|
|||||||||
|
|
|
|
|
|
|
|
|
|
|
NEOPLASIA
From the Hematologic Malignancies and Immunology
Programs, H. Lee Moffitt Cancer Center and Research Institute and the
Veterans Administration Hospital; Departments of Internal Medicine and
Microbiology/Immunology, University of South Florida, College of
Medicine, Tampa, FL
Altered expression of the Fas-Fas ligand apoptotic pathway leads to
lymphoproliferative and autoimmune diseases. In
lpr/lpr mice and children with autoimmune
lymphoproliferative syndrome, defective apoptosis is due to Fas
mutations. Large granular lymphocyte (LGL) leukemia is a clonal
lymphoproliferative disorder associated with rheumatoid arthritis.
Leukemic LGLs are resistant to Fas-dependent apoptosis despite
expressing high levels of Fas. Such resistance can be overcome by
activating leukemic LGLs in vitro, suggesting inhibition of Fas
signaling in leukemic cells. We report that sera from patients with LGL
leukemia contain high levels of soluble Fas. Ten of these 33 patients
with LGL leukemia also had rheumatoid arthritis. Cloning and sequencing
revealed expression of multiple Fas messenger RNA variants in leukemic
LGL. These Fas variants, including 3 newly described here, encode
soluble Fas molecules. Supernatants from cells transfected with these
Fas variants blocked Fas-dependent apoptosis of leukemic LGLs. These
results suggest that blockade of Fas-signaling by soluble Fas may be a
mechanism leading to apoptosis resistance in leukemic LGLs.
(Blood. 2002;100:1449-1453) Apoptosis, or programmed cell death, is a
process fundamental to the normal development and hemostasis of
multicellular organisms.1-4 Dysregulation of apoptosis has
been implicated in a number of human diseases, including cancer,
leukemia, neurodegenerative disorders, and acquired immunodeficiency
syndrome.3-5 One apoptotic pathway involves the Fas/Fas
ligand system. Fas, also designated as Apo-1 or CD95, is a member of
the tumor necrosis factor (TNF) receptor family of cell surface
proteins, and Fas ligand is a member of the TNF family of proteins.
6,7 Fas has a broad distribution on normal tissues, whereas
Fas ligand is expressed primarily only on activated cytotoxic
lymphocytes.8-11 Interaction of Fas with Fas ligand
induces apoptotic cell death.7-12 Altered levels of
expression of Fas and Fas ligand have been implicated in the
pathogenesis of diseases associated with immune
regulation.2,5,13-15
Large granular lymphocyte (LGL) leukemia is a neoplastic disorder of
either CD3+ or CD3-LGLs.16 The T-cell form of
this disease is associated with neutropenia and autoimmune disorders
such as rheumatoid arthritis. CD3+ LGL leukemia cells are
thought to represent in vivo-activated cytotoxic T lymphocytes
(CTLs) of unknown antigen specificity.17 The
mechanisms involved in prolonging survival of these leukemic LGLs are
not entirely understood. A primary role of Fas-mediated apoptosis is
deletion of peripheral antigen-activated T cells in the normal immune
system.18 We have found that leukemic LGLs, like
antigen-activated CTLs, express high levels of both Fas and Fas ligand.
