Download Notes-Blood and Immunity

Blood & Immunity
Biology 11
A. Allen
C.P. Allen High School
Blood…Interesting Facts
• There are about 5.5 million red blood cells per
cubic millimetre of blood in a healthy adult male.
(4.5 million in a female).
• insufficient iron in your diet may cause anemia;
decreased ability of your blood to transport
oxygen.
• The average body (70 kg) contains about 5 L of
Blood.
• Your body mass is about 8% blood.
• All iron in your body amounts to the same mass as
a 2.5 cm iron nail.
Blood…Interesting Facts
• A human needs 24 hours to recover plasma levels
following a blood donation, but it takes three to
four weeks to replenish red blood cells.
• Red Blood Cells carry oxygen in the blood. They
last for about 4 months before they are replaced.
• A red blood cell will travel through about 1100
km of blood vessels in its lifetime.
• The replacement rate of red blood cells is about 5
million cells per minute!
Blood…Interesting Facts
• Years ago, before the days of
modern medicine, it was believed
that cutting a person so they bled
would help them get rid of
sickness. This was called
bloodletting.
• The first U.S. president, George
Washington, died from a throat
infection in 1799 after being
drained of nine pints of blood
within 24 hours.
http://webpub.allegheny.edu/employee/l/lcoates/CoatesPage/FS101/FS101_Images/BloodLetting.jpg
Blood…Interesting Facts
• Oxygenated blood is bright red.
Deoxygenated blood is a darker red. It
looks blue in your veins due to a yellow
pigment in your skin.
Components of Blood
• Blood cells come from stem cells in bone
marrow.
Blood
functions of blood;
• transport of life sustaining nutrients, O2
hormones
• transport of wastes such as CO2 and urea.
• protection from disease.
• Clotting.
• maintaining constant body temperature.
• helps with regulation of fluid levels in body.
Blood Types: Antibodies and Antigens
Why is it important for Doctors to
know your blood type when you
receive blood?
Antibodies and Antigens
• antibody:
immune substances in the blood
and body fluids. They protect you
against foreign bodies.
• antigen:
substances, usually proteins, that
stimulate the formation of
antibodies in the fluids. (can be a
foreign body)
Antibodies and Antigens
Clumping (agglutination) is a
problem…
Antibodies and Antigens
Blood Type Antigen Antibodies
Who can this blood type
receive from safely?
Who can this blood type
safely give to?
A
A
anti-B
A, O
A, AB
B
B
anti-A
B, O
B, AB
AB
AB
None
A, B, AB, O
AB
O
none
anti-A and
anti-B
O
A,B,AB,O (everyone)
1
5
9
13
2 3 4
6 7 8
10 11 12
14 15 16
How Common is Your Blood type?
Alleles
0.2 A
0.1 B
0.7 O
0.2 A
AA
4%
AB
2%
AO
14%
0.1 B
AB
2%
BB
1%
BO
7%
0.7 O
AO
14%
BO
7%
OO
49%
Blood Processing
• Donated blood is usually processed after it
is collected, to make it suitable for specific
uses. Examples include:
• Leukoreduction is the removal of white blood
cells from the blood product by filtration.
Leukoreduced blood is less likely to cause
alloimmunization (development of antibodies
against specific blood types).
Rh Factor
• Rh factor is antigen present on RBC
of 85% of pop. of US.
• Rh positive and Rh negative
• Rh neg pregnant woman may
develop antibodies to the Rh protein
of her Rh-positive fetus.
• hemolytic disease of the newborn
• prevented with RhoGAM (anti-RhD
immune serum)
Erythroblastosis Fetalis
• Toward the end of pregnancy (usually during delivery), fetal blood may leak
through the placenta and mix with the mother’s blood.
• If the mother is Rh- and the baby is Rh+, the mother usually produces antibodies
against the baby’s Rh+ antigens.
• These antibodies do not usually cause a problem during the first pregnancy because
the baby is usually born by the time the mother produces sufficient antibodies.
