Immunity to parasites

Question 1

are the protozoan parasites intracellular or extracellular ?

Answer 1

they can be both

Question 2

are the protozoans big or small in size ?

Answer 2

small

Question 3

how is malaria transmitted ?

Answer 3

by the female anopheles mosquito

Question 4

what is the natural resistance to malaria ?

Answer 4

sickle cell anemia

Question 5

what does species specificity mean in malaria ?

Answer 5

so having immunity against 1 species does not protect against others

Question 6

what does stage specificity mean in malaria ?

Answer 6

immunity against one life-cycle stage does not protect against another

Question 7

malaria shows antigenic variation , what does this mean ?

Answer 7

the parasite changes it’s antigens to allow reinfection and evade killing

Question 8

malaria shows immune suppression , what does this show a strong correlation with ?

Answer 8

Burkitt’s Lymphoma which is a cancer

Question 9

what do you need to destroy to combat malaria ?

Answer 9

The parasite itself and

the immune cells or RBC infected with the pathogen

Question 10

what in the immune system is involved in combating ?

Answer 10

CD4+ T cells - TH1 and Th2
Cd8+ cT cells - killer cells
Antibodies

Question 11

what are our responses to the parasite controlled by ?

Answer 11

genetic and environmental factors

Question 12

how is leishmania transmitted ?

Answer 12

by an infected sandfly

Question 13

what is the promastigotes ?

Answer 13

the parasite inside the insect , the sandfly

Question 14

what are the intracellular amastigotes ?

Answer 14

when the parasite enters the macrophages inside the human.

Question 15

what do the APC , dendritic cells , produce and what does this result in ?

Answer 15

IL 12 which activates the macrophages to kill the intramacrophage parasite

Question 16

what do the NK cells and TH1 cells release which help to combat the parasite ?

Answer 16

IFN gamma which also activates the macrophages

Question 17

what do the activated macrophages release?

Answer 17

microbicidal products such as superoxide , nitric oxide which kill the parasite

Question 18

how does leishmania evade detection ?

Answer 18

as it lives inside the macrophage it can turn off cell killing so the macrophages are no longer activated.

Question 19

what is the definitive host for toxoplasma gondii ?

Answer 19

a cat

Question 20

what does the host produce ?

Answer 20

oocyst

Question 21

what can the oocysts infect ?

Answer 21

any host

Question 22

what does the parasite live inside ?

Answer 22

cysts

Question 23

what’s the main response to toxoplasma gondi ?

Answer 23

the CD8+ T cells that produce IFN gamma
IgA
IgG

Question 24

what can occur to AIDS patients ?

Answer 24

the cysts in the brain can reactivate causing encephalitis

Question 25

what does IgA do ?

Answer 25

they play a role in protecting the gut mucosa by neutralisation

Question 26

how are the IgG coated parasites killed ?

Answer 26

inside the macrophage following the phagolysosome fusion

Question 27

what is trypanosoma brucei also called ?

Answer 27

sleeping sickness

Question 28

what's the 2 stages called ?

Answer 28

a slender stage and a stumpy stage

Question 29

where does the parasite live ?

Answer 29

in the bloodstream

Question 30

is the parasite extracellular or intracellular ?

Answer 30

extracellular

Question 31

what is used in the humoral response ?

Answer 31

antibodies

Question 32

what produces the IgM antibody and how does this fight the infection?

Answer 32

the plasma B cell and this is directed against the variant surface glycoprotein

Question 33

what is antigenic variation ?

Answer 33

this is when the surface coat changes it's antigens

Question 34

what is the Th1 response?

Answer 34

this is when IFN gamma is produced and this acts on the macrophage and reactive oxygen intermediates and reactive nitrogen intermediates are also released.

Question 35

how often does the switch occur ?

Answer 35

every 100 divisions

Question 36

what does trypanosoma Cruzi cause ?

Answer 36

the Chaga's disease

Question 37

is the parasite intracellular or extracellular ?

Answer 37

it can be both

Question 38

what is the trypomastigote ?

Answer 38

this is the extracellular

Question 39

what is the amastigote ?

Answer 39

this is the intracellular

Question 40

what does the parasite infect ?

Answer 40

the macrophages which affects the muscles

Question 41

how can this parasite lead to death?

Answer 41

the host can no longer swallow and the heart muscle can stop beating

Question 42

what are the immune responses induced ?

Answer 42

the IFN gamma stimulates the macrophages and cytotoxic T cell kills the infected muscle cell

Question 43

what is the theory around this parasite and autoimmunity?

Answer 43

is the antigen on the parasite so similar to our own cells that this causes autoimmunity?

Question 44

what T cell prevents autoimmunity ?

Answer 44

the Treg cell

Question 45

how does the body expel gut nematodes ?

Answer 45

They do so by increased mucus production and iincreased peristalsis, which is the movement in the gut.