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1.
Pain Physician ; 18(5): E685-712, 2015.
Article in English | MEDLINE | ID: mdl-26431128

ABSTRACT

The unfunded mandate for the implementation of International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) is scheduled October 1, 2015. The development of ICD-10-CM has been a complicated process. We have endeavored to keep Interventional Pain Management doctors apprised via a variety of related topical manuscripts. The major issues relate to the lack of formal physician participation in its preparation. While the American Health Information Management Association (AHIMA) and American Hospital Association (AHA) as active partners in its preparation. Centers for Medicare and Medicaid Services (CMS) and Centers for Disease Control and Prevention (CDC) are major players; 3M and Blue Cross Blue Shield Association are also involved. The cost of ICD-10-CM implementation is high, similar to the implementation of electronic health records (EHRs), likely consuming substantial resources. While ICD-10, utilized worldwide, includes 14,400 different codes, ICD-10-CM, specific for the United States, has expanded to 144,000 codes, which also includes procedural coding system. It is imperative for physicians to prepare for the mandatory implementation. Conversion from ICD-9-CM to ICD-10-CM coding in interventional pain management is not a conversion of one to one that can be easily obtained from software packages. It is a both a difficult and time-consuming task with each physician, early on, expected to spend on estimation at least 10 minutes per visit on extra coding for established and new patients. For interventional pain physicians, there have been a multitude of changes, including creation of new codes and confusing conversion of existing codes. This manuscript describes a variety of codes that are relevant to interventional pain physicians and often utilized in daily practices. It is our objective that this manuscript will provide coding assistance to interventional pain physicians.


Subject(s)
International Classification of Diseases , Nervous System Diseases/classification , Pain/classification , Humans
2.
J Theor Biol ; 374: 66-82, 2015 Jun 07.
Article in English | MEDLINE | ID: mdl-25846273

ABSTRACT

The primary CD8 T cell immune response constitutes a major mechanism to fight an infection by intra-cellular pathogens. We aim at assessing whether pathogen-specific dynamical parameters of the CD8 T cell response can be identified, based on measurements of CD8 T cell counts, using a modeling approach. We generated experimental data consisting in CD8 T cell counts kinetics during the response to three different live intra-cellular pathogens: two viruses (influenza, vaccinia) injected intranasally, and one bacteria (Listeria monocytogenes) injected intravenously. All pathogens harbor the same antigen (NP68), but differ in their interaction with the host. In parallel, we developed a mathematical model describing the evolution of CD8 T cell counts and pathogen amount during an immune response. This model is characterized by 9 parameters and includes relevant feedback controls. The model outputs were compared with the three data series and an exhaustive estimation of the parameter values was performed. By focusing on the ability of the model to fit experimental data and to produce a CD8 T cell population mainly composed of memory cells at the end of the response, critical parameters were identified. We show that a small number of parameters (2-4) define the main features of the CD8 T cell immune response and are characteristic of a given pathogen. Among these parameters, two are related to the effector CD8 T cell mediated control of cell and pathogen death. The parameter associated with memory cell death is shown to play no relevant role during the main phases of the CD8 T cell response, yet it becomes essential when looking at the predictions of the model several months after the infection.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Influenza, Human/immunology , Listeriosis/immunology , Models, Biological , Vaccinia/immunology , Algorithms , Animals , CD8-Positive T-Lymphocytes/microbiology , CD8-Positive T-Lymphocytes/virology , Humans , Immunologic Memory , Listeria monocytogenes , Lymphocyte Count , Mice , Orthomyxoviridae , Orthomyxoviridae Infections/immunology , Reproducibility of Results , Vaccinia virus
3.
Article in English | MEDLINE | ID: mdl-28664162

