Biomedical subjects

D V Goeddel

Publications and source records attributed to D V Goeddel.

At least 37 records · Page 2Linked to original sources

PubMed1997

Early lethality, functional NF-kappaB activation, and increased sensitivity to TNF-induced cell death in TRAF2-deficient mice.

TRAF2 is an intracellular signal-transducing protein recruited to the TNFR1 and TNFR2 receptors following TNF stimulation. To investigate the physiological role of TRAF2, we generated TRAF2-deficient mice. traf2-/- mice appeared normal at birth but became progressively runted and died prematurely. Atrophy of the thymus and spleen and depletion of B cell precursors also were observed. Thymocytes and other hematopoietic progenitors were highly sensitive to TNF-induced cell death and serum TNF levels were elevated in these TRAF2-deficient animals. Examination of traf2-/- cells revealed a severe reduction in TNF-mediated JNK/SAPK activation but a mild effect on NF-kappaB activation. These results suggest that TRAF2-independent pathways of NF-kappaB activation exist and that TRAF2 is required for an NF-kappaB-independent signal that protects against TNF-induced apoptosis.

Animals↗

PubMed1997

Casper is a FADD- and caspase-related inducer of apoptosis.

Caspases are cysteine proteases that play a central role in apoptosis. Caspase-8 may be the first enzyme of the proteolytic cascade activated by the Fas ligand and tumor necrosis factor (TNF). Caspase-8 is recruited to Fas and TNF receptor-1 (TNF-R1) through interaction of its prodomain with the death effector domain (DED) of the receptor-associating FADD. Here we describe a novel 55 kDa protein, Casper, that has sequence similarity to caspase-8 throughout its length. However, Casper is not a caspase since it lacks several conserved amino acids found in all caspases. Casper interacts with FADD, caspase-8, caspase-3, TRAF1, and TRAF2 through distinct domains. When overexpressed in mammalian cells, Casper potently induces apoptosis. A C-terminal deletion mutant of Casper inhibits TNF- and Fas-induced cell death, suggesting that Casper is involved in these apoptotic pathways.

Adaptor Proteins, Signal Transducing↗

PubMed1996

A death-domain-containing receptor that mediates apoptosis.

The cell-killing effects of the cytokines TNF-alpha and FasL are mediated by the distinct cell-surface receptors TNFR1, TNFR2 and Fas (also known as CD95/APO-1), which are all members of a receptor superfamily that is important for regulating cell survival. The cytoplasmic regions of TNFR1 and Fas contain a conserved 'death' domain which is an essential component of the signal pathway that triggers apoptosis and activation of the transcription factor NF-kappaB (refs 5,6). Here we report the isolation of a 54K receptor that is a new member of the TNFR superfamily, using the death domain of TNFR1 in a yeast two-hybrid system. This protein, WSL-1, is most similar to TNFR1 itself, particularly in the death-domain region. The gene wsl-1 is capable of inducing apoptosis when transfected into 3T3 and 293 cells, and can also activate NF-kappaB in 293 cells. Like TNFR1, WSL-1 will homodimerize in yeast. WSL-1 also interacts specifically with the TNFR1-associated molecule TRADD. The tissue distribution is very restricted and significantly different from that of Fas and TNFR1.

Amino Acid Sequence↗

PubMed1996

The tumor necrosis factor receptor 2 signal transducers TRAF2 and c-IAP1 are components of the tumor necrosis factor receptor 1 signaling complex.

