B CellsB CellsAdaptive or Specific Immune Adaptive or Specific Immune
ResponseResponse
Lymphatic systemLymphatic system Looks similar to Looks similar to
circulatory systemcirculatory system Primary lymphoid Primary lymphoid
organs: bone marrow organs: bone marrow and thymusand thymus– Lymphocytes develop Lymphocytes develop
and matureand mature– Circulating Circulating
lymphocytes parole for lymphocytes parole for foreign cells or foreign cells or substances “substances “immune immune surveillance”surveillance”
http://a248.e.akamai.net/7/248/430/20020531071023/www.merck.com/pubs/mmanual_home/illus/i167_1.gif
Lymphocytes develop from stem cells in bone marrow
http://www.acm.uiuc.edu/sigbio/project/updated-lymphatic/lymph_cell.gif
Lymph NodesLymph Nodes Secondary Secondary
lymphoid organslymphoid organs– Junctions where Junctions where
circulating circulating lymphocytes lie and lymphocytes lie and wait for pathogenswait for pathogens
Infection causes Infection causes lymphocytes to lymphocytes to multiplymultiply– Lymph nodes swellLymph nodes swell
www.drpaul.com/illnesses/ enlarged.html
Bone MarrowBone Marrow hemopoietic stem cellshemopoietic stem cells
– Form of adult stem cellsForm of adult stem cells– Do not have a specific Do not have a specific
function yetfunction yet– Can develop into any blood Can develop into any blood
cellcell Red blood cells, platelets, Red blood cells, platelets,
T-cells, macrophages, B T-cells, macrophages, B cellscells
Today, we’re learning about B Today, we’re learning about B cellscells– Humorial mediated immunityHumorial mediated immunity
Take care of free antigens Take care of free antigens floating in bloodfloating in blood
www.cancerbacup.org.uk/ info/myelo/myelo-2.htm
B-cells: One type of B-cells: One type of lymphocytelymphocyte
2 main lymphocytes2 main lymphocytes– B cellB cell
Matures in Matures in bonebone marrow marrow– T cellT cell
Primary rolePrimary role: produce : produce antibodies to a specific antibodies to a specific antigenantigen– Each B cell has one Each B cell has one
certain antibodycertain antibody– Each cell covered with Each cell covered with
thousands of these thousands of these identical antibodiesidentical antibodies
Antibodies(Ab)Antibodies(Ab) A family of proteins encoded A family of proteins encoded
by Immunoglobin geneby Immunoglobin gene Constant region puts Constant region puts
Ab(antibodies) in one of five Ab(antibodies) in one of five classes of Abclasses of Ab– 1. IgM1. IgM– 2. IgA2. IgA
Major in intestinal and Major in intestinal and respiratory liningrespiratory lining
– 3. IgD3. IgD– 4. IgG4. IgG
Major response against Major response against bacteriabacteria
– 5. IgE5. IgE Allergic responsesAllergic responses
http://www.biology.arizona.edu/immunology/tutorials/antibody/graphics/antibody.gif
AntibodiesAntibodies Defense against Defense against
antigensantigens Immune system Immune system
related proteins called related proteins called immunoglobinsimmunoglobins
Amino acids vary in Amino acids vary in variable regionvariable region at at antigen binding siteantigen binding site
Many different Many different variable regionsvariable regions
http://www.biology.arizona.edu/immunology/tutorials/antibody/graphics/antibody.gif
B cells recognize an antigenB cells recognize an antigen B cells antibodies B cells antibodies
act as receptors on act as receptors on cell surfacecell surface
Recognize antigenRecognize antigen Signal B cell to Signal B cell to
start dividingstart dividing ProliferationProliferation=divid=divid
e and multiply e and multiply rapidlyrapidly
http://www.griffindesign.com/media/illust/titan/monochromal_antibody.jpg
http://www.medhelp.org/NIHlib/GF-739-b_cell.gif
