scholarly journals BZLF1-DEC205 Fusion Protein Enhances EBV-Protective Immunity in a Spontaneous Model of EBV-Driven Lymphoproliferative Disease

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 342-342 ◽  
Author(s):  
Elshafa Hassan Ahmed ◽  
Eric Brooks ◽  
Shelby Sloan ◽  
Sarah Schlotter ◽  
Frankie Jeney ◽  
...  
Keyword(s):  
T Cell ◽  
Fusion Protein ◽  
Graft Rejection ◽  
Lymphoproliferative Disease ◽  
T Cell Response ◽  
Effector Memory ◽  
P Value ◽  
Autologous Tumor ◽  
Solid Organ ◽  
Early Protein

Abstract Epstein-Barr virus (EBV) is a human herpes virus that infects over 90% of the world's population and is linked with cancer development. In immune-competent individuals, EBV-infection is controlled by a highly efficient virus-specific T cell response. Following primary infection, the virus achieves lifelong persistence within the human host. Risk of EBV-driven cancers increases with immune suppression (IS). Solid organ transplant recipients receive IS medications to prevent graft rejection and are at highest risk of developing EBV-associated lymphomas known as post-transplant lymphoproliferative disease (PTLD). PTLD represents a serious complication of organ transplantation, associated with poor prognosis. Currently, no standard approach for prevention or treatment exists. Reducing the level of IS medication may control PTLD but often leads to graft-rejection. In order to promote long-term protection from EBV-driven cancers, we have developed a vaccine to bolster EBV-specific immunity by targeting the EBV immediate early protein, BZLF1. BZLF1 initiates the activation of lytic stage in EBV-infected cells and promotes B-cell transformation. Work by our group has shown BZLF1-specific T cell expansion following reduction in IS medications correlates with PTLD tumor regression and improved patient survival. Here we specifically delivered the protein (BZLF1) to dendritic cells (DCs) through its endocytic receptor DEC205. DCs were generated from HLA-B8+ donor monocytes incubated with interleukin-4 (IL4) and granulocyte-macrophage colony-stimulating factor (GM-CSF). Mature DCs were then loaded with DEC205-BZLF1 fusion protein or control protein (DEC205-Human Chorionic Gonadotropin (DEC205-HCG)). Antigen-loaded DCs were co-cultured with autologous peripheral blood mononuclear cells (PBMCs) in the presence of IL-2 for 10 days. Cells were analyzed by flow cytometry using HLA-tetramers to detect and quantify antigen-specific cytotoxic T leukocyte (CTL) response. To test the EBV vaccine in-vivo, we utilized a human-murine chimeric model of EBV-driven lymphoproliferative disease (EBV-LPD). Severe combined immune deficient (SCID) mice were engrafted with PBMCs from EBV+ donors (Hu-PBL-SCID model). The spontaneous EBV-LPD that develops in this model is comprised of human CD20+, EBV+ lymphoblasts that closely resembles PTLD. Mice were immunized with DCs loaded with DEC205-BZLF1 or DEC205-HCG at the time of PBMC transplant and received booster doses at day 14 and 28. Splenocyte from vaccinated mice were stimulated with autologous tumor (lymphoblastoid cells line, (LCL)) pulsed with BZLF1 pepmix, BZLF1 pepmix alone, and anti-CD3. Secretion of IFNg by stimulated splenocytes was detected using Human IFNg Enzyme-Linked Immunosorbent Spot (ELISpot). In vitro co-cultures treated with DEC205-BZLF1-loaded DCs showed increased expansion of EBV-specific CTLs (p-value: 0.0002) capable of abundant IFNg production and potent cytotoxicity against autologous tumor. This vaccine significantly improved survival in vaccinated mice (p-value: 0.035). Splenocytes from mice in the DEC205-BZLF1 vaccination group revealed higher responsiveness to autologous LCLs and BZLF1 pepmix compared to controls as determined by ELISpot. Human cells recovered from mouse spleen will be analyzed by mass cytometry using a multi-parametric antibody panel to evaluate central/effector memory status, CD4+ Th, CD8+ CTL, NK, and monocyte subsets. These results further support pre-clinical and clinical development of vaccine approaches utilizing the BZLF1 protein as an immunogen to harness adaptive cellular responses to prevent EBV-associated LPD in vulnerable patient populations. Disclosures No relevant conflicts of interest to declare.

