Immunogenecity of CML-DC Is Maintained upon Imatinib Mesylate: Implication for Vaccination Regimens.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4666-4666
Author(s):  
Theresia M. Westers ◽  
Jeroen J.W.M. Janssen ◽  
Niels C.L. Snoijs ◽  
Arjan A. van de Loosdrecht ◽  
Gert J. Ossenkoppele

Abstract Chronic myeloid leukemia (CML) is characterized by the presence of the Philidelphia chromosome which encodes for the fusion protein bcr-abl, a constitutively active tyrosine kinase. Imatinib mesylate (Gleevec, Novartis) is an inhibitor of the kinase activity of bcr-abl and therefore a treatment modality for CML. High rates of cytogenetic responses are found, although in many patients minimal residual disease (MRD) is detected by molecular techniques. Immunotherapy using leukemic dendritic cell (DC) based vaccination might be a feasible approach to eradicate MRD. In a pilot study on CML-DC-based vaccination in advanced CML DTH responses towards CML cells were achieved. (Ossenkoppele et al., Leukemia, 2003, 17, 1424). However, little is known about the effects of Imatinib mesylate on bcr-abl positive CML-DC during vaccination. In this study we investigated effects of Imatinib on culture of CML-DC, their viability, T cell stimulating and migratory capacity in vitro in 17 patients. Imatinib hardly affected the immunophenotypical profile of CML-DC. Expression of CD40, CD80, CD83, HLA-DR and chemokine receptors (CCR5, CCR7, CXCR4) remained stable during overnight exposure. Only the fluorescence intensity of CD86 was significantly higher (1–10μM, p=0.043) and that of CD54 significantly decreased in the highest Imatinib concentration tested (p=0.043). Exposure of Imatinib-free cultured CML-DC to Imatinib significantly reduced the recovery of viable cells and hence the DC yield in a dose-dependent manner (5.3–26% reduction after 20h. for 1–10μM, p=0.043). Migration of mature CML-DC towards CCL19 (MIP3β) was significantly improved in the presence of 1 and 5μM Imatinib which implies increased ability to reach the lymph nodes (p=0.043, mean 27, 36 and 34% migration for 0, 1 and 5μM Imatinib, respectively). Imatinib did not affect T cell stimulating capacity of CML-DC, except at concentrations higher than 3μM (p=0.028). No significant changes were observed for Imatinib exposure of CD34+ DC isolated from normal subjects. In conclusion, Imatinib at low concentrations maintains the immunogenecity of CML-DC. Since Imatinib plasma levels in CML patients are 1.5 and 3.0μM upon 400 and 800mg daily, respectively, our data justify continuation of Imatinib treatment during CML-DC-based vaccination regimens.

Blood ◽  
2006 ◽  
Vol 108 (10) ◽  
pp. 3406-3413 ◽  
Author(s):  
Sabine Mumprecht ◽  
Matthias Matter ◽  
Viktor Pavelic ◽  
Adrian F. Ochsenbein

Abstract Imatinib mesylate (imatinib) is a potent inhibitor of defined tyrosine kinases (TKs) and is effective in the treatment of malignancies characterized by constitutive activation of these TKs such as chronic myeloid leukemia and gastrointestinal stromal tumors. TKs also play an important role in T-cell receptor (TCR) signal transduction. Inhibitory as well as stimulating effects of imatinib on T cells and dendritic cells have been described. Here, we analyzed the effects of imatinib treatment on antiviral immune responses in vivo. Primary cytotoxic T-cell (CTL) responses were not impaired in imatinib-treated mice after infection with lymphocytic choriomeningitis virus (LCMV) or after immunization with a tumor cell line expressing LCMV glycoprotein (LCMV-GP). Similarly, neutralizing antibody responses to vesicular stomatitis virus (VSV) were not affected. In contrast, secondary expansion of LCMV-specific memory CTLs was reduced in vitro and in vivo, resulting in impaired protection against reinfection. In addition, imatinib treatment delayed the onset of diabetes in a CTL-induced diabetes model. In summary, imatinib treatment in vivo selectively inhibits the expansion of antigen-experienced memory CTLs without affecting primary T- or B-cell responses. Therefore, imatinib may be efficacious in the suppression of CTL-mediated immunopathology in autoimmune diseases without the risk of acquiring viral infections.