B cells proliferateB cells proliferate Activated B cells Activated B cells
becomebecome 1. Plasma cells1. Plasma cells
– Live for a few daysLive for a few days– Tiny factories that Tiny factories that
produce thousands of produce thousands of antibodies(Ab)antibodies(Ab)
– Ab now are free to float Ab now are free to float through bodythrough body
2. Memory cells2. Memory cells– Live for a lifetimeLive for a lifetime– Body is ready for next Body is ready for next
time you encounter time you encounter same pathogensame pathogen
http://www.medhelp.org/NIHlib/GF-739-b_cell.gif
AntibodiesAntibodies 1. Neutralize antigen1. Neutralize antigen
– Coats pathogenCoats pathogen– Prevents it from Prevents it from
causing diseasecausing disease– Causes it to clotCauses it to clot
2. Antibody 2. Antibody promotes promotes phagocytosisphagocytosis– Mark them for Mark them for
destructiondestruction
Overview of B cell Overview of B cell ActivationActivation
Macrophage “eating Macrophage “eating vaccuum” eats vaccuum” eats bacteriabacteria
B cell sees antigenB cell sees antigen Becomes Becomes plasma cellplasma cell
to make Abto make Ab– Ab latches onto free Ab latches onto free
bacteriabacteria B cell also becomes B cell also becomes
memory cellmemory cell for next for next time(not shown)time(not shown)
http://www.medimagery.com/physiology/B-cell.jpg
Blood TypingBlood Typing Blood type depends on Blood type depends on
presence or absence of presence or absence of antigens on red blood cellsantigens on red blood cells
Most familiar is A, B and OMost familiar is A, B and O– Blood type A has A antigensBlood type A has A antigens– Blood type B has B antigensBlood type B has B antigens– Type AB has both A and BType AB has both A and B antigensantigens– Type O has neitherType O has neither
http://gslc.genetics.utah.edu/units/basics/blood/images/ABObloodsystem.gif
Rh factorsRh factors Rh factor: another blood Rh factor: another blood
proteinprotein Found when we were Found when we were
studying rhesus monkeysstudying rhesus monkeys Either you have it or you Either you have it or you
don’tdon’t B- means B with no RhB- means B with no Rh AB + means AB with RH AB + means AB with RH
presentpresenthttp://www.abc.net.au/science/news/img/tetra.jpg
Rh SicknessRh Sickness Important for pregnant mothersImportant for pregnant mothers to know Rh factors of babyto know Rh factors of baby Baby may inherit Rh from fatherBaby may inherit Rh from father
Ex. Rh- mom may have Rh+ babyEx. Rh- mom may have Rh+ baby– If fetal blood gets into mother’s bloodstream If fetal blood gets into mother’s bloodstream
during laborduring labor– Mom makes antibodies against Rh proteinMom makes antibodies against Rh protein
Attacks baby blood causing anemia, brain Attacks baby blood causing anemia, brain damage and even deathdamage and even death
– Baby may need blood transfusionBaby may need blood transfusion Treatment: inect RhIg and/or induce Treatment: inect RhIg and/or induce
laborlaborhttp://www.rit.ac.th/homepage-sc/charud/bioweek/pic1/pregnancy.gif
Wrong Blood TypeWrong Blood Type Body will produce antibodies to proteins Body will produce antibodies to proteins
you don’t haveyou don’t have– Antibodies coat foreign blood cellsAntibodies coat foreign blood cells– Cause it to clot togetherCause it to clot together– May block blood vessels and cause May block blood vessels and cause
serious health risksserious health risks Jessica Jessica SantillanSantillan
– @Duke University@Duke University– 17 years old girl17 years old girl– O + blood typeO + blood type– Received type A organs during a Received type A organs during a
transplanttransplanthttp://www.cnn.com/2003/HEALTH/02/22/transplant.error/
http://www.lifesci.utexas.edu/faculty/sjasper/images/john24.13.jpg