FINAL EXAM REVIEW (units 3 and 4)

primary pathogen

micro-orgs that cause a disease in healthy people in anybody at any time

opportunistic pathogen

micro-orgs that can only cause a disease when someone is immunocompromised (normal/healthy people can’t get sick from an opportunistic pathogen)

how do micro-orgs avoid antibodies?

• IgA Protease - destroys our IgA’s

• Antigenetic Variation - changes the 3D shape of proteins → antibodies no longer good

• Mimic Host Cell - produces 2 acids (sialic and hyaluronic acid) to confuse us

how does bacteria get around phagocytosis?

• Ca peptidase destroys C5a (a chemotaxic agent that tells your cells where to go)

• pathogen can release cytolytic toxins (pokes holes in macrophage and falls apart)

• pathogens with capsules inactivate C3b

• pathogens have the ability to bind to antibodies backwards

some pathogens (very few) have the ability to survive in the phagocyte

what are the 3 main types of exotoxins?

• AB toxins

• membrane damaging toxins

• superantigens

what are AB toxins?

consists of two components, A and B

• “A” part that codes for an enzyme that makes you sick

• “B” part that binds to your cells

what are membrane damaging toxins?

releases a protein called phospholipase that destroys the phospholipid membrane and causes the cells to fall apart

what are superantigens?

they turn on too many T cells. 1/5 cells instead of 10,000 T cells. this overloads the system, goes into shock and kills you

endotoxins

only part of gram- bacteria

• involved in only the LIPID portion of the polysaccharide (LPS)

what do reservoirs refer to in epidemiology?

it refers to where the pathogen lives

• can live in rodents, pets, humans, wild animals, dirt, trees, etc.

what are the different types of reservoirs?

• wild animals - difficult to control but not impossible → exterminators

• humans - problem with someone who is asymptomatic

• environment - resides in dust, pollen, air, etc.

endemic

a disease that is always present in the population

epidemic

an unusual large # of cases

pandemic

epidemic that spreads worldwide

what is lockjaw/tetanus caused by?

caused by clostridium tetani which is a bacteria that resides in dust and dirt (relation with environment reservoirs)

what are nosocomial infections?

they are hospital acquired infections and people who get it are immunocompromised

what are neutrophils

most abundant, act as phagocytes to remove bacteria and damaged cells

what are basophils

involved in allergic reactions and inflammation

what are eosinophils

involved in removing parasitic worms and also helps basophils

what are macrophages

acts as phagocytes like the neutrophils

dendrites

uses toll like receptors that goes around and decides what’s dangerous or not

what do B cells do?

makes the antibodies

what are cytokines?

it’s how our immune cells communicate with one another

• small proteins that occur in low concentrations

• produced by immune cells and released into the blood

• short lived and bind to receptors on surface of cells

what are the different types of cytokines?

• chemokines

• colony-stimulating factors

• interferons

• interleukins

• tumor necrosis factors

• pyrogens

what are chemokines?

involved in chemotaxis (tells our cells where to go when there’s an infection)

what are colony-stimulating factors?

tells our cells to go into mitosis and start producing more copies

what are interferons?

primarily involved in the inflammation response and control of viral infections

• controls viral infections by shutting down transcription and translation of viral products

what are interluekins?

aide in inflammation and adaptive immunity

tumor necrosis factors

involved in apoptosis (programmed cell death), inflammation, and destruction of tumor cells

pyrogens

causes fevers

what are the types of toll like receptors?

• detects LPS

• detects bacterial flagella

• detects peptidoglycan

• detects DNA sequence in bacteria

all these tell us if we’ve been invaded by a foreign pathogen/organism

what are the 2 types of phagocytes?

microphages and neutrophils

difference for macrophages

• lives in the tissue

• very long half life

• not very strong

difference for neutrophils

• always in blood, only in tissue when called on

• very short half life

• very powerful

how do interferons work?

a cell turns on the production of interferons when it detects DS RNA

what is the structure of antibodies?

• 4 separate subunits

  • 2 small, light subunits

  • 2 long, heavy subunits

• tips of the Y are the variable regions (what binds to the epitope)

• the stem is the constant region (binds to the macrophages to hold in place)

all these are held together by disulfide bonds

what are the different families/classes of antibodies?

• IgG

• IgM

• IgA

• IgE

• IgD

IgG

• longest lived antibody

• very important in the secondary immune response

IgM

• important in the primary immune response and blood infections

• exists as a pentamer, the largest one

IgA

• protects the intestinal tract

• exists as a dimer

IgE

• involved in the elimination of allergic reactions and parasites

IgD

• involved in the activation of B cells

what cell produces antibodies?

only B CELLS produce antibodies but can be helped by T cells

what do B cells eventually turn into?

memory cells or plasma cells

what’s the difference between memory and plasma cells?

memory cells protect us in the future so we don’t get sick

plasma cells make the antibody and release it in the environment

T helper cells (colony-stimulating factor)

once recognizing an antigen-MHC, T helper cells:

• release cytokines, leading to proliferation of B cells and formation of memory cells

• also turns on macrophages to produce more lysozymes and more nitric oxide to kill the pathogen

T cytotoxic cells (in charge of destroying cells)

• kills cells that have become infected

• kills cancer cells

• alerts neighboring cells of danger and activates the process of apoptosis

• produces perforins (punches holes in the membrane of bad cells)

• produces proteases that destroy all proteins

• macrophages engulfs/digests verything

active immunity

YOU make the antibodies on your own

Natural:

• you get sick and recover

Artificial:

• getting injected with vaccines

passive immunity

your body can’t wait to make the antibodies so it’s given right away

Natural:

• a baby getting IgG in the mother’s womb

• a baby getting IgA from mother’s milk

Artificial:

• injecting a person with a solution containing a larger amount of antibodies

is this active or passive artificial?

