Antigen: (Ag) something that stimulates an immune response ~ 10 amino acids long. Can be any molecule: components of bacterial cell walls to exotic chemicals like poison ivy sap to your own proteins Antibody (Ab): a family of defensive proteins your body makes when it is stimulated by Ag. Ab contains a receptor that specifically binds one Ag and not another. Example : IgG Essential definitions
What are the key characteristics of an effective defense system? Not looking for CTL, NK cells, ADCC
A way of amplifying selectively particular immune responses
Diversification: converting one response into multiple types
Turning responses off so that they don’t get out of control
The ability to respond to a changing environment by inventing new Ag receptors
Essential characteristics of an immune response
One component that is quick to develop and Ag non-specific to contain the pathogen initially: INNATE IMMUNITY A second component that is Ag specific to allow you to select the most appropriate of the ~30 different types of immune responses you have available, keep them highly targeted , exhibit memory ...: ADAPTIVE IMMUNITY The optimal immune response
Key characteristics: Specificity Memory Adaptability Adaptive/ Acquired/ Specific Immunity
1. Inflammation brings Ag specific cells to the site, promoting expansion of the Ag-specific component of the response and targeting it. 2. Ab bind to several types of immune cells to confer specificity on Ag non-specific cells 3. The activities of the innate response help determine the type of specific response that develops (enhancing Ab production vs stimulating more cytotoxic cells) Integration of innate and adaptive immunity to form a more effective defense system
inducing and maintaining desirable specific immunity: (vaccines…)
coping with immune disorders (ie allergic disease, autoimmunity, cancer).
Attempts to manipulate the immune response for specific practical purposes (ie transplantation, prevention of Rh disease) also important for small subsets of the population.
Two main applied aspects of immunology of concern to Canadian pharmicists
Passive immunity: transfer of Ab Advantages : intense, immediately effective. Disadvantages: Short duration. Does not activate the host’s own immune response, so no memory develops. Active vs. Passive Specific immunity
Active immunity Results from natural (or vaccine induced) exposure to a pathogen. Advantages: stronger, more diverse response, longer lasting, memory develops Disadvantages: takes several days to months to fully mature.