Term
What makes an ideal antigen |
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Definition
High antigenicity!
-doesn't degrade quickly (structurally stable) -can be recognized as different -can be degraded by cells for presentation to adaptive immune system |
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Term
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Definition
antigen = intact molecule recognized by a B or T cell
epitope = the portion of an antigen that binds to a B or T cell receptor |
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Term
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Definition
-molecule that is too small on its own to be an antigen, but can combine with larger molecules to create a new epitope |
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Term
What role do haptens play in poison ivy rashes? |
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Definition
-poison ivy produes urushiol (a hapten) -urushiol can bind to proteins on skin creating a novel epitope -immune system now thinks skin proteins are dangerous
Allergic contact dermatitis results! |
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Term
Deleterious role of cross-reactive antibodies in managing brucellosis in cattle |
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Definition
cross-reaction = antibodies respond to similar epitopes, confusing one for another
e.g. Yersinia entercolitica (insignificant disease) and Brucella abortis (reportable disease) have similar epitopes
-brucella testing may result in detecting false positives, culling cattle needlessly |
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Term
What cell is most efficient at inducing primary adaptive immune responses? What other cells can act as APCs? |
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Definition
dendritic cells
macrophages B cells |
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Term
Sequence of events from an immature DC acquiring a “dangerous” antigen to activation of a T cell |
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Definition
-if DC captures a non-dangerous antigen, it will not mature -T cells that recognize antigens presented by immature DCs will die or remain tolerant
-if DCs acquire a dangerous antigen, they upregulate molecule expression to activate T cells -travel to lymphoid tissue to present to naive T cells |
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Term
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Definition
benign tumour caused by excessive proliferation of macrophags or dendritic cells in connective tissues |
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Term
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Definition
MHC Class I -presents epitopes from intracellular antigens (e.g. viruses)
MHC Class II - pressents epitopes from extracellular antigens (bacteria) |
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Term
Alternate names for MHC in key species (human, cat, dog, swine, bovine) |
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Definition
HLA - human leukocyte antigen
FeLa = feline
DLA = dog
SLA =swine
BoLa = bovine |
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Term
Potential consequences of having fewer vs more diverse MHC haplotypes |
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Definition
Diverse haplotype - can present a larger variety of epitopes to T cells, but greater risk of autoimmune disease
Less complex haplotype - limited array of epitope presentation abilities, so greater risk of infectious diseases |
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Term
True or False
Haptens on their own are non-antigenic |
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Definition
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Term
Key mediators of DC maturation |
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Definition
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Term
What are langerhans cells? |
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Definition
specialized DCs in the skin, often cause histiocytomas |
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Term
What is an MHC haplotype? |
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Definition
the full set of MHC molecules that an animal expresses on their cells (unique to each individual) |
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Term
What effect does inbreeding have on MHC diversity? |
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Definition
reduces it, so highly inbred species are at greater risk of mortality due to infections disease |
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