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Volume 272, Number 28, Issue of July 11, 1997 pp. 17255-17257
©1997 by The American Society for Biochemistry and Molecular Biology, Inc.

COMMUNICATION:
I-FLICE, a Novel Inhibitor of Tumor Necrosis Factor Receptor-1- and CD-95-induced Apoptosis^*

(Received for publication, May 6, 1997, and in revised form, May 19, 1997)

Shimin Hu , Claudius Vincenz , Jian Ni ^§, Reiner Gentz ^§ and Vishva M. Dixit ^¶

From the Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109 and ^§ Human Genome Sciences, Inc., Rockville, Maryland 20850-9998

ABSTRACT

INTRODUCTION

MATERIALS AND METHODS

RESULTS AND DISCUSSION

FOOTNOTES

ACKNOWLEDGEMENTS

REFERENCES

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ABSTRACT

The pivotal discovery that the death proteases caspase 8 (FLICE) and caspase 10 (Mch4/FLICE2) are recruited to the CD-95 and tumor necrosis factor receptor-1 signaling complexes suggested a mechanism used by these cytotoxic receptors to initiate apoptosis. In this report, we describe the cloning and characterization of I-FLICE, a novel inhibitor of tumor necrosis factor receptor-1- and CD-95-induced apoptosis. The overall architecture of I-FLICE is strikingly similar to that of FLICE and Mch4/FLICE2. However, I-FLICE lacks both a catalytic active site and residues that form the substrate binding pocket, in keeping with its dominant negative inhibitory function. I-FLICE is the first example of a catalytically inert caspase that can inhibit apoptosis.

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INTRODUCTION

The cell death machinery is conserved throughout evolution and is composed of activators, inhibitors, and effectors (1). The effector arm of the cell death pathway is composed of a rapidly growing family of cysteine aspartate-specific proteases termed caspases (2). As implied by the name, these cysteine proteases cleave substrates following an aspartate residue (2, 3). Caspases are normally present as single polypeptide zymogens and contain an N-terminal prodomain and large and small catalytic subunits (4-6). The two-chain active enzyme (composed of the large and small subunits) is obtained following proteolytic processing at internal Asp residues (4-6). As such, caspases are capable of activating each other in a manner analogous to zymogen activation that is observed in the coagulation cascade (7). The identification of FLICE and Mch4/FLICE2 as receptor-associated caspases suggested a surprisingly direct mechanism for activation of the death pathway by the cytotoxic receptors CD-95 and TNFR-1¹ (7-10). Upon activation, both receptors use their death domains to bind the corresponding domain in the adaptor molecule FADD (Fas-associated death domain protein) (8-10). Dominant negative versions of FADD that lack the N-terminal segment but still retain the death domain potently inhibit both CD-95- and TNFR-1-induced apoptosis (11, 12). Given the importance of the N-terminal segment in engaging the death pathway, it has been termed the death effector domain (DED) (11).

Remarkably, the DED is present within the prodomain of FLICE and Mch4/FLICE2, and mutagenesis studies suggest that a homophilic interaction between the DED of FADD and the corresponding domain in FLICE or Mch4/FLICE2 is responsible for the recruitment of these proteases to the CD-95 and TNFR-1 signaling complexes (8-11). Taken together, these data are consistent with FLICE and Mch4/FLICE2 being apical enzymes that initiate precipitous proteolytic processing of downstream caspases resulting in apoptosis (7, 13-15). A number of viral gene products antagonize CD-95- and TNFR-1-mediated killing as a means to persist in the infected host (16). The poxvirus-encoded serpin CrmA and baculovirus gene product p35 are direct caspase inhibitors (3). In contrast, the molluscum contagiosum virus protein MC159 and the equine herpesvirus protein E8 encode DED-containing decoy molecules that bind to either FADD (MC159) or FLICE (E8) and disrupt assembly of the receptor signaling complex, thereby abrogating the death signal (17-19). The existence of these viral inhibitors has raised the question of whether functionally equivalent molecules are encoded in the mammalian genome.

Here, we report the cloning and characterization of a novel mammalian inhibitor designated I-FLICE (for inhibitor of FLICE), a catalytically inactive structural homologue of FLICE and Mch4/FLICE2 that inhibits both TNFR-1- and CD-95-induced apoptosis. This is the first example of a naturally occurring catalytically inactive caspase that can act as a dominant negative inhibitor of apoptosis.

