scholarly journals Human antigen-presenting cell/tumour cell hybrids stimulate strong allogeneic responses and present tumour-associated antigens to cytotoxic T cells in vitro

Immunology ◽  
1999 ◽  
Vol 98 (4) ◽  
pp. 541-550 ◽  
Author(s):  
D. J. Dunnion ◽  
A. L. Cywinski ◽  
V. C. Tucker ◽  
A. K. Murray ◽  
A. B. Rickinson ◽  
...  
Keyword(s):  
T Cells ◽  
Tumour Cell ◽  
Cytotoxic T Cells ◽  
Cell Tumour ◽  
Antigen Presenting Cell ◽  
Cell Hybrids ◽  
Tumour Associated Antigens ◽  
Antigen Presenting

Enhancement of the Antigen-Presenting Cell Function of Mantle Cell Lymphomas (MCL) by Novel Molecularly Based Immunotherapeutic Strategies.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2315-2315
Author(s):  
Hongwei Wang ◽  
Fengdong Cheng ◽  
D. Noyes ◽  
K. Wright ◽  
S. Mohapatra ◽  
...  
Keyword(s):  
T Cells ◽  
B Cell ◽  
Histone Deacetylases ◽  
Cell Function ◽  
Antigen Presenting Cell ◽  
Ifn Gamma ◽  
Stat3 Signaling ◽  
Antigen Presenting ◽  
In Vitro Treatment

Abstract MCL is an aggressive and incurable B-cell malignancy with an intrinsic characteristic to relapse after an initial good response to treatment. Manipulation of the immune system to unleash its well-known specificity and long-lasting protective effect might provide a unique opportunity to induce more durable responses in MCL. In previous studies in an A20 B-cell lymphoma murine model we have demonstrated that augmentation of the antigen-presenting cell function of the malignant B-cell is required for elicitation of an effective anti-lymphoma immunity1. Inhibition of Stat3 signaling, a negative regulator of inflammatory responses, and modulation of histone deacetylases function were identified as two novel targets to augment the immunogenicity of the malignant B-cell. In this study we determined therefore whether manipulation of these intracellular pathways in murine and human MCL cells could result in priming of antigen-specific T-cells and/or restoration of the responsiveness of tolerant T-cells. First, in vitro treatment of FC-muMCL1 cells - cell line derived from a MCL tumor that arise following pristine injection into Em-cyclin D1 transgenic mice- with increasing concentrations of the Stat3 inhibitors, Cucurbitacin I (CuI) or CPA-7 resulted in an enhanced presentation of OVA-peptide to naive CD4+ T-cells specific for a MHC class II restricted epitope of Ovalbumin (OT-II cells). Indeed, these antigen-specific T-cells produce higher levels of IL-2 and IFN-gamma compared to anti-OVA T cells that encountered cognate antigen in FC-muMCL1 cells treated with LPS alone. Similarly, we found that culture of the human MCL cells JEKO or Z138 with allogeneic human peripheral blood mononuclear cells in the presence of increasing concentrations of the Stat3 inhibitors also resulted in increased IL-2 production by T-cells. In the next set of experiments, we determined whether treatment of FC-muMCL1 cells with the hydroxamic acid analogue pan-HDAC inhibitor LAQ824 could influence their antigen-presenting capabilities and their ability to activate T-cell responses. Unlike, MCL cells treated with LPS alone, FC-muMCL1 cells treated with LPS and LAQ824 effectively prime antigen-specific CD4+ T-cells as determined by their production of both IL-2 and IFN-gamma in response to cognate peptide. Furthermore, in vitro treatment of Z138 MCL cells with LAQ824 also led to enhanced IFN-gamma production by allogeneic human PBMCs. Taken together, our findings points to inhibition of Stat3 signaling and inhibition of histone deacetylases as appealing molecularly based immunotherapeutic strategies to augment the immunogenicity of MCL cells.

scholarly journals Tumour Cell Generation of Inducible Regulatory T-Cells in Multiple Myeloma Is Contact-Dependent and Antigen-Presenting Cell-Independent

PLoS ONE ◽  
2012 ◽  
Vol 7 (5) ◽  
pp. e35981 ◽  
Author(s):  
Sylvia Feyler ◽  
Gina B. Scott ◽  
Christopher Parrish ◽  
Sarah Jarmin ◽  
Paul Evans ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
Regulatory T Cells ◽  
Tumour Cell ◽  
Cell Generation ◽  
Antigen Presenting Cell ◽  
Antigen Presenting

scholarly journals Cholera Toxin and Escherichia coli Heat-Labile Enterotoxin, but Not Their Nontoxic Counterparts, Improve the Antigen-Presenting Cell Function of Human B Lymphocytes

