Transcript Virus / Immunology Notes

Viruses /
Immunology
“virus” means poison
Variable
Irritating
Repugnant
Ulcerating
Scum bags
Parasites
Totally dependent
on host
It’s alive!
or is it?
Cells?
Reproduce?
Genetic code?
Grow and develop?
Respond?
Use energy?
Change over time?
It’s alive!
or is it?
Cells?
Reproduce?
Genetic code?
Grow and develop?
Respond?
Use energy?
Change over time?
No
It’s alive!
or is it?
Cells?
Reproduce?
Genetic code?
Grow and develop?
Respond?
Use energy?
Change over time?
No
Yes using host
It’s alive!
or is it?
Cells?
Reproduce?
Genetic code?
Grow and develop?
Respond?
Use energy?
Change over time?
No
Yes using host
Yes
It’s alive!
or is it?
Cells?
Reproduce?
Genetic code?
Grow and develop?
Respond?
Use energy?
Change over time?
No
Yes using host
Yes
No
It’s alive!
or is it?
Cells?
Reproduce?
Genetic code?
Grow and develop?
Respond?
Use energy?
Change over time?
No
Yes using host
Yes
No
Kind of
It’s alive!
or is it?
Cells?
Reproduce?
Genetic code?
Grow and develop?
Respond?
Use energy?
Change over time?
No
Yes using host
Yes
No
Kind of
No
It’s alive!
or is it?
Cells?
Reproduce?
Genetic code?
Grow and develop?
Respond?
Use energy?
Change over time?
No
Yes using host
Yes
No
Kind of
No
Yes
STRUCTURE
CORE =
nucleic acid
CAPSID =
Shell of protein
How small are they?
Too small for light microscope
20 - 400 nm
1015 would fit into a drop of water.
CLASSIFICATION
By nucleic acid Virus
DNA
Retrovirus
RNA
By nucleic acid Virus
DNA
Retrovirus
Warts
Polio
Herpes
Common cold
Chickenpox
Influenza
Mono
Measles
Smallpox
HIV (AIDS)
Shingles
Rabies
RNA
Shape of Capsid Sphere
Rod
Polyhedran
Host they infect Examples:
Influenza - humans
Rabies -warm blooded vertebrates
HOW VIRUSES WORK
THE
HOSTILE
TAKE
OVER !!
Life Cycle
wow
SOME ONLY
TAKE
25-45
MINUTES -
Surface attachment
protein lock and key system
Insertion of Nucleic acid
DNA - directly into cell’s DNA
RNA DNA copy
is made then
inserted.
Reproduction
Production and assembly of
viral particles by the host cell.
Lysis
cell bursts and releases many virus
particles
The cycle
starts over
Types of life cycles
1. Lytic
non stop action once
inside the cell
Ex. Common cold & influenza
Types of life cycles
2. Lysogenic
after insertion waits until
triggered into action.
Ex. HIV (AIDS) & Warts &
Herpes
Immune system
Your
defense
system
Nonspecific defenses
st
1
Skin
Flexible barrier
Oil and sweat
create an acidic
environment +
contain lysozyme
line
st
1
Nose hairs - trap
particles.
Mucus - trap
particles, some
enzymes.
Cilia - remove
particles from throat
line
st
1
Cough / sneeze expels antigens and
waste.
line
st
1
Stomach
acid
line
nd
2
line
Inflammatory response
White blood cells
(phagocytes)
attack invaders
(ex. Macrophage & Natural Killer cells)
battle debris = pus
Natural Killer Cells
Nonspecific T-cells that patrol
the body and fight infection
directly
* are responsible for tissue rejection
* they kill virus / bacteria & your cells that are
infected
can!!!!
lead to…….
Sore….this
throat
Pus
Macrophage
Wbc - clean up
debris
Interleukins
(Chemicals released by macrophages which
trigger…….)
Body aches - nerves become sensitive.
Chills - tricks body into thinking it is cold
to maintain fever.
Fever - dilates blood vessels to increase
flow- can lead to headache (high temp also
kills bacteria / viruses)
Interferon
Protein produced
to inhibit
viral synthesis.
Lymph system
1) Lymph vessels -
collects and distributes
intercellular fluid which
has escaped from the
blood vessels (back to
the blood)
2) Lymph organs -
house phagocytes &
lymphocytes for bodies
defense - ex. swollen
glands
Lymph system
The Bubonic Plague
The typical sign of the most
common form of human plague
is a swollen and very tender
lymph gland, accompanied by
pain. The swollen gland is
called a "bubo." Bubonic plague
should be suspected when a
person develops a swollen
gland, fever, chills, headache,
and extreme exhaustion, and
has a history of possible
exposure to infected rodents,
rabbits, or fleas. A person
usually becomes ill with bubonic
plague 2 to 6 days after being
infected. If plague patients are not given specific antibiotic therapy, the
disease can progress rapidly to death. About 14% (1 in 7) of all plague
cases in the United States are fatal.
The
Bubonic
Plague
Doctor’s
Mask
In the seventeenth and eighteenth centuries, some doctors wore a beaklike mask which was filled with aromatic items. The masks were designed
to protect them from putrid air, which (according to the miasmatic theory
of disease) was seen as the cause of infection.
Specific Defenses
Attack a particular invader
The substance that
triggers this assault is
called an ANTIGEN
Tools of this
army
Where do our immune
cells originate?
All of our immune cells
originate in the bone
marrow!
From there they make their
way to the lymph system
(ex. Thymus Gland)
Antibodies
Y shaped Proteins
that bind to antigens
Antibodies
A polio virus particle is attacked by
four IgG antibodies.
Helper T cells
Takes the antigen “ID” to B and T cells
(Identifies virus spikes
from macrophages)
Helper T-cell transfer information
Helper T - cells
B-lymphocytes
(B-cells) The “B” is named
for the bone marrow
Make plasma cells
which make antibodies
B- cells
Antigen triggers clones of B-cells
These clones make
plasma cells
to make the antibodies
memory cells
for future invasions.
Killer T-cells
Killer T-cell Mr. T-cell
Killer T-cells
* Made in the Thymus gland
• also get virus “spikes” from
Helper T’s … but do not make
antibodies
• they now hunt down / attack the
specific antigen
Suppressor T-cells:
Turns off the B-cells
when the battle is over.
Numbers
Body can make 100 billion
different types of B and T cells.
Max production of 2000
antibodies per sec.
Types of
immunity
1) Active:
Primary Response
1st time exposed to a disease;
Millions of B-cells are made.
Time to peak deployment; 3-10 days.
Active:
Secondary response
Memory cells (& Helper
T-cells) recognize old invader
& set up antibody production.
Time to peak deployment = 1-2 days
Active:
Vaccination
2) Passive:
Antibodies from a different
organism introduced into body.
Work for a couple of weeks.
Allergies
An overreaction of the
immune system to a
particular antigen.
Mast cells in your body
release histamines Results:
increased blood & fluid
flow causing
runny nose,
sneezing,
watery eyes
Common allergy antigens
dust mites
Beds are a prime habitat (where 1/3 of life
occurs). A typical used mattress may have
anywhere from 100,000 to 10 million mites
inside. (Ten percent of the weight of a two
year old pillow can be composed of dead
mites and their droppings.)
pollen:
mold
animal
dander
• food allergies cause roughly 125 deaths a
year in the U.S., most of which are
blamed on…..
Peanuts
Immune diseases
Arthritis
immune system attacks
joints
Asthma
muscles of bronchial tubes contract
cutting down air supply.
Aids attacks helper T cells