Targeting Inhibition of Foxp3 by MMP2/9 Sensitive Short Peptide Linked P60 Fusion Protein 6(P60-MMPs) to Enhance Antitumor Immunity

Tumor Microenvironment as a Therapeutic Target in Melanoma Treatment

The role of the tumor microenvironment in tumor growth and therapy has recently attracted more attention in research and drug development. The ability of the microenvironment to trigger tumor maintenance, progression, and resistance is the main cause for treatment failure and tumor relapse. Accumulated evidence indicates that the maintenance and progression of tumor cells is determined by components of the microenvironment, which include stromal cells (endothelial cells, fibroblasts, mesenchymal stem cells, and immune cells), extracellular matrix (ECM), and soluble molecules (chemokines, cytokines, growth factors, and extracellular vesicles). As a solid tumor, melanoma is not only a tumor mass of monolithic tumor cells, but it also contains supporting stroma, ECM, and soluble molecules. Melanoma cells are continuously in interaction with the components of the microenvironment. In the present review, we focus on the role of the tumor microenvironment components in the modulation of tumor progression and treatment resistance as well as the impact of the tumor microenvironment as a therapeutic target in melanoma.

MMP11 is associated with the immune response and immune microenvironment in EGFR-mutant lung adenocarcinoma

Background

High expression of matrix metalloproteinase-11 (MMP11) is associated with various tumors and immune microenvironments. Conversely, poor response to immunotherapy in epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma (LUAD) patients is closely related to the characteristics of immune microenvironment.

Methods

The Cancer Genome Atlas (TCGA)-LUAD database and our gathered clinical LUAD samples were used to examine the relationship between MMP11 expression and EGFR mutation. Then the correlation between MMP11 and immune response and the difference of immune cell infiltration in different groups were analyzed. Compared the differences in the immune microenvironment between the MMP11-positive and MMP11-negative expression groups using immunohistochemistry (IHC) and multiplex immunohistochemistry.

Results

The expression of MMP11 in samples with exon 19 deletions, exon 21 L858R or de novo exon 20 T790M mutations was higher than wild type, but there was no difference between the samples with uncommon mutation and the wild-type. The high MMP11 expression group had a higher Tumor Immune Dysfunction and Exclusion (TIDE) score. Pathways associated with enrichment in the extracellular matrix (ECM) were the main biological functions of differential genes between the high and low MMP11 groups. The IHC score of MMP11 in the EGFR-mutant group was higher than in the EGFR-wild group. In TCGA-LUAD, the high MMP11 group had a lower proportion of T cell CD8+ and NK cells activated. In the clinical samples, the infiltration levels of T cell CD8+ and NK cells in the tumor parenchyma of EGFR-mutant LUAD was lower in the MMP11-positive than in the MMP11-negative group. The expression levels of tumor cell PD-L1 were higher in the MMP11-positive expression group than in the MMP11-negative expression group, and the proportion of PD1+CD8+ T cells infiltrated was reduced in the MMP11-positive group compared to the MMP11-negative group.

Conclusions

High expression of MMP11 was associated with EGFR mutations. Patients with EGFR-mutant LUAD with high expression of MMP11 responded poorly to immunotherapy, and the percentage of T cell CD8+ and NK cells in immune cell infiltration was lower in MMP11. Consequently, MMP11 is related to the immunological microenvironment of EGFR-mutant lung adenocarcinoma, which may be a predictor of possible immunotherapeutic response.

Lymph node-targeted neoantigen nanovaccines potentiate anti-tumor immune responses of post-surgical melanoma

Background

Neoantigens are considered ideal targets for immunotherapy, especially tumor vaccine, because of their strong specificity and immunogenicity. Here, we developed a neoantigen nanovaccine used liposomes with lymph-node targeting characteristic.

Methods

Our nanovaccine was composed of neoantigens, an amphiphilic liposome and an adjuvant Montanide™ ISA 51. Small animal imaging system and immunofluorescence staining were used to identify the distribution of nanovaccines. A subcutaneous-tumor-resection mouse model of melanoma was established to evaluate the anti-tumor efficacy. Flow cytometry was performed to assay the immune responses initiated by nanovaccines.

