Magdalena Tary-Lehmann | Case Western Reserve University (original) (raw)

Papers by Magdalena Tary-Lehmann

Cellular Immunology, 2005

Non-obese diabetic (NOD) mice develop spontaneous T-cell responses against pancreatic beta-cells,... more Non-obese diabetic (NOD) mice develop spontaneous T-cell responses against pancreatic beta-cells, leading to islet cell destruction and diabetes. Despite high genetic similarity, non-obese resistant (NOR) mice do not develop diabetes. We show here that spleen cells of both NOD and NOR mice respond to the islet cell antigen glutamic acid decarboxylase-65 in IFN-gamma-ELISPOT assays. Moreover, NOR-T cells induce periinsulitis in NOD SCID recipient mice. Thus, a potentially pathogenic islet cell-specific T-cell response arises in NOR and NOD mice alike; the mechanism that prevents the autoimmune progression of self-reactive T cells in NOR mice presumably acts at the level of effector function. Consistent with this hypothesis, CD4+CD25+ cell-depleted spleen cells from NOR mice mediated islet cell destruction and overt diabetes in NOD SCID mice. Therefore, islet cell-specific effector cells in NOR mice appear to be under the control of CD4+CD25+ regulatory T cells, confirming the importance of regulatory cells in the control of autoimmune diabetes.

PEDIATRICS, 1999

Treatment-resistant Lyme arthritis is associated with immune reactivity to outer surface protein ... more Treatment-resistant Lyme arthritis is associated with immune reactivity to outer surface protein A (OspA) of Borrelia burgdorferi, the agent of Lyme disease, and the major histocompatibility complex class II allele DRB1*0401. The immunodominant epitope of OspA for T helper cells was identified. A homology search revealed a peptide from human leukocyte function-associated antigen-1 (hLFA-1) as a candidate autoantigen. Individuals with treatment-resistant Lyme arthritis, but not other forms of arthritis, generated responses to OspA, hLFA-1, and their highly related peptide epitopes. Identification of the initiating bacterial antigen and a cross-reactive autoantigen may provide a model for development of autoimmune disease.

Clinical immunology (Orlando, Fla.), 2007

It is unknown to what extent the heterogeneity of antigen presenting cells (APC) influences the I... more It is unknown to what extent the heterogeneity of antigen presenting cells (APC) influences the IFN-gamma response of CD4 memory cells. We re-stimulated DO11.10 T cell receptor (TCR)-transgenic cells and wild-type CD4 memory cells with OVA-peptide 323-339 presented on purified dendritic cells (DC), macrophages, and B cells. Using IFN-gamma ELISPOT assays, we measured the number of cytokine producing T cells and the amount of cytokine produced by individual T cells at different time points after antigen encounter. The data showed that, when CD4 cells recognized antigen on DC, the induction of cytokine production was accelerated compared to macrophages and B cells. In contrast, the per-cell cytokine productivity was independent of the type of APC by which the T cells were re-stimulated. Moreover, the peptide concentration required for CD4 cell activation was comparable for the different APC. The data suggest that DC induce cytokine production in memory cells with accelerated activatio...

Transplantation, 1998

Background. Despite improvements in the shortterm survival of renal transplants, many allografts ... more Background. Despite improvements in the shortterm survival of renal transplants, many allografts fail over the 5-10 years after transplantation. We sought to identify an immunologic assay that could identify those patients at high risk for future allograft failure.

Validation of Cell-Based Assays in the GLP Setting, 2008

ABSTRACT SummaryELISPOT assays have recently emerged as a primary tool for monitoring antigen-spe... more ABSTRACT SummaryELISPOT assays have recently emerged as a primary tool for monitoring antigen-specific low frequency measurements of cellular immunity, recording two cardinal features of cell-mediated immunity: the clonal sizes and the cytokine effector class. Obtaining information on these parameters is crucial for the comprehensive assessment, among other things, of any immunotherapy. This is particularly useful in the field of pre-clinical/clinical studies and vaccine trials, where high sample numbers from various sites have to be collected and stored before they can be processed in a timely fashion. With relatively little cell material and labor involved, ELISPOT assays would ideally lend themselves for high throughput analysis. While long employed in the academic research setting, the ability to obtain valid ELISPOT data on study samples is beginning to greatly enhance ex vivo immune monitoring capabilities for the pharmaceutical companies. To be used in a regulated environment, however, the assay needs to be validated. This chapter will focus on the standardization and validation of an ELISPOT assay using reference samples.

