1. Introduction Flashcards
Stranger model
To destroy foreign cells/microbes and to tolerate self cells
Danger model
Revised concept of immunity: Distinguishing between harmful and harmless (instead of self/non-self)
Production of DAMPs leads to..?
Produced from dying/stressed cells-> acts on dendritic cells (APC) -> migration to lymphoid tissue -> antigen presentation to T cells
Primary lymphoid organs
Bone marrow and thymus
Secondary lymphoid organs
Lymph nodes, spleen, tonsils and mucous mem. of associated tissues
Antigen
Any molecule that provokes an immune response
Epitope of antigen
A portion of the antigen that is recognized by a given T or B cell receptor
How does B-cells recognize the antigens?
By surface bound immunoglobulin
How does T cells recognize an antigen?
T cells recognize peptide fragments represented by the APCs on their surface MHC molecule
Clonal selection
Once a cell in the recirculating lymphocyte pool encounter an antigen specific to its receptor it will stop migrating -> activation -> proliferation to form colony of several thousand cells
Instruction theory
States that there is only one common receptor encoded in he germline-> specific receptors generated using the antigen as a template
(theory that came earlier than the clonal selection theory)
Innate immunity
Inborn immunity which provides an immediate response
Adaptive immunity
Acquired or developed during life
Cells of the innate immune system (7)
- Macrophages
- Granulocytes
- Mast cells
- NK cells
- Immature dendritic cells
- Innate lymphoid cells
- Natural autoantibodies
Characteristics of the innate immunity (4)
- Limited receptor specificity
- No latency
- No memory
- Linear increase
Characteristics of adaptive immunity (4)
- High specificity
- Latency (1-2 weeks)
- Memory
- Exponential amplification
Cells of adaptive immune system
T cells, B cells and antibodies
Phases of the immune response
- Recognition phase: activation and blast transformation
- Central phase: clonal proliferation and differentiation
- Effector: destruction and elimination of the pathogens
3 differences between primary and secondary immune responses
Primary: slow, low amplitude, predominantly IgM prod.
Secondary: fast, high amplitude, predominantly IgG prod.
Cytokines
Small, soluble proteins and glycoproteins that have messenger and regulatory functions
Pleiotropic effect
When one cell/molecule has an effect on many different cells
5 features shared by the immune system and the nervous system
- Complexity
- Networking
- Synapse formation
- Memory
- Cognitive
