607 Regional delivery of a TLR9 agonist to boost checkpoint inhibitor responsiveness in liver metastases

BackgroundClass C TLR9 agonists, CpG oligodeoxynucleotides (ODNs) enhance responsiveness to anti-PD1 therapy in solid tumors through favorable modulation of the tumor microenvironment (TME) [1]. Recently, we reported that regional delivery of a TLR9 agonist eliminated myeloid derived suppressor cells (MDSC) and promoted pro-inflammatory/anti-tumorigenic M1 macrophage programming in the TME of liver metastases (LM) [2]. Further, we found enhanced TLR9 activation in LM following regional TLR9 agonist infusion compared to the systemic treatment. We hypothesize that regional delivery of a TLR9A into LM will enhance the responsiveness to systemically infused anti-PD1 therapy.MethodsIn this study, we treated mice with established MC38-CEA-Luc LM with ODN-2395 (30µg/mouse) regionally with or without anti PD-1 antibody (250µg/mouse) intraperitoneally.ResultsControl of LM growth (Figure 1) was significantly higher with combinatorial treatment as compared to anti-PD1 (p<0.01) or PBS treatments (p<0.05). To study the impact of TLR9 activation on human MDSC, we treated healthy donor PBMCs with ODN-2395 or SD101. We found that both reduced the hu-MDSC (CD11b+CD33+HLADR-) population in a dose-dependent manner with an increase in PD-L1 expression as determined by flow cytometry (FC) analysis (Figure 2). Moreover, by using Luminex, demonstrated that ODN-2395 and SD101 enhanced expression of IL 29, IFNα, and NFκB, along with downstream cytokines IL 6 and IL 10. To investigate the effect of SD101 in modulating the differentiation of huMDSC from huPBMC, we treated huPBMC with IL6+GM-CSF in the presence or absence of SD101. By FC analysis, we found that SD-101 blocked huMDSC development induced by IL6+GM-CSF, preferentially limited the more immunosuppressive monocytic MDSC subtype, and drove M1 macrophage polarization. Treatment of SD101 only once for 48hrs was sufficient to inhibit huMDSC differentiation for two weeks.Abstract 607 Figure 1Combinatorial treatment of CPI and ODN’s reduces tPV = portal vein; IP = intraperitoneal.Eight to twelve weeks old male C57/BL6 mice were challenged intra-splenic with 0.5e6 MC38-CEA-Luc cells for a week. Bioluminescence value was determined by IVIS on D0, and mice were randomized accordingly and treated with 30 µg/mouse ODN2395 via PV with or without 250 µg/mouse anti-PD1 antibody via IP on D0, D+3 and D+6. PBS served as the vehicle (Veh) control and administered via PV. Fold change of the tumor burden was calculated based on D0 baseline bioluminescence. Tumor progression was analyzed unpaired t test among groups. (*p <0.05).Abstract 607 Figure 2Human PBMC treated with ODN2395 and SD101 reducesCtrl = control; MDSC = ODN = oligodeoxynucleotide’ PBMC = peripheral blood monocytes.Human PBMC were isolated from the Leukoreduction system chamber. 1e6/ml PBMCs were treated with increasing concentrations (0.04–10 µM) SD101, ODN2395 along with ctrl ODN5328 (1µM) for 48 hours. Panels A and B: MDSC population and their corresponding PD–L1 expression were evaluated (n=12). Four donors with three replicates were used. Data represented as mean ± SEM.ConclusionsBoth the in vitro and in vivo findings suggest that regional TLR9 stimulation in a model of LM improves responsiveness to systemic anti-PD-1 therapy through elimination of MDSC, and the effect on huMDSC was confirmed in vitro. Increased PDL-1 expression in response to TLR9 stimulation among MDSC may further enhance the anti-PD-1 effect. Therefore, combing regional infusions of a TLR9 agonist with systemic anti-PD-1 agents may be a promising approach for liver tumor treatment.ReferencesWang, 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): p. E7240-E7249.Ghosh CC, H.K., O’Connell K, Laporte J, Guha P, Cox B, Jaroch D, Katz SC, Regional administration of class C CpG Oligodeoxynucleotides results in superior intrahepatic TLR9 activation and immunomodulation compared to systemic infusion, Abstract: AACR Annual Meeting. 2021.