ABSTRACT

The fields of risk analysis and prognostics and health management (PHM) have developed in a largely independent fashion. However, both fields share a common core goal. They aspire to manage future adverse consequences associated with prospective dysfunctions of the systems under consideration due to internal or external forces. This paper describes how two prominent risk analysis theories and methodologies - Hierarchical Holographic Modeling (HHM) and Risk Filtering, Ranking, and Management (RFRM) - can be adapted to support the design of PHM systems in the context of smart manufacturing processes. Specifically, the proposed methodologies will be used to identify targets - components, subsystems, or systems - that would most benefit from a PHM system in regards to achieving the following objectives: minimizing cost, minimizing production/maintenance time, maximizing system remaining usable life (RUL), maximizing product quality, and maximizing product output. HHM is a comprehensive modeling theory and methodology that is grounded on the premise that no system can be modeled effectively from a single perspective. It can also be used as an inductive method for scenario structuring to identify emergent forced changes (EFCs) in a system. EFCs connote trends in external or internal sources of risk to a system that may adversely affect specific states of the system. An important aspect of proactive risk management includes bolstering the resilience of the system for specific EFCs by appropriately controlling the states. Risk scenarios for specific EFCs can be the basis for the design of prognostic and diagnostic systems that provide real-time predictions and recognition of scenario changes. The HHM methodology includes visual modeling techniques that can enhance stakeholders' understanding of shared states, resources, objectives and constraints among the interdependent and interconnected subsystems of smart manufacturing systems. In risk analysis, HHM is often paired with Risk Filtering, Ranking, and Management (RFRM). The RFRM process provides the users, (e.g., technology developers, original equipment manufacturers (OEMs), technology integrators, manufacturers), with the most critical risks to the objectives, which can be used to identify the most critical components and subsystems that would most benefit from a PHM system. A case study is presented in which HHM and RFRM are adapted for PHM in the context of an active manufacturing facility located in the United States. The methodologies help to identify the critical risks to the manufacturing process, and the major components and subsystems that would most benefit from a developed PHM system.

4.
Oncogene ; 27(20): 2923-8, 2008 May 01.
Article in English | MEDLINE | ID: mdl-18026133

ABSTRACT

We have previously shown that human keratinocytes expressing E6 and E7 from the cutaneous human papillomavirus (HPV) type 38 have high levels of a specific form of p53, which in turn activate the transcription of DeltaNp73 gene. Expression of HPV38 E6 and E7 in mouse skin also promotes p53 and DeltaNp73 accumulation. Interestingly, keratinocytes of these mice do not undergo cell cycle arrest after skin ultraviolet (UV) irradiation. Here, we provide several lines of evidence that DeltaNp73 expression and lack of the UV response are directly linked. Loss of p53 gene in HPV38 E6/E7 transgenic mice abolished DeltaNp73 expression and partially restored the UV-activated cell cycle checkpoints. Similarly, loss of p73, and consequently DeltaNp73, led to restoration of the p53 pathways. In fact, keratinocytes of p73-/- HPV38 E6/E7 transgenic mice upon UV irradiation express high levels of p21(WAF1) and are cell cycle arrested. Thus, HPV38 E6 and E7, via DeltaNp73 accumulation, are able to alter the regulation of cell cycle checkpoints activated by UV radiation. These data suggest that UV and HPV may cooperate in skin carcinogenesis.


Subject(s)
Betapapillomavirus/genetics , Cell Cycle/radiation effects , DNA-Binding Proteins/genetics , Genes, p53 , Nuclear Proteins/genetics , Papillomavirus E7 Proteins/genetics , Tumor Suppressor Protein p53/deficiency , Tumor Suppressor Proteins/genetics , Ultraviolet Rays , Animals , Cell Cycle/genetics , Cells, Cultured , DNA-Binding Proteins/deficiency , Humans , Keratinocytes/cytology , Keratinocytes/metabolism , Keratinocytes/radiation effects , Mice , Mice, Knockout , Mice, Transgenic , Nuclear Proteins/deficiency , Tumor Protein p73 , Tumor Suppressor Proteins/deficiency
5.
Oncogene ; 25(53): 7096-105, 2006 Nov 09.
Article in English | MEDLINE | ID: mdl-16715126

ABSTRACT

Transcription factor Sp1 has recently been shown to be overexpressed in a number of human cancers and its overexpression contributes to malignant transformation. Sp1 regulates the expression of a number of genes participating in multiple aspects of tumorigenesis such as angiogenesis, cell growth and apoptosis resistance. To better understand the role of increased Sp1 levels on apoptosis regulation we have used retroviruses to overexpress this protein in haematopoietic Baf-3 cells and in 3T3 fibroblasts. We have also used inducible expression systems to control ectopic Sp1 levels in different cell types. Surprisingly, Sp1 overexpression on its own induces apoptosis in all the cellular models tested. The apoptotic pathways induced by Sp1 overexpression are cell type specific. Finally, using a truncated form of Sp1, we show that Sp1-induced apoptosis requires its DNA-binding domain. Our results highlight that Sp1 levels in untransformed cells must be tightly regulated as Sp1 overexpression leads to the induction of apoptosis. Our results also suggest that cancer cells overexpressing Sp1 can avoid Sp1-induced apoptosis.


