Parasite Evasion Mechanism Flashcards
Major mechanisms include
Induction of immune suppression
Antigenic variation
Host mimicry
Sequestration among others.
T or F
Protozoa and helminth enter the bloodstream or tissue because they are resistant to the host immunr respons.
True
Macrophages can phagocytose what?
A. Protozoa
B. Helminths
C. Ectoparasites
D. All of the above
Only A because Helminths have cuticles and integument that makes them resistant to cytotoxic effects of both neutrophils and macrophage
Trypanolytic factors that destroy non-human trypanosomes except what???
Trypanosoma brucei
Example of trypanolytic factors.
Apoliprotein L-1 (APOL1)
How does Trypanasoma brucei suppress the immune system?
By producing large amounts of surface glycoproteins.
Effect of surface glycoproteins.
Affects the protein synthesis Due to antigenic competition at the same time, it impairs the B-and T-Lymphocyte
E. histolytica suppresses macrophages burst and consequent ____.
Nitric acd production
They can inhibit monocytes to the site of invasion and inhibit the complement assembly.
Entamoeba histolytica
This species can down regulation of Th1 lymphocytes.
Fasciola infection
Antibodies lack specificity against Brugia malayi and Wuchereria and plasmodium spp. bancrofti because of …
Polyclonal hypergammaglobulinemia
How Wucherreria bancrofti affects the immune response?
They produced blocking antibodies
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
Necator americanus
Immune complexes produced in cysticercus cullulosae infection suppress inflammatory response through inhibition of complement activities. In what’s parasites is this applicable?
Plasmodium spp. and Trypanosoma cruzi
In ___ complement cannot participate in the destruction of the parasite; it was found out that it was consumed by its soluble antigens
Schistosoma spp. infection.
Changing antigenic profile of parasite’s surface coat giving rise to variant surface glycoprotein (VSG)
T. gambiense and G. lamblia
The mechanism is through repeat variation of encoded polypeptides. They consist of tandem sequence of amino acids.
Antigenic diversity
Two seq. Of amino acids is oserved in
Merozoites surface antigen (MSA)
Ring-infected Erythrocytes surface antigen (RESA)
T or F
Antigenic diversity can be the reason why antibodies fail to recognize the antigen.
True
Species of malaria that have antigenic diversity.
Plasmodium falciparum
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
D
This spp. of parasites proliferates in macrophages in various organs.
Amastigotes of T. cruzi and Leishmania spp.
It multiplies inside macrophages as well as other nucleared cells.
Toxoplasma gondii
The late stage of ___ is sequested from the deep vasculator bed.
Plasmodium falciparum
How falciparum sequested in deep vascular beds?
Through the knobs in infected RBCs that enable them to attach to endothelial cells of capillaries.
