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Stohl W, Elliott JE, Li L, Podack ER, Lynch DH, Jacob CO. Impaired nonrestricted cytolytic activity in systemic lupus erythematosus: involvement of a pathway independent of Fas, tumor necrosis factor, and extracellular ATP that is associated with little detectable perforin. ARTHRITIS AND RHEUMATISM 1997; 40:1130-7. [PMID: 9182924 DOI: 10.1002/1529-0131(199706)40:6<1130::aid-art17>3.0.co;2-o] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To determine the cytolytic effector pathway involved in impaired generation of nonrestricted cytolytic activity in systemic lupus erythematosus (SLE). METHODS Peripheral blood mononuclear cells (PBMC) from normal subjects and SLE patients were stimulated in vitro with anti-CD3 monoclonal antibody (MAb) and interleukin-2 to promote the generation of nonrestricted cytolytic activity. On day 13 of culture, the PBMC were assayed for cytolytic activity against Fas-Daudi cells and Fas+ Jurkat cells. The effects on cytotoxicity of calcium chelation, antagonist anti-Fas MAb, tumor necrosis factor (TNF) alpha and beta, and ATP were measured. Intracellular perforin expression was determined by intracellular staining, and perforin messenger RNA levels were determined by quantitative competitive reverse transcription-polymerase chain reaction. RESULTS We demonstrated the existence of a cytolytic pathway that is independent of Fas, TNF alpha, TNF beta, and ATP, but is dependent upon extracellular calcium. Despite its calcium dependence, this pathway is associated with low-to-undetectable levels of perforin. CONCLUSION Impaired generation of nonrestricted cytolytic activity in SLE is likely due to decreased activity of this Fas-, TNF alpha-, TNF beta-, ATP-independent pathway associated with very low levels of perforin.
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Stohl W, Elliott JE, Li L, Podack ER, Lynch DH, Jacob CO. Impaired nonrestricted cytolytic activity in systemic lupus erythematosus. ACTA ACUST UNITED AC 1997. [DOI: 10.1002/art.1780400618] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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78
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Badley AD, Dockrell D, Simpson M, Schut R, Lynch DH, Leibson P, Paya CV. Macrophage-dependent apoptosis of CD4+ T lymphocytes from HIV-infected individuals is mediated by FasL and tumor necrosis factor. J Exp Med 1997; 185:55-64. [PMID: 8996241 PMCID: PMC2196110 DOI: 10.1084/jem.185.1.55] [Citation(s) in RCA: 198] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Apoptosis of bystander uninfected CD4+ T lymphocytes by neighboring HIV-infected cells is observed in cell culture and in lymphoid tissue of HIV-infected individuals. This study addresses whether antigen-presenting cells such as human macrophages mediate apoptosis of CD4+ T cells from HIV-infected individuals. Uninfected human macrophages, and to a larger degree, HIV-infected macrophages mediate apoptosis of T cells from HIV-infected, but not from uninfected control individuals. This macrophage-dependent killing targets CD4+, but not CD8+ T lymphocytes from HIV-infected individuals, and direct contact between macrophages and lymphocytes is required. Additional analyses indicated that the apoptosis-inducing ligands, FasL and tumor necrosis factor (TNF), mediate this macrophage-induced apoptosis of CD4+ T cells. These results support a role for macrophage-associated FasL and TNF in the selective depletion of CD4+ T cells in HIV-infected individuals.
