How To Reverse Aging in the Brain

The aging global population is the greatest challenge faced by 21st-century healthcare systems. Even COVID-19 is, in a sense, a disease of aging. The risk of death from the virus roughly doubles for every nine years of life, a pattern that is almost identical to a host of other illnesses. But why are old people vulnerable to so many different things?

It turns out that a major hallmark of the aging process in many mammals is inflammation. By that, I don’t mean intense local response we typically associate with an infected wound, but a low grade, grinding, inflammatory background noise that grows louder the longer we live. This “inflammaging” has been shown to contribute to the development of atherosclerosis (the buildup of fat in arteries), diabetes, high blood pressure , frailty, cancer and cognitive decline.

Now a new study published in Nature reveals that microglia — a type of white blood cells found in the brain — are extremely vulnerable to changes in the levels of a major inflammatory molecule called prostaglandin E2 (PGE2). The team found that exposure to this molecule badly affected the ability of microglia and related cells to generate energy and carry out normal cellular processes.

Fortunately, the researchers found that these effects occurred only because of PGE2’s interaction with one specific receptor on the microglia. By disrupting it, they were able to normalize cellular energy production and reduce brain inflammation. The result was improved cognition in aged mice. This offers hope that the cognitive impairment associated with growing older is a transient state we can potentially fix, rather than the inevitable consequence of aging of the brain. Levels of PGE2 increase as mammals age for a variety of reasons — one of which is probably the increasing number of cells in different tissues entering a state termed cellular senescence. This means they become dysfunctional and can cause damage to tissue by releasing PGE2 and other inflammatory molecules.

But the researchers also found that macrophages — another type of white blood cells related to microglia — from people over the age of 65 made significantly more PGE2 than those from young people. Intriguingly, exposing these white blood cells to PGE2 suppressed the ability of their mitochondria — the nearest thing a cell has to batteries — to function. This meant that the entire pattern of energy generation and cellular behavior was disrupted.

Although PGE2 exerts its effects on cells through a range of receptors, the team were able to narrow down the effect to interaction with just one type (the “EP2 receptor” on the macrophages). They showed this by treating white blood cells, grown in the lab, with drugs that either turned this receptor on or off. When the receptor was turned on, cells acted as if they had been exposed to PGE2. But when they were treated with the drugs that turned it off, they recovered. That’s all fine, but it was done in a petri dish. What would happen in an intact body?

The researchers took genetically modified animals in which the EP2 receptor had been removed and allowed them to grow old. They then tested their learning and memory by looking at their ability to navigate mazes (something of a cliche for researchers) and their behavior in an “object location test.” This test is a bit like someone secretly entering your house, swapping your ornaments around on the mantelpiece and then sneaking out again. The better the memory, the longer the subject will spend looking suspiciously at the new arrangement, wondering why it has changed.

It turned out that the old genetically modified mice learned and remembered just as well as their young counterparts. These effects could be duplicated in normal old mice by giving them one of the drugs that could turn the EP2 receptor off for one month. So it seems possible that inhibiting the interaction of PGE2 with this particular receptor may represent a new approach to treating late-life cognitive disorders.

Source: https://www.theconversation.com/

How Do Killer Immune Cells Protect Themselves?

White blood cells, which release a toxic potion of proteins to kill cancerous and virus-infected cells, are protected from any harm by the physical properties of their cell envelopes, find scientists from UCL and the Peter MacCallum Cancer Centre in Melbourne. Until now, it has been a mystery to scientists how these white blood cells – called cytotoxic lymphocytesavoid being killed by their own actions and the discovery could help explain why some tumours are more resistant than others to recently developed cancer immunotherapies.

The research, published in Nature Communications, highlights the role of the physical properties of the white blood cell envelope, namely the molecular order and electric charge, in providing such protection.

Cytotoxic lymphocytes, or white blood cells, rid the body of disease by punching holes in rogue cells and by injecting poisonous enzymes inside. Remarkably, they can do this many times in a row, without harming themselves. We now know what effectively prevents these white blood cells from committing suicide every time they kill one of their targets,” according to Professor Bart Hoogenboom (London Centre for Nanotechnology, UCL Physics & Astronomy and UCL Structural & Molecular Biology), co-author of the study.

The scientists made the discovery by studying perforin, which is the protein responsible for the hole-punching. They found that perforin’s attachment to the cell surface strongly depends on the order and packing of the molecules – so-called lipids – in the membrane that surrounds and protects the white blood cells.