Subject(s)
Apoptosis , Sp1 Transcription Factor/metabolism , Animals , DNA , Gene Expression , Humans , Mice , Sp1 Transcription Factor/genetics
6.
Cell Death Differ ; 10(9): 1059-67, 2003 Sep.
Article in English | MEDLINE | ID: mdl-12934080

ABSTRACT

We analyzed regulation of the prosurvival Bcl-2 homologue A1, following T-cell receptor (TCR) or cytokine receptor engagement. Activation of CD4(+) or CD8(+) T cells by antigenic peptides induced an early but transient IL-2-independent expression of A1 and Bcl-xl mRNA and proteins, whereas expression of Bcl-2 was delayed and required IL-2. Cytokines such as IL-2, IL-4, IL-7 or IL-15 prevented apoptosis of activated T cells that effect being associated with the maintenance of Bcl-2, but not of A1 expression. However, restimulation of activated or posteffector T cells with antigenic peptide strongly upregulated A1 mRNA and maintained A1 protein expression. IL-4, IL-7 or IL-15 also prevented cell death of naive T cells. In those cells, cytokines upregulated Bcl-2, but not A1 expression. Therefore, in naive, activated and posteffector T cells, expression of A1 is dependent on TCR but not on cytokine receptor engagement, indicating that A1 is differently regulated from Bcl-xl and Bcl-2.


Subject(s)
Proto-Oncogene Proteins c-bcl-2/biosynthesis , Receptors, Antigen, T-Cell/immunology , T-Lymphocytes/immunology , Animals , Antigens/immunology , CD8-Positive T-Lymphocytes/drug effects , CD8-Positive T-Lymphocytes/immunology , Cells, Cultured , Cytokines/pharmacology , Gene Expression , Lymphocyte Activation , Mice , Mice, Transgenic , Minor Histocompatibility Antigens , Peptides/immunology , Protein Isoforms/biosynthesis , Protein Isoforms/genetics , Proto-Oncogene Proteins c-bcl-2/genetics , RNA, Messenger/metabolism , Receptors, Antigen, T-Cell/genetics , Receptors, Cytokine/metabolism
7.
Cell Death Differ ; 9(10): 1147-57, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12232803

ABSTRACT

IL-3 regulates the glycolytic pathway. In Baf-3 cells IL-3 starvation leads to a decrease in glucose uptake and in lactate production. To determine if there is a link between the decreased metabolism induced by growth factor-starvation and the induction of cell death, we have compared the cell death characteristics and the metabolic modifications induced by IL-3-deprivation or glucose-deprivation in Baf-3 cells. We show that in both conditions cells die by an apoptotic process which involves the activation of similar Caspases. Different metabolic parameters (i.e. intracellular ATP levels and lactate accumulation in the culture medium) were measured. We show that IL-3 deprivation leads to a partial decrease in lactate production in contrast to glucose deprivation that completely inhibits lactate production. Similarly following IL-3-starvation a significant drop in the intracellular ATP levels in live cells is observed only after 16 h when a large fraction, more than 50 per cent of cells, is already apoptotic. On the contrary, glucose deprivation is followed by an abrupt decrease in ATP levels in the first 2 h of treatment. However, in the presence of IL-3, cells are able to survive for an extended time in these conditions since 70% of cells survived with low ATP levels for up to 16 h. This was not due to partial inhibition of the apoptotic process by the low level of ATP as glucose-deprivation in the absence of IL-3 led to faster death kinetics of Baf-3 cells compared with IL-3 starvation only. These results indicate that the drop in ATP levels and the triggering of apoptosis can be dissociated in time and that when the glycolytic pathway is strongly inhibited, cells are able to survive with relatively low ATP levels if IL-3 is present. Finally we show that induction of bcl-x by IL-3 protects cells from glucose-deprivation induced cell death.


