Allogeneic CAR-T Therapy Technologies: Has the Promise Been Met?

This last decade, chimeric antigen receptor (CAR) T-cell therapy has become a real treatment option for patients with B-cell malignancies, while multiple efforts are being made to extend this therapy to other malignancies and broader patient populations. However, several limitations remain, including those associated with the time-consuming and highly personalized manufacturing of autologous CAR-Ts. Technologies to establish "off-the-shelf" allogeneic CAR-Ts with low alloreactivity are currently being developed, with a strong focus on gene-editing technologies.

Efficient shRNA-based knockdown of multiple target genes for cell therapy using a chimeric miRNA cluster platform.

Genome engineering technologies are powerful tools in cell-based immunotherapy to optimize or fine-tune cell functionalities. However, their use for multiple gene edits poses relevant biological and technical challenges. Short hairpin RNA (shRNA)-based cell engineering bypasses these criticalities and represents a valid alternative to CRISPR-based gene editing.

CYAD-01, an autologous NKG2D-based CAR T-cell therapy, in relapsed or refractory acute myeloid leukaemia and myelodysplastic syndromes or multiple myeloma (THINK): haematological cohorts of the dose escalation segment of a phase 1 trial.

Background: CYAD-01 is an autologous chimeric antigen receptor (CAR) T-cell product based on the natural killer (NK) group 2D (NKG2D) receptor, which binds eight ligands that are overexpressed in a wide range of haematological malignancies but are largely absent on non-neoplastic cells. Initial clinical evaluation of a single infusion of CYAD-01 at a low dose in patients with relapsed or refractory acute myeloid leukaemia, myelodysplastic syndromes, and multiple myeloma supported the feasibility of the approach and prompted further evaluation of CYAD-01. The aim of the present study was to determine the safety and recommended phase 2 dosing of CYAD-01 administered without preconditioning or bridging chemotherapy.

Chimeric Antigen Receptor-T Cells for Targeting Solid Tumors: Current Challenges and Existing Strategies.

Chimeric antigen receptor-T cells (CAR-Ts) are an exciting new cancer treatment modality exemplified by the recent regulatory approval of two CD19-targeted CAR-T therapies for certain B cell malignancies. However, this success in the hematological setting has yet to translate to a significant level of objective clinical responses in the solid tumor setting. The reason for this lack of translation undoubtedly lies in the substantial challenges raised by solid tumors to all therapies, including CAR-T, that differ from B cell malignancies.

Saturation of acyl chains converts cardiolipin from an antagonist to an activator of Toll-like receptor-4.

Cardiolipins (CLs) are tetra-acylated diphosphatidylglycerols found in bacteria, yeast, plants, and animals. In healthy mammals, CLs are unsaturated, whereas saturated CLs are found in blood cells from Barth syndrome patients and in some Gram-positive bacteria. Here, we show that unsaturated but not saturated CLs block LPS-induced NF-κB activation, TNF-α and IP-10 secretion in human and murine macrophages, as well as LPS-induced TNF-α and IL-1β release in human blood mononuclear cells.

DOTAP, a lipidic transfection reagent, triggers Arabidopsis plant defense responses.

DOTAP triggers Arabidopsis thaliana immunity and by priming the defense response is able to reduce bacterial pathogen attack. DOTAP is a cationic lipid widely used as a liposomal transfection reagent and it has recently been identified as a strong activator of the innate immune system in animal cells. Plants are sessile organisms and unlike mammals, that have innate and acquired immunity, plants possess only innate immunity.

Cationic lipids as one-component vaccine adjuvants: A promising alternative to alum.

Effective vaccine formulations consist of several components: an antigen carrier, the antigen, a stimulator of cellular immunity such as a Toll-like Receptors (TLRs) ligand, and a stimulator of humoral response such as an inflammasome activator. Here, we investigated the immunostimulatory and adjuvant properties of lipopolyamines, cationic lipids used as gene carriers. We identified new lipopolyamines able to activate both TLR2 and TLR4 and showed that lipopolyamines interact with TLRs via a mechanism different from the one used by bacterial ligands, activating a strong type-I IFN response, pro-inflammatory cytokines and IL-1β secretion.

Large supramolecular structures of 33-mer gliadin peptide activate toll-like receptors in macrophages.

Gliadin, an immunogenic protein present in wheat, is not fully degraded by humans and after the normal gastric and pancreatic digestion, the immunodominant 33-mer gliadin peptide remains unprocessed. The 33-mer gliadin peptide is found in human faeces and urine, proving not only its proteolytic resistance in vivo but more importantly its transport through the entire human body. Here, we demonstrate that 33-mer supramolecular structures larger than 220 nm induce the overexpression of nuclear factor kappa B (NF-κB) via a specific Toll-like Receptor (TLR) 2 and (TLR) 4 dependent pathway and the secretion of pro-inflammatory cytokines such as IP-10/CXCL10 and TNF-α.

Celyad's novel CAR T-cell therapy for solid malignancies.

Celyad recently initiated several clinical trials with the CYAD-01 product, a natural killer group 2D (NKG2D)-based chimeric antigen receptor (CAR), in both solid and hematologic tumor types. This review discusses the unique properties of CYAD-01, expecting to provide a new paradigm to fight against solid tumors.

