Everything there ever was Lecture 5-8 Flashcards
How are macrophages activated?
LPS (TLR4) and IFN-gamma
What are the cytokines that act locally on the endothelial tissues?
TNF and IL-6
Which 3 cytokines are involved in the protective systemic effects including fever, APP synthesis in the liver, and leukocytosis in the bone marrow?
TNF
IL-1
IL-6
What results physiologically if there is an increase in the systemic TNF?
decreased cardiac function
thrombosis
insulin resistance
What are the functions of CRP and SAP and when do their levels increase?
They are acute phase proteins (APPs) that are synthesized int eh liver after an alert from IL-1 and IL-6; they recognize phospholcholine and phosphatidylethanolamine which are in bacteria and apoptotic cells
They can activate the complement pathway (classical) via C1q activation
When are IFN alpha and beta made and why are they made?
They are made to bind to the infected cells (self) and enhance cell mediated killing
They can also be made by the infected cells to go an initiate the JAK stat pathways in the neighboring cells which induces the expression of genes whose products interfere with viral replication ( so the neighbors dont get sick I think)
Describe the basic structure of an Ab
- 4 chains; two light and two heavy that are divided into V and C regions
- can be cleaved to form 2 fab and one fc fragment
What does the V region on the Ab do? The C region?
V- Ag binding site
C- determines the fate of Ag
Describe the breakdown of IgG when it is exposed to papain
2 separate Fab’s with one that is still joined to Fc
Describe the break down of IgG when it is exposed to Pepsin
The Fc chain is degraded, and the 2 Fab remain fused so that they are able to bind Ags
Describe antibody affinity and explain the differences between primary responses and memory responses
affinity is the tightness of the bond between the Ag and the Ab, a primary response has a lower affinity and the memory response has a higher affinity
valence is important for affinity because having more binding sites will result in tighter bonds
Define avidity
measure of the strength of an Ab-Ag complex
Depends on: affinity of the Ab for the epitope and the valence of the Ab and the Ag
What are the Ab proliferation cytokines
IL-2, IL-4, IL-5
What are the Ab differentiation cytokines?
IL-2, IL-4, IL_5, IFN gamma and TGF beta
What happens on the V region of the antibody?
Antibody recognition
What happens on the C region of the antibody?
determines the fate of the Ag
What happens when IgG is exposed to papain?
the 2 Fab’s separate with one still being joined to the Fc region
What happens when the IgG is exposed to pepsin?
The Fc region is disintegrated
What happens to the Ab when there is a high Ka?
It is less likely to give up the ag
Describe IgG
It is the most abundant in the blood and provides immunity against blood bourne pathogens
ONLY one to cross the placenta
Describe IgD
-low quant in the circulation
It is an Ag receptor and helps initiate the humoral response
Describe IgM
Acts as a BCR initially and is the main defense until the IgG is made
First ab produced
HIGH avidity
Describe IgA
Mucous
involved in external secretions
-has two extra chains SC and J chain
-synthesized by plasma cells
Describe IgE
low levels in the serum
- acute inflammation
- protects agains worms and allergic rxns
-binds to mast cell and promotes inflammation