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79
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Lu L, Qian S, Starzl TE, Lynch DH, Thomson AW. Blocking of the B7-CD28 pathway increases the capacity of FasL+ (CD95L+) dendritic cells to kill alloactivated T cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1997; 417:275-82. [PMID: 9286373 DOI: 10.1007/978-1-4757-9966-8_45] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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80
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Lu L, Qian S, Hershberger P, Rudert WA, Li Y, Chambers FG, Starzl TE, Lynch DH, Thomson AW. Blocking of the B7-CD28 pathway increases apoptosis induced in activated T cells by in vitro-generated CD95L (FasL) positive dendritic cells. Transplant Proc 1997; 29:1094-5. [PMID: 9123216 PMCID: PMC2965041 DOI: 10.1016/s0041-1345(96)00424-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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81
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Maraskovsky E, Teepe M, Morrissey PJ, Braddy S, Miller RE, Lynch DH, Peschon JJ. Impaired survival and proliferation in IL-7 receptor-deficient peripheral T cells. THE JOURNAL OF IMMUNOLOGY 1996. [DOI: 10.4049/jimmunol.157.12.5315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Mice genetically deficient in IL-7R(alpha) are highly lymphopenic in the peripheral lymphoid organs. The functional competence of T cells that have developed in the absence of an IL-7R signal was investigated. Three important observations were made using several in vitro activation regimens. First, stimulation of T cells from IL-7R -/- mice at limiting dilution with immobilized Abs to CD3, CD4 or CD8, and CD18 revealed a six- to sevenfold reduction in the frequency of clonogenic T cells compared with T cells from IL-7R +/+ mice. IL-7R -/- T cells were also significantly less responsive to alloantigen as well as to receptor-independent stimuli such as PMA and ionomycin. Furthermore, the average clone size of single IL-7R -/- T cells was 50% smaller than that of IL-7R +/+ T cells. These data suggest that the reduced clonogenicity was predominantly due to intrinsic deficiencies in the ability of IL-7R -/- T cells to proliferate upon stimulation. Second, analysis of the kinetics of cell growth of IL-7R -/- T cells revealed that a significant proportion of T cells failed to proliferate within the first 72 h of in vitro stimulation, with the majority undergoing programmed cell death. Third, both clonogenic IL-7 -/- T cells and IL-7R +/+ T cells showed a similar proliferative response in the presence of IL-2 and similar survival kinetics, indicating that a subpopulation of IL-7R -/- T cells is functionally mature. We propose that an absence of IL-7R signaling not only affects T cell development in the thymus, but also results in the accumulation of functionally inactive T cells in the periphery.
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82
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Maraskovsky E, Teepe M, Morrissey PJ, Braddy S, Miller RE, Lynch DH, Peschon JJ. Impaired survival and proliferation in IL-7 receptor-deficient peripheral T cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1996; 157:5315-23. [PMID: 8955178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Mice genetically deficient in IL-7R(alpha) are highly lymphopenic in the peripheral lymphoid organs. The functional competence of T cells that have developed in the absence of an IL-7R signal was investigated. Three important observations were made using several in vitro activation regimens. First, stimulation of T cells from IL-7R -/- mice at limiting dilution with immobilized Abs to CD3, CD4 or CD8, and CD18 revealed a six- to sevenfold reduction in the frequency of clonogenic T cells compared with T cells from IL-7R +/+ mice. IL-7R -/- T cells were also significantly less responsive to alloantigen as well as to receptor-independent stimuli such as PMA and ionomycin. Furthermore, the average clone size of single IL-7R -/- T cells was 50% smaller than that of IL-7R +/+ T cells. These data suggest that the reduced clonogenicity was predominantly due to intrinsic deficiencies in the ability of IL-7R -/- T cells to proliferate upon stimulation. Second, analysis of the kinetics of cell growth of IL-7R -/- T cells revealed that a significant proportion of T cells failed to proliferate within the first 72 h of in vitro stimulation, with the majority undergoing programmed cell death. Third, both clonogenic IL-7 -/- T cells and IL-7R +/+ T cells showed a similar proliferative response in the presence of IL-2 and similar survival kinetics, indicating that a subpopulation of IL-7R -/- T cells is functionally mature. We propose that an absence of IL-7R signaling not only affects T cell development in the thymus, but also results in the accumulation of functionally inactive T cells in the periphery.
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83
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Lynch DH, Campbell KA, Miller RE, Badley AD, Paya CV. FasL/Fas and TNF/TNFR interactions in the regulation of immune responses and disease. BEHRING INSTITUTE MITTEILUNGEN 1996:175-84. [PMID: 8950475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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84
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Foote LC, Schneider TJ, Fischer GM, Wang JK, Rasmussen B, Campbell KA, Lynch DH, Ju ST, Marshak-Rothstein A, Rothstein TL. Intracellular signaling for inducible antigen receptor-mediated Fas resistance in B cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1996; 157:1878-85. [PMID: 8757305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
CD40 ligand-activated B cells are sensitive targets for CD4+ Th1 effector cells that kill in a Fas-dependent fashion. Susceptibility to apoptosis is counteracted by Ag receptor binding that produces a state of resistance to Fas engagement in otherwise sensitive targets. In the present study, protection from Th1-mediated apoptosis was found to be induced by protein kinase C and calcium signals, which in combination mimicked the level of Fas resistance produced by surface Ig engagement. Signaling for Fas resistance did not alter Fas expression. Furthermore, B cells that were protected against Th1-mediated apoptosis were also resistant to apoptosis mediated by soluble, rFas ligand. Taken together, these results indicate that signaling for protection against Fas-mediated apoptosis does not depend on alteration of the interaction between B cell target and Th1 effector populations. Instead, surface IgM-derived protein kinase C and calcium signals appear to produce an intracellular change in the Fas signaling pathway that develops over a period of hours and interferes with the apoptotic process through a mechanism that depends on protein synthesis.
