Humoral Immune Response
What happens in acute intracellular infection?
Antigen is presented on MHC-I to CD8 helper cells and CD8s produce CTL effectors, which kill infected cells via apoptosis. Also makes memory cells.
When activated, B cells produce antibodies specific for the same antigen as their _?
BCR
Why don't plasma cells express BCR's?
Because they are not involved in the recognition of antigen just production of antibodies to bind to it
Why do memory B cells retain their BCRs?
Because they need to be able to recognize the antigen in the event of re exposure
Cell-mediated immunity is important in defending against what?
Intracellular infection (antibodies cannot get into cells)
What kind of cell enables a 'secondary immune response'?
Memory B cells
B cells get their variability/uniqueness via _ _ _?
Random gene reshuffling
Memory B cells do not need Th cells to become activated for a secondary response, T or F?
T
Why are live vaccines preferred?
They ensure a cell-mediated response, and stimulate IgA.
T or F, antibodies can live on after the plasma cell is dead?
True.
Characteristics of the primary immune response
- Long lag phase for adaptive response - Innate immune system the most active - Takes 7-14 days before sufficient antibody is produced to eliminate pathogen - Main antibody: IgM
Why do vaccines fail? (4)
- Poor vaccine potency - Inadequate storage - Immunocompromised patients (pregnancy, malnourishment, AIDS) - Genetic susceptibility
Characteristics of the secondary immune response
- Relies on memory B cells - Fast-acting; 2-3 days for sufficient antibody to be produced to eliminate pathogen - Main antibody: IgG
The humoral immune response is part of the immune response that involves what?
Antibodies (B cells)
Plasma cells can be thought of as _ factories
Antibody (huge ER for making proteins)
Humoral immunity is also known as?
Antibody-mediated immunity
What happens in chronic intracellular infection?
Antigen is presented on MHC-II to CD4 helper cells, and CD4 helper cells produce special cytokines (e.g. interferon-gamma) that signals macrophages to enhance killing of intracellular bacteria/parasites
What are the four types of vaccines?
Attenuated pathogen, recombinant protein, recombinant vector, DNA vaccine
Why are plasma cells derived from B memory cells better than naïve B cells at stopping pathogens from causing disease?
Because they make IgG immediately (instead of IgM then IgG which is better at neutralizing antigen)
What is a chemical adjuvant and what does it do?
Enhances response to vaccine. ↑ inflammation ↑ macrophage activation ↑ antigen-presenting cell interaction ↑ release time
Humoral immunity is important in defending against what?
Extracellular infection
What do killed vaccines stimulate?
IgM/IgD production
Does IgA fix complement?
No - this is done by IgM and IgG
How do CTLs induce apoptosis?
Use perforin to make pore -> granzymes go through and turn on apoptotic pathway
IgA targets what?
Viruses and bacteria
What is a secondary response?
Where B memory cells encounter the same antigen and respond (become active, proliferate and differentiate into more plasma and memory cells)
How long can memory B cells last in our body?
months- entire lifetime
