Immunogenicity of personalized dendritic-cell therapy in HIV-1 infected individuals under suppressive antiretroviral treatment: interim analysis from a phase II clinical trial

Abstract Background We developed a personalized Monocyte-Derived Dendritic-cell Therapy (MDDCT) for HIV-infected individuals on suppressive antiretroviral treatment and evaluated HIV-specific T-cell responses. Methods PBMCs were obtained from 10 HIV+ individuals enrolled in trial NCT02961829. Monocytes were differentiated into DCs using IFN-α and GM-CSF. After sequencing each patient’s HIV-1 Gag and determining HLA profiles, autologous Gag peptides were selected based on the predicted individual immunogenicity and used to pulse MDDCs. Three doses of the MDDCT were administered every 15 days. To assess immunogenicity, patients’ cells were stimulated in vitro with autologous peptides, and intracellular IL-2, TNF, and interferon-gamma (IFN-γ) production were measured in CD4+ and CD8+ T-cells. Results The protocol of ex-vivo treatment with IFN-α and GM-CSF was able to induce maturation of MDDCs, as well as to preserve their viability for reinfusion. MDDCT administration was associated with increased expression of IL-2 in CD4+ and CD8+ T-cells at 15 and/or 30 days after the first MDDCT administration. Moreover, intracellular TNF and IFN-γ expression was significantly increased in CD4+ T-cells. The number of candidates that increased in vitro the cytokine levels in CD4+ and CD8+ T cells upon stimulation with Gag peptides from baseline to day 15 and from baseline to day 30 and day 120 after MDDCT was significant as compared to Gag unstimulated response. This was accompanied by an increasing trend in the frequency of polyfunctional T-cells over time, which was visible when considering both cells expressing two and three out of the three cytokines examined. Conclusions MDDC had a mature profile, and this MDDCT promoted in-vitro T-cell immune responses in HIV-infected patients undergoing long-term suppressive antiretroviral treatment. Trial registration NCT02961829: (Multi Interventional Study Exploring HIV-1 Residual Replication: a Step Towards HIV-1 Eradication and Sterilizing Cure, https://www.clinicaltrials.gov/ct2/show/NCT02961829, posted November 11th, 2016)

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Immunogenicity of Personalized Dendritic-cell Therapy in HIV-1 Infected Individuals Under Suppressive Antiretroviral Treatment: Interim Analysis From a Phase II Clinical Trial.

10.21203/rs.3.rs-869990/v1 ◽

2021 ◽

Author(s):

Marcela Vassão de Almeida Batista ◽

Laís Teodoro Silva ◽

Sadia Samer ◽

Telma Miyuki Oshiro ◽

Iart Luca Shytaj ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Antiretroviral Treatment ◽

Ex Vivo ◽

Gm Csf ◽

T Cell Immune Responses ◽

Ifn Γ ◽

Dendritic Cell Therapy ◽

Hiv 1

Abstract BackgroundWe developed a personalized Monocyte-Derived Dendritic Therapy (MDDCT) for HIV-infected individuals on suppressive antiretroviral treatment and evaluated HIV-specific T-cell responses.MethodsPBMCs were obtained from 10 HIV+ individuals enrolled in trial NCT02961829. Monocytes were differentiated into DCs using IFN-α and GM-CSF. After sequencing each patient’s HIV-1 Gag and determining HLA profiles, autologous Gag peptides were selected based on the predicted individual immunogenicity and used to pulse MDDCs. Three doses of the MDDCT were administered every 15 days. To assess immunogenicity, patients’ cells were stimulated in vitro with autologous peptides, and intracellular IL-2, TNF, and interferon-gamma (IFN-γ) production were measured in CD4+ and CD8+ T-cells. ResultsThe protocol of ex-vivo treatment with IFN-α and GM-CSF was able to induce maturation of MDDCs, as well as to preserve their viability for reinfusion. MDDCT administration was associated with increased expression of IL-2 in CD4+ and CD8+ T-cells at 15 and/or 30 days after the first MDDCT administration. Moreover, intracellular TNF and IFN-γ expression was significantly increased in CD4+ T-cells. The number of candidates that increased in vitro the cytokine levels in CD4+ and CD8+ T cells upon stimulation with Gag peptides from baseline to days 15 and from baseline to days 30 and days 120 after MDDCT was significant as compared to Gag unstimulated response. This was accompanied by an increasing trend in the frequency of polyfunctional T-cells over time, which was visible when considering both cells expressing two and three out of the three cytokines examined. ConclusionsMDDC has a mature profile, and this MDDCT promoted in-vitro T-cell immune responses in HIV-infected patients undergoing long-term suppressive antiretroviral treatment.NCT02961829: (Multi Interventional Study Exploring HIV-1 Residual Replication: a Step Towards HIV-1 Eradication and Sterilizing Cure, https://www.clinicaltrials.gov/ct2/show/NCT02961829, posted November 11th, 2016).