2009 ◽  
Vol 77 (5) ◽  
pp. 1924-1935 ◽  
Author(s):  
Donatella R. M. Negri ◽  
Dora Pinto ◽  
Silvia Vendetti ◽  
Mario Patrizio ◽  
Massimo Sanchez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
T Cells ◽  
B Cells ◽  
Cholera Toxin ◽  
B Lymphocytes ◽  
Antigen Presenting Cell ◽  
Heat Labile ◽  
Human B Cells ◽  
Antigen Presenting

ABSTRACT B lymphocytes play an important role in the immune response induced by mucosal adjuvants. In this study we investigated the in vitro antigen-presenting cell (APC) properties of human B cells upon treatment with cholera toxin (CT) and Escherichia coli heat-labile enterotoxin (LT) and nontoxic counterparts of these toxins, such as the B subunit of CT (CT-B) and the mutant of LT lacking ADP ribosyltransferase activity (LTK63). Furthermore, forskolin (FSK), a direct activator of adenylate cyclase, and cyclic AMP (cAMP) analogues were used to investigate the role of the increase in intracellular cAMP caused by the A subunit of CT and LT. B lymphocytes were cultured with adjuvants and polyclonal stimuli necessary for activation of B cells in the absence of CD4 T cells. Data indicated that treatment with CT, LT, FSK, or cAMP analogues, but not treatment with CT-B or LTK63, upregulated surface activation markers on B cells, such as CD86 and HLA-DR, and induced inhibition of the proliferation of B cells at early time points, while it increased cell death in long-term cultures. Importantly, B cells treated with CT, LT, or FSK were able to induce pronounced proliferation of both CD4+ and CD8+ allogeneic T cells compared with untreated B cells and B cells treated with CT-B and LTK63. Finally, only treatment with toxins or FSK induced antigen-specific T-cell proliferation in Mycobacterium tuberculosis purified protein derivative or tetanus toxoid responder donors. Taken together, these results indicated that the in vitro effects of CT and LT on human B cells are mediated by cAMP.

scholarly journals CD4+ Th1 Cells Induced by Dendritic Cell-Based Immunotherapy in Mice Chronically Infected with Leishmania amazonensis Do Not Promote Healing

2004 ◽  
Vol 72 (8) ◽  
pp. 4455-4463 ◽  
Author(s):  
Yannick F. Vanloubbeeck ◽  
Amanda E. Ramer ◽  
Fei Jie ◽  
Douglas E. Jones
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Leishmania Amazonensis ◽  
Interleukin 12 ◽  
Mrna Levels ◽  
Antigen Presenting Cell ◽  
Th1 Response ◽  
Ifn Γ ◽  
Antigen Presenting

ABSTRACT The susceptibility of mice to Leishmania amazonensis infection is thought to result from an inability to develop a Th1 response. Our data show that the low levels of gamma interferon (IFN-γ) produced by the draining lymph node (DLN) cells of chronically infected mice could be enhanced in vitro and in vivo with L. amazonensis antigen-pulsed bone marrow-derived dendritic cells (BM-DC) and the Th1-promoting cytokine interleukin-12 (IL-12). Given intralesionally to chronically infected mice, this treatment induced the upregulation of mRNA levels for IFN-γ, the transcription factor T-box expressed in T cells, and IL-12 receptor β2 in CD4+ T cells from the DLN and an increase in parasite-specific immunoglobulin G2a in the serum. However, this Th1 response was not associated with healing, and the antigen-specific enhancement of IFN-γ production remained impaired in the DLN. However, addition of IL-12 to the in vitro recall response was able to recover this defect, suggesting that antigen-presenting cell-derived IL-12 production may be limited in infected mice. This was supported by the fact that L. amazonensis amastigotes limited the production of IL-12p40 from BM-DC in vitro. Altogether, our data indicate that the immune response of mice chronically infected with L. amazonensis can be enhanced towards a Th1 phenotype but that the presence of Th1 CD4+ T cells does not promote healing. This suggests that the phenotype of the CD4+ T cells may not always be indicative of protection to L. amazonensis infection. Furthermore, our data support growing evidence that antigen-presenting cell function, such as IL-12 production, may limit the immune response in L. amazonensis-infected mice.