2021 ◽  
Vol 22 (10) ◽  
pp. 5394
Author(s):  
Tomas Lidak ◽  
Nikol Baloghova ◽  
Vladimir Korinek ◽  
Radislav Sedlacek ◽  
Jana Balounova ◽  
...  

Multisubunit cullin-RING ubiquitin ligase 4 (CRL4)-DCAF12 recognizes the C-terminal degron containing acidic amino acid residues. However, its physiological roles and substrates are largely unknown. Purification of CRL4-DCAF12 complexes revealed a wide range of potential substrates, including MOV10, an “ancient” RNA-induced silencing complex (RISC) complex RNA helicase. We show that DCAF12 controls the MOV10 protein level via its C-terminal motif in a proteasome- and CRL-dependent manner. Next, we generated Dcaf12 knockout mice and demonstrated that the DCAF12-mediated degradation of MOV10 is conserved in mice and humans. Detailed analysis of Dcaf12-deficient mice revealed that their testes produce fewer mature sperms, phenotype accompanied by elevated MOV10 and imbalance in meiotic markers SCP3 and γ-H2AX. Additionally, the percentages of splenic CD4+ T and natural killer T (NKT) cell populations were significantly altered. In vitro, activated Dcaf12-deficient T cells displayed inappropriately stabilized MOV10 and increased levels of activated caspases. In summary, we identified MOV10 as a novel substrate of CRL4-DCAF12 and demonstrated the biological relevance of the DCAF12-MOV10 pathway in spermatogenesis and T cell activation.


Blood ◽  
1991 ◽  
Vol 78 (7) ◽  
pp. 1770-1780 ◽  
Author(s):  
M Massaia ◽  
A Bianchi ◽  
C Attisano ◽  
S Peola ◽  
V Redoglia ◽  
...  

Abstract Cellular immunity was investigated in 43 patients with multiple myeloma (MM) by assessing 3HTdR uptake induced by monocyte-dependent [CD3 monoclonal antibodies (MoAbs), phytohemagglutinin (PHA)] and monocyte- independent (CD2 MoAbs, ionomycin + phorbolester) stimulations. The former were evaluated in peripheral blood mononuclear cells (PBMNC) and purified T cells; the latter were evaluated in purified T-cell preparations only. MM showed significantly lower PBMNC responses to PHA (P less than .001), soluble OKT3 (CD3) (P = .01), and immobilized OKT3 MoAbs (P = .01). On purification of T cells, MM responses were still defective to soluble T11(2) + T11(3) (CD2) MoAbs (P = .004), phorbol myristate acetate (PMA) plus ionomycin (P less than .001), but significantly higher to plastic-immobilized OKT3 (P = .004). In some MM, 3HTdR uptake, interleukin-2 (IL-2) receptor (CD25) expression, and IL-2 production were as high on stimulation with plastic-immobilized OKT3 as that observed in normal subjects under optimal conditions (ie, plastic-immobilized OKT3 plus accessory signals). CD3 hyperreactivity correlated with the number of CD8+ HLA-DR+ cells in MM T-cell preparations. MM patients with more than 10% CD8+ HLA-DR+ cells had significantly higher responses to immobilized OKT3 (P less than .001), but lower responses to T11(2) plus T11(3) (P = .01), and PMA plus ionomycin (P = .03) than patients with less than 10% CD8+ HLA-DR+ cells. Phenotyping of CD45RA (naive) and CD45R0 (memory) expressions in resting MM T cells showed a lower ratio of CD45RA to CD45R0 in both CD4 (P less than .05) and CD8 (P less than .001) subpopulations. These data indicate that (a) some MM T cells require significantly fewer accessory signals (if any) to express the IL-2 receptor fully, secrete IL-2, and proliferate on multivalent cross-linking of the CD3/TCR complex; and (b) this peculiar state of activation is associated with high HLA-DR expression in CD8+ lymphocytes.


2021 ◽  
Author(s):  
N Bhaskaran ◽  
E Schneider ◽  
F Faddoul ◽  
A Paes da Silva ◽  
R Asaad ◽  
...  

