Introduction to the immune system Flashcards
2 reasons we have an immune system?
1) tissue homeostasis
2) tissue defense
why do we need tissue homeostasis?
1) to remove damaged cells
2) promoting wound healing (from normal wear & tear)
what does tissue defense consist of?
1) prevent pathogen entry
2) remove/clear invading pathogens
3) Remove/clear pathogen toxins
4) Limit spread of pathogens in body
- do all w/o killing beneficial commensal organisms*
What does the immune system protect us from?
1) extracellular bacteria, parasites, fungi
2) intracellular bacteria, parasites
3) viruses
4) parasitic worms
what are the two types of immune response?
1) innate: early & preformed
2) adaptive: later & “adapts” response to the specific pathogen infecting an individual
which form of immunity generates memory of infections?
- ADAPTIVE
- innate has no memory of infection that have occurred to an individual
How does the immune system work?
- is a controlled set of responses w/ multiple choices at each step
- choice at first step influences next choice
- 2 types of responses
- “innate drives adaptive which drives innate”
process of innate immunity response?
- immediate, 0-4 hrs
1) infection
2) recognition by preformed nonspecific effectors
3) removal of infectious agent - STOP*
- we do this all the time for minor bugs
early induced immune response
- 4-96hrs
1) infection
2) recognition of microbial-associated molecular patterns
3) inflammation & activation of effector cells
4) removal of infectious agent
adaptive immune response
> 96 hours
1) infection
2) transport of antigens to lymph nodes
3) recognition by naive B & T cells
4) clonal expansion/ differentiation to effector cells
5) removal of infectious agent
innate immune response?
- early & preformed
- involves tissue cells AND professional immune cells
adaptive immune response?
- only professional immune cells
- clonal expansion of specific lymphocyte population
- recruiting and directing subsequent amplification of innate response
Kinetics of a successful inflammatory response to infection? (5 steps)
1) entry of microorganism, causes innate response
2) organisms reaches threshold and adaptive response induced
3) as adaptive induction occurs amount of microorganisms increasing
4) adaptive activated, start decreasing microorganisms amount until cleared
5) create immunological memory
specific cell types involved with innate response?
1) granulocytes
2) macrophages
specific cell types involved with adaptive response?
-lymphocytes (T and B cells)
what is the initiation of the adaptive response dependent on?
- dependent on the innate immune response
- adaptive response is initiated if innate response fails to eliminate pathogenic insult
two ways the innate response drives/ effect the adaptive response?
1) w/o an innate immune response, an effective lymphocyte (Adaptive) response can’t be generated
2) type of innate immune response helps determine & form the type of lymphocyte (adaptive) immune response
5 steps of successful inflammatory response to infection?
1) local infection, penetration of epithelium
2) macrophages/dendrites eat them, activated, go to lymph node w/ antigen presented on surface
3) activate only T cells that recognize the presented antigen
4) T cell activated, clonally expand & attack the pathogen
5) come back and tell innate immune system how to respond
what happens if you lack innate immunity?
- if lack innate will not activate adaptive immunity/lymphocytes
- you die quickly
what happens if you lack adaptive immunity?
- innate immunity can keep you alive for a while, but pathogen replication & evolution will eventually overpower innate w/o an adaptive response
- you die later on but still dead
what happens if have leaked innate & adaptive but still present?
- can give supplements/ help control it and can survive
- but still dangerous/deadly for major infections if don’t have medical help
innate immune cell production process?
1) pluripotent RBC stem cell
2) common myeloid progenitor
3) granulocyte /macrophage progenitor
4) innate immune cells
what are the 5 innate immune cells?
1) neutrophil
2) eosinophil
3) basophil
4) monocytes
5) mast cell
what are the two “middle ground” cells? (cells on border between innate & adaptive)
1) dendritic cells
2) macrophages