Immunology Today, 1995

Severe combined immunodeficiency (SClD) mice can be stably grafted with human peripheral blood ly... more Severe combined immunodeficiency (SClD) mice can be stably grafted with human peripheral blood lymphocytes, creating hu-PBL-SCID chimeras; essentially, these are mice with a human immune system. Here, Magdalena Tary-Lehmann, Andrew Saxon and Paul Lehmann discuss the immunobiology of these chimeras. The authors propose that hu-PBL-SCID chimerism evolves in two phases. During the first three weeks after grafting, many of the injected cells survive and the human immune system is functional. Subsequently, anti-mouse-reactive clones are selected and the immune system becomes nonfunctional. The implications of this scenario for the utilization of the bu-PBL-SCID model are discussed.

Neurobiology of Aging, 2010

A␤ 1-42 -specific antibodies and T-cell proliferation point to the existence of a memory response... more A␤ 1-42 -specific antibodies and T-cell proliferation point to the existence of a memory response to A␤ 1-42 in humans. Using ELISPOT, we studied A␤ 1-42 -specific T cells in individuals of various ages, and in subjects with Trisomy 21 or Alzheimer's disease. We show for the first time that A␤ 1-42 -specific Th1-type T-cell memory is present in young humans, producing high levels of IFN-␥ and IL-2. With increasing age, the production of IFN-␥ and IL-2 decreases but is not discontinued in healthy subjects and is accompanied by a sharp rise in CD4 + T-cell-derived regulatory IL-10 production. In contrast, individuals with Trisomy 21 and with Alzheimer's disease produce IL-10 only in the absence of any effector cytokine. This signifies a switch from a Th1 effector to an IL-10 mediated regulatory response.

Journal of Virology, 2009

These data indicate that during uncontrolled HIV infection, PDC-dependent NK cell function is imp... more These data indicate that during uncontrolled HIV infection, PDC-dependent NK cell function is impaired, which is in large part attributable to defective IFN-␣-induced NK cell activity and not to altered IFN-␣ receptor, NKP30, NKP44, NKP46, or NKG2D expression.

Journal of Neuroimmunology, 2005

Experimental allergic encephalomyelitis (EAE) is an animal model of multiple sclerosis. While EAE... more Experimental allergic encephalomyelitis (EAE) is an animal model of multiple sclerosis. While EAE is mediated by the cytokines produced by specific T cells, the cytokine signature of these effector cells is unresolved. We tested CD4 cells from MOG peptide 35-55 immunized C57BL/6 mice for their peptide induced cytokine production on antigen presenting cells of the respective cytokine knockout mice, or wild type mice. IL-4 and IL-6 production was seen on wild type antigen presenting cells, suggesting that IL-4 and IL-6 are not T cell products. In contrast, IFN-gamma, IL-2 and IL-3 were found to be produced by the MOG specific CD4 cells. Understanding the cognate vs. bystander cytokine production in EAE might help dissect the contribution of cytokines to the pathogenesis of the disease.

Journal of Neuroimmunology, 2006

Gene knock-out and knock-in mice are becoming increasingly indispensable for mechanism-oriented s... more Gene knock-out and knock-in mice are becoming increasingly indispensable for mechanism-oriented studies of EAE. Most gene-modified mice are on the C57BL/6 background, for which presently there are only two EAE models available, the MOG peptide 35-55 and the PLP 178-191 peptide induced disease. However, because MS is not a single pathogenic entity, different EAE models are required to reproduce and study its various features. Here we are introducing MBP-PLP fusion protein (MP4)-induced EAE for C57BL/6 mice. B cell- and CD8+ T cell-dependence, as well as multi-determinant recognition are among the unique features of this demyelinating EAE.

