evolution of immunity - L7 Flashcards
define immune system
a system of structures and processes to protect against infection
what are two secondary functions of the immune system
autoimmunity
allergy
what is innate immunity
defence system we were born with
genetically programmes
what is adaptive immunity
where immune system destroys invading pathogens and any toxic molecules
what occurs in the primary lymphoid organs
where lymphocytes reproduced and mature
what are examples of primary lymphoid organs
bone marrow
thymus
what are secondary lymphoid organs
highly organised and structures of mature lymphocytes
what are examples of secondary lymphoid organs
spleen
lymph nodes
why is compartmentalisation important for secondary lymphoid organs
allows dendritic cells, T cells, B cells to communicate and drive adaptive immune response
how do immune cells arise in haumatopoeisis
from pluripotent haematopoietic stem cells
what does the common lymphoid and myeloid progenitor do
Differentiate through various steps to give rise to multiple cells of immune system
what do pluripotent haemotopoietic stem cells give rise to in bone marrow
common lymphoid progenitor
common myeloid progenitor
what does a mast cell precursor differentiate into
differentiates into macrophages in tissues
what do common myeloid progenitors give rise to
MACROPHAGE/DC PROGENITOR (MDP) which gives rise to COMMON DC PROGENITOR (CDP)
how many genes in organisms are devoted to immunity
10%
can pathogens outside body be detected by antibodies
yes
can pathogens inside body be detected by antibodies
no - they’re invisible
what do B cells and T cells do
express numerous receptors to recognise any type of antigen
what is the B cell receptor
the antibody
what do most T cells have
alpha and beta subunit
small number of them are gamma and delta
what do naive T cells require
co-stimulation fro antigen presenting cell to become activated
what is anticipatory immunity
Ability of the immune system is already present before exposure to pathofen
what is the anticipatory states
ability to respond is already present before the appearance of a pathogen
what is the adaptive state
the ability to respond develops during the lifetime of an individual once the pathogen has been seen in response to particular features of the pathogen
what is the bacterial immune system
CRISPR
what happens after phage infection in CRISPR
some bacteria acquire phage derived spacer
what does the CAS protein
long RNA -> short RNA fragments which associate with more CAS protein
what does the short RNA with CAS bind to
phage nucleic acid and degrades it
why is CRISPR important
acts as memory for the bacteria
remember the infection by recording it in the genome (adaptive)
pass this resistance to their descendants (heritability)
name 2 models of innate immunity
- cells express a pattern recognition receptor (PRR) that recognise a particular pathogen molecular pattern (PAMP)
- cells express a PRR that recognise a danger associated molecular pattern (DAMP)
what do receptors do
can activate or inhibit responses
Can recognise self and pathogenic ligands
What is monoclonal antibody
Man made antibody for a single antigen
How does crisper work
Edits genes by precisely cutting dna and then letting natural dna repair processes to take over