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Phosphate-modified CpG oligonucleotides induce in vitro maturation of human myeloid dendritic cells

Vavilov Journal of Genetics and Breeding ◽

10.18699/vj20.659 ◽

2020 ◽

Vol 24 (6) ◽

pp. 653-660

Author(s):

A. A. Ostanin ◽

O. Y. Leplina ◽

E. A. Burakova ◽

T. V. Tyrinova ◽

A. A. Fokina ◽

...

Keyword(s):

Dendritic Cells ◽

Cpg Odn ◽

Blood Monocytes ◽

Myeloid Dendritic Cells ◽

Gm Csf ◽

Cpg Oligodeoxynucleotides ◽

Cpg Oligonucleotides ◽

Cpg Odns ◽

Dc Maturation

Myeloid dendritic cells (DCs) play an important role in the immune response; therefore, the search for compounds that can effectively activate DCs is a needful goal. This study was aimed to investigate the effect of synthetic CpG oligodeoxynucleotides (CpG-ODN) on the maturation and allostimulatory activity of myeloid DCs in comparison with other PAMP and DAMP molecules. For the research, we synthesized known CpG-ODN class C (SD-101 and D-SL03) containing thiophosphate internucleotide groups, and their original phosphate-modified analogues (SD-101M and D-SL03M) with mesylphosphoramide internucleotide groups (M = μ-modification). The effects of CpG-ODN and other activators were evaluated on DCs generated from blood monocytes in the presence of GM-CSF and IFN-α (IFN-DC) or IL-4 (IL4-DC). Evaluation of the intracellular TLR-9 expression showed that both types of DCs (IFN-DC and IL4-DC) contained on average 52 and 80 % of TLR-9-positive cells, respectively. The CpG-ODNs studied enhanced the allostimulatory activity of IFN-DCs, and the effect of μ-modified CpG-ODNs was higher than that of CpG-ODNs with thiophosphate groups. The stimulating effect of CpG-ODN at a dose of 1.0 μg/ml was comparable (for D-SL03, D-SL03M, SD-101) with or exceeded (for SD-101M) the effect of LPS at a dose of 10 μg/ml. At the same time, IFN-DCs were characterized by greater sensitivity to the action of CpG-ODNs than IL4-DCs. The enhancement of DC allostimulatory activity in the presence of CpG-ODNs was associated with the induction of final DC maturation, which was confirmed by a significant decrease in the number of CD14+DC, an increase in mature CD83+DC and a trend towards an increase in CD86+DC. Interestingly, the characteristic ability of LPS to enhance the expression of the co-stimulatory molecule OX40L on DCs was revealed only for the μ-analogue SD-101M. In addition, CpG-ODNs (SD-101 and SD-101M) had a stimulatory effect on IFN-γ production comparable to the action of LPS. The data obtained indicate a stimulating effect of CpG-ODN on the maturation and allostimulatory activity of human myeloid DCs, which is more pronounced for μ-modified analogs.

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Macrophages Impair TLR9 Agonist Antitumor Activity through Interacting with the Anti-PD-1 Antibody Fc Domain

Cancers ◽

10.3390/cancers13164081 ◽

2021 ◽

Vol 13 (16) ◽

pp. 4081

Author(s):

Simone Camelliti ◽

Valentino Le Noci ◽

Francesca Bianchi ◽

Chiara Storti ◽

Francesca Arnaboldi ◽

...

Keyword(s):

Innate Immunity ◽

Antitumor Activity ◽

Immune Cells ◽

Polarization State ◽

Antibody Fragment ◽

Tlr9 Agonist ◽

Cpg Oligodeoxynucleotides ◽

Immunocompetent Mice

Background. A combination of TLR9 agonists and an anti-PD-1 antibody has been reported to be effective in immunocompetent mice but the role of innate immunity has not yet been completely elucidated. Therefore, we investigated the contribution of the innate immune system to this combinatorial immunotherapeutic regimens using an immunodeficient mouse model in which the effector functions of innate immunity can clearly emerge without any interference from T lymphocytes. Methods. Athymic mice xenografted with IGROV-1 human ovarian cells, reported to be sensitive to TLR9 agonist therapy, were treated with cytosine–guanine (CpG)-oligodeoxynucleotides (ODNs), an anti-PD-1 antibody or their combination. Results. We found that PD-1 blockade dampened CpG-ODN antitumor activity. In vitro studies indicated that the interaction between the anti-PD-1 antibody fragment crystallizable (Fc) domain and macrophage Fc receptors caused these immune cells to acquire an immunoregulatory phenotype, contributing to a decrease in the efficacy of CpG-ODNs. Accordingly, in vivo macrophage depletion abrogated the detrimental effect exerted by the anti-PD-1 antibody. Conclusion. Our data suggest that if TLR signaling is active in macrophages, coadministration of an anti-PD-1 antibody can reprogram these immune cells towards a polarization state able to negatively affect the immune response and eventually promote tumor growth.

