Development and characterization of a HCMV multiantigen therapeutic vaccine for GBM using the UNITE platform.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e14565-e14565
Author(s):  
Amit Adhikari ◽  
Juliete Macauley ◽  
Yoshimi Johnson ◽  
Mike Connolly ◽  
Tim Coleman ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
Mouse Model ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cd8 T Cell ◽  
T Cell Response

e14565 Background: Glioblastoma (GBM) is an aggressive form of brain cancer with a median survival of 15 months which has remained unchanged despite technological advances in the standard of care. GBM cells specifically express human cytomegalovirus (HCMV) proteins providing a unique opportunity for targeted therapy. Methods: We utilized our UNITE (UNiversal Intracellular Targeted Expression) platform to develop a multi-antigen DNA vaccine (ITI-1001) that codes for the HCMV proteins- pp65, gB and IE-1. The UNITE platform involves lysosomal targeting technology, fusing lysosome-associated protein 1 (LAMP1) with target antigens resulting in increased antigen presentation by MHC-I and II. ELISpot, flow cytometry and ELISA techniques were used to evaluate the vaccine immunogenicity and a syngeneic, orthotopic GBM mouse model that expresses HCMV proteins was used for efficacy studies. The tumor microenvironment studies were done using flow cytometry and MSD assay. Results: ITI-1001 vaccination showed a robust antigen-specific CD4 and CD8 T cell response in addition to a strong humoral response. Using GBM mouse model, therapeutic treatment of ITI-1001 vaccine resulted in ̃56% survival with subsequent long-term immunity. Investigating the tumor microenvironment showed significant CD4 T cell infiltration as well as enhanced Th1 and CD8 T cell activation. Regulatory T cells were also upregulated upon ITI-1001 vaccination and would be an attractive target to further improve this therapy. In addition, tumor burden negatively correlated with number of activated CD4 T cells (CD4 IFNγ+) reiterating the importance of CD4 activation in ITI-1001 efficacy and potentially identifying treatment responders and non-responders. Further characterization of these two groups showed high infiltration of CD3+, CD4+ and CD8+ T cells in responders compared with non- responders along with higher CD8 T cell activation. Conclusions: Thus, we show that vaccination with HCMV antigens using the ITI-1001-UNITE platform generates strong cellular and humoral immune responses, triggering significant anti-tumor activity that leads to enhanced survival in mice with GBM.

scholarly journals Targeting of the Cancer-Associated Fibroblast—T-Cell Axis in Solid Malignancies

2019 ◽  
Vol 8 (11) ◽  
pp. 1989 ◽  
Author(s):  
Tom J. Harryvan ◽  
Els M. E. Verdegaal ◽  
James C. H. Hardwick ◽  
Lukas J. A. C. Hawinkels ◽  
Sjoerd H. van der Burg
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
T Cell Activation ◽  
Cell Activation ◽  
Suppressor Cells ◽  
T Cell Response ◽  
Cytotoxic T Cell ◽  
Cell Axis ◽  
Wide Range

The introduction of a wide range of immunotherapies in clinical practice has revolutionized the treatment of cancer in the last decade. The majority of these therapeutic modalities are centered on reinvigorating a tumor-reactive cytotoxic T-cell response. While impressive clinical successes are obtained, the majority of cancer patients still fail to show a clinical response, despite the fact that their tumors express antigens that can be recognized by the immune system. This is due to a series of other cellular actors, present in or attracted towards the tumor microenvironment, including regulatory T-cells, myeloid-derived suppressor cells and cancer-associated fibroblasts (CAFs). As the main cellular constituent of the tumor-associated stroma, CAFs form a heterogeneous group of cells which can drive cancer cell invasion but can also impair the migration and activation of T-cells through direct and indirect mechanisms. This singles CAFs out as an important next target for further optimization of T-cell based immunotherapies. Here, we review the recent literature on the role of CAFs in orchestrating T-cell activation and migration within the tumor microenvironment and discuss potential avenues for targeting the interactions between fibroblasts and T-cells.

scholarly journals A gammaherpesvirus-secreted activator of Vβ4+ CD8+ T cells regulates chronic infection and immunopathology

2008 ◽  
Vol 205 (3) ◽  
pp. 669-684 ◽  
Author(s):  
Andrew G. Evans ◽  
Janice M. Moser ◽  
Laurie T. Krug ◽  
Veranika Pozharskaya ◽  
Ana L. Mora ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Response ◽  
Cell Activation ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Murine Gammaherpesvirus

