scholarly journals 743 Resistance to oncolytic vaccinia can be reversed by targeting regulatory T cells with vaccinia-directed delivery of a TGFβ inhibitor

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A774-A774
Author(s):  
Kristin DePeaux ◽  
Dayana Rivadeneira ◽  
McLane Watson ◽  
Andrew Hinck ◽  
Stephen Thorne ◽  
...  
Keyword(s):  
T Cells ◽  
Treg Cell ◽  
Cytokine Production ◽  
Treg Cells ◽  
Oncolytic Viruses ◽  
Cell Phenotype ◽  
Cancer Model ◽  
Stat1 Signaling ◽  
Determining Factor

BackgroundOncolytic viruses are an underappreciated immunotherapy capable of inflaming the tumor microenvironment (TME), vaccinating a patient against their own tumor, and delivering gene therapy to the TME. However, apart from the oncolytic HSV T-vec, these therapies have not seen widespread use, due in part to incomplete understanding of their immunologic mechanisms of action. We sought to determine features of oncolytic vaccinia virus (VV) response and resistance using subclones of the HPV+ head and neck cancer model MEER rendered sensitive or resistant to VV.MethodsA VV sensitive MEER tumor resisting treatment was serially passaged in mice and treated with VV until a stably resistant line was generated (Fig1). Sensitive or resistant MEER tumors were implanted, treated with a single intratumoral dose of VV, and harvested 4–7 days later for cytometric analysis. A genetically encoded TGFβ inhibitor was recombined into oncolytic VV (VV-TGFβi).ResultsWe used serial in vivo passaging to generate a VV-resistant MEER line (MEERvvR) from one sensitive to VV (MEERvvS, figure 1) and compared their immune infiltrate. While VV promoted acute cytokine production and cytotoxicity in conventional T cells, the major determining factor between sensitivity and resistance was the phenotype of Treg cells. At baseline, Treg cells in MEERvvS had lower Nrp1 expression and higher IFNγ-STAT1 signaling compared to MEERvvR, indicative of Treg 'fragility'. VV treatment induced MEERvvS Treg cells to become immunostimulatory and produce IFNγ (figure 2). RNAseq revealed MEERvvR produced more TGFβ than MEERvvS cells, suggesting these tumors directly stabilize Treg cells. To determine if MEERvvR could be sensitized to VV, we engineered oncolytic vaccinia to produce a genetically-encoded TGFβ inhibitor which binds TGFβRII, preventing TGFβ1-3 binding (VV-TGFβi). When MEERvvR were treated with VV-TGFβi, elite responses were restored, with commensurate increase in survival (figure 3) associated with increased STAT1 signaling in Treg cells.ConclusionsResistance to oncolytic vaccinia is controlled by Treg cell phenotype; tumors harboring more fragile Treg cells respond exquisitely to VV. An oncolytic vaccinia engineered to produce a novel TGFβi could remodel the TME to be less supportive of Tregs, rendering resistant tumors sensitive to VV. Our data highlight the importance of Treg cell status in resistance to oncolytic virus therapy and suggest TGFβ can be effectively targeted through an inhibitor encoded within the virus. Importantly, this TME directed production of the TGFβi carries no toxicity previously associated with systemic TGFβ inhibition, suggesting a viral approach to TGFβ inhibition can be an effective strategy support broader immunotherapy response.Abstract 743 Figure 1Strategy used to generate a vaccinia resistant MEER (MEERvvR) from vaccinia sensitive MEER (MEERvvS)Abstract 743 Figure 2IFNγ production in Treg cells in MEERvvS and MEERvvR after treatment with PBS or control vaccinia (VV-Ctrl)Abstract 743 Figure 3Survival of VV-resistant MEER treated with PBS, control vaccinia (VV-Ctrl), or vaccinia engineered to deliver a potent inhibitor of TGFβ (VV-TGFβi)

scholarly journals Androgen receptor modulates Foxp3 expression in CD4+CD25+Foxp3+ regulatory T-cells