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MATERIALS AND METHODS

Cell Lines and Expression Vectors

Human embryonic kidney 293, 293T, and 293-EBNA cells were cultured in Dulbecco's modified Eagle's medium containing 10% fetal bovine serum, nonessential amino acids, L-glutamine, and penicillin/streptomycin. Expression constructs were made in pcDNA3 or pcDNA3.1/MycHisA (Invitrogen) using standard recombinant methodologies (20).

Cloning of I-FLICE

cDNAs corresponding to the partial open reading frame of I-FLICE were identified as sequences homologous to FLICE and Mch4/FLICE2 on searching the Human Genome Sciences data base using established expressed sequence tag methods (21, 22). Full-length cDNAs were obtained by screening a random-primed human umbilical vein endothelial cell cDNA library constructed in the pcDNA1 vector (Invitrogen). The sequence of I-FLICE was confirmed by sequencing plasmid DNA template on both strands by the dideoxy chain termination method employing modified T7 DNA polymerase (Sequenase, U. S. Biochemical Corp.)

Northern Blotting

Human multiple tissue and human cancer cell line poly(A)⁺ RNA blots were obtained from CLONTECH and processed according to the manufacturer's instructions.

Transfection, Coimmunoprecipitation, and Western Analysis

Transient transfections of 293T cells were performed as described previously (23). Cells were harvested 40 h following transfection, immunoprecipitated with the indicated antibodies, and analyzed by immunoblotting.

Cell Death Assay

Human embryonic kidney 293 (for TNFR-1 killing) or 293 EBNA cells (for CD-95 killing) were transiently transfected with 0.1 µg of the reporter plasmid pCMV -galactosidase plus 0.5 µg of test plasmid in the presence or the absence of 2.0 µg of inhibitory plasmids. 22-24 h following transfection, cells were fixed in 0.5% glutaraldehyde and stained with 5-bromo-4-chloro-3-indolyl -D-galactopyranoside. Percentage of apoptotic cells was determined by calculating the fraction of membrane blebbed blue cells as a function of total blue cells. All assays were evaluated in duplicate, and the mean and standard deviations were calculated.

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RESULTS AND DISCUSSION

Sequence of I-FLICE

Sequence analysis of a full-length cDNA revealed a 1443-base pair open reading frame that encoded a novel protein with a predicted molecular mass of 55.3 kDa (Fig. 1A). Given that the protein had striking homology to FLICE and Mch4/FLICE2 but lacked an active site, making it a potential dominant negative inhibitor, it was designated I-FLICE (for inhibitor of FLICE).

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Fig. 1. Sequence analysis of I-FLICE. A, deduced amino acid sequence of I-FLICE. The pentapeptide corresponding to the conserved active site (QACR(Q)G) of other caspases is boxed. Shown underneath are schematic models of I-FLICE, FLICE, and Mch4. The N-terminal portion of each molecule contains two DED-like domains (shaded boxes), and the C-terminal portion contains both large and small catalytic subunits (p20/p10). The pentapeptide QNYVV of I-FLICE and the corresponding motifs in FLICE and Mch4 are indicated. B, the two DED motifs of I-FLICE were aligned with DED motifs present in FADD, FLICE, and Mch4. C, the C-terminal region of I-FLICE was aligned with the catalytic domains of FLICE and Mch4.  symbols indicate residues involved in catalysis, and  symbols identify residues that form the binding pocket for the carboxylate side chain of P1 Asp.
[View Larger Version of this Image (69K GIF file)]

