Immune system Flashcards
what is the immune system?
specialist cells which protect body from invasion/infection
what is innate immune system?
it is the bodys 1st/2nd line of defence.
it is non specific so it detects general types of pathogens.
it has no memory capacity.
it is antigen independent (does not need antigens to work)
it is rapid
1st line of defence for innate immune system
intact skin
mucous membrane
normal microbiota e.g. tears
if this fails it goes onto second line of defence
2nd line of defence for innate immune system
natural killer + phagocytic white blood cells
inflammation, fever, antimicrobial substances
if this fails it goes onto the 3rd line of defence
what is the adaptive/acquired immune system?
bodys 3rd line of defence.
its is specific.
it has memory capacity
it is antigen dependant.
it is slower.
3rd line of defence for adaptive immune system
specialised lymphocytes
T+B cells, antibodies
how does the innate immune system work?
pathogen enters body
pathogen bypasses first line of defence
pathogen is detected by macrophage
pathogen is engulfed (phagocytosis of pathogen)
what triggers immunity?
when pattern recognition receptors detect pathogen associated molecular patterns
if any of the recognition receptors are activated it activates the immune system.
what are the cellular locations of PAMPS?
outside of the cells (extracellular recognition) - TLR/Lectin
inside cell - cystolic recognition - NLR/RLR
Protein/lipid sorting - endosomal recognition - TLR
why do pathogens such as viruses and bacteria like to reside in the endosome?
endosome full of protein so they can grow
acts as a hideout as it is within the cell.
what do PRP use to activate destruction process by phagocytes?
macrophages and neutrophils
what are macrophages?
‘big eaters’
phagocytotic
cytokine production
what are neutrophils?
most common leukocyte in the blood
highly motile
also phagocytotic
what are the two main strategies of the innate immune system?
recruiting leukocytes and phagocytes via inflammation to destroy microbes.
blocking viral replication/killing viruses by mechanisms different to inflammation
what are cytokines?
small proteins released by cells that have a specific effect on the interactions and communications between cells.
they bind to cytokine receptors
has roles in innate and adaptive immune system
they can be autocrine, pancrine or endocrine
many therapuetics target these molecule to treat diseases of an immune/autoimmune origin.
