Cytokine-armed dendritic cell progenitors for antigen-agnostic cancer immunotherapy.

Dendritic cells (DCs) are antigen-presenting myeloid cells that regulate T cell activation, trafficking and function. Monocyte-derived DCs pulsed with tumor antigens have been tested extensively for therapeutic vaccination in cancer, with mixed clinical results. Here, we present a cell-therapy platform based on mouse or human DC progenitors (DCPs) engineered to produce two immunostimulatory cytokines, IL-12 and FLT3L.

Dendritic cell cross-dressing and tumor immunity.

In addition to direct and cross-presentation, dendritic cells (DCs) can present tumor antigens (TAs) to T cells via a hitherto poorly understood mechanism called "cross-dressing." DC cross-dressing involves the acquisition of preformed peptide-major histocompatibility class I/II (p-MHC) complexes from cancer cells. This process has been documented both in cell culture and in tumor models; may occur via the uptake of tumor-derived extracellular vesicles or the horizontal transfer of plasma membrane fragments from cancer cells to DCs; and can be enhanced through DC engineering for therapeutic applications.

Overcoming microenvironmental resistance to PD-1 blockade in genetically engineered lung cancer models.

Immune checkpoint blockade (ICB) with PD-1 or PD-L1 antibodies has been approved for the treatment of non-small cell lung cancer (NSCLC). However, only a minority of patients respond, and sustained remissions are rare. Both chemotherapy and antiangiogenic drugs may improve the efficacy of ICB in mouse tumor models and patients with cancer.

An Immunomodulatory Gallotanin-Rich Fraction From Enhances the Therapeutic Effect of Anti-PD-L1 in Melanoma.

PD-1/PD-L1 pathway plays a role in inhibiting immune response. Therapeutic antibodies aimed at blocking the PD-1/PD-L1 interaction have entered clinical development and have been approved for a variety of cancers. However, the clinical benefits are reduced to a group of patients.

Enhanced Phenotype Definition for Precision Isolation of Precursor Exhausted Tumor-Infiltrating CD8 T Cells.

In the context of adoptive T cell transfer (ACT) for cancer treatment, it is crucial to generate large amounts of tumor-specific CD8 T cells with high potential to persist . PD-1, Tim3, and CD39 have been proposed as markers of tumor-specific tumor-infiltrating CD8 T lymphocytes (CD8 TILs). However, these molecules are highly expressed by terminally differentiated exhausted CD8 T cells (Tex) that lack proliferation potential.

miR-155 Overexpression in OT-1 CD8 T Cells Improves Anti-Tumor Activity against Low-Affinity Tumor Antigen.

Therapy by adoptive transfer of -expanded tumor-infiltrating or genetically modified T cells may lead to impressive clinical responses. However, there is a need to improve persistence and functionality of the transferred T cells, in particular, to face the highly immunosuppressive environment of solid tumors. Here, we investigate the potential of miR-155, a microRNA known to play an important role in CD8 T cell fitness.

Generation of affinity ranged antigen-expressing tumor cell lines.

The interaction strength between CD8 T cells' TCR and cognate peptide-MHC (pMHC) impacts on the CD8 T cell response against pathogens and tumors (Martinez-Usatorre, Donda, Zehn, & Romero, 2018; Zehn, Lee, & Bevan, 2009). CD8 T cell responses against tumors are characterized by the presence of low affinity CD8 T cells specific for nonmutated tumor associated self-antigens (TAA) and potentially high affinity tumor specific CD8 T cells recognizing mutated self-antigens (Gros et al., 2016; Kvistborg et al.

A LIGHTning Strike to the Metastatic Niche.

Tumor-induced vascular alterations in distant organs have been linked to the spreading of cancer. In this issue of Cell Reports, He et al. (2019) show that targeting the cytokine LIGHT to the pulmonary vasculature prevents the establishment of lung metastasis in mice.

MicroRNA-155 Expression Is Enhanced by T-cell Receptor Stimulation Strength and Correlates with Improved Tumor Control in Melanoma.

microRNAs are short noncoding RNAs that regulate protein expression posttranscriptionally. We previously showed that miR-155 promotes effector CD8 T-cell responses. However, little is known about the regulation of miR-155 expression.

Prophylactic vs. Therapeutic Treatment With P2Et Polyphenol-Rich Extract Has Opposite Effects on Tumor Growth.

Polyphenols have tumoricidal effects via anti-proliferative, anti-angiogenic and cytotoxic mechanisms and have recently been demonstrated to modulate the immune response through their anti- or pro- oxidant activity. Nevertheless, it remains controversial whether antioxidant-rich supplements have real beneficial effects on health, especially in complex diseases such as cancer. We previously identified a polyphenol-rich extract obtained from (P2Et) with anti-tumor activity in both breast carcinoma and melanoma.

PD-1 Blockade Unleashes Effector Potential of Both High- and Low-Affinity Tumor-Infiltrating T Cells.

Antitumor T cell responses involve CD8 T cells with high affinity for mutated self-antigen and low affinity for nonmutated tumor-associated Ag. Because of the highly individual nature of nonsynonymous somatic mutations in tumors, however, immunotherapy relies often on an effective engagement of low-affinity T cells. In this study, we studied the role of T cell affinity during peripheral priming with single-peptide vaccines and during the effector phase in the tumor.

Tumour-derived PGD2 and NKp30-B7H6 engagement drives an immunosuppressive ILC2-MDSC axis.

Group 2 innate lymphoid cells (ILC2s) are involved in human diseases, such as allergy, atopic dermatitis and nasal polyposis, but their function in human cancer remains unclear. Here we show that, in acute promyelocytic leukaemia (APL), ILC2s are increased and hyper-activated through the interaction of CRTH2 and NKp30 with elevated tumour-derived PGD2 and B7H6, respectively. ILC2s, in turn, activate monocytic myeloid-derived suppressor cells (M-MDSCs) via IL-13 secretion.

Curtailed T-cell activation curbs effector differentiation and generates CD8 T cells with a naturally-occurring memory stem cell phenotype.

Human T memory stem (T ) cells with superior persistence capacity and effector functions are emerging as important players in the maintenance of long-lived T-cell memory and are thus considered an attractive population to be used in adoptive transfer-based immunotherapy of cancer. However, the molecular signals regulating their generation remain poorly defined. Here we show that curtailed T-cell receptor stimulation curbs human effector CD8 T-cell differentiation and allows the generation of CD45RO CD45RA CCR7 CD27 CD95 -phenotype cells from highly purified naïve T-cell precursors, resembling naturally-occurring human T .

Immune-system-dependent anti-tumor activity of a plant-derived polyphenol rich fraction in a melanoma mouse model.

Recent findings suggest that part of the anti-tumor effects of several chemotherapeutic agents require an intact immune system. This is in part due to the induction of immunogenic cell death. We have identified a gallotannin-rich fraction, obtained from Caesalpinia spinosa (P2Et) as an anti-tumor agent in both breast carcinoma and melanoma.