scholarly journals Human fetal liver MSCs are more effective than adult bone marrow MSCs for their immunosuppressive, immunomodulatory, and Foxp3+ T reg induction capacity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yi Yu ◽  
Alejandra Vargas Valderrama ◽  
Zhongchao Han ◽  
Georges Uzan ◽  
Sina Naserian ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Immune Responses ◽  
Molecular Mechanisms ◽  
Fetal Liver ◽  
Cytotoxic T Cells ◽  
Cell Contact ◽  
Adult Bone Marrow ◽  
Adult Bone

Abstract Background Mesenchymal stem cells (MSCs) exhibit active abilities to suppress or modulate deleterious immune responses by various molecular mechanisms. These cells are the subject of major translational efforts as cellular therapies for immune-related diseases and transplantations. Plenty of preclinical studies and clinical trials employing MSCs have shown promising safety and efficacy outcomes and also shed light on the modifications in the frequency and function of regulatory T cells (T regs). Nevertheless, the mechanisms underlying these observations are not well known. Direct cell contact, soluble factor production, and turning antigen-presenting cells into tolerogenic phenotypes, have been proposed to be among possible mechanisms by which MSCs produce an immunomodulatory environment for T reg expansion and activity. We and others demonstrated that adult bone marrow (BM)-MSCs suppress adaptive immune responses directly by inhibiting the proliferation of CD4+ helper and CD8+ cytotoxic T cells but also indirectly through the induction of T regs. In parallel, we demonstrated that fetal liver (FL)-MSCs demonstrates much longer-lasting immunomodulatory properties compared to BM-MSCs, by inhibiting directly the proliferation and activation of CD4+ and CD8+ T cells. Therefore, we investigated if FL-MSCs exert their strong immunosuppressive effect also indirectly through induction of T regs. Methods MSCs were obtained from FL and adult BM and characterized according to their surface antigen expression, their multilineage differentiation, and their proliferation potential. Using different in vitro combinations, we performed co-cultures of FL- or BM-MSCs and murine CD3+CD25−T cells to investigate immunosuppressive effects of MSCs on T cells and to quantify their capacity to induce functional T regs. Results We demonstrated that although both types of MSC display similar cell surface phenotypic profile and differentiation capacity, FL-MSCs have significantly higher proliferative capacity and ability to suppress both CD4+ and CD8+ murine T cell proliferation and to modulate them towards less active phenotypes than adult BM-MSCs. Moreover, their substantial suppressive effect was associated with an outstanding increase of functional CD4+CD25+Foxp3+ T regs compared to BM-MSCs. Conclusions These results highlight the immunosuppressive activity of FL-MSCs on T cells and show for the first time that one of the main immunoregulatory mechanisms of FL-MSCs passes through active and functional T reg induction.

scholarly journals Mechanisms of Hepatocellular Injury in Hepatitis A

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 861
Author(s):  
Minghang Wang ◽  
Zongdi Feng
Keyword(s):  
T Cells ◽  
Liver Injury ◽  
Hepatitis A ◽  
Acute Viral Hepatitis ◽  
Hepatitis A Virus ◽  
Current Knowledge ◽  
Cytotoxic T Cells ◽  
Host Factors ◽  
Hepatocellular Injury

Hepatitis A virus (HAV) infection is a common cause of acute viral hepatitis worldwide. Despite decades of research, the pathogenic mechanisms of hepatitis A remain incompletely understood. As the replication of HAV is noncytopathic in vitro, a widely accepted concept has been that virus-specific cytotoxic T cells are responsible for liver injury. However, accumulating evidence suggests that natural killer (NK) cells, NKT cells, and even non-HAV-specific CD8+ T cells contribute to liver damage during HAV infection. In addition, intrinsic death of virus-infected hepatocytes has been implicated as a cause of liver injury in a murine model of hepatitis A. Furthermore, genetic variations in host factors such as T cell immunoglobulin-1 (TIM1) and IL-18 binding protein (IL-18BP) have been linked to hepatitis A severity. This review summarizes the current knowledge of the mechanisms of hepatocellular injury in hepatitis A. Different mechanisms may be involved under different conditions and they are not necessarily mutually exclusive. A better understanding of these mechanisms would aid in diagnosis and treatment of diseases associated with HAV infection.

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