Use of CMV gB/pp65 eVLPs to harness the immunogenicity of foreign viral antigens to target solid tumors.

2017 ◽  
Vol 35 (7_suppl) ◽  
pp. 165-165
Author(s):  
David E Anderson ◽  
Tanvir Ahmed ◽  
Catalina Soare ◽  
Anne-Catherine Fluckiger ◽  
Barthelemy Ontsouka ◽  
...  

165 Background: Human cytomegalovirus (CMV) is a ubiquitous, generally asymptomatic virus that is present in over 90% of GBM and breast cancer tumors which have comparatively low mutational burdens and predicted neoantigens relative to melanoma or lung cancer. Memory CD4+ and CD8+T cells are most frequently directed against the gB and pp65 antigens, respectively. Thus, CMV gB and pp65 represent highly immunogenic “foreign” antigen components of a vaccine against GBM and breast cancer. Methods: Enveloped virus-like particles (eVLPs) are produced after transfection of HEK 293 cells with a plasmid encoding murine leukemia virus Gag plasmid fused in-frame with CMV pp65 antigen, which gives rise to particles. Co-transfected CMV gB plasmid enables particles budding from the cell surface to incorporate the gB protein into the lipid bilayer. Surface expression of gB and internal expression of pp65 have been confirmed by CryoEM and immunogold labelling. Production and purification of multiple batches at a GMP-compliant manufacturer has demonstrated consistent purity and yields that meet regulatory requirements. Results: eVLPs restimulate IFN-g secreting CD4+ and CD8+ T cells in ex vivo PBMCs from healthy subjects (n=8) at mean frequencies of 0.27% and 1.28%, respectively. eVLP formulation with GM-CSF augments IFN-g and CCL3 secretion in stimulated PBMCs from healthy subjects (n=5), GBM patients (n=5), and breast cancer (n=1) patients to comparable levels. This vaccine candidate also induces de novo CD4+ and CD8+responses in mice. The vaccine induces high titer antibody responses against CMV gB, and the potential for ADCC activity against gB-expressing GBM tumor cells is currently being investigated. Conclusions: CMV gB/pp65 eVLPs address several shortcomings of past theraeputic vaccines, including: 1) the poor immunogenicity of "self" tumor-associated antigens, 2) failure to induce robust CD4+ responses that support CD8+ tumor-specific responses, 3) inclusion of only one or a few epitopes that rapidly encourage tumor cell immunoselection of variants that no longer express the target(s). An IND submission to FDA for a phase I/IIa trial in GBM patients is planned for H1 2017.

2021 ◽  
Vol 12 ◽  
Author(s):  
Molly Javier Uyeda ◽  
Robert A. Freeborn ◽  
Brandon Cieniewicz ◽  
Rosa Romano ◽  
Ping (Pauline) Chen ◽  
...  

Type 1 regulatory T (Tr1) cells are subset of peripherally induced antigen-specific regulatory T cells. IL-10 signaling has been shown to be indispensable for polarization and function of Tr1 cells. However, the transcriptional machinery underlying human Tr1 cell differentiation and function is not yet elucidated. To this end, we performed RNA sequencing on ex vivo human CD49b+LAG3+ Tr1 cells. We identified the transcription factor, BHLHE40, to be highly expressed in Tr1 cells. Even though Tr1 cells characteristically produce high levels of IL-10, we found that BHLHE40 represses IL-10 and increases IFN-γ secretion in naïve CD4+ T cells. Through CRISPR/Cas9-mediated knockout, we determined that IL10 significantly increased in the sgBHLHE40-edited cells and BHLHE40 is dispensable for naïve CD4+ T cells to differentiate into Tr1 cells in vitro. Interestingly, BHLHE40 overexpression induces the surface expression of CD49b and LAG3, co-expressed surface molecules attributed to Tr1 cells, but promotes IFN-γ production. Our findings uncover a novel mechanism whereby BHLHE40 acts as a regulator of IL-10 and IFN-γ in human CD4+ T cells.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e21004-e21004
Author(s):  
Tomoharu Sugie ◽  
Kaoru Murata-Hirai ◽  
Masashi Iwasaki ◽  
Craig T Morita ◽  
Wen Li ◽  
...  

