Dendritic cells transduced with Rsf-1/HBXAP gene generate specific cytotoxic T lymphocytes against ovarian cancer in vitro

Single-cell analysis of myeloid cells in HPV+ tonsillar cancer

The incidence of human papillomavirus-positive (HPV+) tonsillar cancer has been sharply rising during the last decades. Myeloid cells represent an appropriate therapeutic target due to their proximity to virus-infected tumor cells, and their ability to orchestrate antigen-specific immunity, within the tonsil. However, the interrelationship of steady-state and inflammatory myeloid cell subsets, and their impact on patient survival remains unexplored. Here, we used single-cell RNA-sequencing to map the myeloid compartment in HPV+ tonsillar cancer. We observed an expansion of the myeloid compartment in HPV+ tonsillar cancer, accompanied by interferon-induced cellular responses both in dendritic cells (DCs) and monocyte-macrophages. Our analysis unveiled the existence of four DC lineages, two macrophage polarization processes, and their sequential maturation profiles. Within the DC lineages, we described a balance shift in the frequency of progenitor and mature cDC favoring the cDC1 lineage in detriment of cDC2s. Furthermore, we observed that all DC lineages apart from DC5s matured into a common activated DC transcriptional program involving upregulation of interferon-inducible genes. In turn, the monocyte-macrophage lineage was subjected to early monocyte polarization events, which give rise to either interferon-activated or CXCL-producing macrophages, the latter enriched in advanced tumor stages. We validated the existence of most of the single-cell RNA-seq clusters using 26-plex flow cytometry, and described a positive impact of cDC1 and interferon-activated DCs and macrophages on patient survival using gene signature scoring. The current study contributes to the understanding of myeloid ontogeny and dynamics in HPV-driven tonsillar cancer, and highlights myeloid biomarkers that can be used to assess patient prognosis.

Combined treatment with epigenetic agents enhances anti-tumor activity of MAGE-D4 peptide-specific T cells by upregulating the MAGE-D4 expression in glioma

OBJECTIVE

The study evaluated the efficacy of combined epigenetic drugs of decitabine (DAC), valproic acid (VPA), and trichostatin A (TSA) on immunotherapy against glioma.

METHODS

The expression and prognosis of MAGE-D4 in glioma were analyzed online, and the expression of MAGE-D4 and HLA-A2 in glioma induced by epigenetic drugs was detected by qRT-PCR, Western blot, and flow cytometry. The methylation status of the MAGE-D4 promoter was determined by pyrosequencing. An HLA-A2 restricted MAGE-D4 peptide was predicted and synthesized. An affinity assay and a peptide/HLA complex stability assay were performed to determine the affinity between peptide and HLA. CCK8 assay, CFSE assay, ELISA and ELISPOT were performed to detect the function of MAGE-D4 peptide-specific T cells. Flow cytometry, ELISA, and cytotoxicity assays were used to detect the cytotoxicity effect of MAGE-D4 peptide-specific T cells combined with epigenetic drugs against glioma in vitro. Finally, the glioma-loaded mouse model was applied to test the inhibitory effect of specific T cells on gliomas in vivo.

RESULTS

MAGE-D4 was highly expressed in glioma and correlated with poor prognosis. Glioma cells could be induced to express MAGE-D4 and HLA-A2 by epigenetic drugs. MAGE-D4-associated peptides were found that induce DCs to stimulate the highest T-cell activities of proliferation, IL-2 excretion, and IFN-γ secretion. MAGE-D4 peptide-specific T cells treated with TSA only or combining TSA and DAC had the most cytotoxicity effect, and its cytotoxicity effect on glioma cells decreased significantly after HLA blocking. In vivo experiments also confirmed that MAGE-D4-specific T cells inhibit TSA-treated glioma.

CONCLUSION

MAGE-D4 is highly expressed in glioma and correlated with the prognosis of glioma. The novel MAGE-D4 peptide identified was capable of inducing MAGE-D4-specific T cells that can effectively inhibit glioma growth, and the epigenetic drug application can enhance this inhibition.