Subject(s)
Apoptosis/physiology , Down-Regulation/physiology , Eukaryotic Cells/metabolism , Glucose/deficiency , Glycolysis/physiology , Interleukin-3/deficiency , Protein Serine-Threonine Kinases , Adenosine Triphosphate/metabolism , Animals , Apoptosis/drug effects , Cell Survival/drug effects , Cell Survival/physiology , Cells, Cultured , Deoxyglucose/pharmacology , Down-Regulation/drug effects , Eukaryotic Cells/drug effects , Gene Expression Regulation/drug effects , Gene Expression Regulation/physiology , Glycolysis/drug effects , Humans , Interleukin-3/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-akt , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA, Messenger/drug effects , RNA, Messenger/metabolism , bcl-X Protein
8.
Nat Immunol ; 2(5): 430-5, 2001 May.
Article in English | MEDLINE | ID: mdl-11323697

ABSTRACT

Inhibitory natural killer receptors (NKRs) such as killer cell immunoglobulin-like receptors (KIRs) in humans and Ly49 molecules in mice are expressed on NK cells and recognize multiple major histocompatibility (MHC) class I proteins. In humans and mice, a subset of CD8+ T cells also expresses NKRs and harbors a memory phenotype. Using mice that are transgenic for KIR2DL3 and its cognate HLA-Cw3 ligand, we show that engagement of inhibitory NKRs selectively drives the in vivo accumulation of a subset of memory-phenotype CD8+ T cells that express the beta chain of the interleukin 2 receptor. In vitro, recognition of MHC class I molecules by inhibitory NKRs on T cells down-regulated activation-induced cell death. These results unveil an MHC class I-dependent pathway that promotes the survival of a subset of memory-phenotype CD8+ T cells and also reveal an unexpected biological function for inhibitory NKRs on T cells.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Immunologic Memory , Killer Cells, Natural/immunology , Receptors, Immunologic/immunology , T-Lymphocyte Subsets/immunology , Animals , Cell Death , HLA-C Antigens/genetics , HLA-C Antigens/immunology , Mice , Mice, Transgenic , Phenotype , Receptors, Immunologic/genetics , Receptors, KIR , Receptors, KIR2DL3 , Spleen/immunology , Vaccination
9.
J Biol Chem ; 276(14): 10935-42, 2001 Apr 06.
Article in English | MEDLINE | ID: mdl-11278333

ABSTRACT

Baf-3 cells are dependent on interleukin-3 (IL-3) for their survival and proliferation in culture. To identify anti-apoptotic pathways, we performed a retroviral-insertion mutagenesis on Baf-3 cells and selected mutants that have acquired a long term survival capacity. The phenotype of one mutant, which does not overexpress bcl-x and proliferates in the absence of IL-3, is described. We show that, in this mutant, Akt is constitutively activated leading to FKHRL1 phosphorylation and constitutive glycolytic activity. This pathway is necessary for the mutant to survive following IL-3 starvation but is not sufficient or necessary to protect cells from DNA damage-induced cell death. Indeed, inhibition of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in Baf-3 cells does not prevent the ability of IL-3 to protect cells against gamma-irradiation-induced DNA damage. This protective effect of IL-3 rather correlates with the expression of the anti-apoptotic Bcl-x protein. Taken together, these data demonstrate that the PI3K/Akt pathway is sufficient to protect cells from growth factor starvation-induced apoptosis but is not required for IL-3 inhibition of DNA damage-induced cell death.


Subject(s)
Apoptosis , DNA Damage , Interleukin-3 , Phosphatidylinositol 3-Kinases/metabolism , Signal Transduction , Animals , Apoptosis/genetics , Cell Division/genetics , Cell Line , Cell Survival/genetics , Enzyme Activation , Humans , Interleukin-3/deficiency , Interleukin-3/genetics , Mutation , Phosphatidylinositol 3-Kinases/genetics , Phosphorylation
10.
Cytotechnology ; 35(2): 115-25, 2001 Mar.
Article in English | MEDLINE | ID: mdl-19003288

ABSTRACT

The density of viable cells in a culture results from a balance between cell proliferation and cell death. The aim of this study was to characterize and compare these two phenomena in Vero cell cultures in one serum containing medium (ScA) and one serum free medium (SfB) in bioreactors. Cell growth was evaluated by cell counting(after crystal violet staining) and cell cycle analysis. Necrosis and apoptosis were characterized and quantified by measuring the release of LDH, trypan blue exclusion,annex in V-FITC/PI staining and TUNEL assay. ScA supported a higher maximal viable-cell density(2.3 x 10(6) vs. 1.8 x 10(6) cells ml(-1)). However, cell cycle analysis showed that cell division was more active in SfB than in ScA. LDH release in the supernatant increased much earlier in SfB than in ScA (one vs. five days), but trypan blue counts showed no apparent difference in the viability of the cultures. Apoptosis, evidenced by annexin V-FITC/PI staining, could be detected in the population of suspension cells detached from microcarriers, but not among adherent cells; positivity of the TUNEL assay occurred later than that of the annexin V-FITC/PI staining. Our data indicate that the lower cell yield in SfB,compared with that in ScA, results from a higher cell death rate. Apparently, cells die from apoptosis followed by secondary necrosis.

