chapter 16-18 micro lecture Flashcards
Active immunity: definition
The person is immune because they have been
exposed to the actual antigen.
Natural active immunity: example
A person had an actual case of measles and
now they cannot get measles again.
Artificial active immunity: example
A person is immune to measles because
they took a vaccine called MMR.
Passive immunity: definition
A person is immune because they have received
a lot of antibodies to fight a certain pathogen.
Natural passive immunity: 2 examples
1) A baby receive IgG antibodies from mother
before they are born.
2) A baby receive IgA antibodies from mother
in breastmilk.
Artificial passive immunity: example
A person receives an RIG shot for rabies.
Immune system: made of
Lymphocytes and antibodies by the millions.
Immune system: specific
Each lymphocyte and each antibody in the
immune system can fit to and fight one pathogen.
Immune system: memory
The immune system produces millions of
memory cells that usually last forever and give
us long-term immunity.
B cells: produced where, mature where
Lymphocytes called B cells are produced
in our bone marrow and they mature in
our bone marrow.
T cells: produced where, mature where
Lymphocytes called T cells are produced in
our bone marrow and they mature in our
thymus gland.
Epitopes: definition
Surface proteins on antigens that can
stimulate the immune system to respond.
Antibody subunit: describe the overall structure
Four polypeptide chains hooked together
by disulfide bonds.
How many different shapes are possible
for the V regions of an antibody subunit?
about 100,000,000
How many different shapes are possible for
the C region of an antibody subunit?
5
Role: IgG antibodies
The only antibodies that can cross the placenta
to a baby’s system; by far the most common
antibodies to fight the infection.
Role: IgA antibodies
Found in body secretions like breastmilk,
saliva, and mucous.
Role: IgM antibodies
The “first response” antibodies;
also the blood typing alloantibodies
Role: IgE antibodies
Attack parasites; very involved in
allergic reactions
Role: IgD antibodies
Help us to make more antibodies.
Discussion question:
the two parts of the immune system
Antibody-mediated:
-involves B cells and T cells
-To fight the current infection, it makes
millions of antibodies.
-To give us long-term immunity, it
millions of memory B cells.
Cell-mediated:
-involves T cells only -To fight the current infection, it makes millions of active cytotoxic T cells -To give us long-term immunity, it makes millions of memory T cells
Allergy: definition
The production of IgE antibodies or
T cells for a substance that is normally harmless.
Anaphylaxis: definition
An actual allergic reaction, with symptoms.
Localized Anaphylaxis: definition
A reaction that results from ingesting or
inhaling something that you are allergic to.
Systemic Anaphylaxis: definition
A reaction that results from something you
are allergic to winding up in your blood.
Localized Anaphylaxis: Pollen–Which
antibodies are involved?
IgE
Localized Anaphylaxis: Pollen–which
cells are involved?
The mast cells in the lining of the nasal cavity.
Localized Anaphylaxis: Pollen–how many
antibodies per mast cell
about 500,000
Localized Anaphylaxis: Pollen–3 effects
of histamine
1) excess mucous production
2) vasodilation
3) itching
Systemic Anaphylaxis: bee sting–which
antibodies are involved?
IgE
Systemic Anaphylaxis: bee sting–which
cells are involved?
Basophils in the blood.
Systemic Anaphylaxis: bee sting–how
many antibodies per basophil?
about 500,000
Systemic Anaphylaxis: bee sting–2 effects
of histamine.
1) make peripheral arteries dilate (anaphylactic shock)
2) make the smooth muscle around the bronchi contract
Discussion question:
Vaccines
Four types:
Toxoid Entire pathogens--messed up Epitopes only Nucleic acid
Vaccines stimulate the production of
antibodies, memory B cells, and
memory T cells. Antibodies tend
to last a few years. Memory B
cells and Memory T cells usually
last the rest of our life.
Vaccine: inactivated pathogen
So messed up it cannot reproduce at all.
Vaccines: inactivated bacterium
dead
Vaccines: inactivated virus
So messed up by a chemical it cannot infect
cells and reproduce at all.
Vaccines: attenuated pathogen
Messed up, but can reproduce slowly.
Vaccines: attenuated bacterium
Messed up by a chemical, alive, can do binary
fission slowly, cannot secrete toxin.
Vaccines: attenuated virus
A mutated virus that can infect cells and reproduce,
but not nearly as much or as fast as usual.
Discussion question:
Virulence factors
Adhesins: surface proteins on bacteria
that can bind to receptors on our cells.
Enzymes: A bacterium called
Staphylococcus aureus releases an
enzyme called coagulase, which causes
a protective blood clot to form around the
bacteria.
Proteins: Some bacteria can bind to
a receptor on our cell and inject
proteins into our cell. The proteins
change our cell’s DNA, causing
apoptosis (cell death) to occur
Exotoxins: describe
Exotoxins are liquid waste products made by some
G+ bacteria and they are made of protein.
Exotoxins:
Cytotoxins: 2 examples
Corynebacterium diphtheriae gives off a cytotoxin that
prevents our cells from making protein.
Streptococcus pyogenes gives off a cytotoxin that
damages blood capillaries (scarlet fever).
Exotoxins:
Neurotoxins: 2 examples
Clostridium botulinum gives off a neurotoxin that
blocks the first nerve impulse to muscle.
Clostridium tetani gives off a neutotoxin that
blocks the second nerve impulse to muscle.
Exotoxins:
Enterotoxins: 2 examples
Vibrio cholerae gives off an enterotoxin that causes
a watery and dehydrating diarrhea (cholera).
Clostridium difficile gives off an enterotoxin that
causes a bloody diarrhea with a very foul
odor (colitis).
Endotoxins: describe
Endotoxins are a component of the cell wall for
some G- bacteria and they are made of
lipopolysaccharide.
Endotoxins: example
Salmonella typhi has an endotoxin as part
of its cell wall.
Endotoxins: IL-1
The chemical called IL-1 tends to cause fever.
Endotoxins: TNF
The chemical called TNF tends to cause shock.
HIV/AIDS: 1959
1959 was the year the first documented case
of AIDs occurred.
HIV/AIDS: 1981
1981 was the year the term AIDS was created
to describe a new syndrome.
HIV/AIDS: 1983
1983 was the year the cause of AIDS
was discovered and named HIV.
CD4
CD4 is a receptor that is designed to
bind to a macrophage.
gp120
gp120 is a subunit of an HIV epitope that
is a perfect fit for a CD4 receptor.
CXCR4
CXCR4 is a receptor designed to bind to
chemicals called IL-1 and IL-2.
gp41
gp41 is a subunit of an HIV epitope that
is a perfect fit for a CXCR4 receptor.
Reverse transriptase
This is an enzyme that takes
RNA and makes DNA.
AZT, 3TC
AZT and 3TC are medications a patient can take
that both block reverse transcriptase.
Protease
Protease is an enzyme that makes
numerous HIV copies inside the cell.
ABT-538
ABT-538 is a medication a patient can take
that blocks the enzyme protease.
HIV/AIDS criteria
If a patient is HIV positive and their helper T cell
count is less than 200, they are HIV positive and
they have full-blown AIDS.
If a patient is HIV positive and their helper T cell
count is greater than or equal to 200, they are
just HIV positive (not AIDS).
Four body fluids that can transmit HIV
blood, semen, vaginal secretions, breastmilk
4 ways to get HIV in order of prevalence
1) unprotected sexual contact
2) the parenteral route
3) as a fetus or baby
4) by way of breastmilk