Unlike normal activated CTLs, however, leukemic LGLs are resistant to
Fas-mediated apoptosis.19
Animal models of lymphoproliferative disorders associated with
autoimmune features are characterized by Fas resistance.15 Serologic features of the autoimmune disorder include antibodies to
rheumatoid factor, high levels of circulating immune complexes, and
polyclonal hypergammaglobulinemia. These serologic abnormalities are
also common features of LGL leukemia. Defective apoptosis in
lpr/lpr mice is due to mutations in
Fas13; a similar pathogenetic mechanism has been discovered
in children with autoimmune lymphoproliferative syndrome.20,21 In contrast, mutations in the death domain
of Fas in leukemic LGLs have not been detected.19 A second
mechanism of Fas resistance is production of soluble Fas receptors,
which can act as decoys for Fas ligand.22 Soluble forms of
cell surface receptors can be produced either by proteolytic cleavage
of membrane-bound receptors or by alternative splicing. Normal
activated T cells (peripheral blood mononuclear cells [PBMCs])
express alternative splicing messenger RNA (mRNA) variants coding for
soluble forms of Fas proteins.23-25 Furthermore,
expression of soluble Fas in mice leads to an autoimmune syndrome and
elevated levels of soluble Fas have been found in some patients with
autoimmune diseases.22 To investigate the mechanism of
apoptosis resistance in LGL leukemia, we cloned and sequenced the Fas
gene from leukemic LGLs. We describe several Fas mRNA variants, which
functionally block Fas-mediated apoptosis. Our results suggest that
blockade of Fas function by decoy Fas receptors may contribute to the
pathogenesis of LGL leukemia.
Patients with LGL leukemia
RNA extraction, complementary DNA synthesis, and reverse
transcription-polymerase chain reaction
Soluble Fas enzyme-linked immunosorbent assay Detection of soluble Fas in the serum of LGL leukemia patients was performed using a soluble Fas enzyme-linked immunosorbent assay (ELISA) kit according to the manufacturer's instructions (Bender Med Systems, Vienna, Austria).Construction of expression vectors Cloned Fas gene transcripts (the Fas full-length, FasExo6Del, and FasExo4,6Del cDNAs) were digested from pGEM-T easy vectors with EcoRI restriction enzyme and subcloned into a mammalian expression vector, pcDNA3.1Zeo(+) (Invitrogen, San Diego, CA). The orientation of each of these cDNA in pcDNA3.1Zeo(+) was verified by restriction mapping. These pcDNA3.1Zeo(+) vectors containing the Fas full-length, FasExo6Del, and FasExo4,6Del cDNAs in correct orientation were then transfected into COS cells by the superfact transfection reagent (Qiagen, Valencia, CA). After 48 hours of transfection, COS cells were selected in RPMI medium containing 400 µg/mL Zeocin for 2 weeks. Individual Zeocin-resistant colonies were then isolated and further expanded in the Zeocin-containing medium. To examine the surface expression of human Fas molecules, transfected cells were stained with phycoerythrin (PE)-labeled anti-Fas antibody (UB2; Kamiya, Tukwila, WA) or PE-labeled isotype control IgG1 (Kamiya), as described previously.19 Briefly, one million cells were incubated with 10 µL of the directly labeled antibodies for 30 minutes at 4°C in 100 µL phosphate-buffered saline (PBS) supplemented with 2% fetal calf serum and 0.02% sodium azide. After 2 washes with the same PBS washing buffer, cells were analyzed on a FACScan (Becton Dickinson, Mountain View, CA). For cytoplasmic staining of Fas and Fas variants, COS cells were fixed with 4% paraformaldehyde for 5 minutes and permeabilized with ethanol and acetic acid. The staining was performed as described as above.Apoptosis assay The PBMCs from healthy donors and patients with LGL leukemia were stimulated with phytohemagglutinin (PHA; 1 µg/mL, 2 days) and interleukin 2 (IL-2; 100 U/mL, 10 days). The apoptosis-inducing anti-Fas (CH11) antibody was then added in the presence of supernatant harvested from COS cells transfected with vector alone, full-length Fas cDNA, or Fas variants. Apoptotic cell detection was determined by flow cytometry using staining with 7 amino-actinomycin D (7-AAD; Calbiochem, San Diego, CA) and propidium iodide (PI; Molecular Probes, Eugene, OR). For 7-AAD staining, cells were incubated with 7-AAD at a concentration of 20 µg/mL for 30 minutes at 4°C in the dark. The cells were then resuspended in PBS and analyzed using flow cytometry.19 For PI staining, cells were washed once with PBS, then 1 mL hypotonic PI solution 2 (50 µg/mL PI in 0.1% sodium citrate solution plus 0.1% Triton X-100) was added. Cells were kept overnight at 4°C in the dark, and then analyzed on a FACScan flow cytometer (Becton Dickinson) in their staining solution, as described previously.19