12.
Cell Immunol ; 206(1): 16-25, 2000 Nov 25.
Article in English | MEDLINE | ID: mdl-11161434

ABSTRACT

The aim of this study was to characterize differences between naive and primed CD8 T cells. Our results show that (i) naive and primed CD8 T cells display similar activation thresholds, with no direct evidence for a difference in their TCR signals, and (ii) primed cells differ mainly in their capacity to secrete IFN-gamma. A comparison of the two populations at the single-cell level demonstrated that the increased production of IFN-gamma by the primed cell subset is due to a larger proportion of single cells that are able to synthesize this cytokine early following activation. These results indicate that the intrinsic effector capabilities of individual CD8 T cells expressing the same TCR are heterogeneous and that cells with identical antigen specificity but increased effector capacities are generated or selected during the primary response.


Subject(s)
CD8-Positive T-Lymphocytes/metabolism , Immunologic Memory/immunology , Interferon-gamma/metabolism , Lymphocyte Activation , Receptors, Antigen, T-Cell/immunology , Animals , Antigens, Viral/immunology , CD8 Antigens/immunology , Calcium Signaling , Cells, Cultured , Flow Cytometry , Immunization , Influenza A virus/immunology , Interferon-gamma/biosynthesis , Lymphokines/biosynthesis , Lymphokines/metabolism , Mice , Mice, Knockout , Mice, Transgenic , Phosphorylation , Protein Processing, Post-Translational , Protein-Tyrosine Kinases/metabolism , Receptor Cross-Talk
13.
J Immunol ; 164(1): 152-60, 2000 Jan 01.
Article in English | MEDLINE | ID: mdl-10605006

ABSTRACT

Thyroid hormones bind to several nuclear receptors encoded by T3R alpha and T3R beta genes. There is now accumulating evidence that thyroid hormones act on the immune system. Indeed, mice deficient for thyroid hormones show a reduction in lymphocyte production. However, the mechanisms involved and, in particular, the role of the different thyroid hormone receptors in lymphocyte development have not been investigated. To address that question, we have studied lymphocyte development in mice deficient for the T3R alpha 1 and T3R alpha 2 gene products. A strong decrease in spleen cell numbers was found compared with wild-type littermates, B lymphocytes being more severely affected than T lymphocytes. A significant decrease in splenic macrophage and granulocyte numbers was also found. In bone marrow, a reduction in CD45+/IgM- pro/pre-B cell numbers was found in these mice compared with wild-type littermates. This decrease seems to result from a proliferation defect, as CD45+/IgM- cells incorporate less 5-bromo-2'-deoxyuridine in vivo. To define the origin of the bone marrow development defect, chimeric animals between T3R alpha-/- and Rag1-/- mice were generated. Results indicate that for B cells the control of the population size by T3R alpha 1 and T3R alpha 2 is intrinsic. Altogether, these results show that T3R alpha 1 or T3R alpha 2 gene products are implicated in the control of the B cell pool size.


Subject(s)
B-Lymphocytes/pathology , Gene Deletion , Integrases , Receptors, Thyroid Hormone/genetics , T-Lymphocytes/pathology , Triiodothyronine/metabolism , Animals , Animals, Newborn/genetics , Animals, Newborn/immunology , B-Lymphocytes/enzymology , B-Lymphocytes/immunology , Bone Marrow Cells/pathology , Cell Differentiation/genetics , Cell Differentiation/immunology , Cell Division/genetics , Cell Division/immunology , DNA Nucleotidyltransferases/deficiency , DNA Nucleotidyltransferases/genetics , Lymphocyte Count , Lymphoid Tissue/immunology , Lymphoid Tissue/pathology , Lymphopenia/genetics , Lymphopenia/immunology , Lymphopenia/pathology , Mice , Mice, Knockout , Mice, Transgenic , Receptors, Thyroid Hormone/physiology , Recombinases , Spleen/immunology , Spleen/pathology , Stem Cells/pathology , T-Lymphocytes/enzymology , T-Lymphocytes/immunology
14.
Int Immunol ; 11(8): 1225-38, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10421780