2015 ◽  
Vol 26 (15) ◽  
pp. 2845-2857 ◽  
Author(s):  
Magdalena Walecki ◽  
Florian Eisel ◽  
Jörg Klug ◽  
Nelli Baal ◽  
Agnieszka Paradowska-Dogan ◽  
...  
Keyword(s):  
T Cells ◽  
Androgen Receptor ◽  
Treg Cell ◽  
Foxp3 Expression ◽  
Treg Cells ◽  
Strong Increase ◽  
Histone H4 ◽  
And Function

CD4+CD25+Foxp3+ regulatory T (Treg) cells are able to inhibit proliferation and cytokine production in effector T-cells and play a major role in immune responses and prevention of autoimmune disease. A master regulator of Treg cell development and function is the transcription factor Foxp3. Several cytokines, such as TGF-β and IL-2, are known to regulate Foxp3 expression as well as methylation of the Foxp3 locus. We demonstrated previously that testosterone treatment induces a strong increase in the Treg cell population both in vivo and in vitro. Therefore we sought to investigate the direct effect of androgens on expression and regulation of Foxp3. We show a significant androgen-dependent increase of Foxp3 expression in human T-cells from women in the ovulatory phase of the menstrual cycle but not from men and identify a functional androgen response element within the Foxp3 locus. Binding of androgen receptor leads to changes in the acetylation status of histone H4, whereas methylation of defined CpG regions in the Foxp3 gene is unaffected. Our results provide novel evidence for a modulatory role of androgens in the differentiation of Treg cells.

Regulation of Hematopoietic Colony Forming Cells by CD4+CD25+ T Cells: A Role for T Regulatory Cells in Hematopoiesis?.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3181-3181
Author(s):  
Maite Urbieta ◽  
Isabel Barao ◽  
Monica Jones ◽  
William J. Murphy ◽  
Robert B. Levy
Keyword(s):  
T Cells ◽  
Growth Factors ◽  
T Cell ◽  
Treg Cell ◽  
Mhc Class Ii ◽  
Progenitor Cell ◽  
Cell Activity ◽  
Class Ii ◽  
Treg Cells

Abstract CD4+CD25+ T cells (Treg) comprise a small population within the normal peripheral CD4 T cell compartment. Their primary physiological role appears to be the regulation of autoimmune responses, however, in recent years it has been established that they can modulate anti-tumor as well as transplantation responses. Treg cells have been found to exert their affects on multiple types of immunologically relevant cells including CD4, CD8 and NK populations. Although model dependent, cytokines including TGFβ and IL-10 have been identified as mediators of this population’s regulatory activity and ex-vivo, the inhibition effected is generally contact dependent. Based upon the expanding application of Treg cells in stem cell transplants for the control of GVHD, rejection (HVG) and GVL responses, we hypothesized that following T cell receptor engagement and activation in recipients, CD4+CD25+ cells may modulate hematopoietic responses via production of effector cytokines. To address this question, various populations of CD4+CD25+ T cells were initially co-cultured with unfractionated syngeneic bone marrow cells (BMC) for 24–48 hours in medium supplemented with growth factors to maintain progenitor cell (i.e. CFU) function. Following co-culture, cells were collected and replated in triplicate in methylcellulose containing medium together with hematopoietic growth factors and five-seven days later, colonies were counted. CD4+CD25+ T cells were purified from BALB/c or B6–CD8−/− mice which were then activated for 3–8 days with anti-CD3/CD28 beads (a gift of Dr. B. Blazar, U. Minn.) These cells inhibited syngeneic CFU-IL3 colony ($25 cells) formation at ratios as low as 2:1 and 0.5:1 CD4+CD25+: BMC. Notably, Tregs from B6-CD8−/− mice exhibited comparable inhibition of allogeneic (BALB/c) CFU-IL3. Non-activated CD4+CD25+ T cells co-cultured with BMC did not exhibit this inhibitory activity nor did CD4+CD25− cells which contaminated (<10%) CD4+CD25+ populations. Activated Treg cells were also found to inhibit the production of CFU-HPP, a multi-potential marrow progenitor cell population. Contact dependency was found to be required for this effect as separation of activated CD4+CD25+ T cells from BMC “targets” in trans-well cultures abrogated inhibition. Prior depletion of CD25+ cells in vivo resulted in increases in CFU-GM 7–9 days after syngeneic BMT in mice suggesting that Tregs can inhibit hematopoietic reconstitution in vivo. To examine a potential contribution of TGFβ in this model, neutralizing anti-TGFβ mab was added during CD4+CD25+ T cell + BMC co-culture. The inhibition of CFU activity was abrogated in the presence of this antibody. To begin investigating the role of MHC class II molecules in this Treg cell activity, c-kit+ enriched (>85%) BMC from B6-MHC class II KO and B6-wt mice were co-cultured with B6 Treg cells from CD8−/− mice. In contrast to B6-wt c-kit enriched populations, CFU inhibition was not detected against the MHC class II deficient c-kit enriched BMC population. Antibody experiments are in progress to determine if cognate interaction is required between c-kit enriched cells and CD4+CD25+ T cells. In summary, this is the first report demonstrating that CD4+CD25+ T cells can alter hematopoietic progenitor cell activity. We hypothesize that membrane bound TGFβ may participate in effecting such regulation via direct Treg cell interactions with progenitor cell populations.