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85
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Herry I, Bonay M, Bouchonnet F, Schuller MP, Lecossier D, Tazi A, Lynch DH, Hance AJ. Extensive apoptosis of lung T-lymphocytes maintained in vitro. Am J Respir Cell Mol Biol 1996; 15:339-47. [PMID: 8810637 DOI: 10.1165/ajrcmb.15.3.8810637] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The phenotypic and functional properties of T cells recovered from the lung indicate that many of these cells have been recently activated. Because such recently activated cells are often more susceptible to death through apoptotic mechanisms, the viability of lung T cells recovered from bronchoalveolar lavage and those isolated from peripheral blood was compared. The progressive loss of viable cells following in vitro culture was considerably greater for lavage T cells than blood T cells, and was observed for cells from both patients with sarcoidosis and control subjects. Following 4 days of culture, 76 +/- 14% of blood cells, but only 31 +/- 13% of lavage cells from sarcoid patients were viable. The evaluation of morphologic features and flow cytometric profiles, as well as the demonstration of typical oligonucleosomal fragmentation of DNA extracted from these cells indicated that lavage T cells were dying by apoptotic mechanisms. CD4+ T cells appeared to be particularly sensitive to apoptosis. Most lavage T cells from controls and sarcoid patients expressed Fas (CD95) antigen. Although some lavage T Cells were sensitive to Fas-induced apoptosis, the viability of lavage T cells was not improved by incubation in the presence of a monoclonal antibody that inhibits Fas-induced apoptosis. Culture in the presence of interleukin 2 did prevent, at least in part, the progressive death of lavage T cells, suggesting that the viability of T cells in the lung may depend on the presence of locally delivered trophic signals. These studies emphasize that T cells on the alveolar surface are in a different state of activation and differentiation compared with that of circulating T cells, and offer a possible explanation for the impaired functional capacities observed for lavage T cells in some in vitro studies.
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86
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Foote LC, Schneider TJ, Fischer GM, Wang JK, Rasmussen B, Campbell KA, Lynch DH, Ju ST, Marshak-Rothstein A, Rothstein TL. Intracellular signaling for inducible antigen receptor-mediated Fas resistance in B cells. THE JOURNAL OF IMMUNOLOGY 1996. [DOI: 10.4049/jimmunol.157.5.1878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
CD40 ligand-activated B cells are sensitive targets for CD4+ Th1 effector cells that kill in a Fas-dependent fashion. Susceptibility to apoptosis is counteracted by Ag receptor binding that produces a state of resistance to Fas engagement in otherwise sensitive targets. In the present study, protection from Th1-mediated apoptosis was found to be induced by protein kinase C and calcium signals, which in combination mimicked the level of Fas resistance produced by surface Ig engagement. Signaling for Fas resistance did not alter Fas expression. Furthermore, B cells that were protected against Th1-mediated apoptosis were also resistant to apoptosis mediated by soluble, rFas ligand. Taken together, these results indicate that signaling for protection against Fas-mediated apoptosis does not depend on alteration of the interaction between B cell target and Th1 effector populations. Instead, surface IgM-derived protein kinase C and calcium signals appear to produce an intracellular change in the Fas signaling pathway that develops over a period of hours and interferes with the apoptotic process through a mechanism that depends on protein synthesis.