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Towards adoptive transfer of human MS into rhesus monkeys: Inhibition of the cellular immune response of rhesus monkeys to human PBMC in vitro by humanised antibodies against the IL-2 receptor α-chain

Immunology Letters ◽

10.1016/s0165-2478(97)88103-5 ◽

1997 ◽

Vol 56 (1-3) ◽

pp. 313

Author(s):

H Brok

Keyword(s):

Immune Response ◽

Adoptive Transfer ◽

Cellular Immune Response ◽

Rhesus Monkeys ◽

Human Pbmc ◽

Α Chain ◽

Cellular Immune

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Reprogrammed M1 macrophages with inhibited STAT3, STAT6 and/or SMAD3 extends lifespan of mice with experimental carcinoma

ZHurnal «Patologicheskaia fiziologiia i eksperimental`naia terapiia» ◽

10.25557/0031-2991.2017.02.4-9 ◽

2017 ◽

pp. 4-9

Author(s):

С.В. Калиш ◽

С.В. Лямина ◽

А.А. Раецкая ◽

И.Ю. Малышев

Keyword(s):

Tumor Growth ◽

Culture Medium ◽

Ehrlich Carcinoma ◽

Macrophage Phenotype ◽

M1 Macrophages ◽

M1 Macrophage ◽

Ec Cells ◽

Experimental Carcinoma

Цель исследования. Репрограммирование М1 фенотипа макрофагов с ингибированными факторами транскрипции М2 фенотипа STAT3, STAТ6 и SMAD и оценка их влияния на развитие карциномы Эрлиха (КЭ) in vitro и in vivo. Методика. Рост опухоли иницировали in vitro путем добавления клеток КЭ в среду культивирования RPMI-1640 и in vivo путем внутрибрюшинной инъекции клеток КЭ мышам. Результаты. Установлено, что M1макрофаги и in vitro, и in vivo оказывают выраженный противоопухолевый эффект, который превосходит антиопухолевые эффекты М1, M1, M1 макрофагов и цисплатина. Заключение. М1 макрофаги с ингибированными STAT3, STAT6 и/или SMAD3 эффективно ограничивают рост опухоли. Полученные данные обосновывают разработку новой технологии противоопухолевой клеточной терапии. Objective. Reprogramming of M1 macrophage phenotype with inhibited M2 phenotype transcription factors, such as STAT3, STAT6 and SMAD and assess their impact on the development of Ehrlich carcinoma (EC) in vitro and in vivo . Methods. Tumor growth in vitro was initiated by addition of EC cells in RPMI-1640 culture medium and in vivo by intraperitoneal of EC cell injection into mice. Results. It was found that M1 macrophages have a pronounced anti-tumor effect in vitro , and in vivo , which was greater than anti-tumor effects of M1, M1, M1 macrophages and cisplatin. Conclusion. M1 macrophages with inhibited STAT3, STAT6 and/or SMAD3 effectively restrict tumor growth. The findings justify the development of new anti-tumor cell therapy technology.

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Faculty Opinions recommendation of Defining GM-CSF- and macrophage-CSF-dependent macrophage responses by in vitro models.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.716398013.791803076 ◽

2012 ◽

Author(s):

Peter Murray

Keyword(s):

In Vitro Models ◽

Gm Csf

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Oncolytic peptides DTT-205 and DTT-304 induce complete regression and protective immune response in experimental murine colorectal cancer

Scientific Reports ◽

10.1038/s41598-021-86239-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Karianne Giller Fleten ◽

J. Johannes Eksteen ◽

Brynjar Mauseth ◽

Ketil André Camilio ◽

Terje Vasskog ◽

...

