Download Viruses, HIV, and Aids

Viruses, HIV, and
Aids
By: Jose Bartolome
Brandon Bonilla
The Immune System
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Lymphocyte receptors provide pathogenspecific recognition for immunity
A network of receptor cells, tissues, and
organs that work together to protect the
body from infection.
Prevents and limits their entry and growth
to maintain optimal health.
This means that the body is able to tell if
an invader (virus, bacteria, etc.) has
entered it.
Body recognizes the invader and uses a
number of different tactics to destroy it.
How the Immune System Works
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First, the body recognizes a foreign pathogen and
delivers it to the lymph system, where it is
ingested by a macrophage.
The virus is processed by macrophage and displays
antigens, which signals a helper T-cell.
The T-cell reads the signal and alarms for all the
other parts of the immune system to respond.
The B-cell responds, and comes to read the
antigen.
It becomes activated and produces millions of
antibodies that are specific to the antigen.
Important because the invading virus can
outnumber the immune system cells.
More How the Immune System Works
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These antibodies then send a signal to
other macrophages and other immune
cells to come and engulf and destroy
the antibody.
The suppressor T-cells are then
released once the number of invaders
have dropped and the infection has
resolved.
This is important as prolonged
activation of your immune response
could eventually lead to damage to
your healthy cells.
The Immune Response
Fighting Infection of Body Cells/Fluids
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The humoral immune response activates and selects effector B cells,
which secrete antibodies that circulate the blood and lymph.
The cell-mediated immune response activates and selects cytotoxic T
cells, which search and destroy target cells.
Helper T cells enhance humoral and cell-mediated responses.
Dendritic cells, macrophages, and B-cells are the main antigenpresenting cells that interact with T-cells.
B-cells create thousands of plasma cells which each secrete antibodies.
Antibodies in Immunity
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Neutralization: antibodies bind to the surface proteins of a virus or
bacterium and block the pathogen from infecting the host cell.
Opsonization: the antibodies bound to antigens increase and facilitate
phagocytosis. Phagocytosis enable macrophages and dendritic cells to
present antigens to and stimulate helper T-cells.
Binding of antigen-antibody complexes
on a microbe or foreign cell to one of
the compliment proteins triggers a cascade
where each compliment system activates
the next.
The proteins generate a membrane attack
complex that forms a pore in the membrane.
Introduction to Viruses
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Viruses depend on host cells to reproduce.
Capsid encloses viral DNA or RNA.
Viruses are not classifiable as alive or dead.
They seem to be in limbo between each
state.
Persistent viruses can enter and exit host
cells without killing them
Unlike bacteria, viruses are usually neither
beneficial or essential to humans
Similar viruses can combine information if
they infect the same cell.
Virus Replication
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Viral replication results in genetic variation
which can be induced into the host
Viruses attach to a host resulting in adsorption
occurring with specific receptors such as
glycoproteins.
Hormones and toxins are then driven into the
cell.
The viral properties uncoat themselves in the
cell.
Virulent viruses, both DNA and RNA, shut off
cellular protein synthesis and separate cellular
polyribosomes, causing a shift to viral synthesis.
Viral replication allows rapid evolution.
Lytic Cycle
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A phage reproductive cycle ending with the death of the host is the lytic
cycle.
The phage uses its tail fibers to bind to the receptor sites of the host.
The tail injects DNA/RNA into the host. The cell’s DNA is hydrolyzed.
The phage directs DNA production of phage
proteins and copies of the phage genome by
host enzymes.
Three sets of proteins assemble to form phage
heads, tails, and tail fibers. The phage genome
is placed in the capsid.
The phage damages the cell wall allowing fluid
to enter bursting the cell.
Lysogenic Cycle
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Once inside the host cell, some viruses, such as HIV, do not reproduce
right away. They mix their genetic instructions with the host.
The viral instructions get copied into the offspring of the host cell.
An environmental or predetermined genetic signal causes the viral
genetic instructions to take over the host and make
new viruses.
The host is not destroyed after the cycle.
Viruses can “sleep” inside a host for years before
reproducing.
An example would be, a person living with HIV can
live without showing signs of AIDS, but they can still
spread the virus to others.
DNA/RNA Viruses
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DNA viruses are mainly double-stranded whereas RNA are single-stranded.