ABSTRACT

In contrast to most organs, the anatomy of the liver may allow naive CD8(+) T cells to make direct contact with liver parenchymal cells. We have previously shown, using a combination of TCR transgenic T cells specific for H-2 K(b) and hepatocytes expressing a transgenic H-2 K(b) molecule, that hepatocytes can induce antigen-specific activation and proliferation of naive CD8(+) T cells independently of CD28 co-stimulation. However, T cell activation by hepatocytes leads to premature T cell death and tolerance, both in vivo and in vitro. In this study, we investigated the mechanisms of T cell death induced by hepatocytes in vitro using primary hepatocytes to activate purified CD8(+) T cells. Neither Fas nor tumor necrosis factor receptor were involved, indicating that hepatocyte- induced death was distinct from activation-induced cell death. Before they started to divide, T cells activated by hepatocytes expressed lower levels of the bcl-x(L) survival gene and 30 times less IL-2 mRNA than CD8(+) cells activated by splenic antigen-presenting cells. Since CD28 co-stimulation increases both IL-2 and bcl-x(L) expression, this suggests that hepatocyte-activated T cells die by neglect because they fail to receive effective co-stimulatory signals. In agreement with this model, premature death promoted by hepatocytes could be prevented by cross-linking CD28. Survival after CD28 cross-linking correlated with increased IL-2 and bcl-x(L) expression, and sustained T cell proliferation, while cytotoxic T lymphocyte activity was prolonged as compared with cells stimulated without CD28 co-stimulation. This study confirms that high- affinity TCR transgenic antigen-specific CD8(+) T cells can be activated to proliferate and differentiate into cytotoxic effector cells. However, prolonged T cell survival and cytotoxicity required CD28 co-stimulation as well. To our knowledge, this is the first report suggesting that tolerance in the context of lack of CD28 co-stimulation can result from Fas-independent peripheral deletion rather than from anergy.


Subject(s)
CD8-Positive T-Lymphocytes/physiology , Clonal Deletion , Liver/immunology , Self Tolerance , Animals , Apoptosis , CD28 Antigens/immunology , CD28 Antigens/metabolism , CD8-Positive T-Lymphocytes/immunology , Coculture Techniques , Cytokines/biosynthesis , Dendritic Cells/immunology , Interleukin-2/genetics , Interleukin-2/metabolism , Liver/cytology , Lymphocyte Activation , Mice , Mice, Inbred C57BL , Mice, Transgenic , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , Receptors, Antigen, T-Cell, alpha-beta/genetics , T-Lymphocytes, Cytotoxic/immunology , bcl-X Protein
15.
Int Immunol ; 11(5): 699-706, 1999 May.
Article in English | MEDLINE | ID: mdl-10330275

ABSTRACT

F5 TCR transgenic mice challenged in vivo with peptide generate long-lived primed CD8 T cells that hyper-proliferate in response to peptide in vitro. These primed CD8 T cells can be subdivided into three distinct populations on the basis of CD44 cell surface expression. In this report, we show that among primed CD8 T cells, those expressing intermediate levels of CD44 appear to be true memory T cells by the measurement of a variety of characteristics. Indeed, these cells hyper-proliferate in response to peptide re-stimulation in vitro, and produce IFN-gamma with faster kinetics and at higher levels than naive populations in vitro. We also show that CD8 T cells expressing high levels of CD44 express several activation markers and cycle in vivo in the absence of antigen. However, this population is unable to respond to peptide stimulation in vitro as measured by both proliferation and IFN-gamma secretion. The origin and specificity of these cells is unknown. These results provide evidence that memory CD8 T cells are functionally different from naive CD8 T cells both in terms of proliferation and cytokine secretion. They identify the CD8/CD44(int) T cells as the population responsible for hyper-reactivity in vitro.


Subject(s)
Antigens/immunology , CD8-Positive T-Lymphocytes/physiology , Hyaluronan Receptors/analysis , Immunologic Memory , Interferon-gamma/biosynthesis , Lymphocyte Activation , Animals , Cells, Cultured , Mice , Mice, Inbred C57BL , Mice, Transgenic
16.
Cell Death Differ ; 6(3): 290-6, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10200580

ABSTRACT

In Baf-3 cells, IL-3 and IGF-1 both inhibit cell death. These growth factors act at least on two different pathways involved in the inhibition of apoptosis. They both upregulate Bcl-X at the mRNA and protein levels and also activate a pathway which inhibits apoptosis in the absence of protein synthesis. Recently, these two growth factors have been shown to activate the PI3-kinase-AKT pathway which leads to the phosphorylation of the pro-apoptotic Bcl-XL regulator Bad. In this study, we have investigated the role of PI3-kinase in the regulation of Bcl-X expression and in the survival of Baf-3 cells. We show that PI3-kinase activation is involved in the upregulation of Bcl-X mRNA induced by both IL-3 and IGF-1. Moreover, PI3-kinase activity is also necessary for inhibition of apoptosis and caspase regulation by IGF-1 but not IL-3.