AbstractResidual systemic inflammation and mucosal immune dysfunction persist in people living with HIV (PLWH) despite treatment with combined anti-retroviral therapy (cART), but the underlying immune mechanisms are poorly understood. Here we report an altered immune landscape involving upregulation of TLR- and inflammasome signaling, localized CD4+ T cell hyperactivation, and counterintuitively, an enrichment of CD4+CD25+FOXP3+ regulatory T cells (Tregs) in the oral mucosa of HIV+ patients on therapy. Using human oral tonsil cultures, we found that HIV infection causes an increase in a unique population of FOXP3+ cells expressing PD-1, IFN-γ, Amphiregulin (AREG), and IL-10. These cells persisted even in the presence of the anti-retroviral drug and underwent further expansion driven by TLR-2 ligands and IL-1β. IL-1β also promoted PD-1 upregulation in AKT1 dependent manner. PD-1 stabilized FOXP3 and AREG expression in these cells through a mechanism requiring the activation of Asparaginyl Endopeptidase (AEP). Importantly, these FOXP3+ cells were incapable of suppressing CD4+ T cells in vitro. Concurrently, HIV+ patients harbored higher levels of PD-1, IFN-γ, Amphiregulin (AREG), and IL-10 expressing FOXP3+ cells, which strongly correlated with CD4+ T cell hyperactivation, suggesting an absence of CD4+ T cell regulation in the oral mucosa. Taken together, this study provides insights into a novel mechanism of FOXP3+ cell dysregulation and reveals a critical link in the positive feedback loop of oral mucosal immune activation events in HIV+ patients on therapy.One Sentence SummaryHIV-induced immune dysfunction in lymphoid and mucosal tissues


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Michela Cioni ◽  
Christian Mittelholzer ◽  
Marion Wernli ◽  
Hans H. Hirsch

Background. Among human polyomaviruses, only BK virus (BKV) and JC virus (JCV) encode an agnoprotein upstream of VP1 on the viral late transcript. BKV agnoprotein is abundantly expressed late in the viral life cycle, but specific cellular and humoral immune responses are low or absent. We hypothesized that agnoprotein might contribute to BKV immune evasion by downregulating HLA expression, similar to Herpes simplex virus-1 ICP47. Methods UTA-6 or primary human renal proximal tubular epithelial cells (RPTEC) were co-transfected with plasmids constitutively expressing agnoprotein, or ICP47, and enhanced green-fluorescent protein (EGFP). EGFP-gated cells were analyzed for HLA-ABC and HLA-DR expression by flow cytometry. HLA-ABC and HLA-DR expression was also analyzed on UTA-6 bearing tetracycline-regulated agnoprotein or ICP47. Effects of agnoprotein on viral peptide-dependent T-cell killing were investigated using51Cr release.Results. ICP47 downregulated HLA-ABC without affecting HLA-DR, whereas agnoprotein did not affect HLA-ABC or HLA-DR expression. Interferon-γtreatment increased HLA-ABC in a dose-dependent manner, which was antagonized by ICP47, but not by agnoprotein. In UTA-6 cells, agnoprotein expression did neither impair HLA-ABC or -DR expression nor peptide-specific killing impaired by HLA-matched T-cells.Conclusion. Unlike the HSV-1 ICP47, BKV agnoprotein does not contribute to viral immune evasion by down-regulating HLA-ABC, or interfere with HLA-DR expression or peptide-dependent T-cell cytotoxicity.


Rheumatology ◽  
2019 ◽  
Vol 58 (11) ◽  
pp. 2051-2060 ◽  
Author(s):  
Giovanni Almanzar ◽  
Felix Kienle ◽  
Marc Schmalzing ◽  
Anna Maas ◽  
Hans-Peter Tony ◽  
...  