Identification and characterization of Fas splicing variant mRNAs in leukemic LGLs Results of reverse transcription-PCR (RT-PCR) analyses of Fas gene transcripts are shown in Figure 1. In addition to the expected fragment corresponding to the full-length cDNA, several distinct smaller products were observed (labeled a to i in Figure 1). Expression of full-length Fas gene transcript (band a) in samples from LGL leukemia patients appeared higher than expression in samples from unactivated PBMCs. These results are consistent with flow cytometric analyses showing high levels of Fas expression on leukemic LGLs.19 Expression of band b, which represents a transmembrane-deleted (exon 6 deletion) Fas mutant (see below), appeared higher in samples from patients with LGL leukemia than from samples of either unactivated or activated normal PBMCs. Bands c to i representing a variety of even smaller Fas mRNA splicing products were found primarily in samples from patients with LGL leukemia. Similar analysis of RNA samples from 4 patients with B-cell non-Hodgkin lymphoma showed the presence of only full-length Fas transcripts (not shown).
To further characterize the smaller fragments, the Fas RT-PCR
products from 7 individuals with LGL leukemia and 1 healthy donor were
cloned into the pGEM-T Easy Vector systems (Promega), and the
nucleotide sequence was determined with T7 and SP6 primers by an
automatic DNA sequencing system (Pharmacia). We found that all of these
smaller transcripts were Fas cDNA variants with deletion of the
transmembrane region of Fas. These Fas cDNA variants are represented
schematically in Figure 2. A common
descriptive nomenclature is used based on which exons are deleted in
the Fas gene structure.25 Bands a (Fas), b
(FasExo6Del), d (FasExo4Del), e (FasExo4,6Del), g (FasExo3,4Del), and h
(FasExo3,4,6Del) have been previously found only in activated normal
PBMCs.25 Band b was previously called Fas TM
De122,23 and lacks exon 6, the transmembrane region of Fas.
Band d encodes for a mature protein of 133 amino acid residues, 38 of
which at the C-terminal end (box A in Figure 2) differ from those of
the Fas protein.25 These same 38 amino acids are seen at
the C-terminal end of band g, which also contains a deletion in exon 3. Band e contains 2 deletions; the second deletion results in an altered
reading frame with a new termination codon at position 765. The last 21 amino acids at the C-terminal end differ from those of the Fas protein
(box B). A similar structure is seen at the C-terminal end of band h,
which contains an additional deletion of exon 3. Bands c
(FasExo6,7Del), f (FasExo4,6,7Del), and I (FasExo3,4,6,7 Del) have not
been described previously. These Fas cDNA variants are slightly
different from bands b, e, and h, respectively, in that they contained
an extra deletion in the 5' end of exon 7. They thus contain an
additional 20 amino acid residues at the C-terminal end (box C in
Figure 2), which are different from those of the Fas protein. As a
result, a new stop codon is generated at the C-terminal end of box
C. The sizes of cDNA's b and c, e and f, and h and i,
respectively, are very similar and they comigrate on 1% agarose gel,
as shown in Figure 1.
High levels of soluble Fas in LGL leukemia sera Because the variant Fas transcripts containing deletions in the transmembrane region of Fas were highly expressed in LGL leukemia samples, we were interested in measuring levels of soluble Fas in these patients. The amount of soluble Fas in sera from patients with LGL leukemia (n = 30) was compared to levels found in healthy donors (n = 10) using an ELISA kit (Figure 3). Each sample was assayed in duplicate and intra-assay variation was less than 5%. Sera from most LGL leukemia patients expressed high amounts of soluble Fas ranging up to 519 U/mL. In contrast, most of the control sera from healthy donors contained negligible quantities of soluble Fas with maximal value being 86 U/mL. The levels of soluble Fas in sera of LGL leukemia patients were significantly higher than control sera (P < .0001, using 2-sided Wilcoxon analyses).