Journal of Neuroimmunology, 2007

Mechanism-oriented studies of EAE rely mostly on gene-modified mice on the C57BL/6 background. He... more Mechanism-oriented studies of EAE rely mostly on gene-modified mice on the C57BL/6 background. Here we report that MP4-induced EAE displays characteristic differences in CNS pathology as compared to MOG peptide 35-55-elicited disease. While in the latter, the topology of CNS infiltration remained unchanged throughout the disease, in MP4-induced EAE it was dynamic and stagedependent shifting from the brain to the spinal cord and finally to the cerebellum. Unlike in the MOG peptide model, the frequencies and sizes of CNS lesions in MP4-induced disease showed a clear correlation with clinical disease severity. These characteristic features of MP4-induced EAE may contribute to modelling the complex spectrum of disease manifestations seen in MS.

Journal of Immunotherapy, 2009

Vaccinations typically rely on immunization with live virus for eliciting protective CD8 T cell i... more Vaccinations typically rely on immunization with live virus for eliciting protective CD8 T cell immunity. There is increasing interest to use subunit vaccination strategies to achieve such responses. Complete Freund&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s adjuvant (CFA) and unmethylated cytosine-guanine dinucleotide containing DNA are considered some of the most potent adjuvants for eliciting immunity. Whereas a wealth of information is available on how these adjuvants affect CD4 T cell responses, their effects on engaging CD8 T cell immunity are not completely understood. We immunized C57BL/6J mice with the class I restricted peptides Uty or SIINFEKL using these 2 adjuvants and tested for cytokine secretion, proliferation, in vivo cytotoxicity, and delayed-type hypersensitivity (DTH). Our data show that CFA-induced CD8 T cells to proliferate, mediate DTH, and to secrete interferon-gamma, interleukin (IL)-2 and IL-17. Despite these markers of CD8 T cell activation, CFA failed to induce an early cytotoxic CD8 T cell response. In contrast, unmethylated cytosine-guanine dinucleotide containing DNA promoted a vigorous cytolytic response without activating substantial cytokine production, proliferation or DTH. These data have implications for CD8 T cell subunit vaccine design in which cytotoxicity versus DTH plays a key role in host defense.

The Journal of Immunology, 2000

Identifying and quantifying autoaggressive responses in multiple sclerosis (MS) has been difficul... more Identifying and quantifying autoaggressive responses in multiple sclerosis (MS) has been difficult in the past due to the low frequency of autoantigen-specific T cells, the high number of putative determinants on the autoantigens, and the different cytokine signatures of the autoreactive T cells. We used single-cell resolution enzyme-linked immunospot (ELISPOT) assays to study, directly ex vivo, proteolipid protein (PLP)-specific memory cell reactivity from MS patients and controls. Overlapping 9-aa-long peptides, spanning the entire PLP molecule in single amino acid steps, were used to determine the frequency and fine specificity of PLP-specific lymphocytes as measured by their IFN-␥ and IL-5 production. MS patients (n ‫؍‬ 22) responded to 4 times as many PLP peptides as did healthy controls (n ‫؍‬ 22). The epitopes recognized in individual patients, up to 22 peptides, were scattered throughout the PLP molecule, showing considerable heterogeneity among MS patients. Frequency measurements showed that the number of PLP peptide-specific IFN-␥-producing cells averaged 11 times higher in MS patients than in controls. PLP peptideinduced IL-5-producing T cells occurred in very low frequencies in both MS patients and controls. This first comprehensive assessment of the anti-PLP-Th1/Th2 response in MS shows a greatly increased Th1 effector cell mass in MS patients. Moreover, the highly IFN-␥-polarized, IL-5-negative cytokine profile of the PLP-reactive T cells suggests that these cells are committed Th1 cells. The essential absence of uncommitted Th0 cells producing both cytokines may explain why therapeutic strategies that aim at the induction of immune deviation show little efficacy in the established disease.

