Adaptive Immunity Flashcards
adaptive immunity
body recognizes and defends itself against invaders and their products
specificity, inducibility, clonality, unresponsiveness to self, memory
antigens
large proteins
structurally complex
haptens
autoantigens: self antigens on own cell surfaces
epitope
3D region of recognition on antigen
6-10 aa’s of antibody that is recognized by lymphocyte
MHC type 1
autoantigen
intracellular proteins
in nucleated cells
label cells normal or infected with epitope
MHC type 2
autoantigen
outside cell proteins
in immune cells
function of the lymphatic system
screen tissue for foreign antigens
remove excess nutrients and waste from tissue as lymph
return lymph to circulatory system
primary lymphoid organs
produce cells
bone marrow
thymus
secondary lymphoid organs
colonize cells spleen lymph nodes lymph nodules- MALT tonsils
B cells
mature in bone marrow
sample of antibodies produced on plasma membrane (B cell Receptor = BCR)
produce specific antibodies when activated
antibodies
proteins produced in response to antigen that can bind to antigen
5 classes
IgG
most common
longest lasting
key for memory
IgM
first produced
5 Y-shaped structures can bind to 10 epitopes
marker of early infection
IgA
body secretions
IgE
response to parasitic infection and allergies
IgD
function not known
action of antibodies
agglutination
opsonization
complement fixation
neutralization of toxins and adhesins (eosinophils, round worms)
oxidation
antibody-dependent cellular cytotoxicity (ADCC)
T cells
mature in thymus
thymus is where auto-immune lymphocytes are destroyed
have TCR on surface, recognize antigen on MHC I or MHC II
T cell process
APC engulfs antigen, presents epitope on surface with MHC II, secretes Il-12
helper cells become Th1, secrete Il-2 and gamma interferon
activates cytotoxic cells, proliferate, memory cells produced
cytotoxic cells bind to infected host cells with antigen + MHC I, secrete perforin and granzyme to induce apoptosis
types of acquired immunity
active (natural, artificial): long-lived, memory, slow-acting
passive (natural, artificial): short-lived, no memory, fast-acting
active immunity
natural: antigen in nature
artificial: vaccine gives antibody
passive immunity
natural: IgG through placenta, IgA in breast milk
artificial: antivenom, antitoxin
attenuated vaccine
live virus with decreased virulence
don’t produce disease
contact immunity
can cause disease in immunosuppressed
inactivated vaccine
whole/subunit
can’t replicate
need boosters throughout life
toxoid vaccine
tetanus and diphtheria
response against toxins (not antigens)
many childhood doses and boosters every 10 years
