HIVHuman Immunodeficiency Virus

Tyler HinklePetia Zamfirova

Anita ZarskaHeather OursSara Webster

White Blood Cells• Provide the body with its

principle line of defense against disease.

• Many types including: NeutrophilsEosinophilsBasophilesMonocytesHelper T cellsCytotoxic T cells Memory T cells Suppressor T cells

Viruses• Cannot reproduce on their own• Reproduce by using the cells of other humans

or animals as hosts• Don't have cell walls or a nucleus and are made

up of genetic information wrapped inside a protective shell

• Can only replicate within the cell• Retroviruses, as is HIV, are RNA viruses that

in order to replicate need to make a DNA copy of their RNA which allows the virus to replicate by incorporating this DNA into the host cell’s genes

Transfer of HIV

• Cannot be transferred through everyday contact as in coughing, shaking hands or insect bites.

• Through direct contact with bodily fluids– Unprotected intercourse heterosexually or

homosexually through vaginal fluids and semen– Shared needles– In saliva in low concentrations

• Can be transmitted through oral sex

– Blood transfusions– Vertical Transmission (Mother to fetus during

pregnancy, labor and delivery, and breast feeding)

What does HIV do?

• Attacks Immune System, specifically, Helper T-cells, making it difficult for the body to fight infection.

• These cells, CD4+ T-cells are crucial to the normal function of the human immune system and without them, all other cells in the immune system are prevented from operating. No reaction against an invader can me made.

• The HIV virus eventually makes Helper T-cells an HIV producing factory.

• The immune system eventually becomes so deteriorated that it is susceptible to all diseases that even a common cold can potentially kill the AIDS infected individual. (Nobody actually dies from HIV or AIDS)

HIV

HIV Virus Anatomy

Image from howstuffworks.com

Process

Fear as Awareness

Education programs use fear as awareness and prevention

PRIMARY FACT – “A person can carry and transmit the HIV virus for many years before any symptoms show themselves. A person can be contagious for a decade or more before any visible signs of disease become apparent”

Symptoms

• Infections• Dry Cough• Rapid Weight Loss• Night Sweats• Fatigue• Diarrhea• Swollen Lymph Glands• Sores• Altered Taste

• Herpes• Difficulty Swallowing• Headaches• Change in Vision• Fatigue• Receding Gums• Fevers• Bruising• Bleeding

FDA Approved Treatments

• Nucleoside Reverse transcriptase inhibitors (NRTIs)

• A nucleoside analog that targets the enzyme reverse transcriptase to inhibit HIV replication.

• AZT (zidovudine)

Protease inhibitors

(Pis)

Compounds that target the protease enzyme to inhibit viral replication.

IDV (Indinavir)

Highly Active Antiretroviral Therapy (HAART) is a combination of three of more medications in a regimen.

FDA Approved Treatments Cont.• Non-nucleoside Reverse

transcriptase inhibitors (NNRTIs)

• Targets structure of reverse transcriptase to inhibit enzyme activity, preventing the virus from reproducing.

• NVP (nevirapine)• Very potent but resistance

develops quickly

Entry (Fusion) Inhibitors

(EIs)

Blocks the viral fusion process and HIV reproduction.

ENF (enfuvirtide)

Shortcomings and Side Effects• Not a cure for HIV• Resistance to drug therapy• Treatment does not prevent the virus from spreading• Not always able to increase CD4+ cell count • Heath issues - Liver problems, diabetes, abnormal fat

distribution (lypodystropy syndrome), high cholesterol, increases bleeding in hemophiliacs, decreased bone density, skin rash, pancreatitis, nerve problems (peripheral neuropathy), hyperlipidemia, and hyperglycemia

Clinical Research

• Coreceptor Inhibitor targets the HIV-1 envelope and inhibits CD4+ receptor binding.

• Activation of viral reservoirs used in combination with HAART to eliminate latent viral reservoirs in cells by stimulating virus expression.

• RNA-based therapeutic approach makes use of short interfering RNAs (siRNAs) which bind to destroy HIV (only synthetic RNA has worked on target cells).

Clinical Research Cont.

• Vaccines stimulate anti-HIV immune response.• Subunit Vaccines – genetically engineered

individual proteins and peptides• DNA Vaccines – DNA containing HIV genes is

injected into the body to produce HIV proteins • Recombinant Vector Vaccines – Harmless levels

of viruses or bacteria are injected into the body to produce proteins from the HIV gene

Testing

• New 20 Minute Test

Positive Negative

• HIV infection global total: 42 million

• Total number of deaths between 1981 and 2003 : 20 million

• More than 6000 become infected with HIV everyday

• 3 million die every year

• Women more vulnerable than men

Global Statistics 2003

U.S. Statistics

• HIV Infections 1.3-1.4 million• AIDS 816,000• Deaths 468,000• HIV & Unaware ~250,000

– May lay dormant for years or decades before symptoms occur

In the US, 1 in 1000 chance of contracting HIV in any sexual encounter

Philadelphia ranked 8th in AIDS cases in U.S.

As of 2001

Statistics Cont.

• Sub-Saharan Africa - 29.4 million • South and Southeast Asia - 6 million • Latin America - 1.5 million • North America - 980,000 • Eastern Europe/Central Asia - 1.2 million

History of HIV/AIDS• 1926-46 - HIV possibly spreads from primates to humans. No one knows

for sure. • 1959 - A man dies in Congo in what many researchers say is the first

proven AIDS death. • 1981 - The Centers for Disease Control and Prevention (CDC) notices

high rate of otherwise rare cancer • 1982 - The term AIDS is used for the first time, and CDC defines it. • 1983/84 - American and French scientists each claim discovery of the

virus that will later be called HIV. • 1985 - The FDA approves the first HIV antibody test for blood supplies. • 1987 - AZT is the first anti-HIV drug approved by the FDA. • 1991 - Basketball star Magic Johnson announces that he is HIV-positive. • 1996 - FDA approves first protease inhibitors. • 1999 - An estimated 650,000 to 900,000 Americans living with

HIV/AIDS. • 2002 - AIDS global death toll reaches nearly 28.1 million

Questions?