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Recek N, Andjelić S, Hojnik N, Filipič G, Lazović S, Vesel A, Primc G, Mozetič M, Hawlina M, Petrovski G, Cvelbar U. Microplasma Induced Cell Morphological Changes and Apoptosis of Ex Vivo Cultured Human Anterior Lens Epithelial Cells - Relevance to Capsular Opacification. PLoS One 2016; 11:e0165883. [PMID: 27832099 PMCID: PMC5104483 DOI: 10.1371/journal.pone.0165883] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 10/19/2016] [Indexed: 11/18/2022] Open
Abstract
Inducing selective or targeted cell apoptosis without affecting large number of neighbouring cells remains a challenge. A plausible method for treatment of posterior capsular opacification (PCO) due to remaining lens epithelial cells (LECs) by reactive chemistry induced by localized single electrode microplasma discharge at top of a needle-like glass electrode with spot size ~3 μm is hereby presented. The focused and highly-localized atmospheric pressure microplasma jet with electrode discharge could induce a dose-dependent apoptosis in selected and targeted individual LECs, which could be confirmed by real-time monitoring of the morphological and structural changes at cellular level. Direct cell treatment with microplasma inside the medium appeared more effective in inducing apoptosis (caspase 8 positivity and DNA fragmentation) at a highly targeted cell level compared to treatment on top of the medium (indirect treatment). Our results show that single cell specific micropipette plasma can be used to selectively induce demise in LECs which remain in the capsular bag after cataract surgery and thus prevent their migration (CXCR4 positivity) to the posterior lens capsule and PCO formation.
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Affiliation(s)
- Nina Recek
- Department of Surface Engineering and Optoelectronics (F4), Jožef Stefan Institute, Ljubljana, Slovenia
| | - Sofija Andjelić
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia
- * E-mail:
| | - Nataša Hojnik
- Department of Surface Engineering and Optoelectronics (F4), Jožef Stefan Institute, Ljubljana, Slovenia
| | - Gregor Filipič
- Department of Surface Engineering and Optoelectronics (F4), Jožef Stefan Institute, Ljubljana, Slovenia
| | - Saša Lazović
- Institute of Physics Belgrade, University of Belgrade, Belgrade, Serbia
| | - Alenka Vesel
- Department of Surface Engineering and Optoelectronics (F4), Jožef Stefan Institute, Ljubljana, Slovenia
| | - Gregor Primc
- Department of Surface Engineering and Optoelectronics (F4), Jožef Stefan Institute, Ljubljana, Slovenia
| | - Miran Mozetič
- Department of Surface Engineering and Optoelectronics (F4), Jožef Stefan Institute, Ljubljana, Slovenia
| | - Marko Hawlina
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia
| | - Goran Petrovski
- Stem Cells and Eye Research Laboratory, Department of Ophthalmology, Faculty of Medicine, University of Szeged, Szeged, Hungary
- Centre of Eye Research, Department of Ophthalmology, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - Uroš Cvelbar
- Department of Surface Engineering and Optoelectronics (F4), Jožef Stefan Institute, Ljubljana, Slovenia
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Gosak M, Markovič R, Fajmut A, Marhl M, Hawlina M, Andjelić S. The Analysis of Intracellular and Intercellular Calcium Signaling in Human Anterior Lens Capsule Epithelial Cells with Regard to Different Types and Stages of the Cataract. PLoS One 2015; 10:e0143781. [PMID: 26636768 PMCID: PMC4670133 DOI: 10.1371/journal.pone.0143781] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 11/09/2015] [Indexed: 11/17/2022] Open
Abstract
In this work we investigated how modifications of the Ca2+ homeostasis in anterior lens epithelial cells (LECs) are associated with different types of cataract (cortical or nuclear) and how the progression of the cataract (mild or moderate) affects the Ca2+ signaling. We systematically analyzed different aspects of intra- and inter-cellular Ca2+ signaling in the human LECs, which are attached to surgically isolated lens capsule (LC), obtained during cataract surgery. We monitored the temporal and spatial changes in intracellular Ca2+ concentration after stimulation with acetylcholine by means of Fura-2 fluorescence captured with an inverted microscope. In our analysis we compared the features of Ca2+ signals in individual cells, synchronized activations, spatio-temporal grouping and the nature of intercellular communication between LECs. The latter was assessed by using the methodologies of the complex network theory. Our results point out that at the level of individual cells there are no significant differences when comparing the features of the signals with regard either to the type or the stage of the cataract. On the other hand, noticeable differences are observed at the multicellular level, despite inter-capsule variability. LCs associated with more developed cataracts were found to exhibit a slower collective response to stimulation, a less pronounced spatio-temporal clustering of LECs with similar signaling characteristics. The reconstructed intercellular networks were found to be sparser and more segregated than in LCs associated with mild cataracts. Moreover, we show that spontaneously active LECs often operate in localized groups with quite well aligned Ca2+ activity. The presence of spontaneous activity was also found to affect the stimulated Ca2+ responses of individual cells. Our findings indicate that the cataract progression entails the impairment of intercellular signaling thereby suggesting the functional importance of altered Ca2+ signaling of LECs in cataractogenesis.
