Search results for "Lymphocyte"

Inhibition of cAMP Degradation Improves Regulatory T Cell-Mediated Suppression

2009

Abstract Naturally occurring regulatory T cells (nTreg cells) are crucial for the maintenance of peripheral tolerance. We have previously shown that a key mechanism of their suppressive action is based on a contact-dependent transfer of cAMP from nTreg cells to responder T cells. Herein, we further elucidate the important role of cAMP for the suppressive properties of nTreg cells. Prevention of cAMP degradation by application of the phosphodiesterase 4 inhibitor rolipram led to strongly increased suppressive potency of nTreg cells for Th2 cells in vitro and in vivo. Detailed analyses revealed that rolipram caused, in the presence of nTreg cells, a synergistic increase of cAMP in responder T…

Activation of the PD-1 Pathway Contributes to Immune Escape in EGFR-Driven Lung Tumors

2013

Abstract The success in lung cancer therapy with programmed death (PD)-1 blockade suggests that immune escape mechanisms contribute to lung tumor pathogenesis. We identified a correlation between EGF receptor (EGFR) pathway activation and a signature of immunosuppression manifested by upregulation of PD-1, PD-L1, CTL antigen-4 (CTLA-4), and multiple tumor-promoting inflammatory cytokines. We observed decreased CTLs and increased markers of T-cell exhaustion in mouse models of EGFR-driven lung cancer. PD-1 antibody blockade improved the survival of mice with EGFR-driven adenocarcinomas by enhancing effector T-cell function and lowering the levels of tumor-promoting cytokines. Expression of m…

Lymphocyte transendothelial passage in postcapillary high endothelial venules (HEV) of lymph nodes and aggregate lymph nodules

2003

Acid Dnase Activities In Peripheral, Mononuclear Blood Cells: A Possible Parameter To Detect Proliferating Cell Populations

1992

After electrophoresis in DNA -containing polyacrylamide gels, two acid DNase activities can be detected in peripheral, mononuclear cells of the human blood. One of these acid DNase activities correlates with cell proliferation; its isoelectrical point is at pI 7.4. By means of this DNase activity, a quantity of less than 1% leukemic cells can be detected. The increased acid DNase activity can indicate the proliferation of malignant cell populations and possibly the proliferation of cell populations during immunological reactions

Microangiectasias: Structural regulators of lymphocyte transmigration

2003

The migration of lymphocytes into inflammatory tissue requires the migrating cell to overcome mechanical forces produced by blood flow. A generally accepted hypothesis is that these forces are overcome by a multistep sequence of adhesive interactions between lymphocytes and endothelial cells. This hypothesis has been recently challenged by results demonstrating wall shear stress on the order of 20 dyn/cm 2 in vivo and infrequent lymphocyte–endothelial adhesion at wall shear stress >1–2 dyn/cm 2 in vitro . Here, we show that lymphocyte slowing and transmigration in the skin is associated with microangiectasias, i.e., focal structural dilatations of microvessel segments. Microangiectasias…

Similar Clinical Course and Significance of Circulating Innate and Adaptive Immune Cell Counts in STEMI and COVID-19

2020

This study aimed to assess the time course of circulating neutrophil and lymphocyte counts and their ratio (NLR) in ST-segment elevation myocardial infarction (STEMI) and coronavirus disease (COVID)-19 and explore their associations with clinical events and structural damage. Circulating neutrophil, lymphocyte and NLR were sequentially measured in 659 patients admitted for STEMI and in 103 COVID-19 patients. The dynamics detected in STEMI (within a few hours) were replicated in COVID-19 (within a few days). In both entities patients with events and with severe structural damage displayed higher neutrophil and lower lymphocyte counts. In both scenarios, higher maximum neutrophil and lower mi…

Characterization of Renal-Cell Carcinoma (RCC)-Reactive Cytotoxic T-Lymphocyte Responses Generated from Peripheral Blood of HLA-Matched Sibling and U…

2004

Abstract Although current allo-transplantation therapy can induce considerable graft-versus-tumor (GvT) effects in RCC patients, it is also accompanied by severe, even life-threatening side effects, mainly due to graft-versus-host disease (GvHD). Efforts aiming to improve the specificity and efficiency of allogeneic cell therapy in this disease (e.g. specific donor lymphocyte infusion or vaccination) will certainly benefit from the identification of potential anti-tumor effector mechanisms and their corresponding target structures. We recently demonstrated that RCC-reactive cytotoxic T-lymphocyte (CTL) clones can be isolated from peripheral blood of healthy donors matched with the RCC stimu…

Low Lymphocyte Count and Cardiovascular Diseases

2011

Inflammation plays a crucial pathophysiological role in the entire continuum of the atherosclerotic process, from its initiation, progression, and plaque destabilization leading ultimately to an acute coronary event. Furthermore, once the clinical event has occurred, inflammation also influences the left ventricular remodelling process. Under the same paradigm, there is evidence that lymphocytes play an important role in the modulation of the inflammatory response at every level of the atherosclerotic process. Low lymphocyte count (LLC) is a common finding during the systemic inflammatory response, and clinical and animal studies suggest that LCC plays a putative role in accelerated atheros…

An anti-inflammatory role for V alpha 14 NK T cells in Mycobacterium bovis bacillus Calmette-Guérin-infected mice.

2003

Abstract The possible contribution of NKT cells to resistance to Mycobacterium tuberculosis infection remains unclear. In this paper we characterized the Vα14 NKT cell population following infection with Mycobacterium bovis bacillus Calmette-Guérin (BCG). BCG infection determined an early expansion of Vα14 NKT cells in liver, lungs, and spleen, which peaked on day 8 and was sustained until day 30. However, an NK1.1+ Vα14 NKT population preferentially producing IFN-γ predominated at an early stage (day 8), which was substituted by an NK1.1− population preferentially producing IL-4 at later stages (day 30). Despite the fact that Vα14 NKT cell-deficient mice eliminated BCG as did control mice…

Intrathymic tolerance induction: determination of tolerance to class II major histocompatibility complex antigens in maturing T lymphocytes by a bone…

1987

Two new experimental approaches were established to analyse the influence of the thymus on tolerance induction to major histocompatibility complex (MHC) antigens: The aim of the first experiment was to perform successful transplantation of adult allogeneic thymus tissue into nude mice, an attempt that has been unsuccessful in the past. Tolerance for the MHC genotype of a prospective thymus graft recipient (A) was induced in mice of strain B by injection of (A X B) splenocytes during the neonatal period. Adult thymic tissue obtained from these allogeneic donors (B) were grafted into the nude mice of strain A. The allogeneic thymus was accepted by the nude mice and immunoreconstitution was ac…