Ex Vivo Expansion of Canine CD4+CD25+ Regulatory T Cells (Treg) with Artificial Antigen Presenting Cells (aAPC).

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3102-3102
Author(s):  
Marina Lesnikova ◽  
Alla Nikitine ◽  
Lina Pogosov ◽  
Nicola Mason ◽  
Richard A. Nash ◽  
...  
Keyword(s):  
T Cells ◽  
Ex Vivo ◽  
Canine Model ◽  
Treg Cells ◽  
Patient Specific ◽  
Cell Phenotype ◽  
Immunomagnetic Selection ◽  
Bulk Culture

Abstract We hypothesize that immune tolerance after allogeneic hematopoietic cell transplantation (HCT) is maintained by an active cellular mechanism that includes regulators of immune function, CD4+CD25+ Treg cells. Furthermore, infusion of patient-specific Treg cells might provide therapeutic benefit, improving the control of graft-versus-host (GVH) and host-versus-graft (HVG) reactions after HCT. In preparation for large-scale in vivo studies with Treg in the well-established canine model of HCT, we characterized the in vitro function of canine CD4+CD25+ Treg cells and asked if canine-specific aAPC could expand Treg cells ex vivo. Responder peripheral blood mononuclear cells (PBMC) were obtained by leukapheresis and ficoll-hypaque separation (n = 7 dogs) and cultured in bulk mixed leukocyte culture (MLC) conditions with 3rd party dog leukocyte antigen (DLA)-mismatched, unrelated and irradiated (22 Gy) CD34+ derived dendritic cells (10:1 responder: stimulator ratio) or PBMC (1:1). The starting number of responder cells ranged from 120 – 555 x106 CD3+ cells. On day 4 of MLC, cells were incubated with anti-CD25 monoclonal antibody (ACT-1). CD25+ cells were isolated by positive immunomagnetic selection (Miltenyi), and assessed for phenotype and in vitro function. After selection, cells were 83% – 97% CD3+CD4+CD25+ by flow cytometry. The CD4+CD25+ T cells expressed the forkhead/winged helix transcription factor foxP3, assessed by Western blot with polyclonal anti-human foxP3 antibody, while CD25− T cells did not express foxP3. In addition, the CD4+CD25+ Treg inhibited proliferation of fresh primary MLCs a median of 79% (range, 54% – 88%) when CD4+CD25+ cells were added at 1:5 or 1:25 ratio (Treg: responder) and pulsed with 3H-thymidine after 6 days. CD4+CD25+ Treg inhibited proliferation of primary MLCs in a cell contact-dependent manner if Treg shared the DLA-type of the responder cells. Addition of CD25− T cells did not inhibit MLCs. The yield of CD4+CD25+ Treg after bulk culture and immunomagnetic selection ranged from 2.2 – 24 x106 cells. On day 5 of cell culture, aAPC were added to stimulate and expand the CD4+CD25+ Treg cells. The aAPC (KT32) expressing the Fcγ receptor CD32, canine CD86, and human IL-15, were loaded with the canine-specific mitogenic anti-CD3ε antibody 17.6F9 (0.5 mg/mL) and irradiated (100 Gy) prior to stimulation of CD4+CD25+ Treg (at 1:1 or 1:10 aAPC:Treg ratio). Seven days later, Treg cells had expanded a median of 23-(range, 8–36) fold. The expanded cells maintained the phenotype and in vitro function as Treg prior to expansion. The expanded Treg were 44–76% (median, 59%) CD4+CD25+, expressed foxP3, and inhibited primary MLCs a median of 85% (range, 64%–97%) at a 1:5 ratio. Bulk culture expansion generated a median of 105 (range, 52–135) x106 Treg, cell doses that are potentially sufficient for assessment of in vivo function in the dog model of HCT. In summary, canine Treg can be isolated from PBMC following short-term allogeneic stimulation, immunomagnetic selection and expansion with canine-specific aAPC. The expanded Treg maintain the cell phenotype and functional characteristics of allo-stimulated CD4+CD25+ Treg cells. In future studies, expanded Treg cells will be evaluated for in vivo function to inhibit GVH and HVG reactions in the canine model of allogeneic HCT.