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Affiliation(s)
- Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, Slovenia.,Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Rene Markovič
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia.,Faculty of Education, University of Maribor, Maribor, Slovenia
| | - Aleš Fajmut
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia.,Faculty of Health Sciences, University of Maribor, Maribor, Slovenia
| | - Marko Marhl
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia.,Faculty of Education, University of Maribor, Maribor, Slovenia
| | - Marko Hawlina
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia
| | - Sofija Andjelić
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia
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Andjelić S, Drašlar K, Lumi X, Yan X, Graw J, Facskó A, Hawlina M, Petrovski G. Morphological and proliferative studies on ex vivo cultured human anterior lens epithelial cells - relevance to capsular opacification. Acta Ophthalmol 2015; 93:e499-506. [PMID: 25631167 DOI: 10.1111/aos.12655] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 11/24/2014] [Indexed: 01/18/2023]
Abstract
PURPOSE To determine the structural characteristics of lens epithelial cells (LECs) found on the anterior portion of the lens capsule and their pluripotency, proliferating and migrating potential when grown ex vivo with relevance to posterior capsular opacification (PCO) after cataract surgery. METHODS The explants of anterior portion of the lens capsule consisting of monolayer of LECs were obtained from uneventful cataract surgery and were cultivated under adherent conditions. The size and shape of the outgrowing cells were recorded by scanning electron microscopy (SEM), while their migration and proliferation potential were followed using light microscopy. Positivity for proliferation (Ki-67)- and pluripotency (Sox2)-specific markers were tested by immunofluorescent staining. RESULTS The proliferation and migration of anterior portion of the lens capsule's LECs filling up the denuded and reverse side regions of the lens capsule as well as their growth on glass culture surfaces could be followed by light microscopy and SEM, while the distribution of LECs and their morphology could be analysed in detail by SEM. The expression of Ki-67 and Sox2 in LECs growing adherently on human anterior portion of the lens capsule could also be detected. CONCLUSIONS Classic light microscopy and SEM can be used to show that human anterior portion of the lens capsule harbours LECs that can proliferate and migrate, suggesting their pluripotency or putative stem cell nature. Similarly, morphological techniques can be used to study PCO and the effect different drugs or physical treatments have against PCO development.