scholarly journals Targeted Delivery of BZLF1 to DEC205 Drives EBV-Protective Immunity in a Spontaneous Model of EBV-Driven Lymphoproliferative Disease

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 555
Author(s):  
Elshafa Hassan Ahmed ◽  
Eric Brooks ◽  
Shelby Sloan ◽  
Sarah Schlotter ◽  
Frankie Jeney ◽  
...  
Keyword(s):  
T Cell ◽  
High Risk ◽  
Targeted Delivery ◽  
Lymphoproliferative Disease ◽  
T Cell Response ◽  
Effector Memory ◽  
Cytotoxic T Cell ◽  
Solid Organ ◽  
Specific Immunity ◽  
Vulnerable Patient

Epstein-Barr virus (EBV) is a human herpes virus that infects over 90% of the world’s population and is linked to development of cancer. In immune-competent individuals, EBV infection is mitigated by a highly efficient virus-specific memory T-cell response. Risk of EBV-driven cancers increases with immune suppression (IS). EBV-seronegative recipients of solid organ transplants are at high risk of developing post-transplant lymphoproliferative disease (PTLD) due to iatrogenic IS. While reducing the level of IS may improve EBV-specific immunity and regression of PTLD, patients are at high risk for allograft rejection and need for immune-chemotherapy. Strategies to prevent PTLD in this vulnerable patient population represents an unmet need. We have previously shown that BZLF1-specific cytotoxic T-cell (CTL) expansion following reduced IS correlated with immune-mediated PTLD regression and improved patient survival. We have developed a vaccine to bolster EBV-specific immunity to the BZLF1 protein and show that co-culture of dendritic cells (DCs) loaded with a αDEC205-BZLF1 fusion protein with peripheral blood mononuclear cells (PMBCs) leads to expansion and increased cytotoxic activity of central-effector memory CTLs against EBV-transformed B-cells. Human–murine chimeric Hu-PBL-SCID mice were vaccinated with DCs loaded with αDEC205-BZLF1 or control to assess prevention of fatal human EBV lymphoproliferative disease. Despite a profoundly immunosuppressive environment, vaccination with αDEC205-BZLF1 stimulated clonal expansion of antigen-specific T-cells that produced abundant IFNγ and significantly prolonged survival. These results support preclinical and clinical development of vaccine approaches using BZLF1 as an immunogen to harness adaptive cellular responses and prevent PTLD in vulnerable patient populations.

scholarly journals Characterization of Varicella-Zoster (VZV) Specific T Cell Response in Healthy Subjects and Transplanted Patients by Using Enzyme Linked Immunospot (ELISpot) Assays

Vaccines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 875
Author(s):  
Irene Cassaniti ◽  
Alessandro Ferrari ◽  
Giuditta Comolli ◽  
Antonella Sarasini ◽  
Marilena Gregorini ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Response ◽  
Healthy Subjects ◽  
Opportunistic Infections ◽  
T Cell Response ◽  
Viral Reactivation ◽  
Effector Memory ◽  
Solid Organ ◽  
Varicella Zoster

Solid organ transplant recipients, due to the administration of post-transplant immunosuppressive therapies, are at greater risk of viral reactivation episodes, mainly from herpes viruses, including varicella-zoster virus (VZV). The aim of this pilot study was to develop functional immunological assays (VZV-ELISpot) for the quantification and characterization of the VZV-specific effector-memory and central-memory responses in healthy subjects and transplanted patients. Glycoprotein gE and immediate-early 63 (IE-63) were used as antigens for in vitro stimulation. VZV-seropositive healthy subjects showed higher responses in respect to seronegative subjects. Even if differences were observed between VZV-seropositive healthy subjects and transplanted subjects at pre-transplant, the VZV-specific T-cell response was reduced at 60 days after transplant, mainly for the high level of immunosuppression. Phenotypical characterization revealed that response against VZV was mainly mediated by CD4 T cells. The results obtained in this study might be useful for the definition of personalized follow-up of the transplanted patients, providing useful information on the status of the patient potentially at risk of viral reactivation or other opportunistic infections.

scholarly journals Diacylglycerol Kinase alpha in X Linked Lymphoproliferative Disease Type 1

2021 ◽  
Vol 22 (11) ◽  
pp. 5816
Author(s):  
Suresh Velnati ◽  
Sara Centonze ◽  
Federico Girivetto ◽  
Gianluca Baldanzi
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Adaptor Protein ◽  
Diacylglycerol Kinase ◽  
Cell Receptor ◽  
Lymphoproliferative Disease ◽  
Disease Type ◽  
T Cell Response ◽  
Receptor Signalling