• In subsequent pregnancies, antibodies may be produced quickly and in large
numbers. These antibodies cross the placenta and cause clumping (agglutination) of
the fetus’ red blood cells (erythrocytes). This condition is called Erythroblastosis
Fetalis, commonly refered to as “blue baby”  caused by decreased O2-rich blood
flow to tissues.
Treatment:
• slowly removing the newborn’s blood and replacing it with Rh- blood. This removes
the mother’s antibodies and provides RBC’s that will not be attacked by the
remaining antibodies.
• Erythroblastosis Fetalis can be prevented if the mother is injected with an
preparation that contains antibodies against Rh+ antigens. It will bind to the fetus’
red blood cells that crossed over to the mother. Therefore the mother will not
produce Rh+ antibodies.
Erythroblastosis Fetalis
Erythroblastosis Fetalis and ABO
Blood Groups
• Incompatible ABO blood types can also cause
erythroblastosis fetalis.
• Rh incompatibility disease and ABO incompatibility
disease diseases have similar symptoms. Rh disease is
much more severe, because anti-Rh antibodies cross
over the placenta more readily than anti-A or anti-B
antibodies. Therefore, a greater percentage of the
baby's blood cells are destroyed by Rh disease.
The IMMUNE System
The IMMUNE System
Lymph: A transparent, slightly yellow fluid that
carries lymphocytes, macrophages and
microorganisms. Lymph is derived from tissue fluids
collected from all parts of the body and is returned to
the blood via lymphatic vessels.
Lymph vessels: A network of vessels that circulate
lymph and branch into all the tissues of the body.
Because of high pressure near the arteriole end of
capillaries, fluid seeps through these tiny blood vessels
and into the tissues. This is tissue fluid. Some of this
tissue fluid enters lymph vessels (closed-ended
vessels). This fluid is now called lymph fluid.
Spleen: An organ that filters the blood, stores blood
cells, and destroys old blood cells. It is located on the
left side of the abdomen near the stomach.
Thymus: An organ that is part of the lymphatic
system, in which T lymphocytes grow and multiply.
The thymus is in the chest behind the breastbone
Lymphatic Vessels
The lymphatic system is a complex system of fluid drainage and transport, and immune
response and disease resistance. Fluid that is forced out of the bloodstream during normal
circulation is filtered through lymph nodes to remove bacteria, abnormal cells and other matter.
This fluid is then transported back into the bloodstream via the lymph vessels. Lymph only
moves in one direction, toward the heart.
B cells make antibodies that
bind to pathogens to enable
their destruction. (B cells not
only make antibodies that
bind to pathogens, but after
an attack, some B cells will
retain the ability to produce
an antibody to serve as a
'memory' system.) B Cells
mature in the bone marrow
Helper T cells co-ordinate the immune
response and are important in the
defence against intracellular bacteria.
Killer T cells are able to kill virusinfected and tumour cells.
(T cells mature in the Thynus gland)
Monocytes are able to
develop into the
professional phagocytosing
macrophage cells after
they migrate from the
bloodstream into the tissue
and undergo differentiation.
Eosinophils
primarily deal
with parasitic
infections and an
increase in them
may indicate
such.
Neutrophils deal with
defence against bacterial
infection and other very
small inflammatory
processes and are usually
first responders to
bacterial infection; their
activity and death in large
numbers forms pus.
Basophils are
chiefly
responsible for
allergic and
antigen response
by releasing the
chemical
histamine causing
inflammation.
Lymphocytes
are much
more common
in the
lymphatic
system
Lymph Nodes
•
•
•
•
•
located in lymph vessels
small round or oval structures (filters)
depositories for cellular debris
bacteria and debris phagocytized.
Can become swollen: may be caused by increased number of lymphocytes
locally as a response to stimulation with a foreign substance (antigen) such as
during an infection.
Animation-lymph nodes
The Immune System
• Your immune system has non-specific and
specific components…
– Non-specific immune responses: does not
distinguish one microbe from another.
– Specific immune responses: DOES distinguish
one microbe from another.