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Affiliation(s)
| | - Kazimir Drašlar
- Department of Biology; Biotechnical Faculty; University of Ljubljana; Ljubljana Slovenia
| | - Xhevat Lumi
- Eye Hospital; University Medical Centre; Ljubljana Slovenia
| | - Xiaohe Yan
- Helmholtz Center Munich German Research Center for Environmental Health; Institute of Developmental Genetics; Neuherberg Germany
| | - Joachim Graw
- Helmholtz Center Munich German Research Center for Environmental Health; Institute of Developmental Genetics; Neuherberg Germany
| | - Andrea Facskó
- Department of Ophthalmology; Faculty of Medicine; University of Szeged; Szeged Hungary
| | - Marko Hawlina
- Eye Hospital; University Medical Centre; Ljubljana Slovenia
| | - Goran Petrovski
- Eye Hospital; University Medical Centre; Ljubljana Slovenia
- Department of Ophthalmology; Faculty of Medicine; University of Szeged; Szeged Hungary
- Stem Cells and Eye Research Laboratory; Department of Biochemistry and Molecular Biology, and Apoptosis and Genomics Research Group of the Hungarian Academy of Sciences; University of Debrecen; Debrecen Hungary
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Andjelić S, Lumi X, Yan X, Graw J, Moe MC, Facskó A, Hawlina M, Petrovski G. Characterization of ex vivo cultured neuronal- and glial- like cells from human idiopathic epiretinal membranes. BMC Ophthalmol 2014; 14:165. [PMID: 25540050 PMCID: PMC4324881 DOI: 10.1186/1471-2415-14-165] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Accepted: 12/11/2014] [Indexed: 01/29/2023] Open
Abstract
Background Characterization of the neuro-glial profile of cells growing out of human idiopathic epiretinal membranes (iERMs) and testing their proliferative and pluripotent properties ex vivo is needed to better understand the pathogenesis of their formation. Methods iERMs obtained during uneventful vitrectomies were cultivated ex vivo under adherent conditions and assessed by standard morphological and immunocytochemical methods. The intracellular calcium dynamics of the outgrowing cells was assessed by fluorescent dye Fura-2 in response to acetylcholine (ACh)- or mechano- stimulation. Results The cells from the iERMs formed sphere-like structures when cultured ex vivo. The diameter of the spheres increased by 5% at day 6 and kept an increasing tendency over a month time. The outgrowing cells from the iERM spheres had mainly glial- and some neuronal- like morphology. ACh- or mechano- stimulation of these cells induced intracellular calcium propagation in both cell types; in the neuronal-like cells resembling action potential from the soma to the dendrites. Immunocytochemistry confirmed presence of glial- and neuronal cell phenotype (GFAP and Nestin-1 positivity, respectively) in the iERMs, as well as presence of pluripotency marker (Sox2). Conclusion iERMs contain cells of neuronal- and glial- like origin which have proliferative and pluripotent potential, show functionality reflected through calcium dynamics upon ACh and mechano- stimulation, and a corresponding molecular phenotype.
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Affiliation(s)
| | | | | | | | | | | | | | - Goran Petrovski
- Eye Hospital, University Medical Centre, Grablovičeva ulica 46, 1000 Ljubljana, Slovenia.
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Abstract
PURPOSE To evaluate whether the gentian violet staining of the anterior lens capsule during the cataract surgery is cytotoxic for the human lens epithelial cells, as an indirect indication of possible toxicity towards the corneal endothelium and the safety of gentian violet application. MATERIALS AND METHODS Two groups of anterior lens capsules obtained during the cataract surgery, gentian violet stained and non-stained, were incubated with fluorescent dye Fura-2. Their fluorescence, upon excitation at 360 and 380 nm, was imaged to monitor changes in free intracellular calcium concentration ([Ca(2+)]i) in response to pharmacological stimulation by acetylcholine. The [Ca(2+)]i homeostasis is the indicator of cellular function. The changes in [Ca(2+)]i were compared between the two groups. RESULTS Epithelial cells responded to acetylcholine in both groups of capsules - gentian violet stained (n = 17) and non-stained ones (n = 33). No significant differences of the elicited responses were found in rise time (p = 0.89), decay time (p = 0.61) or amplitude of [Ca(2+)]i (p = 0.96 for 63× and p = 0.26 for 40× objectives) between the two groups of capsules (Student t test). CONCLUSIONS The staining of the anterior lens capsule with gentian violet during phacoemulsification in concentration of 0.01%, does not have detectable cytotoxic effects, which would affect the [Ca(2+)]i homeostasis in lens epithelial cells. The data, if extrapolated to corneal endothelium, exposed to the same concentration, suggest that gentian violet in concentration of 0.01% is safe as an adjunct for capsule visualization in cataract surgery.
