Adaptive immunity

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What’s a disadvantage of adaptive immunity?

slow acting

What are advantages of adaptive immunity?

specificity and memory

How is foreign material recognised in adaptive immunity?

by specific receptors on T and B lymphocytes

In its healthy state, how does adaptive immunity treat the body’s own cells and molecules?

tolerant towards them

What cells are lymphocytes T and B derived from?

stem cell precursors in bone marrow

Where do lymphocytes T mature?

in thymus

Where do lymphocytes B mature?

in bone marrow

What receptors allow lymphocytes B to recognise foreign material?

antibodies

What receptors allow lymphocytes T to recognise foreign material?

t cell receptor

Where’s the thymus?

small organ overlying the heart

What is primary lymphoid tissue? How does is differentiate?

Where are lymphocytes found in cases of infection?

lymph nodes, spleen etc

How do lymphocytes B respond to the recognition of an antigen? Lymphocytes T
?

secrete antibodies

kill infected host cells or make cytokines to

What is lymphocyte B mediated immunity termed? Why?

humoral bc works through bodily fluids that used to be called humours

What is lymphocyte T mediated immunity termed? Why?

cell-mediated bc they kill other cells or make other cells kill them

In what types of infection are lymphocytes B deployed?

EC bacterial, 2ndary viral

In what types of infection are lymphocytes T deployed?

viral, IC bacterial, IC parasitic

What does antibody stand for? What does it respond to?

anti-foreign bodies

antigens (antibody generating material)

Where are antigens found? How is this a limit to adaptive immunity?

on surface of bacteria

has to be an antigen on the surface of the cell to be destroyed

What happens to lymphocytes that recognise self? What happens if this process doesn’t work properly?

deleted early in development

autoimmune disease

Are cells specifically produced to respond to an antigen?

no, millions of cells are produced independently from antigen presence - when the two bind this triggers the cell to duplicate and many clones are made to bind and destroy the antigen presenting cell

Who put forward the clonal selection hypothesis? Briefly explain it

macfarlane burnett

• each lymphocyte (T or B cell) has a unique receptor specific for a particular antigen

• upon encountering its specific antigen, that lymphocyte undergoes clonal expansion

• creating a population of cells with the same specificity

What occurs in primary lymphoid tissues? Which tissues does this include?

lymphocytes reach maturity, acquire their specific receptors

thymus and bone marrow

What occurs in secondary lymphoid tissues? Which tissues does this include?

mature lymphocytes are stimulated by antigen

lymph nodes, appendix, spleen, tonsils and adenoids, lymphatic vessels

Why are there more lymphoid tissues located near the respiratory, urogenital and gi tracts?

locations where pathogens are more likely to enter = more immediate and local reaction

Why would an infcetion cause the throat to swell?

specific differentiating lymphocytes are proliferating in lymph nodes

What does the recognition of an antigen by a lymphocyte B trigger?

plasma cells release soluble antibodies = defence against infection

What class do antibodies belong to?

immunoglobulins: soluble glycoproteins

How does the structure of an antibody reflect the dual role of the adaptive immune response?

• fab regions: bind specifically to different antigens

• fc region: binds to complement

What region of antibodies recognises antigens?

fab region

What region of antibodies eliminates antigens?

fc region

Which sequence of an antibody is variable? What does this region bind to?

fab region

different antigens specifically

On which cells are fc receptors found?

phagocytes and NK cells

What’s the hinge of an antibody?

the fork part of the antibody, flexible region without immunoglobulin domains

What acts as a label for infectious material? What happens to these labels?

antibodies

eliminated

Where are disulphide bridges found in an antibody?

at the intra-chain spaces, between light and heavy chains; heavy and heavy chains at the hinge