Splicing variant mRNA are translated as soluble Fas To confirm the existence of the soluble Fas translation products, Fas, FasExo6Del, and FasExo4,6Del coding regions were inserted into a mammalian expression vector, pcDNA3.1Zeo(+) and transfected into COS cells. The transfected COS cells were first grown in nonselected regular medium for 2 days and selection was begun on day 3 by the addition of 400 µg/mL Zeosin (Invitrogen) for 2 to 4 weeks. About 20 single colonies were isolated from each transfection. Evidence for production of proteins encoded by the clones was obtained by flow cytometry analyses with anti-Fas monoclonal antibody (mAb). These analyses showed the surface expression of Fas on COS cells transfected with the full-length Fas cDNA but not on COS cells transfected with the FasExo6Del or FasExo4,6Del expression plasmids. Production of the FasExo6Del and FasExo4,6Del proteins from transfected COS cells was shown by cytoplasmic Fas staining (Figure 4).
Prevention of programmed cell death by soluble Fas variants High levels of soluble Fas can block Fas-mediated apoptosis of normal activated T cells. We wanted to know whether such a mechanism mediated Fas resistance of leukemic LGLs. Sera from patients with LGL leukemia contain high levels of soluble Fas. We found that in contrast to normal sera, LGL leukemia sera abrogated Fas-induced apoptosis of normal activated T cells (Figure 5). We showed previously that Fas resistance in leukemic LGLs could be reversed by activation with IL-2.19 In this study, we found that sera from LGL leukemia patients would also protect activated leukemic LGL from apoptosis. Sera from these patients blocked apoptosis by 67% to 82%, whereas serum from a fourth patient inhibited apoptosis by 30% (Figure 6).
We then investigated the hypothesis that the Fas variants cloned from
leukemic LGLs could protect both normal PBMCs and leukemic LGLs from
apoptotic death. Activated cells were cultured with apoptosis-inducing
Fas mAb in the presence of serial dilutions of supernatants from
transfected COS cells. We found that supernatants from COS cells
transfected with Fas Exo6Del and Fas Exo4,6 Del blocked apoptosis of
activated PBMCs from both healthy donors and from patients with LGL
leukemia in a dose-dependent fashion (Figure
7). In contrast, supernatants from COS
cells transfected with full-length Fas cDNA or with control constructs
did not inhibit Fas-mediated apoptosis.
We found that sera from most patients with LGL leukemia contained high levels of soluble Fas. The amount of soluble Fas in most normal sera was less than 50 U/mL. In contrast, levels of up to 519 U/mL were observed in sera from patients with LGL leukemia. Elevated levels of soluble Fas have been reported in other hematologic malignancies as well as some autoimmune diseases.26,27 Whether elevated levels of soluble Fas contribute to the pathogenesis of these disorders is not known. A central feature of LGL leukemia is a dysregulated Fas/Fas ligand apoptotic pathway. Despite expressing high levels of Fas, leukemic LGLs are Fas-resistant.19 Fas resistance underlies the pathogenesis of autoimmune lymphoproliferative diseases in both animal models and humans. In these circumstances, defects in Fas-mediated apoptosis are due to mutations in Fas.13,20,21 In contrast, however, we had shown a normal-sized Fas gene transcript in patients with LGL leukemia, without any function-ablating mutations.19 Previous studies indicated that Fas resistance can be reversed by activating leukemic LGLs in vitro.19 These data suggest that inhibition of Fas signaling rather than defective Fas was responsible for Fas resistance. High levels of soluble Fas can block Fas-mediated apoptosis.22 We found that LGL sera abrogated Fas-mediated apoptosis of normal PBMCs as well as leukemic LGLs activated in vitro. These results suggested that high levels of soluble Fas might be one mechanism responsible for Fas resistance in leukemic LGLs. We identified and characterized 8 variant Fas mRNA transcripts encoding for soluble