Diacylglycerol kinases are intracellular enzymes that control the balance between the secondary messengers diacylglycerol and phosphatidic acid. DGKα and DGKζ are the prominent isoforms that restrain the intensity of T cell receptor signalling by metabolizing PLCγ generated diacylglycerol. Thus, their activity must be tightly controlled to grant cellular homeostasis and refine immune responses. DGKα is specifically inhibited by strong T cell activating signals to allow for full diacylglycerol signalling which mediates T cell response. In X-linked lymphoproliferative disease 1, deficiency of the adaptor protein SAP results in altered T cell receptor signalling, due in part to persistent DGKα activity. This activity constrains diacylglycerol levels, attenuating downstream pathways such as PKCθ and Ras/MAPK and decreasing T cell restimulation induced cell death. This is a form of apoptosis triggered by prolonged T cell activation that is indeed defective in CD8+ cells of X-linked lymphoproliferative disease type 1 patients. Accordingly, inhibition or downregulation of DGKα activity restores in vitro a correct diacylglycerol dependent signal transduction, cytokines production and restimulation induced apoptosis. In animal disease models, DGKα inhibitors limit CD8+ expansion and immune-mediated tissue damage, suggesting the possibility of using inhibitors of diacylglycerol kinase as a new therapeutic approach.

scholarly journals Human Immunodeficiency Virus Type 1 (HIV-1)-Specific CD8+ TEMRA Cells in Early Infection Are Linked to Control of HIV-1 Viremia and Predict the Subsequent Viral Load Set Point

2007 ◽  
Vol 81 (11) ◽  
pp. 5759-5765 ◽  
Author(s):  
John W. Northfield ◽  
Christopher P. Loo ◽  
Jason D. Barbour ◽  
Gerald Spotts ◽  
Frederick M. Hecht ◽  
...  
Keyword(s):  
T Cells ◽  
Viral Load ◽  
T Cell ◽  
Absolute Number ◽  
T Cell Response ◽  
Effector Memory ◽  
Set Point ◽  
Effector Memory T Cells ◽  
Viral Load Set Point ◽  
Hiv 1

ABSTRACT CD8+ T cells are believed to play an important role in the control of human immunodeficiency virus type 1 (HIV-1) infection. However, despite intensive efforts, it has not been possible to consistently link the overall magnitude of the CD8+ T-cell response with control of HIV-1. Here, we have investigated the association of different CD8+ memory T-cell subsets responding to HIV-1 in early infection with future control of HIV-1 viremia. Our results demonstrate that both a larger proportion and an absolute number of HIV-1-specific CD8+ CCR7− CD45RA+ effector memory T cells (TEMRA cells) were associated with a lower future viral load set point. In contrast, a larger absolute number of HIV-1-specific CD8+ CCR7− CD45RA− effector memory T cells (TEM) was not related to the viral load set point. Overall, the findings suggest that CD8+ TEMRA cells have superior antiviral activity and indicate that both qualitative and quantitative aspects of the CD8+ T-cell response need to be considered when defining the characteristics of protective immunity to HIV-1.

scholarly journals Combination of a Sindbis-SARS-CoV-2 spike vaccine and αOX40 antibody elicits protective immunity against SARS-CoV-2 induced disease and potentiates long-term SARS-CoV-2-specific humoral and T-cell immunity

2021 ◽  
Author(s):  
Antonella Scaglione ◽  
Silvana Opp ◽  
Alicia Hurtado ◽  
Christine Pampeno ◽  
Ziyan Lin ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Protective Immunity ◽  
T Cell Response ◽  
Spike Protein ◽  
Effector Memory ◽  
World Population ◽  
Vaccine Platform ◽  
Vaccine Approach