The two cell surface receptors for tumor necrosis factor (TNF) interact with a number of intracellular signal transducing proteins. The association of TRADD, a 34-kDa cytoplasmic protein containing a C-terminal death domain, with aggregated TNF receptor 1 (TNF-R1) through their respective death domains leads to NF-kappa B activation and programmed cell death. In contrast, TNF receptor 2 (TNF-R2) interacts with the TNF receptor associated factors 2/1 (TRAF2/TRAF1) heterocomplex, which mediates the recruitment of two cellular inhibitor of apoptosis proteins (c-IAP1 and c-IAP2) to TNF-R2. Here we show that the TNF-R2 signal transducers TRAF2 and c-IAP1 are a part of the TNF-R1 signaling complex. The recruitment of TRAF2 and c-IAP1 to TNF-R1 is TNF-dependent, is mediated by TRADD, and is independent of TNF-R2. These data establish the physiological involvement of TRAF2 and c-IAP1 in TNF-R1 signaling and help provide a molecular explanation for both the overlapping and distinct signals generated by the two TNF receptors.

Antigens, CD↗

PubMed1996

Dissection of TNF receptor 1 effector functions: JNK activation is not linked to apoptosis while NF-kappaB activation prevents cell death.

Through its type 1 receptor (TNFR1), the cytokine TNF elicits an unusually wide range of biological responses, including inflammation, tumor necrosis, cell proliferation, differentiation, and apoptosis. We investigated how TNFR1 activates different effector functions; the protein kinase JNK, transcription factor NF-kappaB, and apoptosis. We found that the three responses are mediated through separate pathways. Recruitment of the signal transducer FADD to the TNFR1 complex mediates apoptosis but not NF-kappaB or JNK activation. Two other signal transducers, RIP and TRAF2, mediate both JNK and NF-kappaB activation. These two responses, however, diverge downstream to TRAF2. Most importantly, JNK activation is not involved in induction of apoptosis, while activation of NF-kappaB protects against TNF-induced apoptosis.

Adenocarcinoma↗

PubMed1996

TRAF6 is a signal transducer for interleukin-1.

Many cytokines signal through different cell-surface receptors to activate the transcription factor NF-kappaB. Members of the TRAF protein family have been implicated in the activation of NF-kappaB by the tumour-necrosis factor (TNF)-receptor superfamily. Here we report the identification of a new TRAF family member, designated TRAF6. When overexpressed in human 293 cells, TRAF6 activates NF-kappaB. A dominant-negative mutant of TRAF6 inhibits NF-kappaB activation signalled by interleukin-1 (IL-1) but not by TNF. IL-1 treatment of 293 cells induces the association of TRAF6 with IRAK, a serine/threonine kinase that is rapidly recruited to the IL-1 receptor after IL-1 induction. These findings indicate that TRAF proteins may function as signal transducers for distinct receptor families and that TRAF6 participates in IL-1 signalling.

Amino Acid Sequence↗

PubMed1996

RANTES secretion by gene-modified tumor cells results in loss of tumorigenicity in vivo: role of immune cell subpopulations.

An immunogenic murine fibrosarcoma cell line was genetically modified to express and produce the human RANTES chemokine stably. In in vitro chemotaxis assays purified recombinant human RANTES as well as human RANTES secreted by the modified murine tumor cells were strongly chemoattractant for mouse CD8+ /Thy-1+ tumor-infiltrating lymphocytes (TIL). RANTES production did not alter the growth of these cytokine gene-modified tumor cells in vitro, but injection of RANTES-secreting cells resulted in the abolition of the ability of those cells to form solid tumors in vivo. The growth of tumors could be restored by co-administration of monoclonal antibodies that inhibit the function of various subsets of immune cells. For example, depletion of CD8+ T cells by antibody administration resulted in complete restoration of solid tumor formation by RANTES-secreting cells, whereas depletion of the CD4+ T cell population resulted in a partial restoration of tumor formation. Additionally, administration of an anti-CR3 monoclonal antibody known to inhibit the in vivo migration of macrophages also completely restored the tumorigenicity of RANTES-secreting fibrosarcoma cells. Thus, the human RANTES chemokine can abolish tumorigenicity of an immunogenic fibrosarcoma in an in vivo murine model, and this process is mediated by various subpopulations of immune effector cells.

Animals↗

PubMed1996

Anatomy of TRAF2. Distinct domains for nuclear factor-kappaB activation and association with tumor necrosis factor signaling proteins.