Comparison of In Vitro and In Vivo Effects of Infliximab on Cytokine Production in Proliferating CD4+ T Cells in Patients with Rheumatoid Arthritis

2015 ◽  
Vol 1 (2) ◽  
pp. 122-128
Author(s):  
Syuichi Koarada ◽  
Yuri Sadanaga ◽  
Natsumi Nagao ◽  
Satoko Tashiro ◽  
Rie Suematsu ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
T Cells ◽  
Cd4 T Cells ◽  
Cytokine Production

scholarly journals Gastric Hyperplasia and Increased Proliferative Responses of Lymphocytes in Mice Lacking the COOH-terminal Ankyrin Domain of NF-κB2

1997 ◽  
Vol 186 (7) ◽  
pp. 999-1014 ◽  
Author(s):  
Hideaki Ishikawa ◽  
Daniel Carrasco ◽  
Estefania Claudio ◽  
Rolf-Peter Ryseck ◽  
Rodrigo Bravo
Keyword(s):  
T Cells ◽  
Lymphocyte Proliferation ◽  
Cytokine Production ◽  
Cell Types ◽  
Homozygous Deletion ◽  
Binding Activity ◽  
Activated T Cells ◽  
Physiological Relevance

The nfkb2 gene encodes the p100 precursor which produces the p52 protein after proteolytic cleavage of its COOH-terminal domain. Although the p52 product can act as an alternative subunit of NF-κB, the p100 precursor is believed to function as an inhibitor of Rel/NF-κB activity by cytoplasmic retention of Rel/NF-κB complexes, like other members of the IκB family. However, the physiological relevance of the p100 precursor as an IκB molecule has not been understood. To assess the role of the precursor in vivo, we generated, by gene targeting, mice lacking p100 but still containing a functional p52 protein. Mice with a homozygous deletion of the COOH-terminal ankyrin repeats of NF-κB2 (p100−/−) had marked gastric hyperplasia, resulting in early postnatal death. p100−/− animals also presented histopathological alterations of hematopoietic tissues, enlarged lymph nodes, increased lymphocyte proliferation in response to several stimuli, and enhanced cytokine production in activated T cells. Dramatic induction of nuclear κB–binding activity composed of p52-containing complexes was found in all tissues examined and also in stimulated lymphocytes. Thus, the p100 precursor is essential for the proper regulation of p52-containing Rel/NF-κB complexes in various cell types and its absence cannot be efficiently compensated for by other IκB proteins.

scholarly journals Granzyme B is not required for regulatory T cell–mediated suppression of graft-versus-host disease