AbstractObjectiveRA is a chronic inflammatory disease characterized by lymphocyte infiltration and release of inflammatory cytokines. Previous studies have shown that treatment with Janus kinase inhibitors, such as tofacitinib, increased the incidence rate of herpes zoster compared with conventional DMARDs. Therefore, this study aimed to investigate the effect of tofacitinib on the varicella-zoster-virus (VZV)-specific T cell immune response.MethodsThe effect of tofacitinib on the VZV-specific T cell immune response was determined by evaluating the IFNγ production, the proliferative capacity, the VZV-induced differentiation into effector and memory T cells, the expression of activation marker CD69 and helper T cell type 1 (Th1)-characteristic chemokine receptors, such as CXCR3 and CCR5, as well as cytotoxic activity (perforin and granzyme B expression) of CD4+ T cells of patients with RA compared with healthy donors upon stimulation with VZV antigen in vitro.ResultsTofacitinib significantly reduced the IFNγ production, proliferation, activation, and CXCR3 expression of VZV-specific CD4+ T cells in a dose-dependent manner in short- and long-term lymphocyte culture. No effect on the distribution of naive, effectors or memory, or on the expression of perforin or granzyme B by VZV-specific CD4+ T cells was observed.ConclusionThis study showed that tofacitinib significantly modulated the Th1 response to VZV. The poor VZV-specific cellular immune response in patients with RA may be considered in recommendations regarding appropriate vaccination strategies for enhancing the VZV-specific Th1 response.


2003 ◽  
Vol 71 (9) ◽  
pp. 5219-5224 ◽  
Author(s):  
Tamara Matysiak-Budnik ◽  
Guillaume van Niel ◽  
Francis Mégraud ◽  
Kathryn Mayo ◽  
Claudia Bevilacqua ◽  
...  

ABSTRACT The increase in the transcellular passage of intact antigens across the digestive epithelium infected with Helicobacter pylori may interfere with the regulation of mucosal immune responses. The aim of this work was to study the capacity of Helicobacter infection to inhibit the development of oral tolerance or to promote allergic sensitization and the capacity of a gastro-protective agent, rebamipide, to interfere with these processes in mice. Oral tolerance to ovalbumin (OVA) was studied in 48 C3H/He 4-week-old mice divided into four groups: (i) OVA-sensitized mice; (ii) OVA-“tolerized” mice (that is, mice that were rendered immunologically tolerant); (iii) H. felis-infected, OVA-tolerized mice; (iv) and H. felis-infected, OVA-tolerized, rebamipide-treated mice. Oral sensitization to hen egg lysozyme (HEL) was studied in 48 mice divided into four groups: (i) controls; (ii) HEL-sensitized mice; (iii) H. felis-infected, HEL-sensitized mice; and (iv) H. felis-infected, HEL-sensitized, rebamipide-treated mice. Specific anti-OVA or anti-HEL immunoglobulin E (IgE) and IgG1/IgG2a serum titers were measured by enzyme-linked immunosorbent assay. Additionally, the capacity of rebamipide to interfere with antigen presentation and T-cell activation in vitro, as well as absorption of rebamipide across the epithelial monolayer, was tested. H. felis infection led to the inhibition of oral tolerance to OVA, but rebamipide prevented this inhibitive effect of H. felis. H. felis infection did not enhance the sensitization to HEL, but rebamipide inhibited the development of this sensitization. Moreover, rebamipide inhibited in a dose-dependent manner antigen presentation and T-cell activation in vitro and was shown to be able to cross the epithelium at a concentration capable of inducing this inhibitory effect. We conclude that H. felis can inhibit the development of oral tolerance to OVA in mice and that this inhibition is prevented by rebamipide.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2563-2563
Author(s):  
Fernando Fierro ◽  
Thomas Illmer ◽  
Duhoui Jing ◽  
Philip Le Coutre ◽  
Gerhard Ehninger ◽  
...  

