Intravenous Stem Cells: Where Do They Go? What Do They Do?

We usually think of stem cell therapy in terms of replacing damaged cells or tissues with stem cells, which can differentiate and become the type of cell or tissue which is being replaced. But there is more to it than that, particularly in the case of intravenous stem cell infusion.

Researchers have tracked the migration of stem cells administered intravenously following an injury. At first the majority of the cells lodge within the lung, where they appear to interact with pulmonary macrophages altering the type of cell signaling molecules those macrophages release into the blood. Next the stem cells migrate to the organs of the reticuloendothelial system which includes the spleen. Surprisingly, less than 3% of infused stem cells migrate into brain tissue. So the immunomodulatory effect does not require the majority of infused stem cells to interact directly with injured brain tissue. _SciAm

It turns out that much of the beneficial effect from the intravenous infusion of stem cells comes from their effect on the immune system. IV infused stem cells apparently shift the immune system's response to injury and rejuvenation, creating a more favourable environment for healing and regeneration.

This allows the few stems cells which make it all the way to the damaged tissue, to promote regeneration locally without a harmful immune response.

Immunomodulatory stem cell studies attempt to adjust the immune response in a way that minimizes the damage associated with the initial injury, and then allows the individual’s native repair machinery to function optimally.

With even mild injury, the immune system is activated. Macrophages are a type of immune cell which participate in the post-injury immune response. With “classic” macrophage activation, the immune response is aggressively induced. Classically activated macrophages are described as having an “M1” phenotype. In the nervous system, the M1 immune response can increase the severity of an injury. Alternatively activated or “M2” macrophages, are associated with a less destructive pattern of immune system activation. This alternate/M2 response results in less immune mediated post-injury damage, as well as the possible disinhibition of native nervous system repair.

Following traumatic brain injury (TBI) children experience a loss of 12-15% of their brain tissue in the 12 months following their injury (Levin). In a study where we treated TBI children with their own bone marrow stem cells, there was minimal post injury brain volume loss in the year after TBI (Cox). In animal models of TBI, animals that experienced injury were found to have M1 macrophages throughout their injured brain tissue.

Animals treated with stem cells after TBI were found to have M2 macrophages in their brain parenchyma. Interestingly, if an animal’s spleen was removed before stem cell infusion, the benefit of the stem cell treatment was eliminated. Somehow stem cell infusion causes a change in the pattern of macrophage activation from M1 to M2, which results in a less aggressive immune response and less post-injury brain tissue death. This effect requires an intact spleen. _SciAm

So you see that in an optimal response to stem cell infusion following an injury, the patient will experience both immunomodulatory effect and a regenerative effect from the IV stem cell infusion.

When the stem cells being infused are of a broad-spectrum nature -- such as cord blood, embryonic stem cells, or pluripotent adult stem cells -- the door is wide open for other effects beyond the immunomodulatory and the regenerative (replacement) effects. It should be clear that other rejuvenative effects are also possible from broad spectrum stem cell infusion. It will simply require a good deal of research and consideration before most of those effects can be discovered and decoded for optimal therapies in the future.

Inflammation Kills! Blocking the Inflammation After MI, CVA

Blocking Complement
A person may survive a severe heart attack (MI) or stroke (CVA) only to succumb to the effects of devastating inflammation which tends to occur after blood supply is restored to tissue that was damaged from temporary loss of perfusion. An effective treatment for preventing such re-perfusion inflammation could save many hundreds of thousands of lives a year.

The lectin pathway is responsible for the potentially devastating inflammatory tissue response that can occur when any bodily tissue or organ is reconnected to blood supply following ischaemia – a temporary loss of that blood supply and the oxygen that it carries. This excessive inflammatory response is, in part, responsible for the morbidity and mortality associated with myocardial infarction (heart attack) and cerebrovascular accidents (CVAs or strokes). Moreover, the work succeeded in finding a way to neutralise this enzyme by raising a therapeutic antibody against it. A single antibody injection in animals has been shown to be sufficient to disrupt the molecular process that leads to tissue and organ destruction following ischaemic events, resulting in significantly less damage and markedly improved outcomes.

"This is a fascinating new achievement in the search for novel treatments to significantly reduce the tissue damage and impaired organ function that occur following ischaemia in widespread and serious conditions such as heart attacks and strokes," said Professor Schwaeble. "This new potential therapy was also shown in animals to significantly improve outcomes of transplant surgery and may be applicable to any surgical procedure where tissue viability is at risk due to temporary interruption of blood flow. _Eurekalert

Of course Professor Schwaeble is correct. Not only would such a treatment be a potential blockbuster drug for preventing complications from MI and CVA, but it would also be immensely useful for surgical procedures where blood supply is temporarily interrupted, or for treating cases of trauma where blood supply is interrupted by the trauma itself and/or by a lifesaving procedure such as a tourniquet or MAST suit used to prevent fatal exsanguination.

