Join us on an exciting journey in the search for a cure for HIV. A recent breakthrough has brought new hope. Picture a world without HIV/AIDS. This dream moves closer with the incredible story of a woman from New York, potentially cured of HIV through an extraordinary stem cell transplant. Embark on a journey tracing the origin of HIV to the latest scientific breakthroughs on the path to a complete cure.
The Latest Breakthrough
A Case Study: The recent case of a woman potentially cured of HIV highlights the transformative potential of stem cell therapy. Following a dual stem cell transplant involving umbilical cord blood stem cells with a CCR5 mutation and adult donor stem cells, the patient achieved 100% engraftment of cord blood cells. Notably, the patient ceased antiretroviral therapy after 37 months post-transplant. The patient exhibited no detectable HIV, except for transient trace levels of HIV DNA. This remarkable achievement underscores the feasibility of achieving HIV remission through innovative treatment modalities.
But first, to understand how this stem cell transplant works, let's go back about 40 years into the past and follow the mysterious story of HIV.
Where Did HIV Come From?
The human immunodeficiency viruses, known as HIV-1 and HIV-2, came from similar viruses found in primates called simian immunodeficiency viruses (SIVs). These HIV viruses spread directly from one person to another. HIV-1 was discovered in 1983, while HIV-2 was found in 1986. HIV-1 came from SIVcpz in chimpanzees, and HIV-2 came from SIVsm in sooty mangabey monkeys.
Contrary to popular belief, the virus didn't enter the human population because of a man who had intercourse with a chimpanzee. Transmission to humans likely occurred during primate hunting and preparation for food. Molecular clock evolutionary assumptions suggest HIV-1 ancestor appeared around 1931, HIV-2 around 1940. Initial transmission led to further spread worldwide.
How Does HIV attack the Immune system
The virus initially enters the cell through a membrane chemokine receptor known as CCR5. These receptors, found on T lymphocytes, monocytes, macrophages, and haematologic precursors, serve as entry points for the virus. Upon attachment to CCR5 receptors, HIV fuses with the cell membrane and releases its contents into the host cell's cytoplasm. Reverse transcriptase, converts viral RNA to DNA, allowing for viral replication and integration into the host cell's genome. In later stages, it infects cells via the CXCR4 receptor.
Structure of HIV
| Component | Description |
|---|---|
| Envelope | Comprised of host lipoprotein and viral glycoproteins, surrounds the virus |
| Viral glycoproteins | Surface projecting spikes (gp120) and anchoring transmembrane pedicles (gp41) |
| Outer icosahedral nuclear capsid shell | Structural component, made of p17, provides protection to the core |
| Inner core | Contains ribonucleoproteins, including p24, gives the virus its shape |
| Nucleocapsid core enzymes | Integrase (p32), Protease (p10), Reverse transcriptase (p55/66) |
| Genomic RNA | Two copies housed inside the core |
| Gene | Protein | Function |
|---|---|---|
| gag | p24, p15 | Nucleocapsid core protein |
| gag | p55 | Precursor of core protein |
| gag | p18 | Polyprotein from gag gene |
| env | gp120 | Outer envelope glycoprotein |
| env | gp 41 | Transmembrane envelope glycoprotein |
| env | gp160 | Precursor of envelope glycoproteins |
| pol | p31, p51, p64 | Reverse transcriptase |
History of HIV Treatments
The journey towards effective HIV treatments began in the early 1980s when the first antiretroviral drug, zidovudine, was approved. Despite its initial efficacy, zidovudine (AZT) had limitations, including the development of drug resistance and adverse side effects. Subsequent decades witnessed the development of various drug classes, including nucleoside reverse transcriptase inhibitors (NRTIs), protease inhibitors, and non-nucleoside reverse transcriptase inhibitors (NNRTIs). Combination therapy, particularly highly active antiretroviral therapy (HAART), revolutionized HIV treatment, significantly prolonging the lives of individuals living with the virus.These treatments were able to cure AIDS, but not HIV.
HIV Drug Development and Future Prospects
Over the past 30 years, NIAID played a vital role in HIV/AIDS therapy development. Approval of zidovudine and integrase inhibitors were major milestones. NIAID research advanced HIV treatment. Efforts aim to find new drug targets and optimize treatments. Also, tackling drug resistance and toxicity is crucial. Today, over 30 antiretroviral drugs are available. Many people manage HIV with one daily pill. But with this new definitive treatment, they will no longer have to keep taking pills as it will make them completely immune to HIV.
Implications for Research and Treatment
The recent case of a woman cured of HIV through stem cell transplant signifies a significant leap forward. Challenges remain, including the need for broader accessibility and scalability of stem cell therapy. This breakthrough boosts efforts to fight HIV/AIDS. Researchers push boundaries and explore new approaches. Hope for an HIV/AIDS-free future grows. Science, tech, and global teamwork offer promising prospects. The goal: an HIV-free world.
While it is clear that HIV is approaching its end, it is still important to continue safe sex practices. Because HIV is only one of the less scary consequences of unprotected sex. There are diseases like herpes, gonorrhoea, and syphilis still out there which can make your life a living hell. So make sure to wear your rubbers and stay safe!