RNA viruses lack replication error checking mechanisms, and thus have
higher rates of diffusion.
DNA replication takes place in the nucleus, RNA
takes place in the cytoplasm.
DNA viruses are stable while RNA viruses are
unstable.
In DNA viruses viral genetic codes are injected in
the host DNA for duplication and decoding. RNA
viruses skip DNA for duplication and decoding.
Virus Life Cycle
https://www.youtube.com/watch?v=uFXuxGuT7H8
HIV
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HIV stands for human immunodeficiency virus.
HIV breaks down the immune system.
HIV causes people to become sick from
infections that normally do not affect them.
HIV causes Aids.
HIV Symptoms
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Flu-like symptoms that last around a week
Yeast infections in the tongue
Genital yeast infection
Pelvic inflammatory disease
Swollen glands
Sore throat
Shingles
Rashes
Fatigue
Muscle and joint aches
How HIV Works
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HIV disrupts this process by infecting the
helper T-cells.
Some HIV is dealt with the immune system,
but some manages to survive.
Infected helper T-cells are activated to
create new viruses and infect important
cells.
Other helper T-cells are destroyed in the
HIV replication process.
HIV Animation
https://www.youtube.com/watch?v=8Csh94TGySQ
How HIV Leads to AIDS
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HIV destroys CD4 positive (CD4+) T cells,
which are white blood cells crucial to
maintaining the function of the human
immune system.
HIV attacks the cells and leaves the
immune system unable to fight off
infection and disease.
Ultimately resulting in the development of
AIDS.
AIDS
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Acquired Immunodeficiency Syndrome
People do not get AIDS, they get HIV which can develop into AIDS.
You can get infected by anyone who has HIV even if they do not look
sick.
HIV becomes AIDS if the immune system is severely damaged.
If a person has less than 200 CD4 cells or if their CD4 percentage is less
than 14%, they have AIDS.
In the mid-1990s, AIDS was a leading cause of death.
Aids Symptoms
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A fever that won’t go away
Sweating while asleep
Constantly feeling tired (not from lack of sleep or stress)
Feeling sick all the time
Losing weight
Swollen glands
Oral thrush
Diarrhea
Treatment For HIV/AIDS
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HIV antiretroviral drug treatment is the main treatment for the disease.
It is not a cure but it can stop people from getting sick for many years.
The treatment consists of drugs that have to be taken every day for the
rest of a person’s life.
Antiretroviral treatment keeps HIV at a low level not allowing the virus
to damage the immune system any further.
Often referred to as: antiretrovirals, ARVs,
anti-HIV or anti-AIDS drugs.
Combination therapy is using two or more
antiretroviral drugs at once.
Current Research
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Evolution has endowed humans with
resistance to most viruses.
Discovering how they were
extinguished and why HIV has gained
resistance to our genomic defenses.
Scientists identified tetherin, a
protein on the surface of human
cells that prevents mutant strains of
HIV from spreading.
Magic Johnson Influence
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Before Magic got the HIV virus the disease was commonly referred to as
the gay disease.
At the time the majority infected were homosexual or addicted to drugs.
Magic Johnson became the well-loved face of HIV and made people
rethink about the disease.
He was also one of the first to initiate
the search for a cure.
Magic is a huge philanthropist and
represents a symbol of hope for people
infected with the virus because he has
been able to live through it.
Works Cited
www.lakersuniverse.com
http://www.ucmp.berkeley.edu/alllife/virus.htm
http://www.bestmedicaldegrees.com/dormant/l
http://www.medicinenet.com/script/main/art.asp?articlekey=42678&page=2#symptoms
www.nbcbayarea.com
https://www.aids.gov/hiv-aids-basics/just-diagnosed-with-hiv-aids/hiv-in-your-body/immune-system-101/
www.hepatit.com
http://www.plannedparenthood.org/health-info/stds-hiv-safer-sex/hiv-aids
aidsinfo.nih.gov
http://www.aids.org/topics/aids-factsheets/aids-background-information/what-is-aids/
www.differencesbetween.net
http://science.howstuffworks.com/life/cellular-microscopic/virus-human4.htm
http://www.adarc.org/current_research_400.html
http://www.tcells.org/beginners/tcells/
gopixpic.com
proteopedia.org