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The architecture of I-FLICE was strikingly similar to that of FLICE and Mch4/FLICE2, including two N-terminal DED-like tandem repeats and a region that resembled the caspase catalytic domain (Fig. 1, B and C). Overall, I-FLICE displayed 19 and 18% identity (32 and 28% similarity) to FLICE and Mch4, respectively. Importantly, I-FLICE did not contain the catalytic cysteine that is normally embedded in the conserved pentapeptide QACRG or QACQG motif present in all known caspases. Rather, the pentapeptide sequence was QNYVV. In addition, based on the x-ray crystal structure of caspase-1 (and caspase-3), amino acid residues His²³⁷ (His¹²¹), Gly²³⁸ (Gly¹²²), and Cys²⁸⁵ (Cys¹⁶³) are involved in catalysis, whereas residues Arg¹⁷⁹ (Arg⁶⁴), Gln²⁸³ (Gln¹⁶¹), Arg³⁴¹ (Arg²⁰⁷), and Ser³⁴⁷ (Ser²¹³) form a binding pocket for the carboxylate side chain of the P1 aspartic acid (4-6). These seven residues are conserved in all caspases, but only three of them (Gly, Gln, and Ser as indicated in Fig. 1C) are found in I-FLICE. Given this lack of conservation of key residues involved in catalysis and substrate binding, it can be concluded that I-FLICE is not a cysteine protease and is incapable of binding Asp at the P1 position. Interestingly, the DED domain of I-FLICE was more related to the corresponding domains present in the viral DED-containing inhibitors, sharing 32, 30, and 29% identity (52, 49, and 39% similarity) to K13, MC159, and E8, but only 23 and 18% identity (44 and 30% similarity) to FLICE and Mch4, respectively (17, 19).

Tissue Distribution of I-FLICE

Human tissue and cell line RNA blots were probed with a ³²P-labeled cDNA specific for I-FLICE. Two transcripts (7.5 and 6 kilobases) were observed, possibly due to differential polyadenylation (Fig. 2). The tissue distribution was similar to that of FLICE and Mch4/FLICE2 (8-10, 15), being expressed in most tissues and cell lines examined except for the brain and the lymphoblastic leukemia line MOLT4. In particular, I-FLICE expression was evident in peripheral blood leukocytes, spleen, placenta, and heart. In mouse tissues the only predominant mRNA species is the 7.5-kilobase form.

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Fig. 2. Tissue distribution of I-FLICE. Human adult and cell lines poly(A)⁺ Northern blots were probed with ³²P-labeled human I-FLICE probe corresponding to codons 215-331. PBL, peripheral blood leukocyte. The mouse tissue was Northern probed with a 200-base pair mouse I-FLICE probe complementary to the 5 end.
[View Larger Version of this Image (43K GIF file)]

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I-FLICE Associates with FLICE and FLICE2

Previous studies have shown that the DED domain is a protein interaction motif that mediates the binding of the adaptor molecule FADD to the effector proteases FLICE and Mch4/FLICE2 (8, 10). Given the striking structural similarity, we asked if I-FLICE interacted with either FADD or other FLICE-like caspases. Co-immunoprecipitation analysis clearly revealed the ability of I-FLICE to bind FLICE and Mch4/FLICE2 (Fig. 3A), but not FADD (Fig. 3B). In this respect, I-FLICE resembles the viral DED-containing molecule E8 in that it binds FLICE but not FADD (17, 18). Because there was no association between I-FLICE and FADD, I-FLICE was not recruited to the CD-95 or TNFR-1 signaling complex as evidenced by its inability to co-precipitate with these receptors (data not shown).

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Fig. 3. I-FLICE binds FLICE and FLICE2 but not FADD. 293T cells were co-transfected with indicated plasmids. Following transfection, cells lysates were immunoprecipitated (IP) and immunoblotted with the respective epitope tag antibodies. W. Blot, Western blot.
[View Larger Version of this Image (21K GIF file)]

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I-FLICE Inhibits TNFR-1 and CD-95-induced Apoptosis

Given the ability of catalytically inactive I-FLICE to complex with FLICE-like caspases, we reasoned that I-FLICE may be acting as a dominant negative inhibitor because the active form of all caspases is a tetramer derived from the processing of two zymogen forms to a four-chain assembly (4-6). It follows that a catalytically inert zymogen, such as I-FLICE, would be processed to inactive subunits that would result in the generation of a nonfunctional tetrameric protease. Although it is presently conjecture, this putative mechanism does predict that I-FLICE should inhibit TNFR-1 and CD-95-induced apoptosis where FLICE-like caspases play an initiating role. Consistent with the prediction, overexpression of I-FLICE resulted in substantial inhibition of TNFR-1-induced cell death comparable with previously characterized inhibitors including CrmA, MC159, dominant negative FLICE, and dominant negative Mch4/FLICE2 (Fig. 4A). However, under the present experimental conditions, I-FLICE appeared to be a less potent inhibitor of CD-95-induced cell death, possibly reflecting the more potent death signal that emanates from this receptor.