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Affiliation(s)
- Sofija Andjelić
- Eye Hospital, University Medical Centre , Ljubljana , Slovenia and
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Abstract
PURPOSE Human anterior lens epithelial cells, attached to surgically isolated capsules, were found to contract upon stimulation. The purpose of this study was to characterize these contractions, which create gaps between cells, and to assess the underlying physiological mechanisms and their possible association with cataract formation. METHODS Lens capsules obtained during cataract surgery were stained with fluorescent dye Fura-2. Its fluorescence, upon excitation at 360 and 380 nm, was imaged to monitor changes in cell morphology and cytosolic free Ca(2+) concentrations ([Ca(2+) ](i) ) in response to pharmacological stimulation by acetylcholine (ACh) and to mechanical stimulation by flow of saline or direct contact. RESULTS Epithelial cells contracted in approximately a third of preparations when stimulated by either ACh application, fluid movement or direct mechanical contact. Contractions started either before or at best simultaneously with the rise in [Ca(2+) ](i). Contractions also occurred when there was hardly any change in [Ca(2+) ](i) upon application of physiological saline alone. The probability of contractions occurring did not differ significantly among cortical, nuclear and combined cortical + nuclear cataract. CONCLUSIONS This study provides the evidence that contractions of the anterior lens epithelial cells take place in significant portion of human lens anterior capsule postoperative preparations after non-specific stimulation. Contractions are at least partially independent of changes in [Ca(2+) ](i). They can be mechanically induced, are localized and reversible and have a fast response and did not differ among different types of cataract. Physiological and clinical significance of this phenomenon remains to be elucidated.
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Affiliation(s)
- Sofija Andjelić
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia
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Tucek-Szabo CL, Andjelić S, Lacy E, Elkon KB, Nikolić-Zugić J. Surface T cell Fas receptor/CD95 regulation, in vivo activation, and apoptosis. Activation-induced death can occur without Fas receptor. The Journal of Immunology 1996. [DOI: 10.4049/jimmunol.156.1.192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Fas-mediated apoptosis is a form of cell death that operates through a receptor-ligand interaction. The FasR has been implicated directly in peripheral T cell tolerance and activation-induced apoptosis of T cells in vitro, although to date its expression on murine peripheral T cells has been characterized incompletely. In this study, we document substantial expression of FasR on the vast majority of recent thymic emigrants and resting peripheral T lymphocytes. FasR ligation can induce death in a minor (approximately 5%) subset of these cells. By contrast to rather slow activation-mediated FasR up-regulation in vitro, we demonstrate that in vivo T cell activation by alpha CD3 mAb or superantigen results in rapid up-regulation of the FasR. This up-regulation is paralleled by the kinetics of activation-induced apoptosis in lymph node T cells. However, we demonstrate that the FasR is not necessary for activation-induced cell death. Lymph node T cells from young, healthy, FasR expression-deficient MRL-Ipr/Ipr and animals could be activated in vivo through the TCR-CD3 complex. Most importantly, MRL-Ipr/Ipr T cells underwent massive activation-induced apoptosis in response to high and intermediate doses of alpha CD3. At a low alpha CD3 dose, however, both MRL-Ipr/Ipr and MRL +/+ T cells were activated similarly, but only the latter underwent adequate apoptosis. Taken together, these findings suggest that in vivo, the Fas pathway may not be the only regulator of activation-induced T cell death, but that this pathway may be critical in regulating responses to weak stimuli.
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Affiliation(s)
- C L Tucek-Szabo
- Specialized Center of Research (SCOR), Memorial Sloan-Kettering Cancer Center, New York USA
| | - S Andjelić
- Specialized Center of Research (SCOR), Memorial Sloan-Kettering Cancer Center, New York USA
| | - E Lacy
- Specialized Center of Research (SCOR), Memorial Sloan-Kettering Cancer Center, New York USA
| | - K B Elkon
- Specialized Center of Research (SCOR), Memorial Sloan-Kettering Cancer Center, New York USA
| | - J Nikolić-Zugić
- Specialized Center of Research (SCOR), Memorial Sloan-Kettering Cancer Center, New York USA
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Tucek-Szabo CL, Andjelić S, Lacy E, Elkon KB, Nikolić-Zugić J. Surface T cell Fas receptor/CD95 regulation, in vivo activation, and apoptosis. Activation-induced death can occur without Fas receptor. J Immunol 1996; 156:192-200. [PMID: 8598462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Fas-mediated apoptosis is a form of cell death that operates through a receptor-ligand interaction. The FasR has been implicated directly in peripheral T cell tolerance and activation-induced apoptosis of T cells in vitro, although to date its expression on murine peripheral T cells has been characterized incompletely. In this study, we document substantial expression of FasR on the vast majority of recent thymic emigrants and resting peripheral T lymphocytes. FasR ligation can induce death in a minor (approximately 5%) subset of these cells. By contrast to rather slow activation-mediated FasR up-regulation in vitro, we demonstrate that in vivo T cell activation by alpha CD3 mAb or superantigen results in rapid up-regulation of the FasR. This up-regulation is paralleled by the kinetics of activation-induced apoptosis in lymph node T cells. However, we demonstrate that the FasR is not necessary for activation-induced cell death. Lymph node T cells from young, healthy, FasR expression-deficient MRL-Ipr/Ipr and animals could be activated in vivo through the TCR-CD3 complex. Most importantly, MRL-Ipr/Ipr T cells underwent massive activation-induced apoptosis in response to high and intermediate doses of alpha CD3. At a low alpha CD3 dose, however, both MRL-Ipr/Ipr and MRL +/+ T cells were activated similarly, but only the latter underwent adequate apoptosis. Taken together, these findings suggest that in vivo, the Fas pathway may not be the only regulator of activation-induced T cell death, but that this pathway may be critical in regulating responses to weak stimuli.
