Humoral and Cellular Immunity Flashcards
Humoral immunity is the oldest form of medicine. What are the 4 humors?
- Phlegm
- Blood
- Liver
- Quality of stool
The concept of humors originated with who? and refined by who?
Hippocrates
Aristotle and Galen
How did they treat disease in the middle ages?
Restore balance to the 4 humors
What is humoral immunity?
Immunity mediated by soluble molecules
Who first suggested the idea of humoral immunity?
von Behring
A serum from an animal immunized to diptheria could confer protection to another individual
von Behring
basis for humoral immunity
“something in the liquid remembered the specific pathogen”
von Behring
basis for humoral immunity
How can we test for humoral immunity?
An adoptive transfer of protective immunity through serum transfer
Jules Bordet
Demonstrated that 2 components in serum mediated humoral immunity
Component 1
ANTIBODIES
- Heat stable
- Specific
Component 2
COMPLIMENT
- Not heat stable
- Not specific
- Kills pathogen
What did Jules Bordet call component 2? What is it modern day?
Alexine
Compliment
Paul Ehrlich
What did he propose that component 1 and 2 were?
1 - proteins produced by cells and both expressed on the cell surface and released into the blood
2 - non-specific blood component that complemented antibodies
Antikoper - side chains that were referred to as
amboceptors - binds both pathogen and self cells
The component that binds and neutralizes?
Antibodies
The component that kills?
complement
Which part of the humoral immunity is in a soluble compnent in the innate?
Complement
Which part of the humoral immunity is the soluble compnent in the adaptive?
Antibodies
How does neutralizing help with infection?
Cover and hide receptors
Can’t see, can’t infect
How does the humoral response enhance later adaptive responses?
Opsonization - flags and something will destroy/eat it
What is complement made of?
40 soluble inactive proteins
Activation of complement leads to a proteolytic cascade that results in the generation of what?
MAC - membrane attack complex
What is MAC?
A non-covalent oligomer of complement proteins
How does MAC kill?
Inserts itself into the membrane of a pathogen creating pores and lysing the target
Is Complement specific?
NO
No memory
Cascade effect amplifies
Does complement have memory?
NO
Are antibodies specific?
YES highly
Antibodies are side chains produced by
B cells
the cellular part of humoral immunity
What is required to make the soluble molecules of the humoral response?
Cells
What are the 3 effector functions of antibodies?
- bind and neutralize
- Opsonize
- Bind and enhance complement activation
Isotypes
Diff flavours of antibodies
Why do we need diff antibodies?
Different functions
some are better some are worse
What dictates the type of immunity an antibody can provide?
The specific effector function spectrum
Metchnikoff
What did he observe? What did it lead to?
Observed some cells from sea urchins were able to internalize matter
phagocytes
cell-mediated immunity
James Gowans 1950-60s
What did he propose? What did he track?
Adaptive was mediated by lymphocytes
Tracked cells that left the thymus, circulated the blood, entered lymph nodes, drained in the lymph, and re-entered the blood
What does the removal of small lymphocytes do?
leads to the loss of adaptive immune responses
Who studied animals following fetal thymectomy - loss of immunity?
Miller - controversial
What two things did Miller propose?
- different subsets of lymphocytes
- B-cell (antibody-producing cells)
T-cells (lymphocytes from the thymus
What was identified that could kill without prior immunization/memory?
Natural killer cells
A lymphocyte isolated from the spleen
Natural killer cells
Permanently angry
isolated from the spleen and do not need education/priming
What is the cellular immune system responsible for clearing? 3 things
virally infected cells
intracelular bacteria
tumors
What are two types of phagocytes invloved in cellular?
macrophages
neutrophils
What 3 things are involved in cellular imm?
- Phagocytyes
- T-cells
- NK cells
Why do we sometimes need to kill macrophages?
Thye can be infected and become a virus factory
What are the 4 mechanisms that cellular imm uses to kill targets?
- Phagocytosis
- Neutrophil Degranulation
- enhance macrohpage phagosomes
- Direct killing
2 types of direct cellular imm killing?
Death receptors (FAS-FAS Ligand) Cytotoxic granules (poke holes in target and induce apoptosis)
What is involved in phagocytosis?
Neutrophils
Macrophages
What does degranulation do?
Neutrophils and granulocytes dump toxins
Helper cell
TH1
What does a helper cell help?
phagosome activity
What cells induce apoptosis?
CD8+
T-cells
NK cells
What directs toxins to a cell?
Cytotoxic granules
- CD8+
- T-cells
- NK cells
Are T-cells able to recognize a pathogen?
NO
What do T-cells require to see a pathogen?
innate immune cells (macrophages, dendritic)
