Tumors escape immunological rejection by a diversity of mechanisms. In this report, we demonstrate that the colon cancer cell SW620 expresses functional Fas ligand (FasL), the triggering agent of Fas receptor (FasR)-mediated apoptosis within the immune system. FasL mRNA and cell surface FasL were detected in SW620 cells using reverse transcription polymerase chain reaction (RT-PCR) and immunohi...

Apoptosis mediated by Fas ligand (FasL) interaction with Fas receptor plays a pivotal regulatory role in immune homeostasis, immune privilege, and self-tolerance. FasL, therefore, has been extensively exploited as an immunomodulatory agent to induce tolerance to both autoimmune and foreign antigens with conflicting results. Difficulties associated with the use of FasL as a tolerogenic factor ma...

We wondered whether the apoptosis known to occur after UV-B irradiation might involve the Fas/Fas ligand (FasL) signaling pathway. We exposed PBLs from normal individuals, and also the Jurkat (E6-1) and U937 cell lines, to graded doses of UV-B irradiation and observed a prompt and marked increase in Fas expression at doses as low as 0.5 mJ/cm2. Increased Fas expression did not require new prote...

Proliferation of vascular smooth muscle cells (VSMCs) in response to injury plays a key role in the pathogenesis of vascular disorders. Fas ligand (FasL) induces apoptosis in Fas-bearing cells, and its expression on activated T cells contributes to the regulation of the immune response and physiological cell turnover. Here, we show that a replication-defective adenovirus encoding FasL (Ad-FasL)...

Chordoma is a rare malignant tumor that recapitulates the notochord phenotype and is thought to derive from notochord remnants not correctly regressed during development. Apoptosis is necessary for the proper notochord development in vertebrates, and the apoptotic pathway mediated by Fas and Fasl has been demonstrated to be involved in notochord cells regression. This study was conducted to inv...

We have previously demonstrated a role for Fas and Fas ligand (FasL) in the pathogenesis of experimental allergic encephalomyelitis (EAE). However, using an active induction paradigm we could not distinguish between FasL expressed on activated CD4(+) T cells from that expressed on other inflammatory or resident central nervous system (CNS) cells. To address this issue, we have conducted recipro...

CD95/Fas ligand (FasL) is a cell death-promoting member of the tumor necrosis factor family with important functions in the regulation of T-cell homeostasis and cytotoxicity. In T cells, FasL expression is tightly regulated on a transcriptional level involving a complex set of different transcription factors. The orphan nuclear receptor liver receptor homolog-1 (LRH-1/NR5a2) is involved in the ...

PURPOSE Ocular immune privilege promotes tumor growth by hindering the development of innate and adaptive immunity. A prior study showed that ocular tumors expressing the membrane-only form of Fas ligand (FasL) terminate immune privilege, induce vigorous inflammation, undergo rejection, and induce systemic protective immunity. In these previous experiments the tumor cells used were genetically ...

The interaction of Fas (CD95), a member of the tumor necrosis factor receptor (TNFR) family, and its ligand (FasL) triggers programmed cell death (apoptosis) and is involved in the regulation of immune responses. Although the Fas-FasL interaction is conserved across species barriers, little is currently known about the molecular details of this interaction. Our aim was to identify residues in F...

Tumor-resident CD8(+) T cells display a quiescent effector/memory phenotype that is maintained in part by infiltrating CD4(+) CD25(+) Foxp3(+) T-suppressor cells. Intratumoral delivery of IL-12, in contrast, can restore cytotoxic function to tumor-associated CD8(+) T cells and induce the apoptotic death of T-suppressor cells. Depletion of CD8(+) T cells from tumors before IL-12 treatment result...