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Fig. 4. I-FLICE inhibits TNFR-1- and CD95-induced apoptosis. Overexpression of I-FLICE attenuated TNFR-1-induced (A) and CD-95-induced (B) cell death. 293 (A) or 293-EBNA (B) cells were co-transfected with the indicated plasmids together with the reporter construct pCMV -galactosidase. The data shown are the percentages of blebbing blue cells as a function of total number of blue cells counted.
[View Larger Version of this Image (24K GIF file)]

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In summary, our studies have identified a catalytically inactive member of the caspase family that can serve as a dominant negative inhibitor of CD-95- and TNFR-1-induced cell death by binding and antagonizing the apical FLICE-like caspases. Additional studies will be necessary to work out in detail the exact nature of the inhibitory mechanism.

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FOOTNOTES

^*   This work was supported by National Institutes of Health Grants ES08111 and AG13671.The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
   These authors made equal contributions to this work.
^¶   Address correspondence to: Dept. of Pathology, University of Michigan Medical School, 1301 Catherine St., Ann Arbor, MI 48109-0602. Tel.: 313-647-0264; Fax: 313-764-4308; E-mail: vmdixit{at}umich.edu.
¹   The abbreviations used are: TNFR-1, tumor necrosis factor receptor 1; FADD, Fas-associated death domain protein; FLICE, FADD-like interleukin-1-converting enzyme; FLICE2, FADD-like ICE2; DED, death effector domain.

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ACKNOWLEDGEMENTS

We thank Justin McCarthy, Arul Chinnaiyan, Marta Muzio, and Karen O'Rourke for providing reagents and helpful discussions and Ian Jones for help in preparing the figures.

