Expanding and Activating a Cancer Patient’s Own T-Cells to Treat Their Cancer

A research team from UH Seidman Cancer Center in Cleveland, Ohio have designed a protocol for culturing activated T-cells from melanoma patients in order to expand and use the patient’s own T-cells to fight their cancer. This research, which may lead to treatments that save lives someday, was published in the Journal of Immunotherapy and will hopefully lead to clinical trials.

T-cells are a type of white blood cell in our bodies. These cells are born in the bone marrow, and they play a central role in orchestrating the immune response against foreign entities that enter our bodies. There are several different types of T-cells; some of the help other cells get revved up to fight an infection, others attack and destroy virus-infected cells, some suppress inappropriate immune responses, and others do a host of other interesting, and in some cases, poorly understood things. One function of T-cells is to identify and attack cancer cells. The problem is that T-cells from our own bodies often have trouble identifying cancer cells as truly foreign entities and deserve the T-cells ire.

Patients who suffer from a deadly type of skin cancer known as melanoma have T-cells coursing through their blood vessels that can trigger a protective immune response against the disease, according to a new study out of University Hospitals Case Medical Center Seidman Cancer Center and Case Western Reserve University School of Medicine. This new study demonstrates that T-cells isolated from lymph nodes of patients with melanoma can be expanded in number and activated in a laboratory-based cell culture system. These laboratory-grown T-cells can then be intravenously administered back into these same patients to treat their cancer.

Julian Kim, MD, Chief Medical Officer at UH Seidman Cancer Center, led the research team that did this fascinating study. According to Dr. Kim., he and his colleagues developed a completely novel technique that allowed them to successfully generate large numbers of activated T-cells that could be reintroduced back into the same patient to stimulate their immune system to attack or destroy their cancer.

“This study is unique in that the source of T-cells for therapy is derived from the lymph node, which is the natural site of the immune response against pathogens as well as cancer,” said Dr. Kim who also serves as a Professor of Surgery at Case Western Reserve University School of Medicine and the Charles Hubay Chair at UH Case Medical Center. “These encouraging results provide the rationale to start testing the transfer of activated T-cells in a human clinical trial.”

In the Kim laboratory at the School of Medicine, Kim and his team developed a new method to grow T-cells from cancer patients and then activate them in a two-week cell culture system. The extracted the immune cells from lymph nodes that were exposed to growing melanoma in the patient’s body. Instead of trying to activate these tumor-sensitized T-cells in the body, the lymph nodes were surgically removed in order to activate and grow the T-cells in a tightly regulated environment in the laboratory. This novel approach to cancer treatment, which is termed ‚Äúadoptive immunotherapy,‚ÄĚ is only offered at a few institutions worldwide.

After these T-cells from melanoma patients were expanded and activated by exposing the cells to bits of proteins known to be on the surfaces of the melanomas, they were sicced on melanoma cells in culture.¬† These activated T-cells dutifully and efficiently killed the melanoma cells.¬† Well that’s all fine and good in culture, but could the cells to this in a living organism?¬† Do answer this question, Kim and others transplanted¬†human melanomas into special laboratory mice that could grow human tumor tissue effective and then gave these mice intravenous infusions of the activated T-cells.¬†These tumor-infested¬†mice¬†typically died from these transplanted tumors, but the mice treated with the patient-specific, activated T-cells survived in a¬†concentration-dependent fashion.¬† In order words, the more activated T-cells the mice were given, the longer they lived and the better their bodies were able to fight the transplanted tumors.

The promising findings of this study have led to the recent launch of a new Phase I human clinical trial at UH Seidman Cancer Center in patients with advanced melanoma. “The infusion of activated T-cells has demonstrated promising results and is an area of great potential for the treatment of patients with cancer,” said Dr. Kim. “We are really excited that our method of activating and expanding T-cells is practical and may be ideal for widespread use. Our goal is to eventually combine these T-cells with other immune therapies which will result in cures. These types of clinical trials place the UH Seidman Cancer Center at the forefront of immune therapy of cancer.”

Kim and his team have also been investigating the possibility of using lymph nodes from patients with pancreatic cancer to develop additional T-cell therapies. Kim and his coworker would like to expand their program to eventually study other tumor types including lung, colorectal and breast cancers.

Preventing the Onset of Type 1 Diabetes

Diabetes researchers at Saint Louis University have discovered a way to prevent the onset of Type I diabetes mellitus in diabetic mice. This strategy involves inhibiting the autoimmune processes that result in the destruction of the insulin-secreting pancreatic beta cells.

Type I diabetes is a life-long disease that results from insufficient production of the vital anabolic hormone insulin. In most cases of Type I diabetes mellitus, the body’s immune system destroys insulin-producing beta cells, and this insulin deficiency causes high blood sugar levels, also known as hyperglycemia. Treatments for the disease require daily injections of insulin.

Dr. Thomas Burris, chair of the university’s pharmacological and physiological science department, and his colleagues, have published their results in the journal Endocrinology. IN this paper, they report a procedure that could potentially prevent the onset of the disease rather than just treating the symptoms

‚ÄúNone of the animals on the treatment developed diabetes even when we started treatment after significant beta cell damage had already occurred,‚ÄĚ Burris explained in a prepared statement. ‚ÄúWe believe this type of treatment would slow the progression of type I diabetes in people or potentially even eliminate the need for insulin therapy.‚ÄĚ

A group of immune cells known as lymphocytes come in two main forms: B lymphocytes, which secrete the antibodies that bind to foreign cells and neutralize them, and T cells, which recognize foreign substances and regulate the immune response. There are several different types of T lymphocytes, but for the purposes of this discussion, two specific subtypes of T lymphocytes seem to be responsible for the onset of Type I diabetes. T ‚Äúhelper cells‚ÄĚ that have the CD4 protein on their surfaces, and T ‚Äúcytotoxic ‚Äú cells have the CD8 protein on their cell surfaces seem to play a role in the onset of Type I diabetes, but a third subtype of T lymphocyte has remained a bit of an enigma for some time. This subtype of T lymphocytes is a subcategory of CD4 T cells and secretes a protein called ‚Äúinterleukin 17,‚ÄĚ and is, therefore, known as TH17.

