T Cell Transduction Methods

Updated on Aug 21, 2023 Share

What Is T Cell Transduction?

The recent development of adoptive cell therapies that specifically and effectively target cancer cells has transformed the field of oncology and the pharmaceutical industry. Early treatments focus on the autologous transfer of a patient’s own cells that have been modified to target their cancer, but newer allogeneic therapies, the transfer of modified cells from a healthy donor, have significant benefits. Modified cells are more readily accessible than a patient’s own, especially in patients with severe illnesses and weakened T cell function.

Scientists often need to alter the function of cells for cell therapy through the introduction of new or modified genetic material, using a viral vector. By inserting genes into the genome of a cell, they can make the cell transcribe and express proteins that it normally would not. After translation from the inserted genetic vector, these proteins carry out specified tasks within the cell. In this way, scientists can add to or alter the function of the cells in question. This is called transduction.

Using a variety of transduction methods, scientists create cells that aggressively fight and destroy cancer cells. However, each of these methods has its own set of benefits and drawbacks.

How Is Transduction Used in Cell Therapy?

Cell therapies, such as CAR T-cell therapy, provide a necessary and promising treatment option for viral infections and cancer. These therapies use harvested T cells from a patient or a healthy donor for genetic modification and infusion into the patient.

The harvested T cells are “infected” with the engineered messenger chimeric antigen-receptor molecules, which provide tumor-specific signals for a targeted immune response. After the introduction of the tumor-specific directive, the T cells are cultured and expanded for clinical use.

Common T-Cell Transduction Methods

The need for reliable transduction leading to robust expansion ex vivo is increasing as CAR T cells reach more treatment centers. There are a few different approaches and limitations to T-cell transduction in the lab. There is no one-size-fits-all method in such a recent medical development with many unknown variables.

Lentiviral Transduction

The most common approach to cell therapy manufacturing T cell transduction is through viral vectors. By equipping viruses with a CAR-encoding nucleic acid message, the viral vector travels into the cell, is absorbed as a pathogen, and its CAR-encoding message transcribed as the antigen.

This method is highly efficient and offers a wide range of delivery options employing various viruses. This method is personalized and costly, which makes it challenging to scale to the necessary level of accessibility.

Viral vectors can also risk proper infusion, as the viral mRNA can activate its immune response. Opposing and concurrent immune responses can diminish the clinical quality of treatment.

Transfection

T cell transfection involves the uptake of nucleic acids into the nucleus of a T cell without viral infection. By artificially introducing T cells to nucleic acids, transfection integrates the messages for translation and transcription. Successful transfection produces a genetically modified cell.

This approach reduces the risk of viral contamination and is less costly, but it is also less effective. This limited efficacy results from the natural transfection rates of mature cells. Typically, a severely ill patient has a high number of exhausted T cells, which transfect at far lower rates than naive T cells.

Electroporation

A process of induced transduction using electric fields designed to increase the efficacy of transfection, electroporation provides an alternative to lentiviral and classic transfection. The T cells become exposed to microseconds of electric charge, which perforates the cell membrane, allowing the entry of nucleic acids into the cytoplasm.

Electroporation has quickly become the most widely used non-viral method of transduction due to its increased efficiency and low cost.

Primary T-Cell Transduction and Expansion for Immunotherapy

Successful transduction and expansion ex vivo are integral to efficient and safe immunotherapy. Cell therapies rely on the human body’s natural mechanisms of recognizing and destroying invading molecules. Immunotherapy uses this relationship to boost the cytotoxic effects of T cells within the body by providing genetically engineered tumor-specific T cells.

The large cell count required for a dose of cell therapy is hard to scale for the number of patients needing treatment. Reliable ex vivo expansion and transduction products are necessary for the widespread clinical implementation of adoptive T cell therapy.

One major obstacle to scalable T cell expansion solutions is overcoming T cell differentiation for a reliable and quality end-product every time. T cells range vastly in phenotype and function, making achieving uniform transduction difficult.

Activation and Expansion using Akadeum’s Products for T-Cell Transduction

Akadeum provides stellar activation and expansion protocol for ex vivo transduction, which utilizes our innovative microbubble technology. BACS™ microbubbles perform seamless cell separation without using a column or bead.

Instead, Akadeum’s microbubble isolation products use natural buoyancy to float unwanted cells to the top of a solution via negative selection. This is the perfect isolation product for CAR or other adoptive T cell therapy research.

In addition, Akadeum’s microbubbles can be used for activation and expansion. Our recently published data shows that by leveraging CD3 and CD28 antibodies and positive selection to isolate, activate, and expand T cells the resulting cells are easily transduced, highly activated, and less exhausted than alternative activation methods. Our products address standard supply and scaling issues by offering dependable and powerful activation and expansion reagents.