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Affiliation(s)
- C L Tucek-Szabo
- Specialized Center of Research (SCOR), Memorial Sloan-Kettering Cancer Center, New York USA
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Andjelić S, Drappa J, Lacy E, Elkon KB, Nikolić-Zugić J. The onset of Fas expression parallels the acquisition of CD8 and CD4 in fetal and adult alpha beta thymocytes. Int Immunol 1994; 6:73-9. [PMID: 7511929 DOI: 10.1093/intimm/6.1.73] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Fas is an apoptosis-related cell surface molecule whose defective transcription results in the lpr defect and autoimmunity. Recent analysis of Fas mRNA and protein expression in normal mice showed high expression in the thymus, on activated T cells, and on 5-10% of peripheral T cells. To investigate the role of Fas in the thymus, we analyzed its expression in fetal and adult thymocyte subsets. Fas was not expressed on fetal nor adult CD8-CD4- (double-negative, DN) T cell precursors. The earliest precursors that expressed low levels of FAS were the immediate precursors of DP thymocytes that bear the CD44-CD25-CD8loCD4loTCRlo phenotype. Other DN cells that expressed Fas appeared to be either non-T cells or mature alpha beta + DN thymocytes. The onset of Fas expression followed the onset of expression of CD8 and CD4 and Fas expression reached its peak in CD8+CD4+ double-positive (DP) thymocytes. Both single-positive (SP) subsets were largely Fas+ (CD8 SP < CD4 SP) but expressed lower levels of Fas than DP cells. However, a majority (> 60%) of the most mature HSA(lo) SP cells (2-5% of all SP thymocytes) were Fas- and the remainder of the HSA(lo) SP cells was Fas(lo). We observed two main differences between Fas expression on fetal versus adult thymocytes. First, up to 90% of fetal gamma delta + DN cells expressed high levels of Fas, in contrast to the very low expression (< 7% Fas+ cells) among adult gamma delta + thymocytes. Second, whereas virtually all adult DP cells were Fas+, up to 75% of fetal day 16 DP cells were Fas-.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S Andjelić
- Immunology Program, Memorial Sloan-Kettering Cancer Center, New York, NY
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10
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Andjelić S, Jain N, Nikolić-Zugić J. Immature thymocytes become sensitive to calcium-mediated apoptosis with the onset of CD8, CD4, and the T cell receptor expression: a role for bcl-2? J Exp Med 1993; 178:1745-51. [PMID: 8228820 PMCID: PMC2191237 DOI: 10.1084/jem.178.5.1745] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
During intrathymic negative selection by clonal deletion, crosslinking of the T cell receptor (TCR) induces cell death by delivering an apoptotic signal(s) to the nucleus along a calcium-dependent pathway. We investigated the reactivity of early precursor-containing thymocytes to Ca(2+)-induced signals, and discovered a breakpoint in their sensitivity to calcium-mediated cell death (CMCD). CD25+CD8-4- TCR- (triple negative [TN]) thymocytes stimulated with a calcium ionophore maintain their viability and precursor activity. By contrast, their immediate progeny, CD25-CD8lo4loTCR alpha beta lo (triple low [TL]) cells react to calcium elevation by abrogation of precursor activity and apoptotic cell death. This developmental difference is specific for CMCD, since both CD25+TN and CD25-TL cells are susceptible to steroid-induced apoptosis. The presence of bcl-2 mRNA correlates directly to the resistance to CMCD-CD25+ TN cells express it and CD25-TL cells do not. These experiments show that thymocytes become sensitive to Ca(2+)-induced apoptosis as soon as they begin to express molecules that mediate thymic selection, and suggest that a concomitant downregulation of bcl-2 may mediate this phenomenon.