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87
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Black RA, Durie FH, Otten-Evans C, Miller R, Slack JL, Lynch DH, Castner B, Mohler KM, Gerhart M, Johnson RS, Itoh Y, Okada Y, Nagase H. Relaxed specificity of matrix metalloproteinases (MMPS) and TIMP insensitivity of tumor necrosis factor-alpha (TNF-alpha) production suggest the major TNF-alpha converting enzyme is not an MMP. Biochem Biophys Res Commun 1996; 225:400-5. [PMID: 8753775 DOI: 10.1006/bbrc.1996.1186] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Tumor necrosis factor-alpha is released from cells by a proteolytic cleavage. Previous work suggested that a specific, non-matrix metalloproteinase carries out this cleavage, but matrix metalloproteinases have also been implicated. In this paper, we report that none of the matrix metalloproteinases tested cleaved peptide substrates as specifically as the non-matrix metalloproteinase. A matrix metalloproteinase did process tumor necrosis factor-alpha extracted from COS cells, but neither tissue inhibitor of metalloproteinases-1 nor -2 blocked tumor necrosis factor-alpha processing by human monocytes. Moreover, tissue inhibitor of metalloproteinases-1 had at most a partial effect on the in vivo release of the cytokine in mice. We conclude that a non-matrix metalloproteinase is the major physiological tumor necrosis factor-alpha convertase.
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88
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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. THE JOURNAL OF IMMUNOLOGY 1996. [DOI: 10.4049/jimmunol.156.12.4622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Fas/Apo-1 molecule, also designated as CD95, is a member of the TNF receptor family. Fas cross-linking by its natural ligand or by agonistic mAbs results in rapid induction of apoptosis in susceptible cells. in addition to the Fas full-length mRNA, human activated PBMC and tumor cell lines express several mRNA Fas variants that derive from alternative splicing of the primary transcript. All five variants identified, two of which are newly described here, code for soluble proteins that, with the exception of FasTMDel, are truncated in the extracytoplasmic region and possess short C-terminal amino acid sequences corresponding to a different reading frame. We have identified Abs that recognize all splicing variants and established a sandwich ELISA by which the soluble Fas molecules could be detected in culture supernatants of transfected cell lines and in PBMC following T cell activation. Next, we have studied in detail the functional role of these variants by apoptosis inhibition studies. We found that all soluble proteins block the apoptosis induced by either an agonistic Ab or, more importantly, by the natural Fas ligand in Fas-positive sensitive cell lines. interestingly, this functional property can be assigned to the first 49 amino acids of the mature protein that is the only region shared by the five soluble Fas molecules.
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89
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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. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1996; 156:4622-30. [PMID: 8648105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Fas/Apo-1 molecule, also designated as CD95, is a member of the TNF receptor family. Fas cross-linking by its natural ligand or by agonistic mAbs results in rapid induction of apoptosis in susceptible cells. in addition to the Fas full-length mRNA, human activated PBMC and tumor cell lines express several mRNA Fas variants that derive from alternative splicing of the primary transcript. All five variants identified, two of which are newly described here, code for soluble proteins that, with the exception of FasTMDel, are truncated in the extracytoplasmic region and possess short C-terminal amino acid sequences corresponding to a different reading frame. We have identified Abs that recognize all splicing variants and established a sandwich ELISA by which the soluble Fas molecules could be detected in culture supernatants of transfected cell lines and in PBMC following T cell activation. Next, we have studied in detail the functional role of these variants by apoptosis inhibition studies. We found that all soluble proteins block the apoptosis induced by either an agonistic Ab or, more importantly, by the natural Fas ligand in Fas-positive sensitive cell lines. interestingly, this functional property can be assigned to the first 49 amino acids of the mature protein that is the only region shared by the five soluble Fas molecules.
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90
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Glass A, Walsh CM, Lynch DH, Clark WR. Regulation of the Fas lytic pathway in cloned CTL. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1996; 156:3638-44. [PMID: 8621897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cloned murine CTL activated via the TCR or by PMA and ionomycin up-regulate surface Fas ligand and show an increased ability to kill non-Ag-specific Fas+ target cells. This up-regulation starts after 45 to 60 min and has a t1/2 for reversal of about 90 min. Up-regulation of lytic function is accompanied by up-regulation of Fas ligand on the CTL surface, which can be blocked by protein synthesis inhibitors. When up-regulation of Fas lytic function was induced by PMA and ionomycin, EGTA blocked both activation of lytic function and expression of Fas ligand detected by FACS analysis. However, when up-regulation was induced by specific Ag, EGTA blocked activation of lytic function, but not up-regulation of Fas ligand. Moreover, EL-4 cells have very high levels of surface Fas ligand, although they are not cytotoxic. Thus, expression of surface Fas ligand may be required, but not sufficient, for Fas-mediated lysis.