Blood ◽  
2010 ◽  
Vol 115 (9) ◽  
pp. 1669-1677 ◽  
Author(s):  
Sheng F. Cai ◽  
Xuefang Cao ◽  
Anjum Hassan ◽  
Todd A. Fehniger ◽  
Timothy J. Ley
Keyword(s):  
Immune Responses ◽  
Treg Cell ◽  
Graft Versus Host Disease ◽  
Granzyme B ◽  
Target Organ Damage ◽  
Organ Damage ◽  
Treg Cells ◽  
Host Disease ◽  
Graft Versus Host

Abstract Regulatory T (Treg) cells can suppress a wide variety of immune responses, including antitumor and alloimmune responses. The mechanisms by which Treg cells mediate their suppressive effects depend on the context of their activation. We previously reported that granzyme B is important for Treg cell–mediated suppression of antitumor immune responses. We therefore hypothesized that granzyme B may likewise be important for suppression of graft-versus-host disease (GVHD). We found that allogeneic mismatch induces the expression of granzyme B in mixed lymphocyte reactions and in a model of graft-versus-host disease (GVHD). However, wild-type and granzyme B–deficient Treg cells were equally able to suppress effector T (Teff) cell proliferation driven by multiple stimuli, including allogeneicantigen-presenting cells. Surprisingly, adoptive transfer of granzyme B–deficient Treg cells prevented GVHD lethality, suppressed serum cytokine production in vivo, and prevented target organ damage. These data contrast strikingly with our previous study, which demonstrated that granzyme B plays a nonredundant role in Treg cell–mediated suppression of antitumor responses. Taken together, these findings suggest that targeting specific Treg cell–suppressive mechanisms, such as granzyme B, may be therapeutically beneficial for segregating GVHD and graft-versus-tumor immune responses.

scholarly journals FOXP3 expression accurately defines the population of intratumoral regulatory T cells that selectively accumulate in metastatic melanoma lesions

Blood ◽  
2008 ◽  
Vol 112 (13) ◽  
pp. 4953-4960 ◽  
Author(s):  
Mojgan Ahmadzadeh ◽  
Aloisio Felipe-Silva ◽  
Bianca Heemskerk ◽  
Daniel J. Powell ◽  
John R. Wunderlich ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Microenvironment ◽  
Metastatic Melanoma ◽  
Treg Cell ◽  
Peripheral Blood ◽  
Ex Vivo ◽  
Production Capacity ◽  
Biological Marker ◽  
Foxp3 Expression ◽  
Treg Cells

Abstract Regulatory T (Treg) cells are often found in human tumors; however, their functional characteristics have been difficult to evaluate due to low cell numbers and the inability to adequately distinguish between activated and Treg cell populations. Using a novel approach, we examined the intracellular cytokine production capacity of tumor-infiltrating T cells in the single-cell suspensions of enzymatically digested tumors to differentiate Treg cells from effector T cells. Similar to Treg cells in the peripheral blood of healthy individuals, tumor-infiltrating FOXP3+CD4 T cells, unlike FOXP3− T cells, were unable to produce IL-2 and IFN-γ upon ex vivo stimulation, indicating that FOXP3 expression is a valid biological marker for human Treg cells even in the tumor microenvironment. Accordingly, we enumerated FOXP3+CD4 Treg cells in intratumoral and peritumoral sections of metastatic melanoma tumors and found a significant increase in proportion of FOXP3+CD4 Treg cells in the intratumoral compared with peritumoral areas. Moreover, their frequencies were 3- to 5-fold higher in tumors than in peripheral blood from the same patients or healthy donors, respectively. These findings demonstrate that the tumor-infiltrating CD4 Treg cell population is accurately depicted by FOXP3 expression, they selectively accumulate in tumors, and their frequency in peripheral blood does not properly reflect tumor microenvironment.

