Apoptosis by death factor.

The TNF and TNF receptor superfamilies: integrating mammalian biology.

Identification and characterization of a new member of the TNF family that induces apoptosis

Apoptosis in the immune system is a fundamental process regulating lymphocyte maturation, receptor repertoire selection and homeostasis Thus, death by apoptosis is as essential for the function of lymphocytes as growth and differentiation This article focuses on death receptor-associated apoptosis and the role of CD95 (Apo-1/Fas)-mediated signalling in T-cell and B-cell development and during the course of an immune response Gaining an insight into these processes improves our understanding of the pathogenesis of diseases such as cancer, autoimmunity and AIDS, and opens new approaches to rational treatment strategies

CD95's deadly mission in the immune system

Tumor necrosis factor (TNF) and lymphotoxin-α were isolated more than 10 years ago, on the basis of their ability to kill tumor cells in vitro and to cause hemorrhagic necrosis of transplantable tumors in mice.1 The complementary DNAs and genes encoding each protein were cloned immediately thereafter.2,3 Concurrently, a factor known as cachectin was isolated from mouse macrophages, sequenced, and shown to be identical to TNF.4,5 Cachectin was identified not as a cytolysin, but as a catabolic hormone that suppressed the expression of lipoprotein lipase and other anabolic enzymes in fat.6–8 Still other studies demonstrated the powerful . . .

https://www.nejm.org/doi/pdf/10.1056/NEJM199606273342607?listPDF=true

The Tumor Necrosis Factor Ligand and Receptor Families

Fas (also known as Apo1 and CD95) is a cell surface receptor involved in apoptotic cell death. Fas expression and function were analyzed in three children (including two siblings) with a lymphoproliferative syndrome, two of whom also had autoimmune disorders. A large deletion in the gene encoding Fas and no detectable cell surface expression characterized the most affected patient. Clinical manifestations in the two related patients were less severe: Fas-mediated apoptosis was impaired and a deletion within the intracytoplasmic domain was detected. These findings illustrate the crucial regulatory role of Fas and may provide a molecular basis for some autoimmune diseases in humans.

C. Hivroz

Papers

Mutations inFasAssociated withHuman Lymphoproliferative Syndrome and Autoimmunity