Humoral immune reponse

When B cell encounters target antigen what happens?

it provokes humoral immune response

when humoral immune response is activated what happens?

atibodies specific for that particular antigen are then produced

B cells are activated when what happens?

when antigens bind to surface receptors, cross-linking them

What does the B-cell activation cause?

triggers receptor-mediated endocytosis of cross-linked antigen receptor complexes (clonal selection) leading to proliferation and differentiation of B cell into effector cells

What do most clone cells become?

plasma cells

what does plasma secrete

antibody-secreating effector cells

How fast does plasma cells secrete specific antibodies

at a rate of 2000 molecules per second for 4 to 5 days then die

Antibodies circulate in blood or lymph, binding and marking what

free antigens, marking them for destruction by innate or other adaptive mechanisms

B clone cells that do not become plasma cells become what?

memory cells

What do B memory cells provide?

immunological memory

what do B memory cells help with in the future?

mount an immediate response to future exposures to same antigen

What is the primary immune response?

cell proliferation and differentiation upon exposure to antigen for first time

how long is the lag period for primary immune response?

3 to 6 days

when is peak levels of plasma antibody reached?

in 10 days

after 10 days what happens to antibody levels?

they decline

What is the secondary immune response?

re-exposure to same antigen gives faster time, more prolonged more effective

senstized memory cells provide what?

immunological memory

how fast does the secondary immune response take?

hours

During secondary immune response how long until antibody levels peak?

2-3 days at much higher levels

During the secondary immune response what changes about the way antibodies bind?

with greater affinity

After the secondary immune response antibody level can ramin high for how long?

weeks to months

Active humoral immunity occurs when what happens?

when B cells encounter antigens and produce specific antibodies against them

what are the two types of active humoral activity

naturally aquired and artifically aquired

naturally aquired

formed in response to actual bacterial or viral infection

artifically acquired

formed in response to vaccine of dead or attenuated pathogens

what does artifically aquried provide?

antigenic determinats that are immunogenic and reactive

waht does the artifical aquring spare us?

sympotoms of primary response

Passive humoral immunity occurs when what happens?

ready-made antibodies (by-pass making B cells) are introduced to the body

When passive humoral immunity occurs B cells are not what?

challenged by antigens 

What does not occure in passive humoral immunity

immunological memory

When does passive humoral immunity protection end?

when antibodies degrade

What are the two types of passive humoral immunity

naturally acquires and artifically acquired

PH: Naturally acquired:

antibodes delivered to fetus via plecenta or into infant via milk

PH: Artifically acquired:

injection of serum, such as gamma globulin

What are antibodies?

proteins secreted by plasma cells, also called immunoglobulins

what do antibodies make up in the blood?

gamma globulin portion

What are antibodies capable of?

binding specifically with antigen detected B cells 

What are antibodies grouped into?

One of five Ig classes

Antibodies do not destory antigens; instead they?

inactivate them and tag them

When antibodies inactivate or tag antigens what do they form

antigen-antibody complexes

what are the defense mechanisms used by antibodies?

neutralization, agglutination, precitation and complement fixation

Neutralization is what?

simplilest but one of most important defensive mechanisms 

during neutralization what happen?

antibodies block specific sites on viruses or bacterial exotoxins

what does neutralization prevent?

antigens from binding to receptors on tissue cells

During neutralization what do antigen-antibody complexes undergo?

phagocytosis

What happens during agglutination?

antibodies can bind same determinant on two different antigens at the same time

what does agglutination allow for?

for antigen-antibody complexes to become cross-linked into large lattice-like clumps

what is an example of agglutination

clumping of mismatched blood cells

what happens during precipitation?

solube molecules are cross-linked into complexes

what do complexes precipitate out of

solutes

precipitated complexes are what?

easier for phagocytes to engulf 

neutralization, aggutination and precipiation all enhance what?

phagocytosis

complement enhances what?

phagocytosis and inflammation

what does complement lead to

cell lysis

complement is what main antibody defense

against cellular antigens (bacteria, mismatched RBC)

parasitic infections by worms such as ascaris and schistosoma require what?

different immune attack stratigies 

IgE antibodies still play a crucial role in worms destruction by doing what?

binding to surface of worm, marking it for destruction by eosinophils

What do eosinophils bind to that triggers eosinophils to realse their toxic contents onto pray, lysing it from the outside

stems of IgE