517 Regulatory T cell functional identity is sustained by a glucose:lactate axis that is exploited in the tumor microenvironment

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A553-A553
Author(s):  
McLane Watson ◽  
Paolo Vignali ◽  
Steven Mullet ◽  
Abigail Overacre-Delgoffe ◽  
Ronal Peralta ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Microenvironment ◽  
Treg Cell ◽  
High Glucose ◽  
Cell Function ◽  
Treg Cells ◽  
Effector T Cells ◽  
Flux Analysis ◽  
Major Barrier ◽  
Suppressive Function

BackgroundRegulatory T (Treg) cells are vital for preventing autoimmunity but are a major barrier to robust cancer immunity as the tumor microenvironment (TME) recruits and promotes their function. The deregulated cellular metabolism of tumor cells leads to a metabolite-depleted, hypoxic, and acidic TME. While the TME impairs the effector function of highly glycolytic tumor infiltrating CD8 T cells, Treg cell suppressive function is maintained. Further, studies of in vitro induced and ex vivo Treg cells reveal a distinct metabolic profile compared to effector T cells. Thus, it may be that the altered metabolic landscape of the TME and the increased activity of intratumoral Treg cells are linked.MethodsFlow cytometry, isotopic flux analysis, Foxp3 driven Cre-lox, glucose tracers, Seahorse extracellular flux analysis, RNA sequencing.ResultsHere we show Treg cells display heterogeneity in terms of their glucose metabolism and can engage an alternative metabolic pathway to maintain their high suppressive function and proliferation within the TME and other tissues. Tissue derived Treg cells (both at the steady state and under inflammatory conditions) show broad heterogeneity in their ability to take up glucose. However, glucose uptake correlates with poorer suppressive function and long-term functional stability, and culture of Treg cells in high glucose conditions decreased suppressive function. Treg cells under low glucose conditions upregulate genes associated with the uptake and metabolism of the glycolytic end-product lactic acid. Treg cells withstand high lactate conditions, and lactate treatment prevents the destabilizing effects of high glucose culture. Treg cells utilize lactate within the TCA cycle and generate phosphoenolpyruvate (PEP), a critical intermediate that can fuel intratumoral Treg cell proliferation in vivo. Using mice with a Treg cell-restricted deletion of lactate transporter Slc16a1 (MCT1) we show MCT1 is dispensable for peripheral Treg cell function but required intratumorally, resulting in slowed tumor growth and prolonged survival.ConclusionsThese data support a model in which Treg cells are metabolically flexible such that they can utilize ‘alternative’ metabolites present in the TME to maintain their suppressive identity. Further, our studies support the notion that tumors avoid immune destruction not only by depriving effector T cells of essential nutrients, but also by metabolically supporting regulatory T cells.

scholarly journals 173 Expression of a membrane-tethered IL-15/IL-15 receptor fusion protein enhances the persistence of MSLN-targeted TRuC-T cells

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A185-A185
Author(s):  
Michelle Fleury ◽  
Derrick McCarthy ◽  
Holly Horton ◽  
Courtney Anderson ◽  
Amy Watt ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Fusion Protein ◽  
T Cell Receptor ◽  
Cytokine Production ◽  
Cell Receptor ◽  
Great Promise ◽  
And Function