Little is known about herpesvirus modulation of T cell activation in latently infected individuals or the implications of such for chronic immune disorders. Murine gammaherpesvirus 68 (MHV68) elicits persistent activation of CD8+ T cells bearing a Vβ4+ T cell receptor (TCR) by a completely unknown mechanism. We show that a novel MHV68 protein encoded by the M1 gene is responsible for Vβ4+ CD8+ T cell stimulation in a manner reminiscent of a viral superantigen. During infection, M1 expression induces a Vβ4+ effector T cell response that resists functional exhaustion and appears to suppress virus reactivation from peritoneal cells by means of long-term interferon-γ (IFNγ) production. Mice lacking an IFNγ receptor (IFNγR−/−) fail to control MHV68 replication, and Vβ4+ and CD8+ T cell activation by M1 instead contributes to severe inflammation and multiorgan fibrotic disease. Thus, M1 manipulates the host CD8+ T cell response in a manner that facilitates latent infection in an immunocompetent setting, but promotes disease during a dysregulated immune response. Identification of a viral pathogenecity determinant with superantigen-like activity for CD8+ T cells broadens the known repertoire of viral immunomodulatory molecules, and its function illustrates the delicate balance achieved between persistent viruses and the host immune response.

scholarly journals CD5 expressing CD8+ T cell subsets differ between children with Type 1 Diabetes and controls

2021 ◽  
Author(s):  
Josefine Wadenpohl ◽  
Julia Seyfarth ◽  
Paul Hehenkamp ◽  
Maximilian Hoffmann ◽  
Sebastian Kummer ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
Type 1 Diabetes ◽  
T Cell ◽  
B Cell ◽  
Quantitative Pcr ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cd8 T Cell

Different lymphocyte subsets are involved in autoimmune pathogenesis of Type 1 Diabetes (T1D). Previous studies suggested a role of CD5 expressing T and B cells including rare unconventional lymphocytes with combined T- and B-cell features (DE cells). We performed algorithm-supported multi-parameter flow cytometry and quantitative PCR to investigate immune cell subsets and DE cells in children with T1D (n=20) and matched controls (n=20). Comparisons of conventional immune cells detected increased proportions of CD3+ T cells in T1D patients whereas CD19+ B cell proportions were comparable to controls. Self-organizing maps for flow cytometry analyses (FlowSOM) showed highly similar CD5 expressing B-cell subsets and no differences for DE cells were detected between the study groups by flow cytometry or specific quantitative PCR. Notably, differences in CD8 positive T cells were indicated by FlowSOM and similarity-based tSNE analyses. Study group comparison confirmed significantly reduced CD8+ T-cell proportions with moderate or low CD5 expression in T1D patients. Finally, In vitro experiments showed stable CD5 expression differences of CD8+ T cells after T-cell activation, cytokine stimulation and culture. We observed differences of T-cell co-receptor CD5 expression in T1D patients with potential relevance for immune regulation of CD8+ T-cell activation.

scholarly journals The circadian clock of CD8 T cells modulates their early response to vaccination and the rhythmicity of related signaling pathways

2019 ◽  
Vol 116 (40) ◽  
pp. 20077-20086 ◽  
Author(s):  
Chloé C. Nobis ◽  
Geneviève Dubeau Laramée ◽  
Laura Kervezee ◽  
Dave Maurice De Sousa ◽  
Nathalie Labrecque ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Signaling Pathways ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Response ◽  
Cell Activation ◽  
Cd8 T Cell ◽  
Time Of Day ◽  
T Cell Response

Circadian variations of various aspects of the immune system have been described. However, the circadian control of T cells has been relatively unexplored. Here, we investigated the role of circadian clocks in regulating CD8 T cell response to antigen presentation by dendritic cells (DCs). The in vivo CD8 T cell response following vaccination with DCs loaded with the OVA257–264 peptide antigen (DC-OVA) leads to a higher expansion of OVA-specific T cells in response to vaccination done in the middle of the day, compared to other time points. This rhythm was dampened when DCs deficient for the essential clock gene Bmal1 were used and abolished in mice with a CD8 T cell-specific Bmal1 deletion. Thus, we assessed the circadian transcriptome of CD8 T cells and found an enrichment in the daytime of genes and pathways involved in T cell activation. Based on this, we investigated early T cell activation events. Three days postvaccination, we found higher T cell activation markers and related signaling pathways (including IRF4, mTOR, and AKT) after a vaccination done during the middle of the day compared to the middle of the night. Finally, the functional impact of the stronger daytime response was shown by a more efficient response to a bacterial challenge at this time of day. Altogether, these results suggest that the clock of CD8 T cells modulates the response to vaccination by shaping the transcriptional program of these cells and making them more prone to strong and efficient activation and proliferation according to the time of day.