Keyword(s):

Colorectal Cancer ◽

Liver Metastases ◽

Cell Lines ◽

Checkpoint Inhibitors ◽

Inhibitory Effect ◽

Systemic Effect ◽

Intratumoral Injection ◽

Complete Regression ◽

Future Drug

AbstractOncolytic peptides represent a novel, promising cancer treatment strategy with activity in a broad spectrum of cancer entities, including colorectal cancer (CRC). Cancer cells are killed by immunogenic cell death, causing long-lasting anticancer immune responses, a feature of particular interest in non-immunogenic CRC. Oncolytic peptides DTT-205 and DTT-304 were administered by intratumoral injection in subcutaneous tumors established from murine CRC cell lines CT26 and MC38, and complete regression was obtained in the majority of animals. When cured animals were rechallenged by splenic injection of tumor cells, 1/23 animals developed liver metastases, compared to 19/22 naïve animals. Treatment with both peptides was well tolerated, but monitoring post-injection hemodynamic parameters in rats, less extensive changes were observed with DTT-205 than DTT-304, favoring DTT-205 for future drug development. DTT-205 was subsequently shown to have strong in vitro activity in a panel of 33 cancer cell lines. In conclusion, both peptides exerted a strong inhibitory effect in two immunocompetent CRC models and induced a systemic effect preventing development of liver metastases upon splenic rechallenge. If a similar effect could be obtained in humans, these drugs would be of particular interest for combinatory treatment with immune checkpoint inhibitors in metastatic CRC.

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Interleukin-3 is significantly more effective than other colony- stimulating factors in long-term maintenance of human bone marrow- derived colony-forming cells in vitro

Blood ◽

10.1182/blood.v73.7.1836.1836 ◽

1989 ◽

Vol 73 (7) ◽

pp. 1836-1841 ◽

Cited By ~ 13

Author(s):

M Kobayashi ◽

BH Van Leeuwen ◽

S Elsbury ◽

ME Martinson ◽

IG Young ◽

...

Keyword(s):

Bone Marrow ◽

Cultured Cells ◽

Bone Marrow Cells ◽

Human Bone ◽

Human Bone Marrow ◽

Interleukin 3 ◽

Gm Csf ◽

Factor G ◽

Marrow Cells

Abstract Human bone marrow cells cultured for 21 days in the presence of recombinant human interleukin-3 (IL-3) produced up to 28 times more colony-forming cells (CFC) than could be obtained from cultures stimulated with granulocyte colony stimulating factor (G-CSF) or granulocyte-macrophage CSF (GM-CSF). IL-3-cultured cells retained a multipotent response to IL-3 in colony assays but were restricted to formation of granulocyte colonies in G-CSF and granulocyte or macrophage colonies in GM-CSF. Culture of bone marrow cells in IL-3 also led to accumulation of large numbers of eosinophils and basophils. These data contrast with the effects of G-CSF, GM-CSF, and IL-3 in seven-day cultures. Here both GM-CSF and IL-3 amplified total CFC that had similar multipotential colony-forming capability in either factor. G-CSF, on the other hand, depleted IL-3-responsive colony-forming cells dramatically, apparently by causing these cells to mature into granulocytes. The data suggest that a large proportion of IL-3- responsive cells in human bone marrow express receptors for G-CSF and can respond to this factor, the majority becoming neutrophils. Furthermore, the CFC maintained for 21 days in IL-3 may be a functionally distinct population from that produced after seven days culture of bone marrow cells in either IL-3 or GM-CSF.

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Histone lactylation drives oncogenesis by facilitating m6A reader protein YTHDF2 expression in ocular melanoma

Genome Biology ◽

10.1186/s13059-021-02308-z ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Jie Yu ◽

Peiwei Chai ◽

Minyue Xie ◽

Shengfang Ge ◽

Jing Ruan ◽

...

Keyword(s):

Macrophage Polarization ◽

Regulation Of Gene Expression ◽

Metabolic Stress ◽

Ocular Melanoma ◽

Rna Modifications ◽

M1 Macrophage ◽

Melanoma Therapy

Abstract Background Histone lactylation, a metabolic stress-related histone modification, plays an important role in the regulation of gene expression during M1 macrophage polarization. However, the role of histone lactylation in tumorigenesis remains unclear. Results Here, we show histone lactylation is elevated in tumors and is associated with poor prognosis of ocular melanoma. Target correction of aberrant histone lactylation triggers therapeutic efficacy both in vitro and in vivo. Mechanistically, histone lactylation contributes to tumorigenesis by facilitating YTHDF2 expression. Moreover, YTHDF2 recognizes the m6A modified PER1 and TP53 mRNAs and promotes their degradation, which accelerates tumorigenesis of ocular melanoma. Conclusion We reveal the oncogenic role of histone lactylation, thereby providing novel therapeutic targets for ocular melanoma therapy. We also bridge histone modifications with RNA modifications, which provides novel understanding of epigenetic regulation in tumorigenesis.

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