Parasite Evasion Mechanism

Question 1

Major mechanisms include

Answer 1

Induction of immune suppression
Antigenic variation
Host mimicry
Sequestration among others.

Question 2

T or F
Protozoa and helminth enter the bloodstream or tissue because they are resistant to the host immunr respons.

Answer 2

True

Question 3

Macrophages can phagocytose what?
A. Protozoa
B. Helminths
C. Ectoparasites
D. All of the above

Answer 3

Only A because Helminths have cuticles and integument that makes them resistant to cytotoxic effects of both neutrophils and macrophage

Question 4

Trypanolytic factors that destroy non-human trypanosomes except what???

Answer 4

Trypanosoma brucei

Question 5

Example of trypanolytic factors.

Answer 5

Apoliprotein L-1 (APOL1)

Question 6

How does Trypanasoma brucei suppress the immune system?

Answer 6

By producing large amounts of surface glycoproteins.

Question 7

Effect of surface glycoproteins.

Answer 7

Affects the protein synthesis Due to antigenic competition at the same time, it impairs the B-and T-Lymphocyte

Question 8

E. histolytica suppresses macrophages burst and consequent ____.

Answer 8

Nitric acd production

Question 9

They can inhibit monocytes to the site of invasion and inhibit the complement assembly.

Answer 9

Entamoeba histolytica

Question 10

This species can down regulation of Th1 lymphocytes.

Answer 10

Fasciola infection

Question 11

Antibodies lack specificity against Brugia malayi and Wuchereria and plasmodium spp. bancrofti because of …

Answer 11

Polyclonal hypergammaglobulinemia

Question 12

How Wucherreria bancrofti affects the immune response?

Answer 12

They produced blocking antibodies

Question 13

In what species does the immune response br directed against deeper layers of cuticle, but the immune response is diverted to the rapidly changing surface of its integument

Answer 13

Necator americanus

Question 14

Immune complexes produced in cysticercus cullulosae infection suppress inflammatory response through inhibition of complement activities. In what’s parasites is this applicable?

Answer 14

Plasmodium spp. and Trypanosoma cruzi

Question 15

In ___ complement cannot participate in the destruction of the parasite; it was found out that it was consumed by its soluble antigens

Answer 15

Schistosoma spp. infection.

Question 16

Changing antigenic profile of parasite’s surface coat giving rise to variant surface glycoprotein (VSG)

Answer 16

T. gambiense and G. lamblia

Question 17

The mechanism is through repeat variation of encoded polypeptides. They consist of tandem sequence of amino acids.

Answer 17

Antigenic diversity

Question 18

Two seq. Of amino acids is oserved in

Answer 18

Merozoites surface antigen (MSA)
Ring-infected Erythrocytes surface antigen (RESA)

Question 19

T or F
Antigenic diversity can be the reason why antibodies fail to recognize the antigen.

Answer 19

True

Question 20

Species of malaria that have antigenic diversity.

Answer 20

Plasmodium falciparum

Question 21

Example of host mimicry
A. Larva stage of Eschinococcus granulosus in the hydatid cyst has been found to carry P blood group atigen.
B. Regument of Schistosoma spp. Adult can aquire antigenic molecules from the host.
C. Atibodies produced against the parasite then fail to recognize non-self from self-antigens
D. All of the above

Answer 21

D

Question 22

This spp. of parasites proliferates in macrophages in various organs.

Answer 22

Amastigotes of T. cruzi and Leishmania spp.

Question 23

It multiplies inside macrophages as well as other nucleared cells.

Answer 23

Toxoplasma gondii

Question 24

The late stage of ___ is sequested from the deep vasculator bed.

Answer 24

Plasmodium falciparum

Question 25

How falciparum sequested in deep vascular beds?

Answer 25

Through the knobs in infected RBCs that enable them to attach to endothelial cells of capillaries.