The Journal of Immunology, 2001

At present it is unclear how Ag dose-dependent T cell functions, such as cytokine production, ref... more At present it is unclear how Ag dose-dependent T cell functions, such as cytokine production, reflect TCR affinity and how the signal strength afforded by the Ag dose affects the kinetics of cytokine production by the individual T cell. We used a computerassisted ELISPOT approach to address these issues. IFN-␥ release by a clonal population of CD4 T cells was monitored on a clonal population of APC while titrating the nominal peptide. The frequency of cytokine-producing cells, the net per-cell output of cytokine, and the onset of cytokine production were each found to be functions of the signal strength. Sigmoidal dose-response curves were seen at the clonal population level, but the activation thresholds for the individual T cells followed a Gaussian distribution. Moreover, the overall dose-response curve of the T cell clone revealed cyclic changes, becoming increasingly shifted toward lower Ag concentrations with the duration of time that elapsed since the last restimulation with Ag. Therefore, responsiveness to Ag ("functional avidity") is not a constant parameter of a T cell clone but a function of the T cell's history of last Ag encounter. The implications of such shifting activation thresholds are discussed for autoimmune disease.

The Journal of Immunology, 2007

Journal of Immunological Methods, 2000

A major goal in immunodiagnostics has been the development of assay systems that can measure CD8 ... more A major goal in immunodiagnostics has been the development of assay systems that can measure CD8 T cell immunity in humans, directly ex vivo, at high resolution, and with high throughput. We established granzyme B (grB) enzyme-linked immunospot assay (ELISPOT) in conjunction with image analysis to this end. Using grB transfected and untransfected Chinese hamster ovary (CHO) cells and T cell lines, we show that the antibody pair utilized was grB-specific and that only activated T cells secrete grB. GrB release began within 4 h after antigen stimulation and stopped within 40 h. Side-by-side comparison showed grB ELISPOT assays to have a higher resolution than classic chromium-release assays in terms of 1 signal-to-noise ratio. The linearity of the relation of the number of CD8 effector T cells plated to grB spots detected suggests that grB ELISPOT assays measure the frequencies of grB-secreting cells directly. Reactivity to HIV peptides was seen in grB ELISPOT assays of freshly isolated PBMC from HIV patients, consistent with the detection of peptide-specific memory cells. The higher resolution and lower labor and material investment should make grB ELISPOT assays an attractive alternative to chromium-release assays in monitoring the clonal sizes of specific CD8 memory cells in vivo.

Journal of Experimental Medicine, 1992

In these studies we have characterized the human cells that repopulate severe combined immunodefi... more In these studies we have characterized the human cells that repopulate severe combined immunodeficient (SCID) mice after injection of adult peripheral blood or cord blood (hu-PBD SCID mice). In all organs of the chimeras, and at any time point tested, single-positive (CD4 + or CD8 +) T cells that expressed the or//3 T cell receptor (TCR) prevailed. All T cells were CD45RO * and the majority were also HLA-DR § . Thus, the human T cells in the chimeras exhibited the phenotype of mature, memory cells that showed signs of recent activation. Cell cycle studies revealed a mitotically active human T cell population in the murine host. However, when freshly isolated from the chimeras, the human T cells were refractory to stimulation by anti-CD3 antibody but proliferated in response to exogenous interleukin 2. Chimera-derived human T cell lines retained this state of unresponsiveness to TCR-triggered proliferation for 4-6 wk in vitro. Subsequently, the T cell lines developed responses to anti-CD3 stimulation and 9 of 11 of the lines also proliferated in response to splenic stimulator cells of SCID mice. These data demonstrate that the human T cells are in a state of reversible anergy in the murine host and that xenoreactivity might play a critical role in hu-PBL-SCID mice. Mechanisms that may determine repopulation of SCID mice with human peripheral blood mononuclear cells are discussed.