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REFERENCES

1. Chinnaiyan, A. M., and Dixit, V. M. (1996) Curr. Biol. 6, 555-562 [CrossRef][Medline] [Order article via Infotrieve]
2. Alnemri, E. S., Livingston, D. J., Nicholson, D. W., Salvesen, G., Thornberry, N. A., Wong, W. W., and Yuan, J. (1996) Cell 87, 171 [CrossRef][Medline] [Order article via Infotrieve]
3. Walker, N. P., Talanian, R. V., Brady, K. D., Dang, L. C., Bump, N. J., Ferenz, C. R., Franklin, S., Ghayur, T., Hackett, M. C., Hammill, L. D., Herzog, L., Hugunin, M., Houy, W., Mankovich, J. A., McGuiness, L., Orlewicz, Z., Paskind, M., Pratt, C. A., Reis, P., Summani, A., Terranova, M., Weich, J. P., Xiong, L., Moller, A., Tracey, D. E., Kamen, R., and Wong, W. W. (1994) Cell 78, 343-352 [CrossRef][Medline] [Order article via Infotrieve]
4. Wilson, K. P., Black, J. A., Thomson, J. A., Kim, E. E., Griffith, J. P., Navia, M. A., Murcko, M. A., Chambers, S. P., Aldape, R. A., Raybuck, S. A., and Livingston, D. J. (1994) Nature 370, 270-274 [CrossRef][Medline] [Order article via Infotrieve]
5. Rotonda, J., Nicholson, D. W., Fazil, K. M., Gallant, M., Gareau, Y., Labelle, M., Peterson, E. P., Rasper, D. M., Ruel, R., Vaillancourt, J. P., Thornberry, N. A., and Becker, J. W. (1996) Nat. Struct. Biol. 3, 619-625 [CrossRef][Medline] [Order article via Infotrieve]
6. Fraser, A., and Evan, G. (1996) Cell 85, 781-784 [CrossRef][Medline] [Order article via Infotrieve]
7. Boldin, M. P., Goncharov, T. M., Goltsev, Y. V., and Wallach, D. (1996) Cell 85, 803-815 [CrossRef][Medline] [Order article via Infotrieve]
8. Muzio, M., Chinnaiyan, A. M., Kischkel, F. C., O'Rourke, K., Shevchenko, A., Ni, J., Scaffidi, C., Bretz, J. D., Zhang, M., Gentz, R., Mann, M., Krammer, P. H., Peter, M. E., and Dixit, V. M. (1996) Cell 85, 817-827 [CrossRef][Medline] [Order article via Infotrieve]
9. Vincenz, C., and Dixit, V. M. (1997) J. Biol. Chem. 272, 6578-6583 [Abstract/Free Full Text]
10. Chinnaiyan, A. M., O'Rourke, K., Tewari, M., and Dixit, V. M. (1995) Cell 81, 505-512 [CrossRef][Medline] [Order article via Infotrieve]
11. Chinnaiyan, A. M., Tepper, C. G., Seldin, M. F., O'Rourke, K., Kischkel, F. C., Hellbardt, S., Krammer, P. H., Peter, M. E., and Dixit, V. M. (1996) J. Biol. Chem. 271, 4961-4965 [Abstract/Free Full Text]
12. Muzio, M., Salvesen, G., and Dixit, V. M. (1997) J. Biol. Chem. 272, 2952-2956 [Abstract/Free Full Text]
13. Srinivasula, S. M., Ahmad, M., Fernandes-Alnemri, T., Litwack, G., and Alnemri, E. S. (1996) Proc. Natl. Acad. Sci. U. S. A. 93, 14486-14491 [Abstract/Free Full Text]
14. Fernandes-Alnemri, T., Armstrong, R. C., Krebs, J., Srinivasula, S. M., Wang, L., Bullrich, F., Fritz, L. C., Trapani, J. A., Tomaselli, K. J., Litwack, G., and Alnemri, E. S. (1996) Proc. Natl. Acad. Sci. U. S. A. 93, 7464-7469 [Abstract/Free Full Text]
15. Henkart, P. A. (1996) Immunity 4, 195-201 [CrossRef][Medline] [Order article via Infotrieve]
16. Shen, Y., and Shenk, T. S. (1995) Curr. Opin. Genet. & Dev. 5, 105-111 [CrossRef][Medline] [Order article via Infotrieve]
17. Hu, S., Vincenz, C., Buller, M., and Dixit, V. M. (1997) J. Biol. Chem. 272, 9621-9624 [Abstract/Free Full Text]
18. Bertin, J., Armstrong, R. C., Ottilie, S., Martin, D. A., Wang, Y., Banks, S., Wang, G. H., Senkevich, T. G., Alnemri, E. S., Moss, B., Lenardo, M. J., Tomaselli, K. J., and Cohen, J. I. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 1172-1176 [Abstract/Free Full Text]
19. Thome, M., Schneider, P., Hofmann, K., Fickenscher, H., Meinl, E., Neipl, F., Mattmann, C., Burns, K., Bodmer, J., Schroter, M., Scaffidi, C., Krammer, P. H., Peter, M. E., and Tschopp, J. (1997) Nature 386, 517-521 [CrossRef][Medline] [Order article via Infotrieve]
20. Sambrook, J., Fritsch, E. F., and Maniatis, T. (1989) Molecular Cloning: A Laboratory Manual, 2nd Ed., pp. 1.1-1.103, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
21. Adams, M. D., Kelley, J. M., Gocayne, J. D., Dubnick, M., Polymeropoulos, M. H., Xiao, H., Merril, C. R., Wu, A., Olde, B., Moreno, R. F., Kerlavage, A. R., McCombie, W. R., and Venter, J. C. (1991) Science 252, 1651-1656 [Abstract/Free Full Text]
22. Adams, M. D., Dubnick, M., Kerlavage, A. R., Moreno, R. F., Kelley, J. M., Utterback, T. R., Nagle, J. W., Feilds, C., and Venter, J. C. (1992) Nature 355, 632-634 [CrossRef][Medline] [Order article via Infotrieve]
23. O'Rourke, K. M., Laherty, C. D., and Dixit, V. M. (1992) J. Biol. Chem. 267, 24921-24924 [Abstract/Free Full Text]

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©1997 by The American Society for Biochemistry and Molecular Biology, Inc.

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				J. C. Fanzo, C.-M. Hu, S. Y. Jang, and A. B. Pernis Regulation of Lymphocyte Apoptosis by Interferon Regulatory Factor 4 (IRF-4) J. Exp. Med., February 3, 2003; 197(3): 303 - 314. [Abstract] [Full Text] [PDF]

				C. W. Xiao, X. Yan, Y. Li, S. A. G. Reddy, and B. K. Tsang Resistance of Human Ovarian Cancer Cells to Tumor Necrosis Factor {alpha} Is a Consequence of Nuclear Factor {kappa}B-Mediated Induction of Fas-Associated Death Domain-Like Interleukin-1{beta}-Converting Enzyme-Like Inhibitory Protein Endocrinology, February 1, 2003; 144(2): 623 - 630. [Abstract] [Full Text] [PDF]