The tumor necrosis factor (TNF) receptor-associated factor (TRAF) family of proteins interact with and transduce signals for members of the TNF receptor superfamily. TRAF1, TRAF2, and TRAF3 share a conserved C-terminal TRAF domain. TRAF2 plays a key role in transducing signals for activation of the transcription factor nuclear factor-kappaB (NF-kappaB). We have performed extensive mutational analysis on TRAF2, examining the requirements for NF-kappaB activation, self-association, and interaction with other molecules involved in TNF signaling. Examination of point mutants and TRAF2-TRAF3 chimeric proteins indicates that the N-terminal RING finger and two adjacent zinc fingers of TRAF2 are required for NF-kappaB activation. The two distinct TRAF-N and TRAF-C subdomains of the TRAF domain appear to independently mediate self-association and interaction with TRAF1. Interaction of TRAF2 with TNF-R2 and TRADD requires sequences at the C terminus of the TRAF-C domain, whereas interaction with the protein kinase receptor-interacting protein V(RIP) occurs via sequences at the N terminus of the TRAF-C domain. Thus, distinct domains of TRAF2 are involved in recruitment and signaling functions.

Antigens, CD↗

PubMed1996

I-TRAF is a novel TRAF-interacting protein that regulates TRAF-mediated signal transduction.

Tumor necrosis factor (TNF) receptor-associated factor (TRAF) proteins associate with and transduce signals from TNF receptor 2, CD40, and presumably other members of the TNF receptor superfamily. TRAF2 is required for CD40- and TNF-mediated activation of the transcription factor NF-kappa B. Here we describe the isolation and characterization of a novel TRAF-interacting protein, I-TRAF, that binds to the conserved TRAF-C domain of the three known TRAFs. Overexpression of I-TRAF inhibits TRAF2-mediated NF-kappa B activation signaled by CD40 and both TNF receptors. Thus, I-TRAF appears as a natural regulator of TRAF function that may act by maintaining TRAFs in a latent state.

Adaptor Proteins, Signal Transducing↗

PubMed1996

Physical mapping and genomic structure of the human TNFR2 gene.

The tumor necrosis factor receptor 2 (TNFR2) gene localizes to 1p36. 2, a genomic region characteristically deleted in neuroblastomas and other malignancies. In addition, TNFR2 is the principal mediator of the effects of TNF on cellular immunity, and it may cooperate with TNFR1 in the killing of nonlymphoid cells. Therefore, we undertook an analysis of the genomic structure and precise physical mapping of this gene. The TNFR2 gene is contained on 10 exons that span 26 kb. Most of the functional domains of TNFR2 are encoded by separate exons, and each of the repeats of the extracellular cysteine-rich domain is interrupted by an intron. The genomic structure reveals a close relationship to TNFR1, another member of the TNFR superfamily. Based on electrophoretic analysis of yeast artificial chromosomes, TNFR2 maps within 400 kb of the genetic marker D1S434. In addition, we have identified a new polymorphic dinucleotide repeat within intron 4 of TNFR2. The genetic sequence information and exon-intron boundaries we have determined will facilitate mutational analysis of this gene to determine its potential role in neuroblastoma, as well as in other cancers with characteristic deletions or rearrangements of 1p36.

Amino Acid Sequence↗

PubMed1996

The tumor necrosis factor-inducible zinc finger protein A20 interacts with TRAF1/TRAF2 and inhibits NF-kappaB activation.

