtb
L. monocytogenes

Question 21

Upon Mtb uptake what happens to the gene expression progile

Answer 21

actively switched on

Question 22

Describe the Mtb. evasion mechanism

Answer 22

1. Mtb is phagocytosed via CR3 uptake but phagosome fail to mature
2. Rab5a effectors (EEA1 and hVPS34) are impaired. No PI(3)P generation.
3. LAM cell wall component is actively shed and so inhibits Ca2+ uptake.
4. PI(3)P depleted, prevents phagocyomal lifecycle to cont.

Question 23

What IFN activates macrophages to kill Mtb, what does it induce

Answer 23

IFN-gamma, autophagy

Question 24

Anti-IFN gamma therapy can retrigger what disease

Answer 24

TB

Question 25

Mycobacterial agonists of TLR2 lead to reduction of which MHC class

Answer 25

MHC II

Question 26

What cytokine allows macrophages to kill Mtb

Answer 26

IL-1beta, by restoring PI(3)P

Question 27

Mtb secreted what to prevent inflammasome activation

Answer 27

ZmpA- metalloprotease

Question 28

Mtb induces host what, via which pathway? This leads to what?

Answer 28

Arginase 1 via MyD88 pathway. Lower NO production, less microbicidal

Question 29

How is L. mono uptaken via what proteins

Answer 29

Cia C1qR and E-cadherin binding bacterial internalin A/B

Question 30

How does Listeria evade killing

Answer 30

5 mins post phagocytosis it secretes listeriolysin O (LLO) preventing lysing plasma membrane

Question 31

LLO is activated by what pH and what enzyme

Answer 31

Low pH and phagosomal enzyme GILT

Question 32

Listeria ActA protein is similar to what

Answer 32

WASPO protein

Question 33

Listeria proteins induce what actin strcuture to spread from cell to cell

Answer 33

Actin comets

Question 34

What cell wall structure is potent in Y. pestis

Answer 34

LPS

Question 35

Evasion of which TLR is necessary for virulence of Y. pestis

Answer 35

TLR4

Question 36

What is YopJ, what does it do and how does it effect signalling

Answer 36

Ubiquitin like cysteine protease, cleaves ubiquitin residues --> prevents signalling