T-Cell Transfer Therapy - A Comprehensive Review

Introduction

T-cell transfer therapy is a cutting-edge approach in immunotherapy that involves transferring functional T-cells, a type of white blood cell, from one individual to another to help fight cancer and other diseases. T-cells play a crucial role in the body's immune response, as they recognize and destroy abnormal or infected cells. In T-cell transfer therapy, T-cells are collected from a donor and modified in a laboratory to enhance the potential to recognize the specific tumor cells and then attack the cancer cells. These modified T-cells, designed to multiply an effective attack, cancer, are then transferred to the patient. T-cells can treat cancer through adoptive T-cell transfer (ACT) and T-cells targeting antibodies. T-cells targeting antibodies is an expensive method. On the other hand, ACT is highly efficient in fighting against tumor cells.

What Is T Cell?

T-cells mature and differentiate in the thymus gland. Therefore it is called T-cell (T for thymus). T-cell is a type of lymphocyte (white blood cells) that helps fight against antigens (foreign particles harmful to the body). In addition, T-cells play an important role in acquired immunity. T-cells have receptors on their cell surface called T-cell receptors (TCR). T-cells are found in the bone marrow. They migrate after maturation from the thymus gland and develop the immune system.

What Is the Function of the T Cell?

T-cells, also known as T-lymphocytes, play a crucial role in the immune system by identifying and destroying infected or abnormal cells.

The following are the functions of T-cells in our body:

• T-cells help to protect the body against viruses, bacteria, and other pathogens.

• T-cells protect against the growth of cancer cells.

• T-cells are equipped with special receptors that enable them to recognize specific antigens on the surface of cells. Once they identify an infected or abnormal cell, they can destroy it.

• T-cells also play a role in regulating and coordinating the overall immune response.

• They release cytokines, which are signaling molecules, to communicate with other cells in the immune system and help to coordinate the immune response.

• T-cells play an important role in maintaining the body's defenses and protecting against disease.

What Is T Cell Transfer Therapy?

T-cells are considered to impact immunosurveillance and the elimination of tumors significantly. Therefore, therapies have been developed to create, train, or strengthen T-cells to target cancers. This therapy is particularly effective in treating certain types of blood cancers. Leukemia and lymphoma can be treated by T-cell transfer therapy. T-cell therapy can be used in cancer patients where the cancer cells have spread throughout the body, and traditional treatments such as chemotherapy or radiation are no longer effective.

T-cells can treat cancer through two methods:

• Adoptive Cell Transfer (ACT) - ACT is done ex-vivo means outside the body. Adoptive cell transfer involves the infusion of personal lymphocytes with anti-tumor properties, which is obtained from naturally occurring T-cells found in removed tumors (known as tumor-infiltrating lymphocytes) or from T-cells that have been genetically modified to identify tumor antigens. Adoptive T-cell Transfer has several benefits. T-cells that are highly effective in recognizing and targeting tumor antigens can be increased in large quantities through in vitro (in the lab) methods, genetically modified, or activated outside the body to gain anti-tumor capabilities.

• T-Cell Targeting Antibodies - The second method is done in vivo, which means inside the body. T-cell targeting antibodies (cells that fight against antigens) directly stimulate patients' lymphocytes through antibodies, such as checkpoint inhibitors and bispecific. The major limitation in the more widespread application of T-cell targeting antibody therapy is the difficulty in identifying antigen-specific T cells in other cancer types.

What Are the Methods of T Cell Transfer Therapy?

T-cell transfer therapy has shown promising results in clinical trials, with many patients experiencing long-lasting remissions and even complete responses to the treatment.

There are two methods of T-cell transfer therapy:

• Autologous T-Cell Transfer - Autologous T-cell transfer therapy involves collecting T-cells from the patient, modifying them, and returning them to the patient. This approach is typically used in cases where the patient's immune system has been compromised due to cancer treatment.

• Allogeneic T-Cell Transfer - Allogenic T-cell transfer therapy, on the other hand, involves collecting T-cells from a healthy donor. After collecting T-cells from them, T-cells are transferred to the patient. This approach is typically used in cases where the patient's cancer cells are highly resistant to traditional treatments.

One of T-cell transfer therapy's biggest challenges is finding a donor with T-cells that match the patient's tissue type. This is particularly important in allogeneic T-cell transfer therapy, as the T-cells from the donor can cause a dangerous immune reaction if they are not a good match. Despite this challenge, T-cell transfer therapy is still considered a highly promising field of research, with many new advances and techniques being developed to improve the success rates of the therapy.

How T Cell Transfer Fight Against Cancer?

T-cell immunotherapy is done by genetically designed T-cells that recognize tumor antigens or by adoptive T-cells transfer. Each of these strategies has its characteristics.

The following are the mechanism of T-cell transfer immunotherapy:

• Identification Of Antigens (Ag) - Identifying a tumor (growing cancerous cell mass) antigen, the type of tumor Ag that is targeted (surface or intracellular) is important to prepare antibodies against tumor antigens.

• T-Cell Response - The nature of the T-cell response generated against the tumor (monoclonal or polyclonal). It helps to fight against a tumor. It helps to stop the growth of the tumor.

• Duration Of Immune Protection - The durability of immune protection (short-term/passive or long-lasting/active) depends on the person. T-cells help to fight against tumors and also helps the immune system to remember the antigen. This enhances the immune response in the next exposure to the same antigen.

What Are the Side Effects of T Cell Transfer?

The side effects caused by T-cell transfer may be different for different patients. The most common side-effect of T-cell transfer is the sudden increase in cytokines in the body. Cytokines are chemicals in our body that control immune responses.

The patients can experience the following symptoms due to a rise in cytokines:

• High body temperature.

• Nausea.

• Headache.

• Skin rashes.

• Difficulty in breathing.

• Rapid heartbeat.

• Hypotension (low blood pressure).

Conclusion

T-cell transfer therapy is a cutting-edge approach in the field of immunotherapy that shows a great prognosis in treating cancer and other diseases. By transferring functional T-cells from one individual to another, this therapy helps to boost the body's immune response and attack cancer cells. Proper understanding and a few challenges need to be overcome in this field, but T-cell transfer therapy is a promising development in the fight against cancer and other diseases.