Treatment with lentiviral vectors encoding shRNA against interleukin 10 modulates the immunosuppressive activity of murine colon carcinoma-associated myeloid-derived suppressor cells

FoxO1 Deficiency in Monocytic Myeloid-Derived Suppressor Cells Exacerbates B Cell Dysfunction in Systemic Lupus Erythematosus

OBJECTIVE

Myeloid-derived suppressor cells (MDSCs) contribute to the pathogenesis of systemic lupus erythematosus (SLE), in part due to promoting the survival of plasma cells. FoxO1 expression in monocytic MDSCs (M-MDSCs) exhibits a negative correlation with the SLE Disease Activity Index score. This study aimed to investigate the hypothesis that M-MDSC-specific FoxO1 deficiency enhances aberrant B cell function in aggressive SLE.

METHODS

We used GEO data sets and clinical cohorts to verify the clinical significance of FoxO1 expression and circulating M-MDSCs. Using Cre-LoxP technology, we generated myeloid FoxO1 deficiency mice (mFoxO1-/-) to establish murine lupus-prone models. The transcriptional stage was assessed by integrating chromatin immunoprecipitation (ChIP)-sequencing with transcriptomic analysis, luciferase reporter assay, and ChIP-quantitative polymerase chain reaction. Methylated RNA immunoprecipitation sequencing, RNA sequencing, and CRISPR-dCas9 were used to identify N6-adenosine methylation (m6A) modification. In vitro B cell coculture experiments, capmatinib intragastric administration, m6A-modulated MDSCs adoptive transfer, and sample validation of patients with SLE were performed to determine the role of FoxO1 on M-MDSCs dysregulation during B cell autoreacted with SLE.

RESULTS

We present evidence that low FoxO1 is predominantly expressed in M-MDSCs in both patients with SLE and lupus mice, and mice with myeloid FoxO1 deficiency (mFoxO1-/-) are more prone to B cell dysfunction. Mechanically, FoxO1 inhibits mesenchymal-epithelial transition factor protein (Met) transcription by binding to the promoter region. M-MDSCs FoxO1 deficiency blocks the Met/cyclooxygenase2/prostaglandin E2 secretion pathway, promoting B cell proliferation and hyperactivation. The Met antagonist capmatinib effectively mitigates lupus exacerbation. Furthermore, alkB homolog 5 (ALKBH5) targeting catalyzes m6A modification on FoxO1 messenger RNA in coding sequences and 3' untranslated regions. The up-regulation of FoxO1 mediated by ALKBH5 overexpression in M-MDSCs improves lupus progression. Finally, these correlations were confirmed in untreated patients with SLE.

CONCLUSION

Our findings indicate that effective inhibition of B cells mediated by the ALKBH5/FoxO1/Met axis in M-MDSCs could offer a novel therapeutic approach to manage SLE.

Advances in Engineering Myeloid Cells for Cell Therapy Applications

Myeloid cells, including macrophages, neutrophils, dendritic cells, and myeloid-derived suppressor cells, play crucial roles in the innate immune system, contributing to immune defense, tissue homeostasis, and organ development. They have tremendous potential as therapeutic tools for diseases such as cancer and autoimmune disorders, but harnessing cell engineering strategies to enhance potency and expand applications is challenging. Recent advancements in stem cell research have made it possible to differentiate human embryonic stem cells and induce pluripotent stem cells into various cell types, including myeloid cells, offering a promising new approach to generate myeloid cells for cell therapy. In this review, we explore the latest techniques for the genetic engineering of myeloid cells, discussing both established and emerging methodologies. We examine the challenges faced in this field and the therapeutic potential of engineered myeloid cells. We also describe examples of engineered macrophages, neutrophils, and dendritic cells in various disease contexts. By providing a detailed overview of the current state and future directions, we aim to highlight progress and ongoing efforts toward harnessing the full therapeutic potential of genetically engineered myeloid cells.

PD1-Targeted Transgene Delivery to Treg Cells

Achieving the precise targeting of lentiviral vectors (LVs) to specific cell populations is crucial for effective gene therapy, particularly in cancer treatment where the modulation of the tumor microenvironment can enhance anti-tumor immunity. Programmed cell death protein 1 (PD-1) is overexpressed on activated tumor-infiltrating T lymphocytes, including regulatory T cells that suppress immune responses via FOXP3 expression. We developed PD1-targeted LVs by incorporating the anti-PD1 nanobody nb102c3 into receptor-blinded measles virus H and VSV-Gmut glycoproteins. We assessed the retargeting potential of nb102c3 and evaluated transduction efficiency in activated T lymphocytes. FOXP3 expression was suppressed using shRNA delivered by these LVs. Our results demonstrate that PD1-targeted LVs exerted pronounced tropism towards PD1+ cells, enabling the selective transduction of activated T lymphocytes while sparing naive T cells. The suppression of FOXP3 in Tregs reduced their suppressive activity. PD1-targeted glycoprotein H provided greater specificity, whereas the VSV-Gmut, together with the anti-PD1 pseudoreceptor, achieved higher viral titers but was less selective. Our study demonstrates that PD1-targeted LVs may offer a novel strategy to modulate immune responses within the tumor microenvironment with the potential for developing new therapeutic strategies aimed at enhancing anti-tumor immunity.