TRAF1 and TRAF2 form an oligomeric complex that associates with the cytoplasmic domains of various members of the tumor necrosis factor (TNF) receptor superfamily. TRAF2 action is required for activation of the transcription factor NF-kappaB triggered by TNF and the CD40 ligand. Here we show that TRAF1 and TRAF2 interact with A20, a zinc finger protein, whose expression is induced by agents that activate NF-kappaB. Mutational analysis revealed that the N-terminal half of A20 interacts with the conserved C-terminal TRAF domain of TRAF1 and TRAF2. In cotransfection experiments, A20 blocked TRAF2-mediated NF-kappaB activation. A20 also inhibited TNF and IL-1-induced NF-kappaB activation, suggesting that it may inhibit NF-kappaB activation signaled by diverse stimuli. The ability of A20 to block NF-kappaB activation was mapped to its C-terminal zinc finger domain. Thus, A20 is composed of two functionally distinct domains, an N-terminal TRAF binding domain that recruits A20 to the TRAF2-TRAF1 complex and a C-terminal domain that mediates inhibition of NF-kappaB activation. Our findings suggest a possible molecular mechanism that could explain A20's ability to negatively regulate its own TNF-inducible expression.

Cell Line↗

PubMed1996

TRADD-TRAF2 and TRADD-FADD interactions define two distinct TNF receptor 1 signal transduction pathways.

Tumor necrosis factor (TNF) can induce apoptosis and activate NF-kappa B through signaling cascades emanating from TNF receptor 1 (TNFR1). TRADD is a TNFR1-associated signal transducer that is involved in activating both pathways. Here we show that TRADD directly interacts with TRAF2 and FADD, signal transducers that activate NF-kappa B and induce apoptosis, respectively. A TRAF2 mutant lacking its N-terminal RING finger domain is a dominant-negative inhibitor of TNF-mediated NF-kappa B activation, but does not affect TNF-induced apoptosis. Conversely, a FADD mutant lacking its N-terminal 79 amino acids is a dominant-negative inhibitor of TNF-induced apoptosis, but does not inhibit NF-kappa B activation. Thus, these two TNFR1-TRADD signaling cascades appear to bifurcate at TRADD.

Adaptor Proteins, Signal Transducing↗

PubMed1996

TNF-dependent recruitment of the protein kinase RIP to the TNF receptor-1 signaling complex.

The death domain of tumor necrosis factor (TNF) receptor-1 (TNFR1) triggers distinct signaling pathways leading to apoptosis and NF-kappa B activation through its interaction with the death domain protein TRADD. Here, we show that TRADD interacts strongly with RIP, another death domain protein that was shown previously to associate with Fas antigen. We also show that RIP is a serine-threonine kinase that is recruited by TRADD to TNFR1 in a TNF-dependent process. Overexpression of the intact RIP protein induces both NF-kappa B activation and apoptosis. However, expression of the death domain of RIP Induces apoptosis, but potently inhibits NF-kappa B activation by TNF. These results suggest that distinct domains of RIP participate in the TNF signaling cascades leading to apoptosis and NF-kappa B activation.

Amino Acid Sequence↗

PubMed1995

The TNFR2-TRAF signaling complex contains two novel proteins related to baculoviral inhibitor of apoptosis proteins.

The 75 kDa tumor necrosis factor receptor (TNFR2) transduces extracellular signals via receptor-associated cytoplasmic proteins. Two of these signal transducers, TRAF1 and TRAF2, were isolated and characterized previously. We report here the biochemical purification and subsequent molecular cloning of two novel TNFR2-associated proteins, designated c-IAP1 and c-IAP2, that are closely related mammalian members of the inhibitor of apoptosis protein (IAP) family originally identified in baculoviruses. The viral and cellular IAPs contain N-terminal baculovirus IAP repeat (BIR) motifs and a C-terminal RING finger. The c-IAPs do not directly contact TNFR2, but rather associate with TRAF1 and TRAF2 through their N-terminal BIR motif-comprising domain. The recruitment of c-IAP1 or c-IAP2 to the TNFR2 signaling complex requires a TRAF2-TRAF1 heterocomplex.

Animals↗

PubMed1995

TRAF2-mediated activation of NF-kappa B by TNF receptor 2 and CD40.

