MedEd Immuno 1 Flashcards
cells of innate immunity (6)
neutrophils
basophils
eosinophils
macrophages
natural killer cells
dendritic cells
cells of adaptive immunity (2)
B and T cells
which type of immunity is fast vs slow
innate = fast
adaptive = slow
soluble components of the innate immune system
complement
acute phase proteins
cytokines / chemokines
describe activation of the innate immune system
produce phagocytes and release them into blood
endothelial cells express adhesion molecules - allows cells to stick and migrate
phagocytosis
oxidative / non oxidative killing
macrophages communicate to t cells
neutrophils die and form pus
which immune cells is pus mainly composed of
neutrophils
what is the point of dendritic cells in terms of the 2 types of immunity
mediate the transition from innate to adaptive immunity
what type of cell is a dendritic cell
phagocyte
what do dendritic cells do after phagocytosis (3)
upregulate expression of HLA
express costimulatory molecules
migrate via lymphatics to lymph nodes
what receptor do dendritic cells use to migrate to lymph nodes
CCR7 receptor
what do B and T cells do in primary vs secondary lymphoid organs
primary - developed and mature
secondary - interaction with pathogens
which organs are primary vs secondary lymphoid organs
primary - bone marrow and thymus
secondary - spleen, lymph nodes, MALT
what is humoral vs cellular immunity
humoral = deals with antigens from freely circulating pathogens (outside cell)
cellular = deals with clearing the infected cell
lifecycle of a T cell
pre T cells made in thymus
selection in thymus
CD4 or CD8 T cells made
lifecycle of B cell
produced in BM: pro B cell –> pre B cell
develop into IgM secreting B cells
then develop into plasma cells or undergo class switching to make IgG / IgE / IgA
how does T cell selection work in the thymus
low affinity for HLA –> not selected (inadequate reactivity)
intermediate affinity for HLA –> selected
high afifnity for HLA –> not selected (autoreactivity)
what % of produced T cells are selected in the thymus
10%
which T cells go on to make CD4 t cells and which go on to make Cd8 T cells
cd4 = affinity for HLA II
cd8 = affinity for HLA I
what are cd4 T cells aka
T helper cells
what are cd8 T cells aka
T killer cells
3 functions of cd 4 / t helper cells
recognise extracellular protein peptides presented on HLA2
help development of full B cell response
help development of some cd8 t cell response
3 functions of cd8 / t killer cells
reconise intraceullar protein peptides presented on HLA1
kill cells
2 ways cd8 / t killer cells can kill
via perforin / granzyme
via Fas ligand expression
describe B cell selection in the BM
no recognition of self = survive
recognition of self = not selected