What is the Origin of Natural Killer Cell Function?

The term "Natural Killer" was coined in the 1970s to describe the unique characteristic of these cells: their inherent, or "natural," capacity to kill target cells without requiring activation or clonal expansion, distinguishing them from T and B lymphocytes. The study of NK cell function is central to immunology, particularly in the fields of oncology and virology.

What is the Mechanism of Natural Killer Cell Function?

NK cell function is governed by a complex mechanism involving the integration of signals from inhibitory and activating receptors expressed on the cell surface. Inhibitory receptors recognize and bind to MHC class I molecules present on healthy cells, preventing attack and ensuring self-tolerance. Activating receptors recognize stress-induced ligands on infected or cancerous cells. When the activating signal overrides the inhibitory signal, the NK cell releases cytotoxic granules containing perforin and granzymes, which induce apoptosis, or programmed cell death, in the target cell.

Natural Killer Cell Function

Meaning

Natural Killer (NK) Cell Function describes the innate ability of a specific type of cytotoxic lymphocyte to recognize and rapidly destroy virus-infected cells and tumor cells without prior sensitization or the need for major histocompatibility complex (MHC) presentation. NK cells are a crucial component of the body’s first line of defense, providing immune surveillance against malignancy and acute viral infection. Optimal function is dependent on a balanced signaling environment, which can be significantly modulated by systemic factors like stress hormones and nutritional status.