BackgroundAdoptive cell therapies have shown great promise in hematological malignancies but have yielded little progress in the context of solid tumors. We have developed T cell receptor fusion construct (TRuC®) T cells, which are equipped with an engineered T cell receptor that utilizes the full complement of TCR signaling subunits and recognizes tumor-associated antigens independent of HLA. In clinical trials, mesothelin (MSLN)-targeting TRuC-T cells (TC-210 or gavo-cel) have shown unprecedented results in patients suffering from advanced mesothelioma and ovarian cancer. To potentially increase the depth of response, we evaluated strategies that can promote intra-tumoral T cell persistence and function. Among the common ??-chain cytokines, IL-15 uniquely supports the differentiation and maintenance of memory T cell subsets by limiting terminal differentiation and conferring resistance to IL-2 mediated activation-induced cell death (AICD). In the studies described here, we evaluated the potential of IL-15 as an enhancement to TRuC-T cell phenotype, persistence and function against MSLN+ targets.MethodsPrimary human T cells were activated and transduced with a lentiviral vector encoding an anti-MSLN binder fused to CD3ε alone or co-expressed with a membrane-tethered IL-15rα/IL-15 fusion protein (IL-15fu). Transduced T cells were expanded for 9 days and characterized for expression of the TRuC, IL-15rα and memory phenotype before subjecting them to in vitro functional assays to evaluate cytotoxicity, cytokine production, and persistence. In vivo efficacy was evaluated in MHC class I/II deficient NSG mice bearing human mesothelioma xenografts.ResultsIn vitro, co-expression of the IL-15fu led to similar cytotoxicity and cytokine production as TC-210, but notably enhanced T-cell expansion and persistence upon repeated stimulation with MSLN+ cell lines. Furthermore, the IL-15fu-enhanced TRuC-T cells sustained a significantly higher TCF-1+ population and retained a stem-like phenotype following activation. Moreover, the IL-15fu-enhanced TRuCs demonstrated robust in vivo expansion and intra-tumoral accumulation as measured by ex vivo analysis of TRuC+ cells in the tumor and blood, with a preferential expansion of CD8+ T cells. Finally, IL-15fu-enhanced TRuC-T cells could be observed in the blood long after the tumors were cleared.ConclusionsThese pre-clinical studies suggest that the IL-15fu can synergize with TC-210 to increase the potency and durability of response in patients with MSLN+ tumors.Ethics ApprovalAll animal studies were approved by the respective Institutional Animal Care and Use Committees.

scholarly journals Transient Depletion of Foxp3+ Regulatory T Cells Selectively Promotes Aggressive β Cell Autoimmunity in Genetically Susceptible DEREG Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Deepika Watts ◽  
Marthe Janßen ◽  
Mangesh Jaykar ◽  
Francesco Palmucci ◽  
Marc Weigelt ◽  
...  
Keyword(s):  
T Cells ◽  
Treg Cell ◽  
Autoimmune Diabetes ◽  
Cell Activity ◽  
Spontaneous Diabetes ◽  
Nod Mice ◽  
Treg Cells ◽  
Β Cell ◽  
Cell Ablation ◽  
Tcr Repertoire

Type 1 diabetes (T1D) represents a hallmark of the fatal multiorgan autoimmune syndrome affecting humans with abrogated Foxp3+ regulatory T (Treg) cell function due to Foxp3 gene mutations, but whether the loss of Foxp3+ Treg cell activity is indeed sufficient to promote β cell autoimmunity requires further scrutiny. As opposed to human Treg cell deficiency, β cell autoimmunity has not been observed in non-autoimmune-prone mice with constitutive Foxp3 deficiency or after diphtheria toxin receptor (DTR)-mediated ablation of Foxp3+ Treg cells. In the spontaneous nonobese diabetic (NOD) mouse model of T1D, constitutive Foxp3 deficiency did not result in invasive insulitis and hyperglycemia, and previous studies on Foxp3+ Treg cell ablation focused on Foxp3DTR NOD mice, in which expression of a transgenic BDC2.5 T cell receptor (TCR) restricted the CD4+ TCR repertoire to a single diabetogenic specificity. Here we revisited the effect of acute Foxp3+ Treg cell ablation on β cell autoimmunity in NOD mice in the context of a polyclonal TCR repertoire. For this, we took advantage of the well-established DTR/GFP transgene of DEREG mice, which allows for specific ablation of Foxp3+ Treg cells without promoting catastrophic autoimmune diseases. We show that the transient loss of Foxp3+ Treg cells in prediabetic NOD.DEREG mice is sufficient to precipitate severe insulitis and persistent hyperglycemia within 5 days after DT administration. Importantly, DT-treated NOD.DEREG mice preserved many clinical features of spontaneous diabetes progression in the NOD model, including a prominent role of diabetogenic CD8+ T cells in terminal β cell destruction. Despite the severity of destructive β cell autoimmunity, anti-CD3 mAb therapy of DT-treated mice interfered with the progression to overt diabetes, indicating that the novel NOD.DEREG model can be exploited for preclinical studies on T1D under experimental conditions of synchronized, advanced β cell autoimmunity. Overall, our studies highlight the continuous requirement of Foxp3+ Treg cell activity for the control of genetically pre-installed autoimmune diabetes.

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