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Human Immunodeficiency Virus Type 1 (HIV-1)-Specific CD4+ T Cells That Proliferate In Vitro Detected in Samples from Most Viremic Subjects and Inversely Associated with Plasma HIV-1 Levels

Journal of Virology ◽

10.1128/jvi.78.22.12638-12646.2004 ◽

2004 ◽

Vol 78 (22) ◽

pp. 12638-12646 ◽

Cited By ~ 26

Author(s):

Eli Boritz ◽

Brent E. Palmer ◽

Cara C. Wilson

Keyword(s):

Human Immunodeficiency Virus ◽

T Cells ◽

T Cell ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Immunodeficiency Virus ◽

Ifn Γ ◽

Hiv 1

ABSTRACT Diminished in vitro proliferation of human immunodeficiency virus type 1 (HIV-1)-specific CD4+ T cells has been associated with HIV-1 viremia and declining CD4+ T-cell counts during chronic infection. To better understand this phenomenon, we examined whether HIV-1 Gag p24 antigen-induced CD4+ T-cell proliferation might recover in vitro in a group of subjects with chronic HIV-1 viremia and no history of antiretroviral therapy (ART). We found that depletion of CD8+ cells from peripheral blood mononuclear cells (PBMC) before antigen stimulation was associated with a 6.5-fold increase in the median p24-induced CD4+ T-cell proliferative response and a 57% increase in the number of subjects with positive responses. These p24-induced CD4+ T-cell proliferative responses from CD8-depleted PBMC were associated with expansion of the numbers of p24-specific, gamma interferon (IFN-γ)-producing CD4+ T cells. Among the 20 viremic, treatment-naïve subjects studied, the only 5 subjects lacking proliferation-competent, p24-specific CD4+ T-cell responses from CD8-depleted PBMC showed plasma HIV-1 RNA levels > 100,000 copies/ml. Furthermore, both the magnitude of p24-induced CD4+ T-cell proliferative responses from CD8-depleted PBMC and the frequency of p24-specific, IFN-γ-producing CD4+ T cells expanded from CD8-depleted PBMC were associated inversely with plasma HIV-1 RNA levels. Therefore, proliferation-competent, HIV-1-specific CD4+ T cells that might help control HIV-1 disease may persist during chronic, progressive HIV-1 disease except at very high levels of in vivo HIV-1 replication.