Source: https://www.ucl.ac.uk/

How Gene-edited White Blood Cells Are Helping Fight Cancer

For the first time in the United States, a gene editing tool has been used to treat advanced cancer in three patients and showed promising early results in a pilot phase 1 clinical trial. So far the treatment appears safe, and more results are expected soon. To develop a safer and more effective treatment for cancer patients, scientists from the University of Pennsylvania, the Parker Institute for Cancer Immunotherapy in San Francisco and Tmunity Therapeutics, a biotech company in Philadelphia, developed an advanced version of immunotherapy. In this treatment, a patient’s own immune cells are removed from the body, trained to recognize specific cancer cells and then finally injected back into the patient where they multiply and destroy them.

Unlike chemotherapy or radiation therapy, which directly kills cancer cells, immunotherapy activates the body’s own immune system to do the work. This team used a gene editing tool called CRISPR to alter immune cells, turning them into trained soldiers to locate and kill cancer cells. By using this technique, the team hoped to develop a more effective form of immunotherapy with minimal side effects.

Better CRISPR-based gene editors for the diagnosis and treatment of cancer and other disorders, . combining chemistry, biology and nanotechnology, are used to engineer, control and deliver gene editing tools more efficiently and precisely.

The first step in making these tumor-killing cells used in the cancer drug trial was to isolate the T-cells – a type of white blood cells that fights pathogens and cancer cells – from the blood of the cancer patients. Two patients with advanced multiple myeloma and one patient with myxoid/round cell liposarcomav were enrolled for this study.

To arm the T-cells and bolster their tumor-fighting skills without harming normal cells, scientists genetically engineered the T-cellsdisabling three genes and adding one gene – before returning them to the patients.

The first two of these deleted genes encode T-cell receptors, which are proteins found on the surface of the T-cells that can recognize and bind specific molecules, known as antigens, on cancer cells. When these engineered T-cells bind to these antigens, it allows them to attack and directly kill the cancer cells. But the problem is that a single T-cell can recognize multiple different antigens in the body, making them less focused on finding the cancer cells. By eliminating these two genes, the T-cells are less likely to attack the wrong target or the host, a phenomenon called autoimmunity, In addition, they disrupted a third gene, called programmed cell death protein 1, which slows down the immune response. Disabling the programmed cell death protein 1 gene improves the efficiency of T-cells.

The final step in the transformation of these cells was adding a gene which produces a new T-cell receptor that recognizes and grabs onto a specific marker on the cancer cells called NY-ESO-1. With three genes deleted and one added, the T-cells are now ready to fight cancer.

Source: https://theconversation.com/

Super-powered Immune Cells Kill Cancer

Ground-breaking immune therapy promises to deliver vital evidence in the fight against cancer as researchers from the Centre for Cancer Biology in Australia open a new clinical trial using genetically engineered immune cells to treat solid cancers. The phase 1 clinical trial will test the feasibility and safety of CAR-T cellsgenetically modified white blood cells harvested from a patient’s own blood with the unique ability to directly attack and kill cancers – to treat advanced solid tumours including small cell lung cancer, sarcomas and triple negative breast cancer.

The new clinical trial will allow researchers to learn more about how CAR-T cells interact with solid tumours in the hope that this form of immune-based therapy may one day treat a wide range of different cancers. Led by the Centre for Cancer Biology – an alliance between University of South Australia (UniSA), the Central Adelaide Local Health Network (CALHN) and the Royal Adelaide Hospital, the trial is funded by Cancer Council’s Beat Cancer Project and sponsored by CALHN.

The research scientist in charge of manufacturing the CAR-T cell product and following the patients’ responses to treatment is UniSA’s Dr Tessa Gargett, a Cancer Council Beat Cancer Project Early Career Fellow from the Centre for Cancer Biology .She says the CAR-T immune therapy shows great potential for developing cancer treatments.

Chimeric antigen receptor (CAR) T cells are a promising new technology in the field of cancer immunotherapy,” Dr Gargett says. “Essentially, CAR-T cells are super-powered immune cells which work by enlisting and strengthening the power of a patient’s immune system to attack tumours. “They’ve had astounding results in treating some forms of chemotherapy-resistant blood cancers, but similar breakthroughs are yet to be achieved for solid cancers – that’s where this study comes in.”

Source: https://www.unisa.edu.au/