Non-Specific Immune Responses
The First Line of Defense
• The body's first line of defense against pathogens uses
mostly physical and chemical barriers such as…
• Skin secretes acids  kills bacteria
• Tears, saliva, mucous secretions contain lysozyme
(enzyme)destroys cell walls of bacteria.
• Mucus - can trap pathogens, which are then sneezed,
coughed, washed away, or destroyed by chemicals.
• Cilia are tiny hair-like structures that line the respiratory
tract. They move bacteria & viruses caught in mucus up
towards the throat.
• Sweat – has chemicals which can kill different
pathogens.
• Stomach Acid – destroys pathogens
• Earwax-Traps particles and microorganisms
• Digestive Acids-HCl kills most pathogens in stomach
• Urine-slightly acidic. Flushes urinary tract
• Defecation-removes pathogens from digestive tract
Non-Specific Immune Responses
The Second Line of Defense
• Second-Line Defenses - If a pathogen is able to get past the body's first
line of defense, and an infection starts, the body can rely on it's second
line of defense. This will result in what is called an inflammatory
response.
Inflammatory response causes…
• Redness - due to capillary dilation resulting in increased blood flow
• Heat - due to capillary dilation resulting in increased blood flow
• Swelling – due to passage of plasma from the blood stream into the
damaged tissue
• Pain – due mainly to tissue destruction and, to a lesser extent, swelling.
Animation:non-specific inflammatory response
cellsalive.com/ouch1.htm
Non-Specific Immune Responses
The Second Line of Defense
Share with a Partner!
• Summarize Inflammatory response using
the following terms/phrases….
•
•
•
•
•
•
•
•
Leak
Damaged cells
Complement proteins
plasma
histamine
Blood vessels
Dilation
Phagocytes
Specific Immune Response The
Third Line of Defense
• Recognizes and targets “specific” pathogens or
foreign substances.
• Has a “memory,” the capacity to store information
from past exposures to respond more quickly to
future invasions of the same pathogen.
• Protects the entire body, the immunity is NOT linked
to the site of infection.
• Specific immunity arises when barriers (first line of
defense) and inflammation (second line) do not
control the infection.
Specific Immune Response The Third Line of Defense
Foreign organisms in the body activates antimicrobial plasma proteins (complement proteins).
Marker proteins from invading microbes activate the complement proteins, which, in turn,
serve as messengers. The proteins aggregate to initiate an attack on the cell membranes of
fungal or bacterial cells. There are three groups of complement proteins that have different
functions:
(a) Form a protective coating around the invader coat/seal the invading cell & immobilize it.
(b) Puncture the cell membrane. Water enters the cell through the pore created by the protein,
causing the cell to swell and burst.
(c) A third group of proteins attaches to the invader. The tiny microbes become less soluble and
more susceptible to phagocytosis by leukocytes.
Antigen-Antibody Reactions
• Antigen: (antibody
generator) any substance
that the body regards as
foreign (virus, bacterium,
toxin).
• Antibody: a Y-shaped
disease fighting protein
developed by the body in
response to the presence
of an antigen.
…Antigen-Antibody Reactions
• Antibodies are specific. An antibody produced to
attack an influenza virus will not work against a
measles virus. The attachment of antibodies to
antigens
…Antigen-Antibody Reactions
• Remember: cells have receptor
sites designed to match a
certain hormone or nutrient.
• Toxins also can get into cells
via receptor cites. They may
have a shape similar to a
hormone or nutrient. The cell
‘thinks’ the toxin is a needed
substance and ingests it!
• Antibodies interfere with the
attachment of the toxins to the cell
membranes by binding with the
toxins. Now the toxins cannot
interact with the cells.
…Antigen-Antibody Reactions
• Viruses use receptor cites as entry ports to
inject its hereditary material. The virus then
forces the cell to make more viruses.
…Antigen-Antibody Reactions
• The attachment of antibodies to antigens increases the
size of the complex  wandering macrophages can
find and engulf them more easily.