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91
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Glass A, Walsh CM, Lynch DH, Clark WR. Regulation of the Fas lytic pathway in cloned CTL. THE JOURNAL OF IMMUNOLOGY 1996. [DOI: 10.4049/jimmunol.156.10.3638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Cloned murine CTL activated via the TCR or by PMA and ionomycin up-regulate surface Fas ligand and show an increased ability to kill non-Ag-specific Fas+ target cells. This up-regulation starts after 45 to 60 min and has a t1/2 for reversal of about 90 min. Up-regulation of lytic function is accompanied by up-regulation of Fas ligand on the CTL surface, which can be blocked by protein synthesis inhibitors. When up-regulation of Fas lytic function was induced by PMA and ionomycin, EGTA blocked both activation of lytic function and expression of Fas ligand detected by FACS analysis. However, when up-regulation was induced by specific Ag, EGTA blocked activation of lytic function, but not up-regulation of Fas ligand. Moreover, EL-4 cells have very high levels of surface Fas ligand, although they are not cytotoxic. Thus, expression of surface Fas ligand may be required, but not sufficient, for Fas-mediated lysis.
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92
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Mollereau B, Deckert M, Déas O, Rieux-Laucat F, Hirsch F, Bernard A, Fischer A, Lynch DH, Charpentier B, Le Deist F, Senik A. CD2-induced apoptosis in activated human peripheral T cells: a Fas-independent pathway that requires early protein tyrosine phosphorylation. THE JOURNAL OF IMMUNOLOGY 1996. [DOI: 10.4049/jimmunol.156.9.3184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Short-term activated peripheral T lymphocytes are susceptible to apoptotic cell death triggered by CD2 mAbs. The aim of this study was to examine whether the CD2-mediated pathway of apoptosis is linked to the Fas death pathway, as this is the case for CD3/TCR-triggered apoptosis in several models of T cells. Using T lymphocytes from patients harboring Fas gene mutations and displaying a profound defect in Fas signaling of cell death, we show that CD2- (but not CD3-) mediated apoptosis still proceeds normally. In normal activated T cells, CD3-mediated apoptosis is prevented by reagents that block the Fas/Fas-ligand interaction, namely soluble M3 (an antagonistic anti-Fas mAb) and soluble human Fas.Fc, a fusion protein able to bind released Fas-ligand. In contrast, CD2 signaling of apoptosis resists these blocking agents. Neither new protein synthesis nor the activation of calcineurin was required for CD2- and Fas-mediated apoptosis, suggesting that latent cytoplasmic "death" molecules were activated upon stimulation of the cells. In both cases, protein tyrosine kinases were transiently activated, as is exemplified by the autophosphorylation and exokinase activity of p56lck, yielding overlapping yet nonidentical profiles of protein tyrosine phosphorylation. Pretreating the cells with herbimycin A, before the addition of the apoptotic stimuli, almost completely inhibited CD2 transmembrane signaling of apoptosis, but left intact Fas-induced apoptosis. Our data suggest that CD2 is a Fas-independent cell death pathway that might contribute directly to the elimination of T cells expanding during an immune reaction.
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93
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Mollereau B, Deckert M, Déas O, Rieux-Laucat F, Hirsch F, Bernard A, Fischer A, Lynch DH, Charpentier B, Le Deist F, Senik A. CD2-induced apoptosis in activated human peripheral T cells: a Fas-independent pathway that requires early protein tyrosine phosphorylation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1996; 156:3184-90. [PMID: 8617939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Short-term activated peripheral T lymphocytes are susceptible to apoptotic cell death triggered by CD2 mAbs. The aim of this study was to examine whether the CD2-mediated pathway of apoptosis is linked to the Fas death pathway, as this is the case for CD3/TCR-triggered apoptosis in several models of T cells. Using T lymphocytes from patients harboring Fas gene mutations and displaying a profound defect in Fas signaling of cell death, we show that CD2- (but not CD3-) mediated apoptosis still proceeds normally. In normal activated T cells, CD3-mediated apoptosis is prevented by reagents that block the Fas/Fas-ligand interaction, namely soluble M3 (an antagonistic anti-Fas mAb) and soluble human Fas.Fc, a fusion protein able to bind released Fas-ligand. In contrast, CD2 signaling of apoptosis resists these blocking agents. Neither new protein synthesis nor the activation of calcineurin was required for CD2- and Fas-mediated apoptosis, suggesting that latent cytoplasmic "death" molecules were activated upon stimulation of the cells. In both cases, protein tyrosine kinases were transiently activated, as is exemplified by the autophosphorylation and exokinase activity of p56lck, yielding overlapping yet nonidentical profiles of protein tyrosine phosphorylation. Pretreating the cells with herbimycin A, before the addition of the apoptotic stimuli, almost completely inhibited CD2 transmembrane signaling of apoptosis, but left intact Fas-induced apoptosis. Our data suggest that CD2 is a Fas-independent cell death pathway that might contribute directly to the elimination of T cells expanding during an immune reaction.