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Cytotoxic CD8+ T Cells Expressing CXCR5 Are Detectable in HIV-1 Elite Controllers After Prolonged In Vitro Peptide Stimulation

Frontiers in Immunology ◽

10.3389/fimmu.2020.622343 ◽

2021 ◽

Vol 11 ◽

Author(s):

Philipp Adams ◽

Gilles Iserentant ◽

Jean-Yves Servais ◽

Linos Vandekerckhove ◽

Guido Vanham ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Subsets ◽

Color Flow ◽

Cell Immunity ◽

Ifn Γ ◽

Peptide Stimulation ◽

Hiv Controllers ◽

Hiv 1

Antiretroviral therapy (ART) is not curative as HIV-1 persists in long-lived viral reservoirs. Consequently, patients are dependent on life-long drug adherence with possible side effects. To overcome these limitations strategies of a functional cure aim at ART free viral remission. In this study, we sought to identify detailed subsets of anti-viral CD8+ T cell immunity linked to natural long-term control of HIV-1 infection. Here, we analyzed HIV controllers and ART suppressed progressors for in vitro viral suppressive capacity (VSC) at baseline and after peptide stimulation. Functional properties and phenotypes of CD8+ T cells were assessed by IFN-γ ELISPOT and 18 color flow cytometry. HIV controllers showed significantly increased suppression at baseline as well as after peptide stimulation. IFN-γ secretion and the proliferation marker Ki67 positively correlated with VSC. Moreover, the detailed phenotype of three distinct multifunctional memory CD8+ T cell subsets were specific traits of HIV controllers of which two correlated convincingly with VSC. Our results underline the importance of multifunctional CD8+ T cell responses during natural control. Especially the role of CXCR5 expressing cytotoxic subsets emphasizes potential surveillance in sites of reservoir persistence and demand further study.

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Human Bone Marrow as a Source of Multifunctional CMV-Specific CD4+ T Cells for Adoptive Cell Therapy.

Blood ◽

10.1182/blood.v110.11.2973.2973 ◽

2007 ◽

Vol 110 (11) ◽

pp. 2973-2973

Author(s):

Il-Kang Na ◽

Anne Letsch ◽

Ines Noack ◽

Sandra Bauer ◽

Jens Geginat ◽

...

Keyword(s):

Bone Marrow ◽

T Cells ◽

T Cell ◽

Cell Therapy ◽

Cd8 T Cells ◽

Peripheral Blood ◽

Cd4 T Cells ◽

Human Bone ◽

Ifn Γ

Abstract Introduction Adoptive cell transfer of ex vivo primed and expanded human cytotoxic T lymphocytes (CTLs) has emerged as a promising approach to treat both infectious and malignant diseases in humans. First clinical studies have shown that transfer of Cytomegalovirus (CMV)-specific CD8+ T cells is safe and effective in reconstitution of cellular immunity against CMV disease. Efficacy of adoptive T cell therapy is limited by the numbers of CTLs in vitro and the survival and function after infusion. CD4+ T cells may enhance activity via direct or indirect effector functions (Matloubian 1994 [1]). In this study we have analysed whether bone marrow is superior to peripheral blood for expansion of CMV-specific T cells. Experimental design Paired peripheral blood and bone marrow samples were obtained from patients who underwent total hip arthroplasty. By using two different protocols T cells were expanded in the presence of IL-2 and IL-7 either from bulk culture with exposure of two different peptide pools (IE1 and pp65) or after selection via IFN-γ secretion by stimulation with pp65. CMV specific immune responses were assessed by using multiparameter flow cytometry staining cells for CD3, CD4, CD8, CCR7 and CD45RA and for the cytokines IFN-γ IL-2 and TNF at day 0 and after 10 days of in vitro expansion. Results Similar frequencies of cytokine-producing pp65– and IE1-specific CD4+ and CD8+ T cells were found in unmanipulated paired PB and BM samples. Expansion of CMV-specific T cells from BM resulted in significantly higher frequencies of specific CD4+ T cells than from PB, whereas no difference in frequencies of CMV-specific CD8+ T cells was observed. Interestingly, significantly higher frequencies of BM pp65 and IE1-specific CD4+ T cells were multifunctional, characterized by producing simultaneously IFN-γ, TNF and IL-2 (IE1: BM mean 0.44% ± 0.16; PB mean 0.09% ± 0.05, p=0.031; pp65: BM mean 3.87% ± 2.46; PB mean 1.24% ± 0.90, p=0.031). Expansion of multi-functional CD4+ T cells from BM was observed with both the bulk and selection assay protocol. Both PB and BM CMV-specific CD4+ and CD8+ T cell lines had a predominant CD45RA-CCR7- effector memory phenotype. Conclusions This study implicates the use of human bone marrow as a source for expansion of multifunctional CMV-specific CD4+ T cells. Recent studies in HIV and Leishmania support the crucial role of multifunctional T cells in disease control (Darrah 2007 [2]).