e21004 Background: Human γδ T cells display potent cytotoxicity against various tumor cells pretreated with zoledronic acid (Zol). Zol has shown benefits when added to adjuvant endocrine therapy for patients with early-stage breast cancer or to standard chemotherapy for patients with multiple myeloma. Although γδ T cells may contribute to this additive effect, the responsiveness of γδ T cells from early-stage breast cancer patients has not been fully investigated. In this study, we determined the number, frequency, and responsiveness of Vγ2Vδ2 T cells from early- and late-stage breast cancer patients and examined the effect of IL-18 on their ex vivo expansion. Methods: Breast cancer patients (n=80) were enrolled after institutional review board approval and with written informed consent. Peripheral blood mononuclear cells (PBMC) were purified and stimulated with Zol/IL-2 or Zol/IL-2/IL-18 for 2 to 10 days. The expanded cells were assessed on flow cytometry and the production of IFN-γ and TNF-α measured through ELISA. Results: The responsiveness of Vγ2Vδ2 T cells from patients with low frequencies of Vγ2Vδ2 T cells was significantly diminished. IL-18, however, enhanced ex vivo proliferative responses of Vγ2Vδ2T cells and helper NK cells (CD3-CD56brightCD11c+CD14-CD16+NKGD2+NKp44low) from patients with either low or high frequencies of Vγ2Vδ2 T cells. Cell-to-cell contact between γδ T and helper NK cells appeared to promote expansion of γδ T cells. Exogenous IL-18 markedly enhanced IFN-γ and TNF-α production from PBMC stimulated by Zol/IL-2, whereas the addition of an anti-IL-18Rα mAb reduced cytokine production. Conclusions: These results demonstrate that Zol elicits immunological responses by γδ T cells from early-stage breast cancer patients and IL-18 enhances proliferative responses and effector functions of γδ T cells in the context of helper NK cells.


2009 ◽  
Vol 122 (1) ◽  
pp. 135-144 ◽  
Author(s):  
Benjamin H. Beck ◽  
Hyung-Gyoon Kim ◽  
Hyunki Kim ◽  
Sharon Samuel ◽  
Zhiyong Liu ◽  
...  

Cancers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1690
Author(s):  
Venkataswarup Tiriveedhi ◽  
Michael T. Ivy ◽  
Elbert L. Myles ◽  
Roy Zent ◽  
Jeffrey C. Rathmell ◽  
...  

Cell based immunotherapy is rapidly emerging as a promising cancer treatment. A modest increase in salt (sodium chloride) concentration in immune cell cultures is known to induce inflammatory phenotypic differentiation. In our current study, we analyzed the ability of salt treatment to induce ex vivo expansion of tumor-primed CD4 (cluster of differentiation 4)+T cells to an effector phenotype. CD4+T cells were isolated using immunomagnetic beads from draining lymph nodes and spleens from tumor bearing C57Bl/6 mice, 28 days post-injection of Py230 syngeneic breast cancer cells. CD4+T cells from non-tumor bearing mice were isolated from splenocytes of 12-week-old C57Bl/6 mice. These CD4+T cells were expanded ex vivo with five stimulation cycles, and each cycle comprised of treatment with high salt (Δ0.035 M NaCl) or equimolar mannitol controls along with anti-CD3/CD28 monoclonal antibodies for the first 3 days, followed by the addition of interleukin (IL)-2/IL-7 cytokines and heat killed Py230 for 4 days. Ex vivo high salt treatment induced a two-fold higher Th1 (T helper type 1) expansion and four-fold higher Th17 expansion compared to equimolar mannitol treatment. Importantly, the high salt expanded CD4+T cells retained tumor-specificity, as demonstrated by higher in vitro cytotoxicity against Py230 breast cancer cells and reduced in vivo syngeneic tumor growth. Metabolic studies revealed that high salt treatment enhanced the glycolytic reserve and basal mitochondrial oxidation of CD4+T cells, suggesting a role of high salt in enhanced pro-growth anabolic metabolism needed for inflammatory differentiation. Mechanistic studies demonstrated that the high salt induced switch to the effector phenotype was mediated by tonicity-dependent transcription factor, TonEBP/NFAT5. Using a transgenic murine model, we demonstrated that CD4 specific TonEBP/NFAT5 knock out (CD4cre/creNFAT5flox/flox) abrogated the induction of the effector phenotype and anti-tumor efficiency of CD4+T cells following high salt treatment. Taken together, our data suggest that high salt-mediated ex vivo expansion of tumor-primed CD4+T cells could induce effective tumor specific anti-cancer responses, which may have a novel cell-based cancer immunotherapeutic application.


2016 ◽  
Vol 113 (12) ◽  
pp. 3329-3334 ◽  
Author(s):  
Maurizio Perdicchio ◽  
Juan M. Ilarregui ◽  
Marleen I. Verstege ◽  
Lenneke A. M. Cornelissen ◽  
Sjoerd T. T. Schetters ◽  
...  