Results

Nanovaccines could traffic to lymph nodes, be uptaken by CD11c⁺ DCs and promote DCs maturity. After the treatment of our neoantigen nanovaccines, the average recurrence time was extended from 11 to 16 days and the median survival time was even prolonged 7.5 days relative to the control group (NS group). Nanovaccines increased neoantigen-specific T cells to 10-fold of free vaccines, and upregulated Th1 cytokines, such as IFN-γ and TNF-α. The anti-tumor activity of spleen lymphocytes in the nanovaccine group was significantly stronger than that of other groups. However, some immune-inhibitory cells or molecules in tumor microenvironment have been detected upregulated under the immune pressure of neoantigen nanovaccines, such as Tregs and PD-L1. The efficacy of the neoantigen nanovaccine combined with anti-PD1 antibody or Treg inhibiting peptide P60 was better than that of the single treatment.

Conclusions

We developed a general vaccine strategy, triggering specific T cell responses, and provided feasible combination strategies for better anti-tumor efficacy.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01397-7.

Polymeric Nanosystems for Immunogenic Cell Death-Based Cancer Immunotherapy

Immunotherapy has pointed out a scientific and promising direction for cancer treatment through the rouse of immunosurveillance and the decrease of possible side effects in recent years. In immunotherapy, immunogenic cancer cell death (ICD) plays a critical role in regulating anti-cancer immune system in vivo via the release of damage-associated molecular patterns. ICD can not only induce in situ cancer cells apoptosis, but also arouse the immune response against metastatic tumors, which is of great clinical significance to eradicate tumors. In cancer immunotherapy, polymer nanoparticles have drawn increasing attention as an important component of ICD-based immunotherapy attributing to their controllable size, excellent biocompatibility, promising ability of protecting cargo from surrounding environment, which delivers the antigens or immune inducers to antigen-presenting cells, and further triggers sinnvoll T cell response. In this review, the recent advances in the development of polymeric material-based nanosystems for ICD-mediated cancer immunotherapy are summarized. The mechanism of ICD and some current restrictions inhibiting the efficiency of immunotherapy and future prospects are also discussed.

Bee venom phospholipase A2 alleviates collagen-induced polyarthritis by inducing Foxp3+ regulatory T cell polarization in mice

The mechanism underlying bee venom (BV) therapy is still controversial, with opinions ranging from constituent-based pharmacological action to homeopathic-like activity. The purpose of this study was to examine whether BV phospholipase A2 (bvPLA2), an enzymatic component of BV, is a novel anti-inflammatory and anti-arthritic mediator capable of stimulating CD25+ Foxp3+ regulatory T cell (Treg) polarization in a mouse model of human rheumatoid arthritis (RA). An experimental model of RA was established in male DBA/1 mouse by 2-week-interval injections of 100 μg type II collagen emulsified in complete (first injection) or incomplete Freund's adjuvant (second injection) at the base of the tail. During arthritis development, bvPLA2 (0.1, 0.5, 1.0 mg/kg) and/or Treg inhibitors such as anti-CD25 antibodies and peptide 60 (P60) were injected intraperitoneally for 5 weeks. Arthritic symptoms and the expansion of Tregs were then assessed by behavioral assessments, histological and micro-CT imaging, and flow cytometry. bvPLA2 injections significantly alleviated arthritic behaviors such as squeaking and joint swelling, consistent with changes seen on both histological and micro-CT images. The anti-arthritic effects of bvPLA2 were blocked by intraperitoneal injections of 0.25 mg/kg anti-CD25 antibody and 10 μg/kg P60, as determined by behavioral assessments. Flow cytometric analysis of dendritic cells, B cells, and major T cell subsets from spleens revealed a significant depletion of Tregs following anti-CD25 antibody, but not P60, treatment. bvPLA2 treatment exerted significant anti-inflammatory and anti-arthritic activities in a mouse model of RA via the induction of Tregs.