Fas from LGL leukemia samples. Of these 8 Fas variants, 5 have been described previously only in activated normal PBMCs.25 Constitutive expression of Fas variants in leukemic LGL further supports the idea that leukemic LGLs have been activated in vivo and most likely represent antigen-activated CTLs.19 Three of the identified Fas variants are novel sequences resulting from deletions in exon 7. The common feature of the splice variants is that they all contain the first 391 nucleotides (exons 1 and 2). This region appears functionally important in the ability of soluble Fas to block Fas-mediated apoptosis.25 We demonstrated that 2 of the Fas variants cloned from leukemic LGL samples could be translated into protein, which functionally blocked Fas-mediated apoptosis. These results suggest that such decoy Fas receptors might contribute to the pathogenesis of LGL leukemia by blocking apoptosis of the leukemic cells. Previously, we found that constitutive signal transducer and activator of transcription 3 (STAT3) activation resulting in up-regulation of antiapoptotic gene Mcl-1 might explain apoptotic resistance in leukemic LGL.28 Taken together, these results suggest that inhibition of apoptotic signaling may be a common pathway of disease causation in this disorder. Autoimmune manifestations are a prominent and characteristic feature of LGL leukemia. Serologic abnormalities are also frequent, including autoantibodies such as rheumatoid factor and antinuclear antibody, circulating immune complexes, and polyclonal hypergammaglobulinemia. Autoimmune disease, particularly rheumatoid arthritis, occurs frequently in LGL leukemia. Indeed, 10 patients in this study had classic rheumatoid arthritis. These serologic features are also observed in animal models of Fas deficiency resulting from function-ablating mutations in Fas.13 The precise mechanisms leading to autoimmunity in these animal models of Fas deficiency are not entirely resolved. Therefore, it is not possible to conclude from our study that high levels of decoy Fas molecules contribute to the observed autoimmune features in our patients with LGL leukemia. Nevertheless, our results suggest that a similar autoimmune lymphoproliferative phenotype may also occur in diseases associated with defective Fas apoptosis secondary to blockade by soluble Fas.
The Flow Cytometry, Molecular Biology, and Biostatitics Cores at H. Lee Moffitt Cancer Center and Research Institute were used in the course of this work.
Submitted September 21, 2001; accepted April 4, 2002.
Supported by a Veterans Administration Merit Review Grant, by National Cancer Institute grants CA83947 and CA90633, and the American Cancer Society's Institutional Research Grant 93-032.
The publication costs of this article were defrayed in part by page charge payment. Therefore, and solely to indicate this fact, this article is hereby marked "advertisement" in accordance with 18 U.S.C. section 1734.
Reprints: Thomas P. Loughran, Jr., MRC-4047, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Dr, Tampa, FL 33612; e-mail: loughrat{at}moffitt.usf.edu.
1. Cleveland JL, Ihle JN. Contenders in FasL/TNF death signaling. Cell. 1995;19:1479-1482. 2. Lynch DH, Ramsdell F, Alderson MR. Fas and FasL in the homeostatic regulation of immune responses. Immunol Today. 1995;16:569-574[CrossRef][Medline] [Order article via Infotrieve]. 3. Van Parijs L, Abbas A.K. Role of Fas-mediated cell death in the regulation of immune responses. Curr Opin Immunol. 1996;8:355-361[CrossRef][Medline] [Order article via Infotrieve]. 4. Abbas AK. Die and let live: eliminating dangerous lymphocytes. Cell. 1996;84:655-657[CrossRef][Medline] [Order article via Infotrieve].
5.
Thompson CB.
Apoptosis in the pathogenesis and treatment of disease.
Science.
1995;267:1456-1462 6. Suda T, Takahashi T, Golstein P, Nagata S. Molecular cloning and expression of the Fas ligand, a novel member of the tumor necrosis factor family. Cell. 1993;75:1169-1178[CrossRef][Medline] [Order article via Infotrieve].
7.
Nagata S, Golstein P.