The emerging role of ISWI chromatin remodeling complexes in cancer

Disordered chromatin remodeling regulation has emerged as an essential driving factor for cancers. Imitation switch (ISWI) family are evolutionarily conserved ATP-dependent chromatin remodeling complexes, which are essential for cellular survival and function through multiple genetic and epigenetic mechanisms. Omics sequencing and a growing number of basic and clinical studies found that ISWI family members displayed widespread gene expression and genetic status abnormalities in human cancer. Their aberrant expression is closely linked to patient outcome and drug response. Functional or componential alteration in ISWI-containing complexes is critical for tumor initiation and development. Furthermore, ISWI-non-coding RNA regulatory networks and some non-coding RNAs derived from exons of ISWI member genes play important roles in tumor progression. Therefore, unveiling the transcriptional regulation mechanism underlying ISWI family sparked a booming interest in finding ISWI-based therapies in cancer. This review aims at describing the current state-of-the-art in the role of ISWI subunits and complexes in tumorigenesis, tumor progression, immunity and drug response, and presenting deep insight into the physiological and pathological implications of the ISWI transcription machinery in cancers.

RNA vaccines for anti-tumor therapy

The immune system is able to recognize tumor antigens and this has been the basis for the development of cancer immunotherapies. The immune system can be instructed to recognize and attack tumor cells by means of vaccination strategies. One such strategy involves the delivery of tumor antigen as genetic material. Herewith we describe the use of RNA encoding tumor antigens for vaccination purposes in tumor settings. RNA has features that are interesting for vaccination. Upon transfection, the RNA has no possibility of integration into the genome, and the tumor translated proteins enter the intrinsic antigen processing pathway thus enabling presentation by MHC-I molecules. This can specifically activate cytotoxic CD8 T cells that can attack and kill tumor cells. RNA can be delivered as a naked molecule for vaccination purposes or can be used to transfect dendritic cells. The combination of RNA technology with dendritic cell vaccination provides a powerful tool for cancer immunotherapies.

Pre-clinical assessment of autologous DC-based therapy in ovarian cancer patients with progressive disease

Dendritic cell-based vaccines offer promise for therapy of ovarian cancer. Previous studies have demonstrated that oxidation of several antigens, including ovarian cancer cells, using hypochlorous acid strongly enhances their immunogenicity and their uptake and presentation by dendritic cells. The response of T cells and dendritic cells to autologous tumour from patients with active disease has not previously been investigated. Monocyte-derived dendritic cells were generated from patients with active disease and activated by co-culture with oxidised tumour cells and the TLR agonist poly I:C. The dendritic cells showed an activated phenotype, but secreted high levels of TGFβ. Co-culture of the antigen-loaded dendritic cells with autologous T cells generated a population of effector T cells that showed a low level of specific lytic activity against autologous tumour, as compared to autologous mesothelium. The addition of neutralising antibody to TGFβ in DC/T cell co-cultures increased the levels of subsequent tumour killing in three samples tested. Co-culture of monocytes from healthy volunteers with the ovarian cell line SKOV-3 prior to differentiation into dendritic cells reduced the ability of dendritic cells to stimulate cytotoxic effector cells. The study suggests that co-culture of dendritic cells with oxidised tumour cells can generate effector cells able to kill autologous tumour, but that the high tumour burden in patients with active disease may compromise dendritic cell and/or T cell function.

Dendritic cells the tumor microenvironment and the challenges for an effective antitumor vaccination

Many clinical trials have been carried out or are in progress to assess the therapeutic potential of dendritic-cell- (DC-) based vaccines on cancer patients, and recently the first DC-based vaccine for human cancer was approved by the FDA. Herewith, we describe the general characteristics of DCs and different strategies to generate effective antitumor DC vaccines. In recent years, the relevance of the tumor microenvironment in the progression of cancer has been highlighted. It has been shown that the tumor microenvironment is capable of inactivating various components of the immune system responsible for tumor clearance. In particular, the effect of the tumor microenvironment on antigen-presenting cells, such as DCs, does not only render these immune cells unable to induce specific immune responses, but also turns them into promoters of tumor growth. We also describe strategies likely to increase the efficacy of DC vaccines by reprogramming the immunosuppressive nature of the tumor microenvironment.