Perforin-1 is one of the major cytolytic proteins of cytolytic granules. One of the main pathways of
lymphocyte-mediated cytolysis entails the secretion onto target membranes of cytolytic granules contained in cytolytic
effector lymphocytes of T-cell or NK-cell type. Perforin has a molecular weight of 70 to 75 kD and shows extensive
similarity in structure to complement component C9 . PRF1 is a pore-forming protein with a mechanism of
transmembrane channel formation similar to C9
General function
Cell death/survival, Apoptosis
Comment
Cellular localization
Plasma membrane
Comment
Ovarian function
Luteolysis
Comment
Hameed A, et al 1995 reported perforin expression in human cell-mediated luteolysis. After ovulation and in the absence of fertilization, the human corpus luteum
regresses in an orderly sequence of morphological changes. This study
demonstrated that luteal regression involved progressive infiltration of
lymphocytes and macrophages. The inflammatory infiltrate began in the theca
externa and gradually invaded granulosa cells, with maximum accumulation of
lymphocytes and macrophages at the time of menstruation. Immunoperoxidase
staining showed that the majority of lymphocytes were CD2+, CD3+, CD8+ T
lymphocytes, and 15% of these T cells expressed perforin, a cytolytic protein
implicated as a mediator of cytotoxicity. The remaining mononuclear infiltrate
showed strong reactivity with monocyte/macrophage markers. These findings
indicate that (a) a physiologic cell-mediated inflammatory process in the
regressing human corpus luteum is mediated mainly by CD8+ T lymphocytes and
cells of monocyte/macrophage lineage and (b) perforin expression in T
lymphocytes supports a possible role for cytolytic T cells during the physiologic
inflammatory response in human luteolysis.
Expression regulated by
Comment
Ovarian localization
Luteal infiltrate
Comment
Follicle stages
Corpus luteum
Comment
Phenotypes
Mutations
1 mutations
Species: mouse
Mutation name: None
type: null mutation fertility: fertile Comment: To evaluate the role of perforin, Lowin et al. (1994) used gene targeting in embryonic stem cells to produce mice
lacking perforin. Mice homozygous for the disrupted gene had no perforin mRNA. The mice were healthy,
however, and activation and granzyme A secretion of perforin-free cytolytic T cells were unaltered. The killing
activity of cytolytic T cells as well as of natural killer (NT) cells was impaired but not abolished.