Dr. Burris and his collaborators from the Department of Molecular Therapeutics at the Scripps Research Institute have been examining TH17 cells for some time and they came upon a pair of nuclear receptors that play a crucial role in the development of TH17 cells. Could hamstringing the maturation of TH17 cells delay the onset of Type 1 diabetes mellitus?

Burris and others targeted these receptors by using drugs that bound to them and prevented them from working. This prevented the maturation of the TH17 T lymphocytes. When two nuclear receptors, Retinoid-related orphan receptors alpha (ROR-alpha) and Gamma-t (ROR-gamma-t) were inhibited, they prevented the autoimmune response that destroyed the beta cells.

To block these ROR alpha and gamma t receptors, Burris and others used a selective ROR alpha inhibitor and a gamma t inverse agonist called SR1001 that was developed by Dr. Burris. These drugs significantly reduced diabetes in the mice that were treated with it.

These findings show that TH17 cells play a significant role in the onset of Type I diabetes, and suggest that the use of drugs like these that target this cell type may offer a new treatment for the illness.

According to the American Diabetes Association, only 5% of people with diabetes have the Type I form of the disease, which was previously known as juvenile diabetes because it is usually diagnosed in children and young adults. The organization said that over one-third of all research they conduct is dedicated to projects relevant to type 1 diabetes.

STAP Cells: The Plot Thickens Even More

You might remember that Charles Vacanti and researchers at the RIKEN Institute in Japan reported a protocol for reprogramming mature mouse cells into pluripotent stem cells that could not only integrate into mouse embryos, but could also contribute to the formation of the placenta. To convert mature cells into pluripotent cells, Vacanti and others exposed the cells to slightly acidic conditions or other types of stressful conditions and the cells reverted to a pluripotent state.

Even though Vacanti and others published these results in the prestigious journal Nature, as other scientists tried to replicate the results in these papers, they found themselves growing more and more frustrated. Also, some gaffes with a few of the figures contributed to a kind of pall that has hung over this research in general.

The original makers of these cells, stress-acquired acquisition of pluripotency or STAP cells, have now made a detailed protocol of how they made their STAP cells publicly available at the Nature Protocol Exchange. Already. it is clear that a few things about the original paper are generating many questions.

First of all, Charles Vacanti’s name does not appear on the protocol. He was the corresponding author of the original paper. Therefore the absence of his name raises some eyebrows. Secondly, the authors seem to have backed off a few of their original claims.

For example one of the statements toward the beginning of the protocol says, “Despite its seeming simplicity, this procedure requires special care in cell handling and culture conditions, as well as in the choice of the starting cell population.‚ÄĚ Whereas the original paper, on the first reading at least, seemed to convey that making STAP cells was fairly straightforward, this seems to no longer be the case, if the words of this protocol are taken at face value.

Also, the protocol notes that cultured cells do not work with their protocol. The authors write, “Primary cells should be used. We have found that it is difficult to reprogram mouse embryonic fibroblasts (MEF) that have been expanded in vitro, while fresh¬†MEF¬†are competent.” ¬†This would probably explain inability of several well-regarded stem cell laboratories to recapitulate this work, since the majority of them probably used cultured cells. This, however, seems to contradict claims made in the original paper that multiple, distinct cell types could be converted into STAP cells.

Another clarification that the protocol provides that was not made clear in the original paper is that STAP cells and STAP stem cells are not the same thing. According to the authors, the protocol provided at Nature Protocol Exchange produces STAP cells, which have the capacity to contribute to the embryo and the placenta. On the other hand, STAP stem cells, are made from STAP cells by growing them in ACTH-containing medium on feeder cells, after which the cells are switched to ESC media with 20% Fetal Bovine Serum. STAP stem cells have lost the ability to contribute to extra-embryonic tissues.

Of even greater concern is a point raised by Paul Knoepfler at UC Davis. Knoepfler noticed that the original paper argued that some of their STAP cells were made from mature T cells. T cells rearrange the genes that encode the T cell receptor. If these mature T cells were used to make STAP cells, then they should have rearranged T cell receptor genes. The paper by Vacanti and others shows precisely that in a figure labeled 1i. However, in the protocol, the authors state that their STAP cells were NOT made from T-cells. In Knoepfler’s words: “On a simple level to me this new statement seems like a red flag.”

Other comments from Knoepfler’s blog noted that the protocol does not work on mice older than one week old. Indeed, the protocol itself clearly states that “Cells from mice older than one week showed very poor reprogramming efficiency under the current protocol. Cells from male animals showed higher efficiency than those from female.” ¬†Thus the universe of cells that can be converted into STAP cells seems to have contracted by quite a bit.

From all this it seems very likely that the STAP paper will need to go through several corrections. Some think that the paper should be retracted altogether. I think I agree with Knoepfler and we should take a “wait and see” approach. If some scientists can get this protocol to work, then great. But even then, multiple corrections to the original paper will need to be submitted. Also, the usefulness of these procedure for regenerative medicine seems suspect, at least at the moment. The cells types that can be reprogrammed with this protocol are simply too few for practical use. Also, to date, we only have Vacanti’s word that this protocol works on human cells. Forgive me, but given the gaffes associated with this present paper, that’s not terribly reassuring.