CIS Lecture Flashcards
(21 cards)
During experiments conducted in the 1940’s, _________ doses of pneumococcal polysaccharides were discovered to be ________ efficiency in provoking an immune response than intermediate or low doses.
Large; less
______________ antigens are T-cell independent antigens
Polysaccharide
The IgM response to polysaccharide (TI Ags) fades quickly due to what?
The short half life of IgM
How can polysaccharide antigens be modified to convert them to T-cell dependent Ags, creating a condition that favors an IgG response and other protective properties of that immunoglobulin?
By covalently coupling them to protein carriers
_____________ ______________ is the inability of an Ag to induce the expected immune response in an individual
Immunologic tolerance
____-cell tolerance is noted to develop after large doses of an Ag are given, developing anergy to the Ag through mechanisms that remain unclear.
B-cells
____-cell anergy is more easily induced by lower doses of the Ag and is of longer duration
T-cell
A special group of structurally-unrelated Ags called ___________ exhibit a unique property inducing a potent IgE only response by very low doses that leads to the development of allergy in susceptible individuals
Allergens
Do infants respond well to polysaccharide antigens?
No because their immune system is not completely developed
**Studies have shown that tolerance to Ags is more easily developed in young rather than adult animals -> immunization schedules are developed accordingly
________ _____________ antigens are almost exclusively polysaccharides, but some synthetic polymers also fall into this grouping
T-cell independent
It is believed that the simple chemistry of polysaccharide Ags results in numerous repetitions of multiple ___________
epitopes
What is related to the ease by which tolerance in B cells can be developed?
The cross-linking of many surface BCRs by polysaccharide Ags with he same epitope specificity
When is tolerance not favored in B cells?
In more complex Ags, in which epitope repetition is unlikely, only 2 BCRs on the B-cell surface are cross-linked -> tolerance not favored
C5a, C3a, and C4a simulate ___________ release and smooth muscle contraction
Histamine
______ on immune complexes binds to _______ on erythrocytes, and the immune complexes are cleared from the circulation as erythrocytes traverse the liver and spleen
C3b; CR1
Immune complex ______________ and _____________ __________ may result from the deposition of Ag-Ab complexes in glomeruli and blood vessel walls
Glomerulonephritis; systemic vasculitis
Defects in _____________ pathway activation have been associated with systemic lupus erythematosus, glomerulonephritis, pyogenic infections and vasculitis
Classical
_______________ pathway activation defects most commonly result in pyogenic infections
Alternative
Abnormalities in what part of the complement cascade are associated with disseminated Neisseria infections, systemic lupus, erythematosus and glomerulonephritis?
Membrane attack complex formation
Hereditary angioedema (HAE) is an autosomal dominant deficiency in __________________ manifested by acute, intermittent attacks of skin and mucosal edema
C1 inhibitor
Paroxysmal nocturnal hemoglobinuria is a complement-mediated intravascular hemolysis caused by deficiencies in the integral membrane protein regulators _____________________
Decay accelerating factor (DAF)
- Blocks C2:C4b interaction -> cant form C3 convertase (Classical and alternative)