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Transgenic CD8αβ co-receptor rescues endogenous TCR function in TCR-transgenic virus-specific T cells

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-001487 ◽

2020 ◽

Vol 8 (2) ◽

pp. e001487

Author(s):

Gagan Bajwa ◽

Inès Lanz ◽

Mara Cardenas ◽

Malcolm K Brenner ◽

Caroline Arber

Keyword(s):

T Cells ◽

T Cell ◽

Cell Therapy ◽

Intracellular Cytokine Staining ◽

Hematopoietic Stem ◽

Cytotoxicity Assays ◽

Viral Activity ◽

Ifn Γ

BackgroundGenetically engineered virus-specific T cells (VSTs) are a platform for adoptive cell therapy after allogeneic hematopoietic stem cell transplantation. However, redirection to a tumor-associated antigen by the introduction of a transgenic T-cell receptor (TCR) reduces anti-viral activity, thereby impeding the possibility of preventing or treating two distinct complications—malignant relapse and viral infection—with a single cell therapy product. Availability of CD8αβ co-receptor molecules can significantly impact class I restricted T-cell activation, and thus, we interrogated whether transgenic CD8αβ improves anti-viral activity mediated by native VSTs with or without a co-expressed transgenic TCR (TCR8).MethodsOur existing clinical VST manufacturing platform was adapted and validated to engineer TCR+ or TCR8+ VSTs targeting cytomegalovirus and Epstein-Barr virus. Simultaneous anti-viral and anti-tumor function of engineered VSTs was assessed in vitro and in vivo. We used pentamer staining, interferon (IFN)-γ enzyme-linked immunospot (ELISpot), intracellular cytokine staining (ICS), cytotoxicity assays, co-cultures, and cytokine secretion assays for the in vitro characterization. The in vivo anti-tumor function was assessed in a leukemia xenograft mouse model.ResultsBoth transgenic CD8αβ alone and TCR8 had significant impact on the anti-viral function of engineered VSTs, and TCR8+ VSTs had comparable anti-viral activity as non-engineered VSTs as determined by IFN-γ ELISpot, ICS and cytotoxicity assays. TCR8-engineered VSTs had improved anti-tumor function and greater effector cytokine production in vitro, as well as enhanced anti-tumor function against leukemia xenografts in mice.ConclusionIncorporation of transgenic CD8αβ into vectors for TCR-targetable antigens preserves anti-viral activity of TCR transgenic VSTs while simultaneously supporting tumor-directed activity mediated by a transgenic TCR. Our approach may provide clinical benefit in preventing and treating viral infections and malignant relapse post-transplant.

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158 Inhibition of PI3Kδ improves tumor specific T cell immunity and metabolic fitness

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0158 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A172-A172

Author(s):

Guillermo Rangel Rivera ◽

Guillermo Rangel RIvera ◽

Connor Dwyer ◽

Dimitrios Arhontoulis ◽

Hannah Knochelmann ◽

...

