L1 Nature of Immunity Flashcards
how was smallpox protected against before vaccines
if infected with cowpox can survive as they have very similar structure= immunological memory
what is the response to a diverse nature of pathogens
range of defence mechanisms
what is the response to a vast range of pathogens
vast range of antigen receptors
what is the response to rapid growth of microbes
a rapid inflammatory response
what is the the response to minimise host damage
regulatory mechanisms
what does an immune response to infection involve
recognition and defence
what is recognition
locate and identify the pathogen
what is defence
repel or destroy the pathogen
what are the cardinal features of immune system
specificity
memory
self-discrimination
what is the levels of defence against a pathogen
physical barrier
innate immune
adaptive immune
what is the innate immune system like
rapid anf generic
what is the adaptive immune system like
slower and specific
what are the limitations to physical barriers
respiratory tract
urogenital tract
gastrointestinal tract
what are the cells of the innate immunity
dendritic
macrophage
mast
granulocytes
what are the granulocyte cells
basophil natural killer cell complement neutrophil eosionphil
what are the cells of the innate and adaptive immunity
natural killer T cell
gamma delta T cell
what are the cells of the adaptive immunity
B cell
T cell
what is the function of a mast cell
rapid inflammatory response - releases histamine
what is the role of a neutrophil
neutrophil in blood circulation – recruited to the location then phagocytose
what is the role of a macropahge
in the tissues - recruited to location then phagocytose
how does the innate immune response occur
PRRs recognised the PAMPs (only on pathogens)
where are PRRs
have surface and endosomal recognition as pathogens hide inside cells- intracellular pathogen
how is a pathogen phagocytosed and killed
chemotaxis adherence via PAMP cell activation via PRR initiate phagocytosis release degradation products bacterial killing and digestion phaolysosome formed phagosome formed
what happens when the complement system is activated
complement opsonises pathogen – puts some complement onto the pathogen
when complement opsonising this section binds to activate mast cells vasodilation
complement receptors recognise tags - bind and digest
what is the effect vasodilation after complement activation
cells circulating in blood can leave blood and go to the tissues to the location of infection
what ate the three pathways
classical
lectin
alternative
what pathways are antibody dependent
classical
what pathways are antibody independent
lectin
alternative
what do the pathways lead to
activation of C3 and generation of C3 convertase
then activation of C5
lytic attack pathway
which pathway activates the complement
lectin
where does the innate immune system take place
in tissue where infection is
how are adaptive immune responses activated
B and T cells need information on the pathogen – taken to local lymph node
Lymph nodes full of B and T cells with specific receptors on surface
Activated B and T go back to blood circulation
how is the B and T cell information taken to the lymph node
via the afferent lymphatic system to local lymph node
how do activated B and T cells get into blood circulation
via thoracic duct
what does adaptive cell mediated immunity involve
T cells
what does adaptive humoral immunity involve
B cells
where does the T/B cells bind to the pathogen
variable region - antigen binding sites
what does the T helper cell do
T helper CD4 helps other cells clear pathogen from body
what does the T CD8 cell do
T cytotoxic CD8 kills virally infected cells
what is the recognition of innate immunity like
rapid- hours
fixed
limited number of specificities
constant during response
what is the adaptive immunity like
slow -days to weeks
variable
numerous highly selective specificities
improves during response
what are the stages of a primary immune response
- epithelial barrier
- immediate local response
- innate inflammatory
- later adaptive response
what are the immediate local responses of the innate
complement proteins
macrophages
what are the innate inflammatory responses
inflammatory mediators from complement, macrophages, mast cells
attract leucocytes and serum proteins (more complement)
what is the later adaptive response
antigen carriage by dendritic cells to lymphoid tissue
activation of specific T and B lymphocytes and AB production
recirculation to infection site
what happens after primary infection - second infection
preformed AB and effector T cells in tissues and blood immediate
memory T and B cells faster and bigger responses
