Mod 3: The Immune Response Flashcards
Phase:
Identify and activate the cells from adaptive immunity that are able to recognize and bind to the antigens from the specific pathogen that’s invading
Antigen Recognition
Phase:
Produce a large quantity of immune cells specific to the pathogen in order to stop the invasion
Lymphocyte activation
Phase:
To completely destroy the pathogen that has invaded the body
Elimination of Pathogens
Phase:
Majority of immune cells die as they are not needed anymore (could cause more damage if they stay)
Contraction (Apoptosis of Immune Cells)
Phase:
When re-exposed to the same antigen, these memory cells proliferate quickly to generate an immune response that is much faster and more robust than the first response to the pathogen
Memory (establishment of immunological memory)
2 Antigen Presenting Cells
Helper T-cells
APCs
Essential in the process to induce an effective adaptive immune response
Are not able to recognize extracellular pathogens by themselves so they require an intermediate to present them the antigens found inside the body
Helper T-cells
Internalize pathogens
by phagocytosis or receptor-mediated endocytosis
Processes pathogens into peptides
Antigen Presenting Cells (APCs)
Most efficient cells that both present antigens thru MHC class II and express costimulatory signals to activate helper t-cells
macrophage
b-cell
dendritic cells
Professional APCs
Can be induced to express MHC class II complexes or stimulatory molecules, but normally they don’t (rarely needed, for short periods)
- fibroblasts
- glial cells
Non-Professional APCs
Pathway:
- MHC Class I (CD8)
- Processed intracellular particles and presents them on cell surface to be recognized
Endogenous pathway (Antigen Processing)
Pathway:
- MHC Class II (CD4)
- 5 steps
Exogenous Pathways (Antigen Processing)
Name the 5 Steps of Exogenous Pathways
- Antigen Engulfment
- Proteolytic Processing
- Formulation of MHC Complex
- Cell Surface Expression
- Recognition by Helper T-cell
Receptor:
•composed of a membrane-bound antibody & signal transduction
molecules (ITAMs)
•they recognize and bind to extracellular pathogens or toxins directly
B-cell Receptor
Receptor:
•formed of membrane-bound antigen-specific molecule and signal
transduction molecules (CD3 and ITAMs)
•in association w/ co-receptor (CD4 & CD8) recognize and
bind to peptide: MHC complex
T-cell Receptor (TCR)