Keyword(s):

T Cells ◽

Cell Differentiation ◽

T Cell ◽

Cell Therapy ◽

Tumor Immunity ◽

Mitochondrial Function ◽

T Cell Differentiation ◽

Tumor Control ◽

T Cell Therapy

BackgroundDurable responses have been observed with adoptive T cell therapy (ACT) in some patients. However, current protocols used to expand T cells often exhibit suboptimal tumor control. Failure in these therapies has been attributed to premature differentiation and impaired metabolism of the infused T cells. Previous work done in our lab showed that reduced PI3Kδ signaling improved ACT. Because PI3Kγ and PI3Kδ have critical regulatory roles in T cell differentiation and function, we tested whether inhibiting PI3Kγ could recapitulate or synergize PI3Kδ blockade.MethodsTo test this, we primed melanoma specific CD8+ pmel-1 T cells, which are specific to the glycoprotein 100 epitope, in the presence of PI3Kγ (IPI-459), PI3Kδ (CAL101 or TGR-1202) or PI3Kγ/δ (IPI-145) inhibitors following antigen stimulation with hgp100, and then infused them into 5Gy total body irradiated B16F10 tumor bearing mice. We characterized the phenotype of the transferred product by flow cytometry and then assessed their tumor control by measuring the tumor area every other day with clippers. For metabolic assays we utilized the 2-NBDG glucose uptake dye and the real time energy flux analysis by seahorse.ResultsSole inhibition of PI3Kδ or PI3Kγ in vitro promoted greater tumor immunity and survival compared to dual inhibition. To understand how PI3Kδ or PI3Kγ blockade improved T cell therapy, we assessed their phenotype. CAL101 treatment produced more CD62LhiCD44lo T cells compared to IPI-459, while TGR-1202 enriched mostly CD62LhiCD44hi T cells. Because decreased T cell differentiation is associated with mitochondrial metabolism, we focused on CAL101 treated T cells to study their metabolism. We found that CAL101 decreased glucose uptake and increased mitochondrial respiration in vitro, indicating augmented mitochondrial function.ConclusionsThese findings indicate that blocking PI3Kδ is sufficient to mediate lasting tumor immunity of adoptively transferred T cells by preventing premature differentiation and improving mitochondrial fitness. Our data suggest that addition of CAL101 to ACT expansion protocols could greatly improve T cell therapies for solid tumors by preventing T cell differentiation and improving mitochondrial function.

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Gamma Interferon Production, but Not Perforin-Mediated Cytolytic Activity, of T Cells Is Required for Prevention of Toxoplasmic Encephalitis in BALB/c Mice Genetically Resistant to the Disease

Infection and Immunity ◽

10.1128/iai.72.8.4432-4438.2004 ◽

2004 ◽

Vol 72 (8) ◽

pp. 4432-4438 ◽

Cited By ~ 52

Author(s):

Xisheng Wang ◽

Hoil Kang ◽

Takane Kikuchi ◽

Yasuhiro Suzuki

Keyword(s):

T Cells ◽

T Cell ◽

Nude Mice ◽

Genetic Resistance ◽

Cytolytic Activity ◽

Gamma Interferon ◽

Toxoplasmic Encephalitis ◽

Wild Type ◽

Ifn Γ

ABSTRACT We previously showed the requirement of both T cells and gamma interferon (IFN-γ)-producing non-T cells for the genetic resistance of BALB/c mice to the development of toxoplasmic encephalitis (TE). In order to define the role of IFN-γ production and the perforin-mediated cytotoxicity of T cells in this resistance, we obtained immune T cells from spleens of infected IFN-γ knockout (IFN-γ−/−), perforin knockout (PO), and wild-type BALB/c mice and transferred them into infected and sulfadiazine-treated athymic nude mice, which lack T cells but have IFN-γ-producing non-T cells. Control nude mice that had not received any T cells developed severe TE and died after discontinuation of sulfadiazine treatment due to the reactivation of infection. Animals that had received immune T cells from either wild-type or PO mice did not develop TE and survived. In contrast, nude mice that had received immune T cells from IFN-γ−/− mice developed severe TE and died as early as control nude mice. T cells obtained from the spleens of animals that had received either PO or wild-type T cells produced large amounts of IFN-γ after stimulation with Toxoplasma gondii antigens in vitro. In addition, the amounts of IFN-γ mRNA expressed in the brains of PO T-cell recipients did not differ from those in wild-type T-cell recipients. Furthermore, PO mice did not develop TE after infection, and their IFN-γ production was equivalent to or higher than that of wild-type animals. These results indicate that IFN-γ production, but not perforin-mediated cytotoxic activity, by T cells is required for the prevention of TE in genetically resistant BALB/c mice.

