Intro to immune system Flashcards
What are the 4 key principles of the immune system?
- Acts as a barrier
- Identify pathogens
- Kill pathogens
- Remember pathogens
What are the 2 components of the immune system?
1) Innate immune system (all plants, vertebrates and invertebrates)
2) Adaptive immune system (only present in vertebrates)
What is the key difference between the innate and adaptive immune systems?
- Innate immune system provides non-specific recognition with no specific memory response
- Adaptive immune system provides specific recognition with an ability for specific memory response
What is the difference between the specific and non-specific recognition provided by the innate and adaptive immune systems?
Innate = recognizes broad groups of pathogens
Adaptive = recognition of specific pathogens down to a strain level
How does innate immune recognition work?
Innate system identified self and non-self cells using antigens
What are pattern recognition receptors?
PRRs are innate cell receptors that recognise non-self molecules
What is an example of a non-self molecule?
A lipopolysaccharide found on the surface of gram -ve bacteria
What are pathogen associated molecular patterns and where are they found?
PAMPs is the collective term for all of the non-self molecules. They are found on the surface of pathogens.
What must happen in order for an immune response to be generated?
The PRR must bind to the PAMP.
What are the 7 major types of immune cells?
1) Dendritic cells
2) Macrophages
3) Neutrophils
4) Eosinophils
5) Basophils
6) Mast cells
7) Natural killer cells
What type of receptor does a LPS bind to on a dendritic cell/ macrophage?
Binds to TLR 4 (toll-like receptor)
What else can trigger the innate immune system?
Damage associated molecules (things such as DNA or proteins associated with DNA that are ordinarily housed in the nucleus)
What type of receptor detect damage associated molecules?
TLRs and RAGE
Summarize the main 3 roles of innate receptors.
- Recognise conserved structures (LPS)
- Are non-specific so can detect broad groups of pathogens
- Can recognise damage related molecules
How does the innate system contribute to arthritis?
- An inflammatory response is triggered as damage associated molecules are found due to the damaged cartilage.
What two types of lymphocytes form the adaptive immune system?
B lymphocyte
T lymphocyte
What is the function of B lymphocytes?
B lymphocytes secrete antibodies (immunoglobulins)
What are the two types of T lymphocyte?
- CD4+ T lymphocyte (helper T cells)
- CD8+ T lymphocyte (cytotoxic T cells)
What are antigen receptors?
Surface transmembrane immunoglobulins
What antigens are present on T cells and B cells?
B cells have B cell receptors
T cells have T cell receptors
What is the definition of an antigen?
Antigen = any substance that can bind to specific lymphocyte receptors and so induce an immune response
What is epitope?
An epitope, also known as an antigenic determinant, is a specific portion of an antigen that the immune system (specifically, antibodies, B cells, or T cells) recognizes
Complete the sentence…
TCRs and BRCs differ highly in the …(1)… immune system, unlike in the …(2)… immune system in which the antibodies for a certain pathogen will be largely the same across all species.
1) Adaptive
2) Innate
How is diversity created during the formation of antibodies?
Initially, each pre-B cell has the same light chain and heavy chain genes, but these genes have multiple ‘options’