Sialic acids are negatively charged nine-carbon carboxylated monosaccharides that often cap glycans on glycosylated proteins and lipids. Because of their strategic location at the cell surface, sialic acids contribute to interactions that are critical for immune homeostasis via interactions with sialic acid-binding Ig-type lectins (siglecs). In particular, these interactions may be of importance in cases where sialic acids may be overexpressed, such as on certain pathogens and tumors. We now demonstrate that modification of antigens with sialic acids (Sia-antigens) regulates the generation of antigen-specific regulatory T (Treg) cells via dendritic cells (DCs). Additionally, DCs that take up Sia-antigen prevent formation of effector CD4+ and CD8+ T cells. Importantly, the regulatory properties endowed on DCs upon Sia-antigen uptake are antigen-specific: only T cells responsive to the sialylated antigen become tolerized. In vivo, injection of Sia-antigen–loaded DCs increased de novo Treg-cell numbers and dampened effector T-cell expansion and IFN-γ production. The dual tolerogenic features that Sia-antigen imposed on DCs are Siglec-E–mediated and maintained under inflammatory conditions. Moreover, loading DCs with Sia-antigens not only inhibited the function of in vitro–established Th1 and Th17 effector T cells but also significantly dampened ex vivo myelin-reactive T cells, present in the circulation of mice with experimental autoimmune encephalomyelitis. These data indicate that sialic acid-modified antigens instruct DCs in an antigen-specific tolerogenic programming, enhancing Treg cells and reducing the generation and propagation of inflammatory T cells. Our data suggest that sialylation of antigens provides an attractive way to induce antigen-specific immune tolerance.


2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 12502-12502
Author(s):  
F. Schuetz ◽  
J. Rom ◽  
K. Ehlert ◽  
V. Schirrmacher ◽  
A. Schneeweiss ◽  
...  

12502 Tumor-reactive CD4 and CD8 memory T cells (MTC) can be found in bone marrow (BM) of the majority of primary and metastatic breast cancer patients. In xenotransplant mouse models these cells, upon specific re-activation ex vivo, mediated efficient rejection of autologous breast tumors suggesting that the polyclonal natural MTC repertoire possesses therapeutic potential. In order to clinically exploit these anti-tumor capacities we treated 11 advanced metastasized breast cancer patients with autologous, tumor-reactive, reactivated MTC of BM in a phase-1 trial. Activation of T cells was done by MCF-7 lysate pulsed dendritic cells (DC). After reactivation both, T cells and pulsed DC were injected once intravenously. Peripheral blood was drawn on day 0, 1, 7, 14, 28. BM-re-aspiration was done on day 28 and 84. While TAA-reactive memory T cells were absent in the peripheral blood (PB) before therapy, 5 from 11 patients (=responders) showed TAA-specific PB T cell reactivity 7 days after therapeutic cell application suggesting a massive proliferation and mobilization into the blood of TAA-reactive T cells in these patients. A comparison of responders to adoptive cellular immunotherapy with non-responders revealed differences in the numbers of therapeutic cells that could be generated ex vivo and in the decreased frequency of tumor-reactive MTC in responders’ BM on days 28 and 84 which could be expained by a mobilization due to in situ activation by co-transferred DCs or due to local or systemic cytokine signals by transferred, activated T lymphocytes. Such effect might have contributed to the high numbers of circulating TAA-reactive T cells observed 7 days after the transfer. Furthermore we observed different concentrations of IL-4, IL-10, TNF-α, and INF-γ in PB and BM between the two groups leading to the hypothesis of a polarization in T cell responses (T1 type in responders vs T2 type in non-responders). No significant financial relationships to disclose.


Blood ◽  
2007 ◽  
Vol 110 (7) ◽  
pp. 2520-2527 ◽  
Author(s):  
Yoshinobu Koguchi ◽  
Timothy J. Thauland ◽  
Mark K. Slifka ◽  
David C. Parker

CD40 ligand (CD40L) is an essential effector cytokine for macrophage activation, dendritic cell licensing, and T-cell–dependent antibody responses. Although CD40L is known to be made de novo following antigen recognition, several reports have described surface mobilization of preformed, intracellular CD40L in certain CD4+ effector T cells. Here we show that rapid surface expression of preformed CD40L following antigen recognition is a general property of both effector and memory CD4+ T cells, including in vitro and in vivo activated T-cell–receptor transgenic T cells, memory phenotype CD4+ T cells from pathogen-free naive mice, and polyclonal virus–specific effector and memory T cells. Intracellular CD40L is stored in secretory lysosomes, and colocalizes more strongly with Fas ligand than with CTLA-4, two other molecules that are delivered to the cell surface following antigen recognition. Stimulated surface expression of preformed CD40L is found in memory CD4+ T cells from CD40-deficient mice, indicating that it does not depend on CD40-induced internalization for delivery to the secretory compartment. We suggest that delivery of preformed CD40L to antigen-presenting cells (APCs) could enable antigen-specific activation of APCs in transient interactions that are too brief to permit de novo synthesis of CD40L.


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