• going into the doctor once every 10 years to get a tetanus shot

active artificial

is this active or passive artificial?

• stepping on a nail and going to the doctor to get a tetanus shot

• getting bit by a wild dog

passive artificial because you need the antibodies right away since they contain immunoglobulins

attenuated vaccine

a weakened form of the pathogen. it works but doesn’t work to the extent it gives you the disease. you make a ton of different antibodies against it and get a very strong immune response

what’s the bad factor of attenuated vaccines?

if it reverts back to wild type, it can give you the disease and kill you

inactivated vaccine

the pathogen is completely destroyed and you’re using a piece of the organism. this vaccine can NOT give you the disease anymore but you have to get booster shots

Jonas Salk vaccine

• inactivated, can never give you polio

• shot in the arm, boosters required

• tested in America

• since 2000, the only vaccine you can get in the US

Albert Sabin vaccine

• attenuated, can still give you polio

• sugar cube/syrup you swallow

• tested in Russia

• available in countries around the world

what does albuterol do?

albuterol is a broncho dilating drug. opens up the bronchial tubes to breathe and taken if you have asthma

what does adrenaline do?

it raises/increases your heart rate and ups your BP. taken for systemic anaphylaxis like bee stains or peanut allergies

what does cyclosporin do?

it slows down/halts the production of T cells. used if you are a transplant patient because you don’t want your body rejecting new organs

what’s the safer therapeutic index?

high TI is the safest TI

how does penicillin work?

it works by preventing the cross linking in the cell wall and only works as the cell wall is being made

how does lysozyme work?

it works by preventing NAM from binding to NAG

pleconaril

prevents the unpackaging of the protein coat and releasing the nucleic acid material

AZT

fake A, C, G, and T (fake bases). these fake bases are used to make the DNA but it’s a problem with base pairing and mutations can occur

protease inhibitors

prevents protease from working. works by preventing the cleavage of proteins from a single amino acid chain

staphylococcus aureus

hair follicle infections, normally harmless unless they spread to heart or brain

• involved in folliculitis, boils, carbuncles

what is folliculitis?

the infection of a hair follicle

what is furuncle?

extension of folliculitis into the surrounding tissue, AKA boils

when several BOILS come together, they form a __, which extends into the organs

carbuncle

what does Borrelia Burgdorferi cause and what’s the vector

causes Lyme Disease and the vector is ticks

what makes Borrelia Burgdorferi unique?

spirochete with a linear genome (unique among prokaryotes because most bacteria have a circular genome)

streptococcus pyrogens

responsible for strep throat and causes serious wound infections

ex: necrotizing fasciitis

which respiratory system infection is more common and more dangerous?

UR infections are more common while LR infections are more dangerous

• URS includes eyes, nose, mouth, inner ear, throat

• LRS includes trachea, bronchial tubes, lungs

what are the proteins of streptococcus pyrogenes?

• C5a peptidase destroys C5a → no more chemotaxic agent

• capsule contains hyaluronic acid → confuses the immune system

• M protein degrades C3b → prevents opsonization

• protein F attaches to host cells → acts as adhesins

• protein G binds to constant region of IgG → binds antibodies backwards and also prevents opsonization

diptheria

a bacterial infection of the URS

• causes sore throat, fever, swelling of neck, coating of throat with white/gray and leads to suffocation (paralysis)

how do you die from Diptheria?

usually because of suffocation but the problem is with the endotoxin that the bacteria releases. it causes heart/kidney failure and paralysis

• the toxin spreads through the bloodstream killing you and prevents translocation

what are the effects of mumps on elderly?

mumps is the swelling of the parotid glands, really fat cheeks

• if males get mumps, it can result in sterility

• if pregnant women get mumps, it can cause a miscarriage

cholera

releases an AB toxin. a part that codes for the enzyme that turns on cyclic A and B production and doesn’t allow it to be turned off

hepatitis B

a DS DNA virus that uses reverse transcriptase (only RNA viruses use it) and takes over 20 years to kill you

• get it by sharing needles, unsafe tattoos, sharing toothbrushes

meningitidis

a gram- bacteria and gotten with inhalation of contaminated air

• mild cold, headache, fever, stiff neck, vomiting. can lead to rapid loss of BP, shock, and death

rabies

an RNA virus that is gotten from being bitten from a wild animal

• fever, headache, nausea, encephalitis, seizures, coma, death, hydrophobia (hurts to swallow)

tetanospasmin

the exotoxin that is released and paralyzes your muscles, eventually killing you

what causes the Plague?

yersinia pestis, a gram- bacteria that is spread by flees, growing on rats and jump off onto humans

P1a

protease that dissolves blood clots and destroys C3b and C5a

F1

gene is expressed only at high temps (37 degrees C) and leads to production of a capsule

Yops proteins

destroys actin filaments in host cells, prevents release of cytokines, and induces apoptosis