The COVID-19 pandemic caused by the coronavirus SARS-CoV-2 is a major global public threat. Currently, a worldwide effort has been mounted to generate billions of effective SARS-CoV-2 vaccine doses to immunize the world population at record speeds. However, there is still demand for alternative effective vaccines that rapidly confer long-term protection and rely upon cost-effective, easily scaled-up manufacturing. Here, we present a Sindbis alphavirus vector (SV), transiently expressing the SARS-CoV-2 spike protein (SV.Spike), combined with the OX40 immunostimulatory antibody (OX40) as a novel, highly effective vaccine approach. We show that SV.Spike plus αOX40 elicits long-lasting neutralizing antibodies and a vigorous T cell response in mice. Protein binding, immunohistochemical and cellular infection assays all show that vaccinated mice sera inhibits spike functions. Immunophenotyping, RNA Seq transcriptome profiles and metabolic analysis indicate a reprogramming of T cells in vaccinated mice. Activated T cells were found to mobilize to lung tissue. Most importantly, SV.Spike plus αOX40 provided robust immune protection against infection with authentic coronavirus in transgenic mice expressing the human ACE2 receptor (hACE2-Tg). Finally, our immunization strategy induced strong effector memory response, potentiating protective immunity against re-exposure to SARS-CoV-2 spike protein. Our results show the potential of a new Sindbis virus-based vaccine platform to counteract waning immune response that can be used as a new candidate to combat SARS-CoV-2. Given the strong T cell responses elicited, our vaccine is likely to be effective against variants that are proving challenging, as well as, serve as a platform to develop a broader spectrum pancoronavirus vaccine. Similarly, the vaccine approach is likely to be applicable to other pathogens.

scholarly journals Short-Lived Effector CD8 T Cells Induced by Genetically Attenuated Malaria Parasite Vaccination Express CD11c

2013 ◽  
Vol 81 (11) ◽  
pp. 4171-4181 ◽  
Author(s):  
Laura A. Cooney ◽  
Megha Gupta ◽  
Sunil Thomas ◽  
Sebastian Mikolajczak ◽  
Kimberly Y. Choi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Inflammatory Cytokines ◽  
Plasmodium Yoelii ◽  
T Cell Response ◽  
Parasite Development ◽  
Effector Memory ◽  
Cell Phenotype ◽  
Effector Cells ◽  
Ifn Γ

ABSTRACTVaccination with a single dose of genetically attenuated malaria parasites can induce sterile protection against sporozoite challenge in the rodentPlasmodium yoeliimodel. Protection is dependent on CD8+T cells, involves perforin and gamma interferon (IFN-γ), and is correlated with the expansion of effector memory CD8+T cells in the liver. Here, we have further characterized vaccine-induced changes in the CD8+T cell phenotype and demonstrated significant upregulation of CD11c on CD3+CD8b+T cells in the liver, spleen, and peripheral blood. CD11c+CD8+T cells are predominantly CD11ahiCD44hiCD62L−, indicative of antigen-experienced effector cells. Followingin vitrorestimulation with malaria-infected hepatocytes, CD11c+CD8+T cells expressed inflammatory cytokines and cytotoxicity markers, including IFN-γ, tumor necrosis factor alpha (TNF-α), interleukin-2 (IL-2), perforin, and CD107a. CD11c−CD8+T cells, on the other hand, expressed negligible amounts of all inflammatory cytokines and cytotoxicity markers tested, indicating that CD11c marks multifunctional effector CD8+T cells. Coculture of CD11c+, but not CD11c−, CD8+T cells with sporozoite-infected primary hepatocytes significantly inhibited liver-stage parasite development. Tetramer staining for the immunodominant circumsporozoite protein (CSP)-specific CD8+T cell epitope demonstrated that approximately two-thirds of CSP-specific cells expressed CD11c at the peak of the CD11c+CD8+T cell response, but CD11c expression was lost as the CD8+T cells entered the memory phase. Further analyses showed that CD11c+CD8+T cells are primarily KLRG1+CD127−terminal effectors, whereas all KLRG1−CD127+memory precursor effector cells are CD11c−CD8+T cells. Together, these results suggest that CD11c marks a subset of highly inflammatory, short-lived, antigen-specific effector cells, which may play an important role in eliminating infected hepatocytes.

scholarly journals Vaccination against RhoC induces long-lasting immune responses in patients with prostate cancer: results from a phase I/II clinical trial

2020 ◽  
Vol 8 (2) ◽  
pp. e001157
Author(s):  
Juliane Schuhmacher ◽  
Sonja Heidu ◽  
Torben Balchen ◽  
Jennifer Rebecca Richardson ◽  
Camilla Schmeltz ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Phase I ◽  
Cell Response ◽  
Small Gtpase ◽  
T Cell Response ◽  
Effector Memory ◽  
Tolerability Profile