The University of Leicester led an international team whose research has been published today in the Early Online Edition of the Proceedings of the National Academy of Sciences (PNAS).

Professor Wilhelm Schwaeble of the Department of Infection, Immunity and Inflammation at the University of Leicester, initiated and co-ordinated research collaborations with King's College London, the Medical University of Fukushima, Japan and the State University of New York, to achieve the present breakthrough findings, which were published today in PNAS.

Professor Schwaeble and collaborators identified an enzyme, Mannan Binding Lectin-Associated Serine Protease-2 (MASP-2), that is found in blood and is a key component of the lectin pathway of complement activation, a component of the innate immune system. _Eurekalert

Bortezomib Prunes Inflammatory T Cells: Hope for Inflammatory Diseases that Make the Young Old and Make the Old Want to Die

Inflammatory diseases such as arthritis, inflammatory bowel disease, multiple sclerosis, lupus, and many more, can strike at any time. Such diseases can create such suffering and disability that they make young people old very quickly, and can make old people wish they were dead.

A fairly new drug in the proteasome inhibitor class, Bortezomib, is used to treat a cancer of the bone marrow cells, multiple myeloma. But now, scientists have discovered a new use for Bortezomib: killing off active and proliferating T cells that cause so much damage in inflammatory diseases -- while leaving the resting T cells alone.

Those looking for a new treatment for a range of inflammatory diseases like arthritis, multiple sclerosis, inflammatory bowel disease, and lupus may need to look no further than a drug already available for treating cancer. In a research report published in the July 2010 print issue of the Journal of Leukocyte Biology (http://www.jleukbio.org), Japanese scientists use mice to show that bortezomib, currently used to treat cancers that affect white blood cells, induces cell death only in harmful (active and proliferating) T cells, leaving the rest unharmed. If the results prove true in humans, it offers hope that this drugs or others similar to it might be used to treat inflammatory diseases without the side effects of current drugs that affect all T cells equally.

"Unfortunately, there are a lot of people who are suffering from autoimmune and inflammatory disease," said Koichi Yanaba, M.D., Ph.D., a scientist from the Department of Dermatology at Nagasaki University Graduate School of Biomedical Sciences who was involved in the research. "We believe that this new-type remedy for autoimmune and inflammatory disease could successfully treat them in the near future."

To make this discovery, scientists used two groups of mice—the first treated with bortezomib and the second with saline. Researchers induced contact hypersensitivity reaction with oxazolone, a chemical allergen used for immunological experiments and found that bortezomib significantly inhibited the contact hypersensitivity responses. Results strongly suggest that bortezomib treatment enhanced T cell death by inhibiting NF-kappa B activation, which plays a key role in regulating the immune response to infection. This in turn led to the suppression of inflammatory responses in immune cells by reducing interferon-gamma production. _Eurekalert

Inflammation complicates many diseases of old age, including Alzheimer's, heart disease, lung and other respiratory diseases, digestive system diseases, and so on. Finding better and more specific treatments for blocking excessive inflammation while allowing normal immune function to continue, would extend life for many and reduce morbidity for many more.

Neural Stimulators Control Inflammatory Processes

Scientists have known about the connection between the mind-brain and the immune system for many decades. From the "laughter cure" devised by Norman Cousins to mitigate a severe inflammatory disease to the decades old scientific discipline of psychoneuroimmunology, the importance of the connection between the brain and the immune system has been known. A malfunctioning immune system leads to both suffering and an early death, so discovering better ways to dampen an out of control immune response is vital to achieving long and healthy lives.

But finding the best way of controlling immune function by way of the brain has not always been easy. One of the latest attempts at such control comes from a business startup in Boston called Setpoint Medical.

The technology is based on a decade of research elucidating how the brain controls the immune system, particularly inflammation. The treatment has not yet been tested in patients, but based on animal research, scientists hope it will provide an alternative treatment that is more effective and have fewer side effects than existing drugs.

...Over the last decade, Kevin Tracey, an immunologist and neurosurgeon at the Feinstein Institute for Medical Research in Manhasset, NY, has shown that inflammation is controlled in part by the vagus nerve, which carries signals between the brain and a number of visceral organs. Most notably for immune function, it makes direct connections to the spleen, which houses different types of immune cells poised for release at times of infection.

Numerous animal studies have shown that stimulating the vagus nerve can put a brake on the immune system, stopping the rapid recruitment of immune cells to the site of injury or infection. "Think of it as a thermostat for the immune system," says James Broderick, interim president of the company and a partner at Morgenthaler Ventures, Setpoint's key investor. "This reflex puts a damper on the immune system."