Conditional T-Cell Activation for Tumor Under Hypoxia

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3906-3906 ◽  
Author(s):  
Sonny O Ang ◽  
Simon Olivares ◽  
Elizabeth J. Shpall ◽  
Dean A. Lee ◽  
Richard Champlin ◽  
...  
Keyword(s):  
Stem Cells ◽  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
T Cell Activation ◽  
Transgene Expression ◽  
Cell Activation ◽  
Oxygen Sensitive ◽  
Hypoxic Tumor

Abstract Solid tumors are characterized by cell clusters experiencing chronic and intermittent hypoxia due to haphazard growth. Importantly, highly migratory tumorigenic stem cells are localized within hypoxic niches, shielded by hypoxia-induced metabolites that inhibit tumor-infiltrating T cells, restricting their survival, cytotoxicity, and beneficial immunomodulatory cytokine responses. To eliminate bulky solid tumors including stem cells, T cells must overcome physiological changes distinctive for the tumor microenvironment, such as hypoxia, depleted nutrient levels, and low extracellular pH. To exploit the hypoxic tumor microenivornment, we introduce a new approach that exploits hypoxia as a condition for T-cell activation. We demonstrate a chimeric antigen receptor (CAR), which is specific for CD19 and capable of activating T cells through chimeric CD28 and/or CD3-zeta signaling endodomain, that can be conditionally expresed in a strictly oxygen-sensitive manner. Using the Sleeping Beauty transposon/transposase system, we can achieve stable, persistent CAR transgene expression without the expense and complexity of retroviral production. Cell surface expression of our CAR is high at 1% O and not detectable at 20% O (Figure). Anticipating the circulatory nature of T cells in vivo, our oxygen-sensitive CAR is designed to deactivate upon exiting from hypoxic tumor microenvironment to minimize deleterious off-target effects. When supplemented with one or more survival factors and/or homing receptors, this approach to CAR expression has the advantage of transforming hypoxia from an adverse factor to a triggering mechanism, efficiency, and high levels of transgene expression. Figure: Flow cytometry expression of CAR under normoxia and hypoxia. Figure:. Flow cytometry expression of CAR under normoxia and hypoxia.

Abstract 350: Synthetic Soluble MHC-I/peptide Complexes Confirm Activation of Functional Antigen-specific CD8+ T cells by Immunization With apoB-100-derived Peptide p210 in ApoE-/- Mice

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Xiaoning Zhao ◽  
Paul C Dimayuga ◽  
Juliana Yano ◽  
Jianchang Zhou ◽  
Wai Man Lio ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Cd8 T Cell ◽  
Cytolytic Activity ◽  
T Cell Response ◽  
Mhc I ◽  
Peptide Complexes

Background: Investigations in our laboratory identified endogenous, antigen-specific CD8+ T cells reactive to apoB-100 related peptide in apoE-/- mice using fluorescent synthetic soluble MHC-I/peptide complexes called Pentamers (Pent). We hypothesized that immunization of apoE-/- mice with the apoB-100 peptide p210, which we and others have reported to reduce atherosclerosis, will result in the activation of a specific CD8+ T cell population that can be detected by Pent analysis. Methods and Results: Binding of the p210 peptide to the mouse MHC-I allele H2Kb was determined in a prior study. A p210-Pent library was generated to screen splenocytes from p210 immunized apoE-/- mice. Mice were immunized with p210 conjugated to cBSA with Alum (p210) at 7, 10 and 12 weeks of age then euthanized at 13 weeks of age. PBS and cBSA/Alum (cBSA) treatment served as controls. The screening assay identified 2 potential Pents that could discriminate the immunized mice from the controls. The Pent with the largest difference, called Pent 5, was selected for further study. Pent 5(+)CD8+ T cells in p210 immunized mice were significantly increased compared to PBS and cBSA controls (1.3±0.9% vs. 0.6±0.4% and 0.7±0.4%, respectively; P<0.05). Immunization of apoE-/- mice expressing GFP on the FoxP3 promoter showed no difference in Pent 5(+)CD8+FoxP3+ T cells. High fat diet feeding for 6 weeks did not affect Pent 5(+)CD8+ T cells compared to normal chow fed mice confirming specificity of the Pent 5(+)CD8+ T cell response to immunization. Pent 5 binding significantly reduced cytolytic activity of p210-immune CD8+ T cells compared to control (1.2±2.2% vs. 17.0±13.8%, respectively), indicating antigen-specific blocking. Pent 5(+)CD8+ T cells cultured for 21 days showed significantly higher cytolytic activity compared to Pent 5(-)CD8+ T cells (16.5±7.0% vs. 2.8±3.6%, respectively). Immunization with the p210 peptide reduced aortic atherosclerosis measured by en face oil red-o stain area compared to PBS and cBSA control groups (4.0±1.7% vs. 6.4±2.3% and 5.7±2.2%, respectively; P<0.01), confirming our previous report. Conclusion: The use of Pentamers provide clear evidence that p210 immunization results in CD8+ T cell activation with functions specific to the p210 antigen.

