Naturally occurring T cell mutations enhance engineered T cell therapies

Adoptive T cell therapies have produced exceptional responses in a subset of patients with cancer. However, therapeutic efficacy can be hindered by poor T cell persistence and function1. In human T cell cancers, evolution of the disease positively selects for mutations that improve fitness of T cells in challenging situations analogous to those faced by therapeutic T cells. Therefore, we reasoned that these mutations could be co-opted to improve T cell therapies. Here we systematically screened the effects of 71 mutations from T cell neoplasms on T cell signalling, cytokine production and in vivo persistence in tumours. We identify a gene fusion, CARD11-PIK3R3, found in a CD4+ cutaneous T cell lymphoma2, that augments CARD11-BCL10-MALT1 complex signalling and anti-tumour efficacy of therapeutic T cells in several immunotherapy-refractory models in an antigen-dependent manner. Underscoring its potential to be deployed safely, CARD11-PIK3R3-expressing cells were followed up to 418 days after T cell transfer in vivo without evidence of malignant transformation. Collectively, our results indicate that exploiting naturally occurring mutations represents a promising approach to explore the extremes of T cell biology and discover how solutions derived from evolution of malignant T cells can improve a broad range of T cell therapies.

Single cell RNA sequencing reveals endothelial cell killing and resolution pathways in experimental malaria-associated acute respiratory distress syndrome

Plasmodium parasites cause malaria, a global health disease that is responsible for more than 200 million clinical cases and 600 000 deaths each year. Most deaths are caused by various complications, including malaria-associated acute respiratory distress syndrome (MA-ARDS). Despite the very rapid and efficient killing of parasites with antimalarial drugs, 15% of patients with complicated malaria succumb. This stresses the importance of investigating resolution mechanisms that are involved in the recovery from these complications once the parasite is killed. To study the resolution of MA-ARDS, P. berghei NK65-infected C57BL/6 mice were treated with antimalarial drugs after onset of symptoms, resulting in 80% survival. Micro-computed tomography revealed alterations of the lungs upon infection, with an increase in total and non-aerated lung volume due to edema. Whole body plethysmography confirmed a drastically altered lung ventilation, which was restored during resolution. Single-cell RNA sequencing indicated an increased inflammatory state in the lungs upon infection, which was accompanied by a drastic decrease in endothelial cells, consistent with CD8+ T cell-mediated killing. During resolution, anti-inflammatory pathways were upregulated and proliferation of endothelial cells was observed. MultiNicheNet interactome analysis identified important changes in the ligand-receptor interactions during disease resolution that warrant further exploration in order to develop new therapeutic strategies. In conclusion, our study provides insights in pro-resolving pathways that limit inflammation and promote endothelial cell proliferation in experimental MA-ARDS. This information may be useful for the design of adjunctive treatments to enhance resolution after Plasmodium parasite killing by antimalarial drugs.

Long-term outcome of endoscopic dilatation in patients with Crohn's disease is not affected by disease activity or medical therapy

BACKGROUND

Endoscopic dilatation of Crohn's disease-related strictures is an alternative to surgical resection in selected patients. The influence of disease activity and concomitant medical therapy on long-term outcomes is largely unknown.

AIM AND METHODS

To study the long-term safety and efficacy of stricture dilatation in a single centre cohort.

RESULTS

Between 1995 and 2006, 237 dilatations where performed in 138 patients (mean age 50.6+/-13.4, 56% female) for a clinically obstructive stricture (<5 cm, 84% anastomotic). Immediate success of a first dilatation was 97% with a 5% serious complication rate. After a median follow-up of 5.8 years (IQR 3.0-8.4), recurrent obstructive symptoms led to a new dilatation in 46% or surgery in 24%. Niether elevated levels of C-reactive protein nor endoscopic disease activity predicted the need for new intervention. None of the concomitant therapies influenced the outcome.

CONCLUSION

This largest series ever reported confirms that long term efficacy of endoscopic dilatation of Crohn's disease outweighs the complication risk. Neither active disease at the time of dilatation nor medical therapy afterwards predict recurrent dilatation or surgery.