The effect is similar to that of a popular class of drugs, called TNF alpha blockers, used to treat arthritis and other autoimmune diseases. These drugs block the release of an immune signaling molecule that is central to inducing inflammation. While they work effectively in 50 to 70 percent of patients, the drugs can lose their effectiveness over time and have been linked to some serious side effects, such as infection and cancer. Vagus nerve stimulation blocks both the signal molecule and other cytokines involved in inflammation. _TechnologyReview

This novel approach to treating autoimmune diseases and hyper-immune responses may be used instead of drug treatment, or along with drug treatment to allow lower doses of drugs.

New Hope for Treating Autoimmune Diseases

Cell
The autoimmune diseases cause untold pain, misery, and hardship -- not to mention expense -- throughout the human lifespan. When the person's immune system attacks other cells in his own body, treatment options are generally limited and sub-optimal. But now, researchers at the University of Alberta, Calgary, have devised a treatment (and prevention) for Type 1 diabetes which may lead to a revolution in the treatment and prevention of autoimmune diseases -- such as multiple sclerosis, rheumatoid arthritis, lupus, and many more.

Researchers from the University of Calgary in Alberta, led by Dr. Pere Santamaria, were looking to halt the autoimmune response that causes type 1 diabetes, but do so without damaging the immune cells that control and regulate the immune system or that protect against infections. So the team focused on developing a highly targeted antigen-specific immunotherapy - one, they explained, that could address the "internal tug-of-war between aggressive T cells that want to cause the disease and weaker T cells that want to stop it from occurring."

The researchers produced a unique vaccine comprising nanoparticles, which are thousands of times smaller than the size of a cell. They coated the particles with type 1 diabetes-relevant peptides, or protein fragments, that were bound to certain molecules that play a critical role in immune cell communication (called MHC molecules).

In the mice, the nanoparticle treatment expanded a type of regulatory T cell -- these cells ultimately suppressed the aggressive immune attack that destroys the insulin-producing beta cells of the pancreas. The researchers noted that the expanded cells shut down the immune attack by preventing autoreactive immune cells from being stimulated, either by the peptide contained in the vaccine or by any other diabetes autoantigen presented simultaneously by antigen-presenting cells. With the immune response that causes diabetes blocked, mice with type 1 diabetes regained normal blood sugars. And those that would have contracted the disease didn't.

The study also provides important - and promising - insight into the ability to translate these findings into therapeutics for people: Nanoparticles that were coated with molecules specific to human type 1 diabetes were able to restore normal blood sugar levels in a humanized mouse model of diabetes (that is, a mouse that has been genetically altered to biologically simulate type 1 diabetes in people). _ jdrf

Article abstract from Cell

H/T Brian Wang

Science is slowly but surely decoding the complex signaling involved in life, disease, and ageing. With the better tools being provided by advanced genetics, nanotechnology, immunology, and information technology, it is easy to feel that there are no secrets of life that will not be unwrapped and decoded sooner or later.

Care for a Brand New Thymus?

Japanese scientists have built an artificial "lymph node" from thymus tissue, and transplanted it into immunodeficient mice.

The researchers, from RIKEN's Research Center for Allergy and Immunology in Yokohama, constructed their mouse aLNs by impregnating a two- to three-millimeter-diameter scaffold of the fibrous structural protein collagen with connective tissue extracted from the thymus of newborn mice and dendritic cells. Earlier work suggests that it is the connective tissue stromal cells which organize the structure of lymph nodes.

The aLNs were initially implanted into mice with a normal, healthy immune system, which had previously been injected with a harmless antigen compound to trigger an immune response. So the aLNs became populated with immune system T-cells and B-cells which specifically recognize and counter germs or cancer cells expressing the injected antigen.

These primed aLNs were then transplanted into two sets of mice--a group with a normal immune system which had never been exposed to the antigen, and a group in which the immune system did not function. When then exposed to the antigen both groups responded immediately by making appropriate protective antibodies--and the response to the antigen lasted for longer than four weeks, which means immune cells which retained 'memory' of the antigen had been generated.

Further investigation of the immunodeficient mice showed that T- and B-cells from the aLNs migrated to their spleens and bone marrows and were there generating large numbers of antigen-specific antibody-forming cells. The results also revealed some of the compounds involved in directing this migration process.

Source
This research has implications for the study of treatments for immune diseases, cancer, aging, and infectious disease such as AIDS. Thymosin is one of the several hormone levels that falls abruptly in the aging human. Growing an artificial thymus to boost thymosin levels appears within reach, if proven to be beneficial.

Also, here is a free collection of articles on Nanotechnology in Cancer.

And, here is more on an improved method for cervical cancer screening.

Better screening and better treatments. The two need to go hand in hand. Add better prevention to the mix and you are getting somewhere.