				H. Higuchi, J.-H. Yoon, A. Grambihler, N. Werneburg, S. F. Bronk, and G. J. Gores Bile Acids Stimulate cFLIP Phosphorylation Enhancing TRAIL-mediated Apoptosis J. Biol. Chem., January 3, 2003; 278(1): 454 - 461. [Abstract] [Full Text] [PDF]

				O. Micheau, M. Thome, P. Schneider, N. Holler, J. Tschopp, D. W. Nicholson, C. Briand, and M. G. Grutter The Long Form of FLIP Is an Activator of Caspase-8 at the Fas Death-inducing Signaling Complex J. Biol. Chem., November 15, 2002; 277(47): 45162 - 45171. [Abstract] [Full Text] [PDF]

				E. Davila, M. G. Velez, C. J. Heppelmann, and E. Celis Creating space: an antigen-independent, CpG-induced peripheral expansion of naive and memory T lymphocytes in a full T-cell compartment Blood, September 18, 2002; 100(7): 2537 - 2545. [Abstract] [Full Text] [PDF]

				S. M. A. Lens, T. Kataoka, K. A. Fortner, A. Tinel, I. Ferrero, R. H. MacDonald, M. Hahne, F. Beermann, A. Attinger, H.-A. Orbea, et al. The Caspase 8 Inhibitor c-FLIPL Modulates T-Cell Receptor-Induced Proliferation but Not Activation-Induced Cell Death of Lymphocytes Mol. Cell. Biol., August 1, 2002; 22(15): 5419 - 5433. [Abstract] [Full Text] [PDF]

				C. Wu Xiao, E. Asselin, and B. K. Tsang Nuclear Factor {kappa}B-Mediated Induction of Flice-Like Inhibitory Protein Prevents Tumor Necrosis Factor {alpha}-Induced Apoptosis in Rat Granulosa Cells Biol Reprod, August 1, 2002; 67(2): 436 - 441. [Abstract] [Full Text] [PDF]

				C. Xiao, B. F. Yang, N. Asadi, F. Beguinot, and C. Hao Tumor Necrosis Factor-related Apoptosis-inducing Ligand-induced Death-inducing Signaling Complex and Its Modulation by c-FLIP and PED/PEA-15 in Glioma Cells J. Biol. Chem., July 5, 2002; 277(28): 25020 - 25025. [Abstract] [Full Text] [PDF]

				F. H. Igney and P. H. Krammer Immune escape of tumors: apoptosis resistance and tumor counterattack J. Leukoc. Biol., June 1, 2002; 71(6): 907 - 920. [Abstract] [Full Text] [PDF]

				S. Cottet, P. Dupraz, F. Hamburger, W. Dolci, M. Jaquet, and B. Thorens cFLIP Protein Prevents Tumor Necrosis Factor-{alpha}-Mediated Induction of Caspase-8-Dependent Apoptosis in Insulin-Secreting {beta}Tc-Tet Cells Diabetes, June 1, 2002; 51(6): 1805 - 1814. [Abstract] [Full Text] [PDF]

				D. Himeji, T. Horiuchi, H. Tsukamoto, K. Hayashi, T. Watanabe, and M. Harada Characterization of caspase-8L: a novel isoform of caspase-8 that behaves as an inhibitor of the caspase cascade Blood, May 13, 2002; 99(11): 4070 - 4078. [Abstract] [Full Text] [PDF]

				L. Liu, M. T. Eby, N. Rathore, S. K. Sinha, A. Kumar, and P. M. Chaudhary The Human Herpes Virus 8-encoded Viral FLICE Inhibitory Protein Physically Associates with and Persistently Activates the Ikappa B Kinase Complex J. Biol. Chem., April 12, 2002; 277(16): 13745 - 13751. [Abstract] [Full Text] [PDF]

				R. K. Thomas, A. Kallenborn, C. Wickenhauser, J. L. Schultze, A. Draube, M. Vockerodt, D. Re, V. Diehl, and J. Wolf Constitutive Expression of c-FLIP in Hodgkin and Reed-Sternberg Cells Am. J. Pathol., April 1, 2002; 160(4): 1521 - 1528. [Abstract] [Full Text] [PDF]