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Affiliation(s)
- S Andjelić
- Immunology Program, Memorial Sloan-Kettering Cancer Center, New York 10021
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Abstract
CD8lo4lo cells are the immediate precursors of immature CD8hi4loTcRlo, CD8lo4hiTcRlo and CD8hi4hiTcRlo double-positive (DP) thymocytes in the adult murine thymus. These cells are the first subset in the adult thymus to express accessory CD8 and CD4 molecules, to rearrange the T cell receptor (TcR) alpha chain genes and to express the TcR alpha beta heterodimer at low levels at the surface. Here, we investigate the fetal ontogeny of CD8lo4lo cells. We detect these cells on day 15 of fetal development. They dominate the thymus on day 15.5, to become progressively less prominent thereafter. An important characteristic of fetal CD8lo4lo cells is the early expression of TcR alpha mRNA (on fetal day 15, 36-48 h earlier than reported previously). Our results also suggest, but do not prove, that the receptor may be expressed on the surface as early as day 15.5. Fetal CD8lo4lo cells, like their adult counterparts, become DP in vitro. However, early fetal CD8lo4lo thymocytes express both CD44 and CD25--unlike the adult subset--and that links them to their putative precursors, fetal CD44+CD25+ double-negative cells. This finding underscores the difference between adult and fetal thymocytes in turnover of membrane molecules and/or the kinetics of progression through phenotypic stages.
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MESH Headings
- Animals
- Base Sequence
- Cells, Cultured
- Female
- Fetus/immunology
- Mice
- Mice, Inbred C57BL
- Molecular Sequence Data
- Pregnancy
- RNA, Messenger/analysis
- Receptors, Antigen, T-Cell, alpha-beta/analysis
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Interleukin-2/analysis
- Receptors, Lymphocyte Homing/analysis
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
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Affiliation(s)
- S Andjelić
- Immunology Program, Memorial Sloan-Kettering Cancer Center, New York 10021
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12
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Abstract
Most murine thymocytes and mature T cells originate from a numerically minor population of CD8-4- (double-negative, DN) thymocytes. In this study, we investigated the effects of rearranged T cell receptor (TcR) alpha and beta transgenes on early T cell development. We analyzed the precursor potential, the expression of CD25 and TcR at mRNA and/or protein level in DN thymocyte subsets in TcR transgenic (Tg) mice. We report the following observations: (i) despite a large overrepresentation of total DN cells in TcR Tg mice, precursor-containing CD25+ DN and CD8lo4lo thymocytes are reduced to a third of the nontransgenic control numbers; (ii) like in the normal mice, CD25+ DN and CD8lo4lo can, and TcR+ DN cells cannot generate other thymic subsets; (iii) TcR alpha mRNA and TcR alpha/beta protein levels are quantitatively increased, but their developmental expression is similar to that in normal mice; and (iv) surface TcR alpha beta expression becomes detectable as the thymocytes down-regulate CD25, paralleling the situation in normal mice. Our findings implicate stringent transcriptional control, rather than TcR gene rearrangement, as a decisive regulator of TcR alpha beta expression in early ontogeny.
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MESH Headings
- Animals
- Base Sequence
- Cell Differentiation
- Flow Cytometry
- Gene Expression
- Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor
- Gene Rearrangement, beta-Chain T-Cell Antigen Receptor
- Mice
- Mice, Transgenic
- Molecular Sequence Data
- Oligodeoxyribonucleotides
- Polymerase Chain Reaction
- RNA, Messenger/genetics
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- Thymus Gland/cytology
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Affiliation(s)
- J Nikolić-Zugić
- Immunology Program, Sloan-Kettering Institute for Cancer Research, New York, NY 10021
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