Specific Immune Response The Third Line of Defense
The human immune system includes tonsils, thymus gland, spleen, lymph
vessels and fluid, lymph nodes, and bone marrow. Blood contains many
different types of cells including white blood cells. Lymphocytes and
macrophages are types of white blood cells.
Lymphocytes: recognize antigens and then destroy pathogens. They are
produced in the bone marrow. If they mature within the bone marrow, they
are called B cells. Some lymphocytes migrate to the thymus gland and then
mature. These lymphocytes are called T cells.
Macrophages: reside in lymph nodes, spleen, tonsils. They eat pathogens
Lymph vessels and Lymph fluid: Because of high pressure near the arteriole
end of capillaries, fluid seeps through these tiny blood vessels and into the
tissues. This is tissue fluid. Some of this tissue fluid enters lymph vessels
(closed-ended vessels). This fluid is now called lymph fluid.
Lymph fluid contains lymphocytes, macrophages and microorganisms. Lymph
nodes contain macrophages which filter microorganisms in the lymph fluid.
Some pathogens are present in the blood and are filtered by the spleen. Others
are inhaled and are trapped by your tonsils.
Specific Immune Response The Third Line of Defense
Animation-Immune response
Major Histocompatibility Complex
• Aka. - MHC
• These proteins act as "signposts" that
display fragmented pieces of an antigen
on the host cell's surface.
• The immune system is able to distinguish
between self and non-self
• Almost all body cells carry molecules that
identify it as ‘self’
Allergies
• An allergy is the result of an over-reactive immune system.
• Substances such as peanut protein, dust, pollen, ragweed etc are mistakenly
recognized by your immune system as something harmful.
• Cells ‘believe’ they are endangered and release bradykinin which
stimulates release of histamine. Histamine is produced by mast cells and
basophils (circulating WBCs)
• Histamine  increased permeability of capillaries  redness.
 proteins and WBCs leave capillary  osmotic pressure changed so less
water is absorbed into capillaries.
• Anaphylactic reaction is a severe allergic reaction.
Asthma
• may be chronic or acute
• involves respiratory system. The
airways (the bronchi and bronchioles)
become inflamed and constrict, and
are lined with large amounts of mucus
• trigged triggered by such things as
exposure to an environmental
stimulant such as an allergen,
environmental tobacco smoke, cold or
warm air, perfume, pet dander, moist
air, exercise or exertion, or emotional
stress.
• In children, the most common triggers are viral illnesses such as those
that cause the common cold.
• Narrowing of airways causes such as wheezing, shortness of breath,
chest tightness, and coughing. The airway constriction responds to
bronchodilators
Autoimmunity
• Autoimmunity is when the body’s immune
system mistakenly attacks cells of the
body. Antibodies are made to attach to the
cells’ membranes.
• It is believed that most people have
renegade T cells and B cells that attack
the body. In most of us, these misguided T
cells and B cells are stopped by
supressor T cells.
Examples of Autoimmunity
• Rheumatoid arthritis
• The arthritis of rheumatoid
arthritis is due to which is
inflammation of the synovial
membrane that covers the joint.
Joints become red, swollen,
tender and warm, and stiffness
prevents their use
Examples of Autoimmunity
• Type I Diabetes
• Insulin-producing cells of the
pancreas are destroyed
• High blood sugar
Examples of Autoimmunity
• Multiple Sclerosis (MS)
• Myelin sheath around nerve axon
deteriorates.
• Symptoms: changes in sensation,
muscle weakness, abnormal muscle
spasms, or difficulty in moving;
difficulties with coordination and
balance; problems in speech or
swallowing, visual problems,
paralysis in advanced stages.
Specific Immune Responses
Definitions:
Antigen: A substance that is foreign to the body which causes the immune system to produce antibodies to fight it.
Antibody: Produced by plasma cells. They bind to the specific antigen that has stimulated the immune system.
Once bound, the antigen can be destroyed by other cells of the immune system.
Close your binder. Explain to a partner the difference between an antigen and an antibody.