TNF receptor-associated factor (TRAF) proteins are candidate signal transducers that associate with the cytoplasmic domains of members of the tumor necrosis factor (TNF) receptor superfamily. The role of TRAFs in the TNF-R2 and CD40 signal transduction pathways, which result in the activation of transcription factor NF-kappa B, was investigated. Overexpression of TRAF2, but not TRAF1 or TRAF3, was sufficient to induce NF-kappa B activation. A truncated derivative of TRAF2 lacking an amino-terminal RING finger domain was a dominant-negative inhibitor of NF-kappa B activation mediated by TNF-R2 and CD40. Thus, TRAF2 is a common mediator of TNF-R2 and CD40 signaling.

Animals↗

PubMed1995

NF-kappa B activation by interleukin-1 (IL-1) requires an IL-1 receptor-associated protein kinase activity.

An important function of interleukin-1 (IL-1) is activation of the transcription factor NF-kappa B, which is signaled via the type I IL-1 receptor (IL-1RI). By receptor mutagenesis studies, we have identified a region of the cytoplasmic domain of IL-1RI that is required for both IL-1-mediated NF-kappa B activation and IL-1-dependent activation of a receptor-associated protein kinase activity we term IRAK. No IL-1RI mutants were found that can activate NF-kappa B in the absence of IRAK activity. Therefore, we propose that IRAK activation is a necessary step in the activation of NF-kappa B by IL-1.

Cells, Cultured↗

PubMed1995

The TNF receptor 1-associated protein TRADD signals cell death and NF-kappa B activation.

Many diverse activities of tumor necrosis factor (TNF) are signaled through TNF receptor 1 (TNFR1). We have identified a novel 34 kDa protein, designated TRADD, that specifically interacts with an intracellular domain of TNFR1 known to be essential for mediating programmed cell death. Overexpression of TRADD leads to two major TNF-induced responses, apoptosis and activation of NF-kappa B. The C-terminal 118 amino acids of TRADD are sufficient to trigger both of these activities and likewise sufficient for interaction with the death domain of TNFR1. TRADD-mediated cell death can be suppressed by the crmA gene, which encodes a specific inhibitor of the interleukin-1 beta-converting enzyme. However, NF-kappa B activation by TRADD is not inhibited by crmA expression, demonstrating that the signaling pathways for TNF-induced cell death and NF-kappa B activation are distinct.

3T3 Cells↗

PubMed1995

Monoclonal antibodies specific for murine p55 and p75 tumor necrosis factor receptors: identification of a novel in vivo role for p75.

Monoclonal antibodies (mAbs) specific for the murine p55 and p75 tumor necrosis factor (TNF) receptors were produced after immunization of Armenian hamsters with the purified soluble extracellular domains of each receptor protein. Four p55- (55R) and five p75 (TR75)-reactive mAbs immunoprecipitated the appropriate receptor from the surface of L929 cells. None of the mAbs cross-reacted with the other TNF receptor form. The mAbs were functionally characterized by their ability to inhibit ligand binding and influence TNF-dependent L cell cytolytic activity or proliferation of the murine cytolytic T cell clone CT6. One p55-specific mAb, 55R-593, displayed agonist activity, while two other p55-specific mAbs (55R-170 and -176) were found to be TNF antagonists. The fourth mAb (55R-286) had no functional effects on cells. Several antibodies specific for the p75 TNF receptor partially inhibited recombinant murine TNF-alpha-dependent cytolytic activity (60%). Blocking mAbs specific for p75 but not anti-p55 inhibited TNF-mediated proliferation of CT6 T cells. When used in vivo, p55- but not p75-specific mAbs protected mice from lethal endotoxin shock and blocked development of a protective response against Listeria monocytogenes infection. In contrast, both p55 and p75 mAbs individually blocked development of skin necrosis in mice treated with murine TNF-alpha. These data thus demonstrate the utility of the two families of murine TNF receptor-specific mAbs and identify a novel function of the p75 TNF receptor in vivo.

Animals↗