Exploiting natural killer group 2D receptors for CAR T-cell therapy.

Chimeric antigen receptors (CARs) are genetically engineered proteins that combine an extracellular antigen-specific recognition domain with one or several intracellular T-cell signaling domains. When expressed in T cells, these CARs specifically trigger T-cell activation upon antigen recognition. While the clinical proof of principle of CAR T-cell therapy has been established in hematological cancers, CAR T cells are only at the early stages of being explored to tackle solid cancers.

Self-assembly of 33-mer gliadin peptide oligomers.

The 33-mer gliadin peptide, LQLQPF(PQPQLPY)3PQPQPF, is a highly immunogenic peptide involved in celiac disease and probably in other immunopathologies associated with gliadin. Herein, dynamic light scattering measurements showed that 33-mer, in the micromolar concentration range, forms polydisperse nano- and micrometer range particles in aqueous media. This behaviour is reminiscent of classical association of colloids and we hypothesized that the 33-mer peptide self-assembles into micelles that could be the precursors of 33-mer oligomers in water.

Role of lipid microdomains in TLR-mediated signalling.

Over the last twenty years, evidence has been provided that the plasma membrane is partitioned with microdomains, laterally mobile in the bilayer, providing the necessary microenvironment to specific membrane proteins for signalling pathways to be initiated. We discuss here the importance of such microdomains for Toll-like receptors (TLR) localization and function. First, lipid microdomains favour recruitment and clustering of the TLR machinery partners, i.

The synthetic cationic lipid diC14 activates a sector of the Arabidopsis defence network requiring endogenous signalling components.

Natural and synthetic elicitors have contributed significantly to the study of plant immunity. Pathogen-derived proteins and carbohydrates that bind to immune receptors, allow the fine dissection of certain defence pathways. Lipids of a different nature that act as defence elicitors, have also been studied, but their specific effects have been less well characterized, and their receptors have not been identified.

Structural characterization of novel cationic diC16-amidine bilayers: Evidence for partial interdigitation.

In this work, the bilayer structure of novel cationic lipid diC16-amidine was compared to the one of zwitterionic dipalmitoyl phosphatidylcholine ( DPPC), which shares the same hydrophobic domain. Differential scanning calorimetry shows that DPPC and diC16-am idine bilayers have similar phase transition temperatures, but diC16-a midine membranes display a less cooperative phase transition and an absence of pretransition. Both bilayers were analyzed from surface to core, using 5-, 7-, 10-, 12-, 14-, and 16-PCSL spin labels.

Cationic lipid nanocarriers activate Toll-like receptor 2 and NLRP3 inflammasome pathways.

Unlabelled: We provide evidence that cationic lipids, usually considered as a safe alternative to viral vectors as nanocarriers for gene therapy or drug intracellular delivery, do not behave as inert material but do activate cellular signalling pathways implicated in inflammatory reactions. We show here that the cationic lipid RPR206252 induces NF-κB activation, and the production of TNF-α, IL-1β, IL-6 and IFN-γ by human or mouse macrophage cell lines. Further, we demonstrate that the activation of inflammatory cascades by RPR206252 is dependent on Toll-like receptor 2 (TLR2), the natural sensor of bacterial lipopeptides and NOD-like receptor protein 3 (NLRP3), the major inflammasome component.

[Corrigendum] Temozolomide-induced modification of the CXC chemokine network in experimental gliomas.

After the publication of the article, the authors noted an error. The changes are as follows: In the initial and published version of Fig. 5, the data relied on triplicates in both the control (SCR) and treated (siCXCL2)conditions.

Oligonucleotide adsorption affects phase transition but not interdigitation of diC14-amidine bilayers.

In this work, we investigate the effect of a small single-stranded oligonucleotide (ODN) on the colloid stability and structure of cationic diC14-amidine liposomes. Dynamic light scattering (DLS) shows that small, stable, anionic assemblies are formed in presence of excess ODN negative charge. This charge overcompensation condition was further characterized.

Activation of innate immunity by lysozyme fibrils is critically dependent on cross-β sheet structure.

Inflammation occurs in many amyloidoses, but its underlying mechanisms remain enigmatic. Here we show that amyloid fibrils of human lysozyme, which are associated with severe systemic amyloidoses, induce the secretion of pro-inflammatory cytokines through activation of the NLRP3 (NLR, pyrin domain containing 3) inflammasome and the Toll-like receptor 2, two innate immune receptors that may be involved in immune responses associated to amyloidoses. More importantly, our data clearly suggest that the induction of inflammatory responses by amyloid fibrils is linked to their intrinsic structure, because the monomeric form and a non-fibrillar type of lysozyme aggregates are both unable to trigger cytokine secretion.

Cationic lipids activate intracellular signaling pathways.

Cationic liposomes are commonly used as a transfection reagent for DNA, RNA or proteins and as a co-adjuvant of antigens for vaccination trials. A high density of positive charges close to cell surface is likely to be recognized as a signal of danger by cells or contribute to trigger cascades that are classically activated by endogenous cationic compounds. The present review provides evidence that cationic liposomes activate several cellular pathways like pro-apoptotic and pro-inflammatory cascades.