NK Cell Function Identified in Mice

A new checkpoint protein that hampers natural killer (NK) cell-mediated tumor immunity was recently discovered by Australian researchers. Results from the study shows that depleting this protein in mice makes them resistant to a lot of solid cancers by turning on NK cell activity. This study, “CIS is a potent checkpoint in NK cell mediated tumor immunity,” was published in Nature Immunology.

These natural killer (NK) cells are effector lymphocytes that control a few types of tumors and microbial infections by regulating their spread and succeeding tissue damage.

According to the study’s lead author, Dr. Sandra Nicholson, NK cells are an important part of our immune system because they search for other cells that are either infected or becoming a cancer cell.

The recognition of immune checkpoints, including the programmed cell loss protein 1 (PD-1), whose inhibition eliminates the brakes of cytotoxic T-cells, has markedly improved cancer outcomes, specifically in metastatic melanoma. Now, experts have recognized a brand new checkpoint within NK cells that manages their ability to recognize and get rid of tumor cells.

The experience of NK cells is mediated, among other indicators, by cytokines such as IL-12, IL-18, and IL-15. The team, led by Nicholson and Dr. Nicholas Huntington, along with their co-workers from the Queensland Institute of Medical Research, has revealed a protein known as CIS that suppresses the NK cells’ capability to react to IL-15, therefore hindering their ability to attack tumor cells.

After genetically designing mice to lack the gene that coded for CIS, called Cish, they discovered that the mice were tolerant to experimental tumor metastasis produced from melanoma, breast cancer and prostate cell lines, which was reliant on NK activity.

According to Huntington, it was about learning how to enable the patient’s NK cells and improve their immune system to fight the disease.

The researchers are hopeful that their research will lead to brand new immunotherapies that boosts the body’s NK cell and keep it in a highly active state to specifically fight cancer more efficiently.