Lecture 7: Humoral vs Cellular immunity Flashcards
Describe adaptive modulation of innate immunity
- antibodies produced by b lymphocytes bind to target cells for;
- complement activation
- tagging targets for phagocytosis
- cytokines produced by activated T lymphocytes modulate phagocytosis
Explain innate modulation of adaptive immunity
- phagocytosis and digestion of the pathogen by cells of the innate immune system activates T-lymphocytes
- phagocytes presents pathogen to lymphocyte
- lymphocytes also need a second signal by innate immune system
What is the definition of humeral immunity?
Immunity mediated by body fluids (soluble molecules)
What is anti-toxin
An antibody with the ability to neutralize a toxin, serum that conveyed passive immunity
Describe what serum transfer is?
Inject killed pathogen and when animal remains healthy inject this animals serum into another animal and then inject a lethal dose of the pathogen. If the animal remains healthy that is passive immunization
What is alexine
Component 2, heat-labile and had non-specific antimicrobial activity. Now known as complement
What is humoral immunity predominantly modulated by?
Complement and antibodies (b-cells)
How does humoral immunity kill pathogens
Soluble proteins bind target pathogens and either neutralize them or directly lyse (kill) them
What is complement?
A series of about 40 soluble proteins that are able to bind to and activate in the presence of microbial cell surfaces
What does the activation of complement result in
Proteolytic (breakdown of proteins) cascade that results in the generation of the membrane attack complex (MAC)
What is the membrane attack complex?
Complement proteins that inserts itself into the membrane of the pathogen creating pores and killing the target
With humoral immunity complement is there specificity?
No, little specificity
Do complement proteins have memory?
No memory
What are the humoral immunity antibodies?
Heat-stable components of humoral immunity that are side chains produced by the B-cells and T cells
What are the effector functions of antibodies?
- bind and neutralize target
- opsonize the target (identify the target)
- bind to the target and enhance complement activation
What are isotypes?
Different flavours of antibodies, each have a different effector function
What is responsible for the specificity and immune protection offered by serum transfer?
Antibodies
What cells comprise the memory of the humoral immune response?
Antibodies
Who discovered and named phagocytes, birth of cell mediated immunity
Metchnikoff
What is adoptive immunization?
Transfer immunized spleen cells to individual than infect them with pathogen
What are natural killer cells
White blood cell and innate immune system kill infected cells and tumorous cells
What cells does cellular immunity involve?
- phagocytes; macrophages and neutrophils
- T-cells
- natural killer cells
What processes does cellular immunity use to kill targets?
- phagocytosis
- neutrophil degranulation
- regulate cellular activity
- direct killing of infected targets
What is needed for T cells to recognize a pathogen directly?
Innate immune cells, macrophages and dendritic cells to present the pathogen to the T cell
What is not required for natural killer cell regulated immunity?
Innate immune cells such as macrophages and dendritic cells presenting pathogens
