Innate Immunity Flashcards
Describe features of the innate immune system
- rapid response (minutes/hours)
- recognises a limited number of different structures characteristic to pathogens
- no change upon re-exposure
Describe the features of the adaptive immune system
- takes time to develop (days/weeks)
- highly specific for a vast number of different structures
- response improves upon re-exposure
What can a hematopoietic stem cell differentiate into?
- common lymphoid progenitor
- common myeloid progenitor
What cells are involved in the innate response?
- NK cell
- dendritic cell
- monocyte
- neutrophil
- eosinophil
- basophil
- mast cell precursor
What are the cells involved in adaptive response?
- T cell
- B cell
- Dendritic cell
Where are monocytes released from and what do they do??
- Released from bone marrow
- Act as sentinels in the tissue which can differentiate into macrophages
When do monocytes differentiate into macrophages?
-when they leave the blood stream
What are the main roles of monocytes?
to phagocytose and kill bacteria and to remove apoptotic cells
How do macrophages recognise bacteria?
can use pattern recognition receptors (PRR) to recognise pathogen associated molecular patterns (PAMPS)
What receptor detects gram positive bacteria?
TLR2
What receptor detects gram negative bacteria?
TLR4
How do macrophages kill bacteria in phagolysosomes?
- acidification
- production of oxygen and nitrogen radicals
- proteolytic enzymes
How does antigen presentation occur?
- peptides derived from killed microbes are presented to effector T cells, leading to their stimulation
- activated T cells will then support macrophages by soluble and surface-bound signals
What are cytokines and where are they released from?
-small proteins released from activated macrophages
Give some examples of cytokines?
TNF
IL-1
IL-6
CXCL8