Inhibition of MC38 colon cancer growth by multicomponent chemoimmunotherapy with anti-IL-10R antibodies, HES-MTX nanoconjugate, depends on application of IL-12, IL-15 or IL-18 secreting dendritic cell vaccines

Background

The tumor microenvironment (TME) provides a conducive environment for the growth and survival of tumors. Negative factors present in TME, such as IL-10, may limit the effectiveness of cellular vaccines based on dendritic cells, therefore, it is important to control its effect. The influence of IL-10 on immune cells can be abolished e.g., by using antibodies against the receptor for this cytokine - anti-IL-10R. Furthermore, the anticancer activity of cellular vaccines can be enhanced by modifying them to produce proinflammatory cytokines, such as IL-12, IL-15 or IL-18. Additionally, an immunomodulatory dose of methotrexate and hydroxyethyl starch (HES-MTX) nanoconjugate may stimulate effector immune cells and eliminate regulatory T cells, which should enhance the antitumor action of immunotherapy based on DC vaccines. The main aim of our study was to determine whether the HES-MTX administered before immunotherapy with anti-IL-10R antibodies would change the effect of vaccines based on dendritic cells overproducing IL-12, IL-15, or IL-18.

Methods

The activity of modified DCs was checked in two therapeutic protocols - immunotherapy with the addition of anti-IL10R antibodies and chemoimmunotherapy with HES-MTX and anti-IL10R antibodies. The inhibition of tumor growth and the effectiveness of the therapy in inducing a specific antitumor response were determined by analyzing lymphoid and myeloid cell populations in tumor nodules, and the activity of restimulated splenocytes.

Results and conclusions

Using the HES-MTX nanoconjugate before immunotherapy based on multiple administrations of anti-IL-10R antibodies and cellular vaccines capable of overproducing proinflammatory cytokines IL-12, IL-15 or IL-18 created optimal conditions for the effective action of these vaccines in murine colon carcinoma MC38 model. The applied chemoimmunotherapy caused the highest inhibition of tumor growth in the group receiving DC/IL-15/IL-15Rα/TAg + DC/IL-18/TAg at the level of 72.4%. The use of cellular vaccines resulted in cytotoxic activity increase in both immuno- or chemoimmunotherapy. However, the greatest potential was observed both in tumor tissue and splenocytes obtained from mice receiving two- or three-component vaccines in the course of combined application. Thus, the designed treatment schedule may be promising in anticancer therapy.

MDSCs might be "Achilles heel" for eradicating CSCs

During tumor initiation and progression, the complicated role of immune cells in the tumor immune microenvironment remains a concern. Myeloid-derived suppressor cells (MDSCs) are a group of immune cells that originate from the bone marrow and have immunosuppressive potency in various diseases, including cancer. In recent years, the key role of cancer stemness has received increasing attention in cancer development and therapy. Several studies have demonstrated the important regulatory relationship between MDSCs and cancer stem cells (CSCs). However, there is still no clear understanding regarding the complex interacting regulation of tumor malignancy, and current research progress is limited. In this review, we summarize the complicated role of MDSCs in the modulation of cancer stemness, evaluate the mechanism of the relationship between CSCs and MDSCs, and discuss potential strategies for eradicating CSCs with respect to MDSCs.

The GDF11 Promotes Nerve Regeneration After Sciatic Nerve Injury in Adult Rats by Promoting Axon Growth and Inhibiting Neuronal Apoptosis

Introduction: Sciatic nerve injury is a common injury of the nervous system. Stem cell-based therapies, drug-based therapies and rehabilitation physiotherapy therapies are currently available, but their limited therapeutic efficacy limits their use. Here, we aimed to explore a novel lentiviral-based gene therapeutic strategy and to elaborate its mechanism.

Materials and Methods: Recombinant GDF11 protein was used for the in vitro treatment of dorsal root ganglion (DRG) cells. Lentivirus was used to construct a vector system for the in vivo expression of GDF11. The nerve conduction function was detected using action-evoked potentials at different time periods, and the regulatory effect of nerves on target organs was detected by weighing the gastrocnemius muscle. Immunofluorescence of NF200 and S100 was used to show the regeneration of the sciatic nerve, and myelin and Nissl staining were performed to observe the pathological features of the tissue. Western was used to validate signaling pathways. The expression of related genes was observed by qPCR and Western blotting, and cell apoptosis was detected by flow cytometry.

Result: GDF11 promotes the axonal growth of DRG cells and inhibits DGR cell apoptosis in vitro. GDF11 acts by activating the Smad pathway. GDF11 promotes the recovery of damaged sciatic nerve function in rats, the regeneration of damaged sciatic nerves in rats, and myelin regeneration of damaged sciatic nerves in rats. GDF11 also exerts a protective effect on neuronal cells in rats.

Conclusion: Based on the present study, we conclude that GDF11 promotes axonal growth and inhibits DRG cell apoptosis in vitro through the Smad pathway, and lentivirus-mediated GDF11 overexpression in vivo can promote the recovery of sciatic nerves after transection by promoting axonal growth and inhibiting neuronal apoptosis in the spinal cord.