Perforin is a protein that plays a crucial role in the immune system, particularly in the function of cytotoxic T cells and natural killer cells. These cells are responsible for eliminating infected cells and tumor cells from the body.
Perforin is a pore‐forming protein primarily expressed by cytotoxic lymphocytes (natural killer [NK] cells and cytotoxic T lymphocytes).
• Its canonical function is to deliver granzymes into target cells (including tumor cells) to trigger apoptosis.
• In this sense, perforin is a key mediator of immune surveillance against tumors.
In the context of cancer, perforin has been found to have both positive and negative effect.
In some cases, higher levels of perforin (and accompanying granzyme expression) have been detected in tumors that are “inflamed” or immunologically “hot” – and these are often associated with better immune surveillance.
• Note that “expression direction” is best interpreted in the context of TIL density and immune phenotype rather than expression by the tumor cells themselves (which generally do not express perforin.
Higher levels of perforin expression in the tumor microenvironment (that is, higher abundance of functional CTLs or NK cells) are generally associated with a more favorable prognosis because they reflect active anti-tumor immunity.
(Will delete Record if Target field = "Delete") Home