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PD-1 dependent expansion of Amphregulin+FOXP3+ cells is associated with oral immune dysfunction in HIV patients on therapy

10.1101/2021.03.13.435273 ◽

2021 ◽

Author(s):

N Bhaskaran ◽

E Schneider ◽

F Faddoul ◽

A Paes da Silva ◽

R Asaad ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Oral Mucosa ◽

Immune Dysfunction ◽

People Living With Hiv ◽

Dependent Manner ◽

Mucosal Tissues ◽

T Cell Regulation ◽

Ifn Γ

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

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P01.02 TLR-mediated suppression of the CCL22-CCR4 axis as a new target for tumor immunotherapy

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-itoc8.6 ◽

2021 ◽

Vol 9 (Suppl 1) ◽

pp. A3.2-A4

Author(s):

J Grün ◽

I Piseddu ◽

C Perleberg ◽

N Röhrle ◽

S Endres ◽

...

Keyword(s):

T Cells ◽

Dendritic Cells ◽

T Cell ◽

B Cells ◽

Regulatory T Cells ◽

Type I ◽

List Type ◽

Gm Csf

BackgroundUnmethylated CpG-DNA is a potent ligand for the endosomal Toll-like-receptor-9, important for the immune activation to pathogen-associated molecules.1 CpG and other TLR-ligands show effective immunotherapeutic capacities in cancer treatment by inducing an antitumorigenic immunity.2 They are able to reduce tumor progression by reduction of intratumoral secretion of the immunoregulating chemokine CCL223 and subsequent recruitment of immunosuppressive regulatory T cells (Treg), which express CCR4 the only so far known receptor for CCL22.4 Our recent work has shown that CCL22 secretion by dendritic cells (DC) in the lymph node, mediates tolerance by inducing DC-Treg contacts.5 Indeed, in the absence of CCL22, immune responses to vaccination were stronger and resulted in tumor rejection.6 Therefore, we are aiming to investigate the effects of TLR-ligands on systemic CCL22 levels, elucidating all involved mechanisms to identify new targets for cancer immunotherapy.Materials and MethodsT, B and CD11c+ DCs of wildtype (wt) and RAG1-/- mice were isolated from splenocytes by magnetic-activated cell sorting for in vitro assays. Different co-cultures were incubated with CpG and GM-CSF, known as an CCL22 inducer.5 For in vivo experiments, wt mice were treated with CpG, R484 or poly(I:C) alone and in combination with GM-CSF. CCL22-levels in a number of organs were analyzed.ResultsAnalyzing the different immune cell compartments in vitro, we found that DCs in whole splenocytes secrete CCL22 during culture while DC cultured alone showed no CCL22 secretion. When treated with CpG, CCL22-levels were reduced in splenocytes, while it was induced in DC culture alone. The same results were seen when RAG splenocytes, that lack functional B and T cells, were cultured with CpG. CpG treated B cells were able to suppress CCL22 secretion by DC unlike T cells alone. Co-cultures of T and B cells treated with CpG, however, induced the strongest CCL22 suppression in DC. In vivo, we could show that all TLR ligands tested reduced CCL22 in a number of organs significantly. Furthermore, CpG showed the strongest suppression of CCL22 even in the presence of the CCL22 inducer GM-CSF.5ConclusionsWe could show that B cells with T cells mediate CCL22 suppression by TLR ligands. The fact that CpG was able to reduce CCL22 levels even in the presence of the inducer GM-CSF demonstrates the potent CCL22 suppressive capacity of TLR ligands.ReferencesO’Neill LA, et al. The history of toll-like receptors – redefining innate immunity. Nat Rev Immunol 2013;13(6):453–60.Rothenfusser S, et al. Recent advances in immunostimulatory CpG oligonucleotides. Curr Opin Mol Ther 2003;5(2):98–106.Wang S, et al. Intratumoral injection of a CpG oligonucleotide reverts resistance to PD-1 blockade by expanding multifunctional CD8+ T cells. Proc Natl Acad Sci U S A 2016;113(46): E7240–E7249.Rapp M, et al. CCL22 controls immunity by promoting regulatory T cell communication with dendritic cells in lymph nodes. J Exp Med 2019;216(5):1170–1181.Piseddu I, et al. Constitutive expression of CCL22 is mediated by T cell-derived GM-CSF. J Immunol 2020;205(8):2056–2065.Anz D, et al. Suppression of intratumoral CCL22 by type i interferon inhibits migration of regulatory T cells and blocks cancer progression. Cancer Res 2015;75(21):4483–93.Disclosure InformationJ. Grün: None. I. Piseddu: None. C. Perleberg: None. N. Röhrle: None. S. Endres: None. D. Anz: None.