Subject(s)
Apoptosis/drug effects , Insulin-Like Growth Factor I/pharmacology , Interleukin-3/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-bcl-2/biosynthesis , Animals , Apoptosis/physiology , Caspases/metabolism , Cell Survival/drug effects , Cell Survival/physiology , Enzyme Activation/drug effects , Enzyme Inhibitors/pharmacology , Mice , Phosphoinositide-3 Kinase Inhibitors , Proto-Oncogene Proteins c-bcl-2/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , bcl-X Protein
17.
J Immunol ; 161(10): 5260-7, 1998 Nov 15.
Article in English | MEDLINE | ID: mdl-9820498

ABSTRACT

The mechanisms responsible for peripheral CD8 T cell tolerance to foreign Ags remain poorly understood. In this study we have characterized the state of CD8 T cell tolerance induced in F5 TCR transgenic mice by multiple peptide injections in vivo. The tolerant state of CD8 T cells is characterized by impaired proliferative responses, increased sensitivity to cell death, and failure to acquire cytotoxic effector function after in vitro antigenic challenge. In vivo monitoring of CD8 T cell proliferation using 5-carboxyfluorescein diacetate succinimidyl ester showed that a large subset of the tolerant T cell population failed to divide in response to peptide. TCR down-regulation could not account for this loss of responsiveness to Ag since recombination-activating gene-1 (RAG-1)-/-F5 CD8 T cell responses were similar to those of RAG-1(-/-)F5 x RAG-1(-/-)F1 T lymphocytes, which express lower levels of the transgenic TCR. Analysis of early signal transduction in tolerant CD8 T cells revealed high basal levels of cytoplasmic calcium as well as impaired calcium mobilization and tyrosine phosphorylation after cross-linking of CD3epsilon and CD8alpha. Together these data indicate that repeated exposure to soluble antigenic peptide in vivo can induce a state of functional tolerance characterized by defective TCR signaling, impaired proliferation, and increased sensitivity to cell death.


Subject(s)
Antigens, Viral/immunology , CD8-Positive T-Lymphocytes/immunology , Immune Tolerance , Lymphocyte Activation , Peptide Fragments/immunology , Receptors, Antigen, T-Cell, alpha-beta/physiology , Signal Transduction/immunology , Viral Core Proteins/immunology , Animals , Antigens, Viral/administration & dosage , Cell Death/genetics , Cell Death/immunology , Cells, Cultured , Dose-Response Relationship, Immunologic , Epitopes, T-Lymphocyte/immunology , Gene Expression Regulation/immunology , Immune Tolerance/genetics , Injections, Intraperitoneal , Lymphocyte Activation/genetics , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Peptide Fragments/administration & dosage , Receptors, Antigen, T-Cell, alpha-beta/biosynthesis , Receptors, Antigen, T-Cell, alpha-beta/genetics , Signal Transduction/genetics , Transgenes/immunology , Viral Core Proteins/administration & dosage
18.
Oncogene ; 16(11): 1399-408, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9525739

ABSTRACT

In order to identify genes capable of inhibiting apoptosis induced by different pathways, without inducing proliferation we have performed retroviral insertion mutagenesis in the IL-3 dependent bone marrow derived Baf-3 cell line. Out of 200 mutants obtained in three separate mutagenesis experiments, four mutants were resistant to multiple apoptosis inducing pathways (including growth factor starvation, staurosporine, etoposide and cyclosporin A) and did not proliferate in the absence of IL-3. These four mutants overexpress the bcl-X gene following a retroviral insertion 5' of the translation initiation site. These results indicate that the bcl-X gene is a major pleiotropic anti-apoptotic gene in Baf-3 cells. They also suggest that the Bcl-2 family of genes might be the only one capable of inhibiting apoptosis induced by multiple pathways without inducing cell proliferation.