The Fas death factor.
Science.
1995;267:1449-1456
8.
Watanabe D, Suda T, Nagata S.
Expression of Fas in B cells of the mouse germinal center and Fas-dependent killing of activated B cells.
Int Immunol.
1995;7:1949-1956 9. Tanaka M, Suda T, Takahashi T, Nagata S. Expression of the functional soluble form of human fas ligand in activated lymphocytes. EMBO J. 1995;14:1129-1135[Medline] [Order article via Infotrieve]. 10. Suda T, Okazaki T, Naito Y, et al. Expression of the Fas ligand in cells of T cell lineage. J Immunol. 1995;154:3806-3813[Abstract]. 11. Lowin B, Hahne M, Mattman C, Tschopp J. Cytolytic T-cell cytotoxicity is mediated through perforin and Fas lytic pathways. Nature. 1994;370:650-652[CrossRef][Medline] [Order article via Infotrieve]. 12. Itoh N, Yonehara S, Ishii A, et al. The polypeptide encoded by the cDNA for human cell surface antigen Fas can mediate apoptosis. Cell. 1991;66:233-243[CrossRef][Medline] [Order article via Infotrieve]. 13. Watanabe-Fukunga R, Brannan CI, Copeland NG, Jenkins NA, Nagata S. Lymphoproliferation disorder in mice explained by defects in Fas antigen that mediates apoptosis. Nature. 1992;356:314-317[CrossRef][Medline] [Order article via Infotrieve] 14. Watanabe D, Suda T, Hashimoto H, Nagata S. Constitutive activation of the Fas ligand gene in mouse lymphoproliferative disorders. EMBO J. 1995;14:12-18[Medline] [Order article via Infotrieve]. 15. Nagata S, Suda T. Fas and Fas ligand: lpr and gld mutations. Immunol Today. 1995;16:39-43[CrossRef][Medline] [Order article via Infotrieve].
16.
Loughran TP Jr.
Clonal diseases of large granular lymphocytes.
Blood.
1993;82:1-14 17. Phillips JH, Lanier LL. Lectin-dependent anti-CD3 induced cytotoxicity are preferentially mediated by peripheral blood cytotoxic T lymphocytes expressing Leu-7 antigen. J Immunol. 1986;136:1579-1585[Abstract]. 18. Singer GG, Abbas AK. The Fas antigen is involved in peripheral but not thymic deletion of T lymphocytes in T cell receptor transgenic mice. Immunity. 1994;1:365-371[CrossRef][Medline] [Order article via Infotrieve].
19.
Lamy T, Liu JH, Landowski TH, Dalton WS, Loughran TP Jr.
Dysregulation of CD95/CD95 ligand-apoptotic pathway in CD3+ large granular lymphocyte leukemia.
Blood.
1998;92:4771-4777
20.
Rieux-Laucat F, Le Deist F, Hivroz C, et al.
Mutations in Fas associated with human lymphoproliferative syndrome and autoimmunity.
Science.
1995;268:1347-1349 21. Fisher GH, Rosenberg FJ, Straus SE, et al. Dominant interfering Fas gene mutations impair apoptosis in a human autoimmune lymphoproliferative syndrome. Cell. 1995;81:935-946[CrossRef][Medline] [Order article via Infotrieve].
22.
Cheng J, Zhou T, Liu C, et al.
Protection from Fas-mediated apoptosis by a soluble form of the Fas molecule.
Science.
1994;263:1759-1762 23. Cascino I, Fiucci G, Papoff G, Ruberti G. Three functional soluble forms of the human apoptosis-inducing Fas molecule are produced by alternative splicing. J Immunol. 1995;154:2706-2713[Abstract]. 24. Ruberti G, Cascino I, Papoff G, Eramo A. Fas splicing variants and their effect on apoptosis. Adv Exp Med Biol. 1996;406:125-134[Medline] [Order article via Infotrieve]. 25. Papoff G, Cascino I, Eramo A, Starace G, Lynch DH, Ruberti G. An N-terminal domain shared by Fas/Apo-1 (CD95) soluble variants prevents cell death in vitro. J Immunol. 1996;156:4622-4630[Abstract].