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94
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Wilson DJ, Fortner KA, Lynch DH, Mattingly RR, Macara IG, Posada JA, Budd RC. JNK, but not MAPK, activation is associated with Fas-mediated apoptosis in human T cells. Eur J Immunol 1996; 26:989-94. [PMID: 8647190 DOI: 10.1002/eji.1830260505] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Fas is a cell surface molecule that is expressed on a wide array of cell types and triggers apoptosis. While in most situations Fas ligation activates programmed cell death, on resting T lymphocytes it can co-stimulate proliferation with the T cell receptor (TCR)/CD3 complex. This incongruity suggests that Fas may elicit signaling events that overlap with those used by proliferation cues. We observe that in the human T cell line Jurkat and in human peripheral blood lymphocytes, Fas stimulation does not signal by the Ras/Raf-1/mitogen-activated protein kinase (MAPK) pathway or by increased intracellular calcium. Rather, Fas ligation strongly activates Jun kinase (JNK). This activity, as well as Fas-induced apoptosis, is blocked by increased levels of cAMP. The balance between proliferation and apoptosis by Fas triggering of T lymphocytes may therefore reflect a signaling ratio between TCR activation of the Ras/Raf-1/MAPK pathway versus JNK activation by Fas.
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95
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Eischen CM, Schilling JD, Lynch DH, Krammer PH, Leibson PJ. Fc receptor-induced expression of Fas ligand on activated NK cells facilitates cell-mediated cytotoxicity and subsequent autocrine NK cell apoptosis. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1996; 156:2693-9. [PMID: 8609385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Ligation of the Fc gamma R on NK cells by Ab-coated target cells initiates a mode of killing referred to as antibody-dependent cell-mediated cytotoxicity (ADCC). There is clear evidence that the release from NK cells of granules containing pore-forming proteins and serine proteases can result in the rapid (within minutes) cell death of Ab-coated targets. However, little information is available as to whether NK cells can initiate subsequent killing through granule-independent mechanisms and as to the mechanisms that down-regulate NK cell-mediated responses. We demonstrate in this study that FcR stimulation of activated human NK cells not only induces granule exocytosis, but also subsequently results in the transcriptional up-regulation of Fas ligand. These FcR-stimulated NK cells can then kill targets that bear Fas (CD95/APO-1), as this cytotoxicity can be inhibited by blocking Abs to the Fas receptor. In addition, as resting NK cells become activated, their Fas receptors become competent to deliver autocrine suicide signals. We demonstrate in this work that the interaction of Fas ligand on the FcR-stimulated NK cells with their Fas receptors can result in apoptosis of the NK cells. These results suggest that the FcR-induced expression of Fas ligand on activated NK cells can critically influence the capacity of these cells to mediate paracrine and autocrine cell death.