Subject(s)
Apoptosis/genetics , Bone Marrow Cells/pathology , Interleukin-3/metabolism , Proto-Oncogene Proteins c-bcl-2/genetics , Retroviridae/genetics , Alleles , Base Sequence , Bone Marrow Cells/metabolism , Cell Line , Cloning, Molecular , DNA , Gene Rearrangement , Molecular Sequence Data , Mutagenesis, Insertional , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA, Messenger/genetics , Virus Integration , bcl-X Protein
19.
Oncogene ; 14(4): 425-30, 1997 Jan 30.
Article in English | MEDLINE | ID: mdl-9053839

ABSTRACT

The inhibition of cell death by growth factors plays a key role in the maintenance of the haematopoietic system homeostasis. However the mechanisms involved in this inhibition are still poorly understood. In order to determine if inhibition of apoptosis by growth factors is dependent only on the expression of survival genes, we have studied that process in the bone marrow derived IL-3 dependent cell line Baf-3. We show that, following IL-3 starvation, mRNA and protein levels of Bcl-X but not Bcl-2 decrease rapidly preceeding the onset of death. The death of IL-3 starved cells is asynchronous, starting between 6 to 8 h with 50% death being reached after 10 to 12 h. At any time point, apoptosis can be rapidly inhibited by growth factor re-addition. This has allowed us to determine that the inhibition of apoptosis by growth factor takes place at two levels. The first one, which we have called short term inhibition, is independent of mRNA and protein synthesis i.e. it takes place in the absence of survival gene neosynthesis and can be demonstrated during the first 6 h following growth factor re-addition. The second one corresponds to long-term survival-more than 24 h survival-and is strongly correlated with the induction of Bcl-X but not Bcl-2 gene expression. This induction of Bcl-X by IL-3 is shown to be dependent on MAP-kinase activation.


Subject(s)
Apoptosis/drug effects , Hematopoietic Stem Cells/cytology , Interleukin-3/pharmacology , Proto-Oncogene Proteins c-bcl-2/biosynthesis , Proto-Oncogene Proteins/biosynthesis , Animals , Bone Marrow , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Cell Cycle/drug effects , Cell Line , Culture Media , Hematopoietic Stem Cells/drug effects , Hematopoietic Stem Cells/physiology , Kinetics , Mice , Protein Biosynthesis , RNA, Messenger/biosynthesis , Time Factors , Transcription, Genetic , bcl-X Protein
20.
J Exp Med ; 184(6): 2141-51, 1996 Dec 01.
Article in English | MEDLINE | ID: mdl-8976170

ABSTRACT

The characteristics of CD8+ T cells responsible for memory responses are still largely unknown. Particularly, it has not been determined whether different activation thresholds distinguish naive from memory CD8+ T cell populations. In most experimental systems, heterogeneous populations of primed CD8+ T cells can be identified in vivo after immunization. These cells differ in terms of cell cycle status, surface phenotype, and/or effector function. This heterogeneity has made it difficult to assess the activation threshold and the relative role of these subpopulations in memory responses. In this study we have used F5 T cell receptor transgenic mice to generate a homogeneous population of primed CD8+ T cells. In the F5 transgenic mice, peptide injection in vivo leads to activation of most peripheral CD8+ T cells. In vivo BrdU labeling has been used to follow primed T cells over time periods spanning several weeks after peptide immunization. Our results show that the majority of primed CD8+ T cells generated in this system are not cycling and express increased levels of CD44 and Ly6C. These cells remain responsive to secondary peptide challenge in vivo as evidenced by short term upregulation of activation markers such as CD69 and CD44. The activation thresholds of naive and primed CD8+ T cells were compared in vitro. We found that CD8+ T cells from primed mice are activated by peptide concentrations 10-50-fold lower than naive mice. In addition, the kinetics of interleukin 2R alpha chain upregulation by primed CD8+ T cells differ from naive CD8+ T cells. These primed hyperresponsive CD8+ T cells might play an important role in the memory response.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Immunologic Memory , Amino Acid Sequence , Animals , Antigens, CD/biosynthesis , Antigens, Differentiation, T-Lymphocyte/biosynthesis , CD8 Antigens/biosynthesis , Cells, Cultured , Flow Cytometry , Hemagglutinin Glycoproteins, Influenza Virus/immunology , Hyaluronan Receptors/biosynthesis , Influenza A virus/immunology , Lectins, C-Type , Lymphocyte Activation , Mice , Mice, Inbred C57BL , Mice, Transgenic , Peptide Fragments/immunology , Spleen/immunology , Thymectomy , Up-Regulation
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