B Cells and T Cells
B Cells
• Lymphocytes that mature in Bone marrow
• Involved in antibody formation
• Protect against bacteria/viruses/chemicals in blood or tissue fluid.
• Has antibodies embedded in membrane. Antibodies are Y-shaped proteins. Each B cell has antibodies of a
slightly different shape.
• B cells ‘recognize’ antigens on a pathogen when the shape of its antibodies matches the shape of an antigen on a
pathogen.
• Each ‘branch’ of the Y has the same shaped bonding site. It can therefore bond to two like antigen molecules.
………..cont.
Specific Immune Responses
How B Cells Work…
•
When a pathogen i.e. bacteria (with antigens) enters your body, it may get past your first line of defense and into your
lymph fluid.
•
B cells are in lymph nodes. They have antibodies that link to antigens.
•
B cell enlarges and divides many times to form plasma cells and memory cells (more on memory cells later).
•
The plasma cells produce thousands of antibodies per second! These antibodies are the same as those on the original B
cell that recognized the antigen.
•
The antibodies are released into the bloodstream and lymphatic system and move to the site of invasion.
•
The free antibodies then bind to the matching antigens. One antibody (has two bonding sites) can bond to antigens on
two different bacteria.
•
The bacteria clump. Macrophages then engulf the bacteria via phagocytosis and digest them (lysosomes).
•
This battles happens in lymph nodes. Have you ever noticed your glands being swollen and sore when you are sick?
T Cells
•
•
•
•
There are tens of millions of different T Cells, each designed to identify different antigens. There
are 4 types of T Cells. Three of these types are…
Helper T Cells: initiate the immune response
Suppressor T Cells: terminate the immune response.
Cytotoxic T Cells: lyse (break open) infected cells.
Types of Leukocytes
Approx. % in
humans
Description
Neutrophi
l
65%
Neutrophils deal with defense against bacterial infection and other very small inflammatory
processes and are usually first responders to bacterial infection; their activity and death in large
numbers forms pus.
Eosinophi
l
4%
Eosinophils primarily deal with parasitic infections and an increase in them may indicate such.
Basophil
<1%
Basophils are chiefly responsible for allergic and antigen response by releasing the chemical
histamine causing inflammation.
25%
Lymphocytes are much more common in the lymphatic system. The blood has three types of
lymphocytes:
B cells: B cells make antibodies that bind to pathogens to enable their destruction. (B cells
not only make antibodies that bind to pathogens, but after an attack, some B cells will retain
the ability to produce an antibody to serve as a 'memory' system.)
T cells:
oCD4+ (helper) T cells co-ordinate the immune response and are important in the
defence against intracellular bacteria.
oCD8+ cytotoxic T cells are able to kill virus-infected and tumor cells.
oγδ T cells possess an alternative T cell receptor as opposed to CD4+ and CD8+ αβ T
cells and share characteristics of helper T cells, cytotoxic T cells and natural killer
cells.
Natural killer cells: Natural killer cells are able to kill cells of the body which are displaying a
signal to kill them, as they have been infected by a virus or have become cancerous.
6%
Monocytes share the "vacuum cleaner" (phagocytosis) function of neutrophils, but are much
longer lived as they have an additional role: they present pieces of pathogens to T cells so that
the pathogens may be recognized again and killed, or so that an antibody response may be
mounted.
Type
Lymphoc
yte
Monocyte
Image
Diagr
am
How Helper T Cells work…
•
Growth and division of B Cells depends on binding with helper T Cells….
Role of Cytotoxic T Cells
Autoimmune Disease
• Sometimes, a person’s own immune system can attack their own body cells. Certain
T Cells attack healthy body cells. This is bad.
• This may cause a variety of autoimmune diseases.
• Scientists are not positive why this happens.
Some such diseases can be treated…
• Scientists can produce an antibody that matches these offending T Cells.
• The antibody is then linked to a toxic chemical.
• These antibodies (with toxin) are injected into the body.
The antibody that was made to match the T Cell bonds
with these T cells. The attached toxin kills the T Cell.
