Immunology MS L1 Flashcards
Look at history scientists
Who is the godfather of microbiology and what did he do?
Louis Pasteur (1885) - rabies vaccination
Who discovered the mRNA vaccines?
Kariko and Weissman (2023)
-covid19 is a RNA vaccine
How is SARS-CoV-2 spread?
A single sneeze can produce up to 10,000 droplets - the virus can remain suspended in the air in very tiny droplets as virus so small
How does SARS-CoV-2 virus remain in the airways?
The spike proteins stick tightly to glycans of mucins in the mucous that line the airway epithelium
-Persistence via mucus - attaches to ACE2 receptor cells on epithelial cells
What does SARS-CoV-2 bind to?
ACE2 receptor on epithelial cells - expressed in all epithelial cells mucosa
Look at diagram
Why do we experience fever?
Innate immune system detection - cytokines in immune system figuring out something is wrong
Why do we feel sick sometimes after vaccines?
Activates cytokines
How much antibodies does the body produce per day?
3-5g antibodies/day
What is the immune system?
An integrated defence system composed of tissues, cells and molecules
-Innate and Adaptive immune responses
What is the process of innate immune response?
(quick, non-specific)
Infection
Recognition of pathogens by sensors
Activation of cells and inflammation
Removal of infectious agent
What is the process of adaptive immune response?
(long term, specific)
Infection
Stimulation of T and B cells in lymphoid organs
Expansion and training of effector T and B cells
Migration to infection site
Removal of infectious agent
What is the first line of defence of the innate immune system made up of?
- Epithelia (skin) as a barrier
- pH - low pH - lactic acid, fatty acids
- Mucosa (mucous layer)
- Enzymes (lyzozymes in eyes attacks gram pos bacteria)
- Commensals e.g bacteria
Lysozyme - what does it do and who found it?
-Lysozyme breaks down peptidoglycan (affects gram pos bacteria)
-Found in tears, nasal secretions and saliva
-Found by Alexander Fleming in 1923 - was studying lysozyme when accidentally found penicillin
What are the layers in the mucosal barrier?
Lumen
Outer mucus layer
Inner mucus layer (protected zone) - has antimicrobial proteins (AMPS)
Epithelial cells - cytokines, goblet cells, paneth cell, club cell
What does PAMPS-PRRS mean?
Pattern recognition receptors recognise pathogen associated molecular patterns
What are 2 membrane PRRs
TLR2 - recognise and attack peptidoglycan - gram pos bacteria
TLR4 - recognise and attack LPS - lipopolysaccharides - gram neg bacteria
How many TLRs are there that recognise microbial components?
9
What happens in primary lymphoid tissues?
-Monocyte emigration from bone marrow
-Virtually all cells of immune response originate from multipotent hematopoietic cells
-T lymphocytes develop functionally in Thymus
What happens in secondary lymphoid tissues?
-The adaptive immune response are induced in the MALT (mucosl-associated lymphoid tissues)
-Site of pathogen encounter at the mucosa
-Simple columnar epithelium in the lungs, large and small intestines, uterus, endocervix
-Stratified squamous epithelium in the ectocervix, vagina, oral cavity, tongue, esophagus
What are examples of MALT?
Respiratory tract, digestive system, urinary tract, salivary glands, lactating breast, lachrymal glands, tonsils, adenoids, appendix
Where are the adaptive immune responses induced?
In the lymph nodes and the spleen
-Pathogens in the body tissues (invasion)
-Pathogens in blood circulation (invasion, sepsis)
Where in the lymph node is i)B cells ii) T cells and iii) Macophages and plasma cells found?
B cells - primary lymphoid follicle
T cells - paracortical area
Macrophages and plasma cells - medullary cords