Abstract P283: Gamma Delta T Cells Drive CD4 + and CD8 + T Cell Activation in Hypertension

Hypertension ◽  
2018 ◽  
Vol 72 (Suppl_1) ◽  
Author(s):  
Pierre Paradis ◽  
Antoine Caillon ◽  
Ernesto L Schiffrin
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cd8 T Cell ◽  
Gamma Delta T Cells ◽  
Gamma Delta

scholarly journals DNAM1 and TIGIT balance the T cell response, with low T cell TIGIT expression corresponding to inflammation in psoriatic disease

2020 ◽  
Author(s):  
M E Jacobs ◽  
J N Pouw ◽  
M A Olde Nordkamp ◽  
T R D J Radstake ◽  
E F A Leijten ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Cytokine Production ◽  
Inverse Correlation ◽  
T Cell Response ◽  
Peripheral Blood Mononuclear ◽  
Psoriatic Disease

Abstract Background Signals at the contact site of antigen-presenting cells (APCs) and T cells help orchestrate the adaptive immune response. CD155 on APCs can interact with the stimulatory receptor DNAM1 or inhibitory receptor TIGIT on T cells. The CD155/DNAM1/TIGIT axis is under extensive investigation as immunotherapy target in inflammatory diseases including cancer, chronic infection and autoimmune diseases. We investigated a possible role for CD155/DNAM1/TIGIT signaling in psoriatic disease. Methods By flow cytometry we analyzed peripheral blood mononuclear cells of patients with psoriasis (n=20) or psoriatic arthritis (n=21), and healthy individuals (n=7). We measured CD155, TIGIT and DNAM1 expression on leukocyte subsets and compared activation-induced cytokine production between CD155-positive and -negative APCs. We assessed the effects of TIGIT and DNAM1 blockade on T cell activation, and related the expression of CD155/DNAM1/TIGIT axis molecules to measures of disease activity. Results High CD155 expression associates with TNF production in myeloid and plasmacytoid dendritic cells (DC). In CD1c+ myeloid DC, activation-induced CD155 expression associates with increased HLA-DR expression. CD8 T cells - but not CD4 T cells - express high levels of TIGIT. DNAM1 blockade decreases T cell pro-inflammatory cytokine production, while TIGIT blockade increased T cell proliferation. Finally, T cell TIGIT expression shows an inverse correlation with inflammation biomarkers in psoriatic disease. Conclusion CD155 is increased on pro-inflammatory APCs, while the receptors DNAM1 and TIGIT expressed on T cells balance the inflammatory response by T cells. In psoriatic disease, low TIGIT expression on T cells is associated with systemic inflammation.

scholarly journals IL4I1 Accelerates the Expansion of Effector CD8+ T Cells at the Expense of Memory Precursors by Increasing the Threshold of T-Cell Activation

2020 ◽  
Vol 11 ◽  
Author(s):  
Marie-Line Puiffe ◽  
Aurélie Dupont ◽  
Nouhoum Sako ◽  
Jérôme Gatineau ◽  
José L. Cohen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Cell Clone ◽  
Cd8 T Cell ◽  
Lymphocytic Choriomeningitis ◽  
T Cell Clone

IL4I1 is an immunoregulatory enzyme that inhibits CD8 T-cell proliferation in vitro and in the tumoral context. Here, we dissected the effect of IL4I1 on CD8 T-cell priming by studying the differentiation of a transgenic CD8 T-cell clone and the endogenous repertoire in a mouse model of acute lymphocytic choriomeningitis virus (LCMV) infection. Unexpectedly, we show that IL4I1 accelerates the expansion of functional effector CD8 T cells during the first several days after infection and increases the average affinity of the elicited repertoire, supporting more efficient LCMV clearance in WT mice than IL4I1-deficient mice. Conversely, IL4I1 restrains the differentiation of CD8 T-cells into long-lived memory precursors and favors the memory response to the most immunodominant peptides. IL4I1 expression does not affect the phenotype or antigen-presenting functions of dendritic cells (DCs), but directly reduces the stability of T-DC immune synapses in vitro, thus dampening T-cell activation. Overall, our results support a model in which IL4I1 increases the threshold of T-cell activation, indirectly promoting the priming of high-affinity clones while limiting memory T-cell differentiation.

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