Immunity and the Prevention of Diseases
….The IMMUNE System: Immunity and the Prevention of Diseases
Active Immunity
• The first response to a particular antigen can take a few days for your immune
system to produce plasma cells or cytotoxic T Cells. Eventually, your immune
system rids your body of the pathogens and you feel better.
• After the first exposure to a particular antigen, memory cells are produced which
may stay in your body for months, years or for the rest of your life. (you need a
tetanus shot every 10 years).
• Memory cells allow your body to react very quickly if you’re exposed to the
pathogen in the future. The pathogen is destroyed before you feel sick! You are
“immune”. (active immunity) Ex chicken pox, measles.
….The IMMUNE System: Immunity and the Prevention of Diseases
Vaccines
• The principle of active immunity is used in the administering of vaccines.
• A vaccine is a solution prepared from weakened or dead microorganisms, viruses or
toxins.
• Injection of the vaccine tricks the body into forming antibodies, or cytotoxic T
Cells.
• The vaccine may make a person feel a bit ill.
• If a person later is exposed to the real pathogen, a quick response is made by your
immune system to destroy it.
• We have vaccines for polio, measles, mumps tetanus, etc.
• We have no vaccine for the common cold. There are many different kinds of cold
viruses and the viruses that cause the common cold keep mutating, changing their
antigens.
….The IMMUNE System: Immunity and the Prevention of Diseases
Passive Immunity
• Immunity resulting from the transfer of antibodies
or antiserum (a serum that contains antibodies)
produced by another individual.
• It works quickly.
Examples:
• Human infants have passive immunity at birth.
Some antibodies crossed from mother to baby
through the placenta.
• Breastfeeding is good for babies because the
mothers antibodies are passed to the infant along
with the breast milk.
• Influenza is highly contagious and is more common
during the colder months of the year. Contrary to
traditional belief, however, the climate itself is not directly
to blame for the increase in incidence, but rather is
attributable to the greater amount of time spent indoors
in close proximity to other individuals during inclement
weather. The influenza virus is chiefly transmitted
through airborne respiratory secretions released when
an infected individual coughs or sneezes. Incubation
typically is from one to two days from the time of
infection, and most people begin to naturally recover
from symptoms within a week. The vast majority of
influenza-related deaths are caused by complications of
the flu rather than the actual influenza virus.
Immunity Definitions
Term
Definition
Leukocyte
Lymphocyte
Specialized white blood cells that produce antibodies
antibody
A protein that is formed within the blood that inactivates or destroys
antigens
antigen
Substances, usually proteins, that stimulate formation of antibodies
Neutrophil
Neutrophils deal with defense against bacterial infection and other very small inflammatory processes
and are usually first responders to bacterial infection; their activity and death in large numbers
forms pus.
Eosinophil
Eosinophils primarily deal with parasitic infections and an increase in them may indicate such.
Basophil
Basophils are chiefly responsible for allergic and antigen response by releasing the chemical histamine
causing inflammation.
Lymphocyte
Lymphocytes are much more common in the lymphatic system. The blood has three types of
lymphocytes:

B cells: B cells make antibodies that bind to pathogens to enable their destruction. (B cells not
only make antibodies that bind to pathogens, but after an attack, some B cells will retain the
ability to produce an antibody to serve as a 'memory' system.)

T cells:
o CD4+ (helper) T cells co-ordinate the immune response and are important in the defence
against intracellular bacteria.
o CD8+ cytotoxic T cells are able to kill virus-infected and tumor cells.
o γδ T cells possess an alternative T cell receptor as opposed to CD4+ and CD8+ αβ T cells
and share characteristics of helper T cells, cytotoxic T cells and natural killer cells.

Natural killer cells: Natural killer cells are able to kill cells of the body which are displaying a
signal to kill them, as they have been infected by a virus or have become cancerous.
Monocytes share the "vacuum cleaner" (phagocytosis) function of neutrophils, but are much longer
• http://users.rcn.com/jkimball.ma.ultranet/Bi
ologyPages/B/B_and_Tcells.html#B_Cells