Abstract Recent data show that the tyrosine kinase inhibitor Imatinib mesylate (IM) also affects normal hematopoietic stem cells (HSC), T lymphocyte activation and dendritic cell function not relying on the specific inhibition of bcr-abl activity. Mesenchymal stem cells (MSC) have been identified in the bone marrow (BM) as multipotent non-hematopoietic progenitor cells that differentiate into osteoblasts, adipocytes, chondrocytes, tenocytes, skeletal myocytes, and cells of visceral mesoderm. MSC interact with HSC, influencing their homing and differentiation through cell-cell contact and the production of factors including chemokines We evaluated possible effects of IM in vitro on human bone marrow-derived MSC. Screening the activity of fourty-two receptor tyrosine kinases by a phospho-receptor tyrosine kinase (RTK)-array revealed an exclusive inhibition of platelet-derived growth factor receptor (PDGFRβ) by IM which consequently affects downstream targets of PDGFRβ as Akt and Erk1/2 signalling pathways in a concentration and time dependent manner. Furthermore, perinuclear multivesicular bodies harbouring PDGFRβ were found within 18–20 hours culture of MSC in the presence of 5 μM IM. Cell proliferation and clonogenicity (evaluated as the capability to form colony forming units - fibroblasts (CFU-F)) of MSC were significantly inhibited by IM in a concentration dependent fashion. IM inhibits significantly the differentiation process of MSC into osteoblasts as evaluated by decreased alkaline phosphatase activity and reduced calcium phosphate precipitates. In contrary, differentiation of MSC into adipocytes was strongly favoured in presence of IM. All these functional deficits described, probably contribute to an observed 50% reduction in the support of clonogenic hematopoietic stem cells, as evaluated by a long term culture-initiating cells (LTC-IC)-based assay. In summary our experiments show that IM inhibits the capacity of human MSC to proliferate and to differentiate into the osteogenic lineage, favouring adipogenesis. This effect is mainly mediated by an inhibition of PDGFRβ autophosphorylation leading to a more pronounced inhibition of PI3K/Akt compared to Erk1/2 signalling. This work confirms the role of PDGFRβ recently described for the proliferation and differentiation potential of MSC and provides a first possible explanation for the altered bone metabolism found in certain patients treated with IM.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2591-2591
Author(s):  
Joshua D. Brody ◽  
Linhong Li ◽  
Stephanie Feller ◽  
Joseph Fratantoni ◽  
Ronald Levy

Abstract Mantle cell lymphoma (MCL) is an aggressive non-Hodgkin’s lymphoma with the worst long-term prognosis of any NHL subtype. Current therapeutic options are unsatisfactory. MCL patients’ malignant B cells are ineffective antigen-presenting cells (APCs), perhaps resulting from low level expression of the immune co-stimulatory molecules that are essential to activate T cells upon interaction with the T-cell receptor. The MCL cells can be engineered to be effective APCs and thereby function as a therapeutic cellular vaccine in combination with chemotherapy and/or stem cell transplantation to eradicate residual disease. However, primary MCL cells are difficult targets for gene transfer by both viral and non-viral methodologies. Ligation of CD40 resulting from co-culturing with hCD40L expressing murine fibroblasts was shown to be superior to a panel of other immune stimulants and cytokines in upregulating co-stimulatory markers and inducing anti-tumor T cell responses (Hoogendoorn et al. 2005). We now report on a technology platform, based on electroporation of mRNA for CD40L, for the introduction of CD40L protein expression and subsequent induction of immune co-stimulatory molecules by MCL tumor cells. Primary MCL malignant B cells were obtained from patients’ lymph node biopsies by mechanical dissociation, placed in single cell suspension and cryopreserved prior to modification. Full-length 5′-end capped hCD40L mRNA transcript was generated by in vitro transcription with a commercially available T7 polymerase kit. The transfected MCL cells were immunostained with fluorophore-conjugated monoclonal antibodies against hCD40L, hCD80 and 86 then analyzed by FACS. Data showed hCD40L could be detected in ≥ 80% of the transfected MCL cells as early as 2 hrs post transfection. At 3 days post manipulation, hDC40L expression could be detected on approximately 30% of the transfected MCL cells. Cell viability remained at approximately 80% during the 3 day in vitro culturing. FACS analysis of the immune co-stimulatory molecules revealed that forced expression of hCD40L caused an up-regulation of CD80/86, which was increased approximately 10 fold compared to the expression levels in naïve, non modified cells. The increased expression level of CD80/86 was maintained for 3 days. Furthermore, when the hCD40L modified MCL cells were mixed with allogeneic PBMC, they stimulated IFN-γ production at a level 4 fold higher than was observed with naïve, non modified MCL cells mixed with allogeneic PBMC. This provides proof-of-concept that MCL cells modified by mRNA-hCD40L transfection have the potential to be used as a cellular vaccine. Such transduced cells function to protect animals from tumor challenge. The process can be scaled up to produce >2×1010 modified tumor cells. This simple, non-viral cell manipulation system is practical and will be a useful tool for immunotherapy of human hematopoietic malignancies such as MCL.


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