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124 Functionalizing CAR T cells for selective proliferation and dual-targeting using the meditope technology

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.124 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A133-A133

Author(s):

Cheng-Fu Kuo ◽

Yi-Chiu Kuo ◽

Miso Park ◽

Zhen Tong ◽

Brenda Aguilar ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Therapy ◽

T Cell Therapy ◽

Car T Cells ◽

Car T Cell ◽

Car T Cell Therapy ◽

Car T

BackgroundMeditope is a small cyclic peptide that was identified to bind to cetuximab within the Fab region. The meditope binding site can be grafted onto any Fab framework, creating a platform to uniquely and specifically target monoclonal antibodies. Here we demonstrate that the meditope binding site can be grafted onto chimeric antigen receptors (CARs) and utilized to regulate and extend CAR T cell function. We demonstrate that the platform can be used to overcome key barriers to CAR T cell therapy, including T cell exhaustion and antigen escape.MethodsMeditope-enabled CARs (meCARs) were generated by amino acid substitutions to create binding sites for meditope peptide (meP) within the Fab tumor targeting domain of the CAR. meCAR expression was validated by anti-Fc FITC or meP-Alexa 647 probes. In vitro and in vivo assays were performed and compared to standard scFv CAR T cells. For meCAR T cell proliferation and dual-targeting assays, the meditope peptide (meP) was conjugated to recombinant human IL15 fused to the CD215 sushi domain (meP-IL15:sushi) and anti-CD20 monoclonal antibody rituximab (meP-rituximab).ResultsWe generated meCAR T cells targeting HER2, CD19 and HER1/3 and demonstrate the selective specific binding of the meditope peptide along with potent meCAR T cell effector function. We next demonstrated the utility of a meP-IL15:sushi for enhancing meCAR T cell proliferation in vitro and in vivo. Proliferation and persistence of meCAR T cells was dose dependent, establishing the ability to regulate CAR T cell expansion using the meditope platform. We also demonstrate the ability to redirect meCAR T cells tumor killing using meP-antibody adaptors. As proof-of-concept, meHER2-CAR T cells were redirected to target CD20+ Raji tumors, establishing the potential of the meditope platform to alter the CAR specificity and overcome tumor heterogeneity.ConclusionsOur studies show the utility of the meCAR platform for overcoming key challenges for CAR T cell therapy by specifically regulating CAR T cell functionality. Specifically, the meP-IL15:sushi enhanced meCAR T cell persistence and proliferation following adoptive transfer in vivo and protects against T cell exhaustion. Further, meP-ritiuximab can redirect meCAR T cells to target CD20-tumors, showing the versatility of this platform to address the tumor antigen escape variants. Future studies are focused on conferring additional ‘add-on’ functionalities to meCAR T cells to potentiate the therapeutic effectiveness of CAR T cell therapy.

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