26.
Knipping E, Debatin KM, Stricker K, Heilig B, Eder A, Krammer PH.
Identification of soluble APO-1 in supernatants of human B- and T-cell lines and increased serum levels in B- and T-cell leukemias.
Blood.
1995;85:1562-1569 27. Knipping E, Krammer PH, Onel KB, Lehman TJ, Mysler E, Elkon KB. Levels of soluble Fas/APO-1/CD95 in systemic lupus erythematosus and juvenile rheumatoid arthritis. Arthritis Rheum. 1995;38:1735-1737[Medline] [Order article via Infotrieve]. 28. Epling-Burnette PK, Liu JH, Catlett-Falcone R, et al. Inhibition of STAT3 signaling leads to apoptosis of leukemic large granular lymphocytes and decreased Mcl-l expression. J Clin Invest. 2001;107:351-362[Medline] [Order article via Infotrieve].
© 2002 by The American Society of Hematology.
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
|
 |
|
  X. Chen, F. Bai, L. Sokol, J. Zhou, A. Ren, J. S. Painter, J. Liu, D. A. Sallman, Y. A. Chen, J. A. Yoder, et al. A critical role for DAP10 and DAP12 in CD8+ T cell-mediated tissue damage in large granular lymphocyte leukemia Blood, April 2, 2009; 113(14): 3226 - 3234. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. V. Shah, R. Zhang, R. Irby, R. Kothapalli, X. Liu, T. Arrington, B. Frank, N. H. Lee, and T. P. Loughran Jr Molecular profiling of LGL leukemia reveals role of sphingolipid signaling in survival of cytotoxic lymphocytes Blood, August 1, 2008; 112(3): 770 - 781. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. W. Wlodarski, Z. Nearman, A. Jankowska, N. Babel, J. Powers, P. Leahy, H.-D. Volk, and J. P. Maciejewski Phenotypic differences between healthy effector CTL and leukemic LGL cells support the notion of antigen-triggered clonal transformation in T-LGL leukemia J. Leukoc. Biol., March 1, 2008; 83(3): 589 - 601. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. L. Peng Fas (CD95)-related apoptosis and rheumatoid arthritis Rheumatology, January 1, 2006; 45(1): 26 - 30. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. W. Wlodarski, C. O'Keefe, E. C. Howe, A. M. Risitano, A. Rodriguez, I. Warshawsky, T. P. Loughran Jr, and J. P. Maciejewski Pathologic clonal cytotoxic T-cell responses: nonrandom nature of the T-cell-receptor restriction in large granular lymphocyte leukemia Blood, October 15, 2005; 106(8): 2769 - 2780. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Roesler, J.-M. Izquierdo, M. Ryser, A. Rosen-Wolff, M. Gahr, J. Valcarcel, M. J. Lenardo, and L. Zheng Haploinsufficiency, rather than the effect of an excessive production of soluble CD95 (CD95{Delta}TM), is the basis for ALPS Ia in a family with duplicated 3' splice site AG in CD95 intron 5 on one allele Blood, September 1, 2005; 106(5): 1652 - 1659. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. G. Rose and N. Berliner T-Cell Large Granular Lymphocyte Leukemia and Related Disorders Oncologist, June 1, 2004; 9(3): 247 - 258. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. L. O'Keefe, M. Plasilova, M. Wlodarski, A. M. Risitano, A. R. Rodriguez, E. Howe, N. S. Young, E. Hsi, and J. P. Maciejewski Molecular Analysis of TCR Clonotypes in LGL: A Clonal Model for Polyclonal Responses J. Immunol., February 1, 2004; 172(3): 1960 - 1969. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
 |
 |
|||||||
 |
 |
 |
 |
 |
 |
 |
 |
||
| Copyright © 2002 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||
Top
Abstract
Introduction