BackgroundPeptide-based vaccination is a rational option for immunotherapy of prostate cancer. In this first-in-man phase I/II study, we assessed the safety, tolerability and immunological impact of a synthetic long peptide vaccine targeting Ras homolog gene family member C (RhoC) in patients with prostate cancer. RhoC is a small GTPase overexpressed in advanced solid cancers, metastases and cancer stem cells.MethodsTwenty-two patients who had previously undergone radical prostatectomy received subcutaneous injections of 0.1 mg of a single RhoC-derived 20mer peptide emulsified in Montanide ISA-51 every 2 weeks for the first six times, then five times every 4 weeks for a total treatment time of 30 weeks. The drug safety and vaccine-specific immune responses were assessed during treatment and thereafter within a 13-month follow-up period. Serum level of prostate-specific antigen was measured up to 26 months postvaccination.ResultsMost patients (18 of 21 evaluable) developed a strong CD4 T cell response against the vaccine, which lasted at least 10 months following the last vaccination. Three promiscuouslypresented HLA-class II epitopes were identified. Vaccine-specific CD4 T cells were polyfunctional and effector memory T cells that stably expressed PD-1 (CD279) and OX-40 (CD134), but not LAG-3 (CD223). One CD8 T cell response was detected in addition. The vaccine was well tolerated and no treatment-related adverse events of grade ≥3 were observed.ConclusionTargeting of RhoC induced a potent and long-lasting T cell immunity in the majority of the patients. The study demonstrates an excellent safety and tolerability profile. Vaccination against RhoC could potentially delay or prevent tumor recurrence and metastasis formation.Trial registration numberNCT03199872.

Delayed acute allograft rejection in elderly recipients is associated with impaired effector/memory t-cell response

2010 ◽  
Vol 211 (3) ◽  
pp. S62
Author(s):  
Damanpreet Singh Bedi ◽  
Christian Denecke ◽  
Xupeng Ge ◽  
Irene K. Kim ◽  
Anke Jurisch ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Response ◽  
Allograft Rejection ◽  
T Cell Response ◽  
Effector Memory ◽  
Acute Allograft Rejection ◽  
Memory T Cell ◽  
Elderly Recipients

Targeting of a B7-1 (CD80) immunoglobulin G fusion protein to acute myeloid leukemia blasts increases their costimulatory activity for autologous remission T cells

Blood ◽  
2001 ◽  
Vol 97 (10) ◽  
pp. 3138-3145 ◽  
Author(s):  
Michael Notter ◽  
Tim Willinger ◽  
Ulrike Erben ◽  
Eckhard Thiel
Keyword(s):  
T Cells ◽  
Acute Myeloid Leukemia ◽  
T Cell ◽  
Fusion Protein ◽  
Immunoglobulin G ◽  
Myeloid Leukemia ◽  
Costimulatory Molecule ◽  
T Cell Response ◽  
Cytotoxic T Cell ◽  
Acute Myeloid

Abstract Transfection of tumor cells with the gene encoding the costimulatory molecule B7-1 (CD80), the ligand for CD28 and cytotoxic T lymphocye antigen-4 on T cells, has been shown to result in potent T-cell–mediated antitumor immunity. As an alternative approach, this study analyzed the costimulatory capacity of a human B7-1 immunoglobulin G (IgG) fusion protein targeted to the cell membrane of human acute myeloid leukemia (AML) blasts. Flow cytometric analysis revealed a low constitutive expression of B7-1 on human AML blasts (on average, 3.0 ± 4.3%; n = 50). In contrast, the expression of B7-2 (CD86) was highly heterogeneous and higher in AML blasts of French-American-British classification types M4 and M5 (P < .0001). The B7-1 IgG fusion protein used in this study efficiently costimulated the proliferation of resting and preactivated T cells when immobilized on plastic. After preincubation with B7-1 IgG, specific binding of the fusion protein to the high-affinity Fcγreceptor I (CD64) on leukemic cells was demonstrated and was found to increase the proliferation of both allogeneic and autologous T cells in costimulation experiments. Furthermore, targeting of B7-1 IgG to the tumor membrane resulted in increased proliferation of autologous remission T cells and had the potential to generate an enhanced redirected cytotoxic T-cell response against autologous AML blasts. In summary, the targeting of B7-1 IgG fusion protein described in this study represents a strategy alternative to gene therapy to restore the expression of the costimulatory molecule B7-1 on human AML blasts, thereby enhancing their immunogenicity for autologous T cells. This new approach may have implications for T-cell–mediated immunotherapy in AML.

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