A senior Chinese scientist has recently elaborated on a theory on effector immune cell deployment (EICD) in the immune system as a new mechanism for combating tumors.

The breakthrough offers a theoretical basis for re-evaluating anti-tumor mechanisms and should help with the formulation of more accurate immunotherapy strategies, according to Song Erwei, an academician at the Chinese Academy of Sciences.

Song and his team recently published their results titled "Turning cold tumors hot: from molecular mechanisms to clinical applications" in the May edition of Elsevier journal Trends in Immunology.

According to Song, who is also president of the Sun Yat-sen Memorial Hospital at Guangzhou's Sun Yat-sen University, the new theory can be applied to the diagnosis and treatment of all kinds of tumors.

The process of tumorigenesis (the production and formation of tumors) arises from a struggle between the tumor and the host immune system. Song said the new concept of effective immune cell array is an important theory in tumor ecology.

"Many people believe that long-term use of Cordyceps sinensis (a fungus that infects certain caterpillars) and Ganoderma lucidum (the Reishi mushroom) by tumor patients helps enhance immunity against tumors," he said.

But the term "immunity", especially as used by the public, is a very broad concept, which essentially refers to the ability of the immune system to protect the body from illnesses, he added.

"However, the body's immune system is specific and responds differently to different substances. Immunity against bacterial and viral infections may not prove useful in fighting tumors," Song said.

"Therefore, the immunity enhanced by eating Ganoderma lucidum and Cordyceps sinensis is not necessarily anti-tumor immunity."

Clinicians have come to use the concept of "cold" and "hot" tumors to evaluate the strength of anti-tumor immunity in recent years, he said. It is generally believed that a "cold" tumor is characterized by little or no T-cell infiltration of the tumor. Patients have a poor prognosis for survival and do not benefit from immunotherapy.

Correspondingly, a "hot" tumor that is rich in T-cell infiltration responds to immunotherapy and presents a good prognosis for survival.

Effector immune cells are the cells in the immune system that fight tumor cells, and these include adaptively immune T-cells and naturally immune Natural Killer cells.

"The immune system deploys against tumor cells through lymph nodes, peripheral blood and the tumor's microenvironment," Song said, adding that this so-called "control deployment" precisely reflects the way the human immune system marshals its forces to fight tumor cells at the cellular and molecular levels.

"In the future, based on the mechanism of EICD, doctors will be able to accurately diagnose the immune phenotype of tumors and generate a corresponding diagnosis and treatment and drug systems. Then, they can screen new treatment targets and take specific treatment measures to transform 'cold' tumors into 'hot' tumors," Song said.

Combined with immune checkpoint therapy, EICD will help strengthen tumor immunity in cancer patients and improve both the effect of treatment and the survival period of patients, he added.

Link to the report: https://epaper.chinadaily.com.cn/a/202207/08/WS62c7883ca3109375516ed778.html