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96
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Eischen CM, Schilling JD, Lynch DH, Krammer PH, Leibson PJ. Fc receptor-induced expression of Fas ligand on activated NK cells facilitates cell-mediated cytotoxicity and subsequent autocrine NK cell apoptosis. THE JOURNAL OF IMMUNOLOGY 1996. [DOI: 10.4049/jimmunol.156.8.2693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Ligation of the Fc gamma R on NK cells by Ab-coated target cells initiates a mode of killing referred to as antibody-dependent cell-mediated cytotoxicity (ADCC). There is clear evidence that the release from NK cells of granules containing pore-forming proteins and serine proteases can result in the rapid (within minutes) cell death of Ab-coated targets. However, little information is available as to whether NK cells can initiate subsequent killing through granule-independent mechanisms and as to the mechanisms that down-regulate NK cell-mediated responses. We demonstrate in this study that FcR stimulation of activated human NK cells not only induces granule exocytosis, but also subsequently results in the transcriptional up-regulation of Fas ligand. These FcR-stimulated NK cells can then kill targets that bear Fas (CD95/APO-1), as this cytotoxicity can be inhibited by blocking Abs to the Fas receptor. In addition, as resting NK cells become activated, their Fas receptors become competent to deliver autocrine suicide signals. We demonstrate in this work that the interaction of Fas ligand on the FcR-stimulated NK cells with their Fas receptors can result in apoptosis of the NK cells. These results suggest that the FcR-induced expression of Fas ligand on activated NK cells can critically influence the capacity of these cells to mediate paracrine and autocrine cell death.
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97
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Mitra D, Steiner M, Lynch DH, Staiano-Coico L, Laurence J. HIV-1 upregulates Fas ligand expression in CD4+ T cells in vitro and in vivo: association with Fas-mediated apoptosis and modulation by aurintricarboxylic acid. Immunology 1996; 87:581-5. [PMID: 8675212 PMCID: PMC1384136 DOI: 10.1046/j.1365-2567.1996.510589.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
CD4+ T-lymphocyte apoptosis has been associated with human immunodeficiency virus (HIV)-1 infection in vitro, paralleling the expression of Fas (APO-1, CD95) on peripheral blood mononuclear cells from patients with HIV disease. However, the link between Fas induction, T-cell activation, and cell death is unclear. We document, for the first time, marked upregulation of expression of mRNA for the ligand for Fas in peripheral blood mononuclear cells from HIV seropositive individuals, and demonstrate the ability of HIV infection to induce such expression in CD4+ T cells in vitro. We also define the relevance of this expression to HIV-mediated CD4+ T cell death. Our ability to downregulate Fas ligand message and suppress HIV-mediated apoptosis with aurintricarboxylic acid, a clinically used protease inhibitor with known activity against programmed cell death in other systems, may open up a new area of therapy for HIV infection.
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Laurence J, Mitra D, Steiner M, Lynch DH, Siegal FP, Staiano-Coico L. Apoptotic depletion of CD4+ T cells in idiopathic CD4+ T lymphocytopenia. J Clin Invest 1996; 97:672-80. [PMID: 8609222 PMCID: PMC507103 DOI: 10.1172/jci118464] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Progressive loss of CD4+ T lymphocytes, accompanied by opportunistic infections characteristic of the acquired immune deficiency syndrome, ahs been reported in the absence of any known etiology. The pathogenesis of this syndrome, a subset of idiopathic CD4+ T lymphocytopenia (ICL), is uncertain. We report that CD4+ T cells from seven of eight ICL patients underwent accelerated programmed cell death, a process facilitated by T cell receptor cross-linking. Apoptosis was associated with enhanced expression of Fas and Fas ligand in unstimulated cell populations, and partially inhibited by soluble anti-Fas mAb. In addition, apoptosis was suppressed by aurintricarboxylic acid, an inhibitor of calcium-dependent endonucleases and proteases, in cells from four of seven patients, The in vivo significance of these findings was supported by three factors: the absence of accelerated apoptosis in persons with stable, physiologic CD4 lymphopenia without clinical immune deficiency; detection of serum antihistone H2B autoantibodies, one consequence of DNA fragmentation, in some patients; and its selectivity, with apoptosis limited to the CD4 population in some, and occurring among CD8+ T cells predominantly in those individuals with marked depletion of both CD4+ T lymphocytes linked to clinical immune suppression have evidence for accelerated T cell apoptosis in vitro that may be pathophysiologic and amenable to therapy with apoptosis inhibitors.
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Lynch DH. The role of FasL and TNF in the homeostatic regulation of immune responses. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1996; 406:135-8. [PMID: 8910679 DOI: 10.1007/978-1-4899-0274-0_14] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Rothstein TL, Foote LC, Schneider TJ, Fischer GM, Jacobson BA, Lynch DH, Ju ST, Marshak-Rothstein A. Inducible resistance to Fas-mediated apoptosis in primary B lymphocytes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1996; 406:177-89. [PMID: 8910684 DOI: 10.1007/978-1-4899-0274-0_19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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