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Exploring Immunotherapy of COVID-19 Using “Personal” Immune Cells

Scientists from Duke-NUS Medical School explore the potential use of an individual’s immune cells for therapy against infectious disease.

With the recent emergence of the COVID-19 pandemic, scientists in the field have been looking for options for treatment and vaccine development. A team from Duke-NUS Medical School are looking into engineering specific virus-targeting receptors in to a patient’s own immune cells for therapeutic use.

This therapy involves extracting immune cells, called T lymphocytes, from a patient’s blood stream and engineering one of two types of receptors onto them: chimeric antigen receptors (CAR) or T cell receptors (TCR). TCRs are naturally found on the surfaces of T lymphocytes while CARs are artificial T cell receptors that are generated in the laboratory. These receptors allow the engineered T lymphocytes to recognise cancerous or virus infected cells.

“This therapy is classically used in cancer treatment, where the lymphocytes of the patients are redirected to find and kill the cancer cells. However, its potential against infectious diseases and specific viruses has not been explored. We argue that some infections, such as HIV and HBV, can be a perfect target for this therapy, especially if lymphocytes are engineered using an approach that keeps them active for a limited amount of time to minimise potential side effects,” said Dr Anthony Tanoto Tan, Senior Research Fellow at the Duke-NUS’ Emerging Infectious Diseases (EID) programme and the lead author of this commentary.

However, the mentioned format of immunotherapy requires specialised personnel and equipment, and needs to be administered indefinitely. This downside makes it cost-prohibitive for treatment on most types of viral infections.

However, in the case of HBV infections, for example, current anti-viral treatments merely suppress viral replication and cure less than 5 percent of patients. Treating these patients with a combination of anti-virals and CAR/TCR T cells could be a viable option. The team’s approach using mRNA electroporation to engineer CAR/TCR T cells limits their functional activity to a short period of time, and hence provides enhanced safety features suited for its deployment in patients with chronic viral diseases.

“We demonstrated that T cells can be redirected to target the coronavirus responsible for SARS. Our team has now begun exploring the potential of CAR/TCR T cell immunotherapy for controlling the COVID-19-causing virus, SARS-CoV-2, and protecting patients from its symptomatic effects,” said Professor Antonio Bertoletti from the Duke-NUS’ EID programme, who is the senior author of this commentary. [APBN]