Endobronchial Gene Transfer of Soluble Type I Interleukin-1 Receptor Ameliorates Lung Graft Ischemia-Reperfusion Injury

Creating superior lungs for transplantation with next-generation gene therapy during ex vivo lung perfusion

Engineering donor organs to better tolerate the harmful non-immunological and immunological responses inherently related to solid organ transplantation would improve transplant outcomes. Our enhanced knowledge of ischemia-reperfusion injury, alloimmune responses and pathological fibroproliferation after organ transplantation, and the advanced toolkit available for gene therapies, have brought this goal closer to clinical reality. Ex vivo organ perfusion has evolved rapidly especially in the field of lung transplantation, where clinicians routinely use ex vivo lung perfusion (EVLP) to confirm the quality of marginal donor lungs before transplantation, enabling safe transplantation of organs originally considered unusable. EVLP would also be an attractive platform to deliver gene therapies, as treatments could be administered to an isolated organ before transplantation, thereby providing a window for sophisticated organ engineering while minimizing off-target effects to the recipient. Here, we review the status of lung transplant first-generation gene therapies that focus on inducing transgene expression in the target cells. We also highlight recent advances in next-generation gene therapies, that enable gene editing and epigenetic engineering, that could be used to permanently change the donor organ genome and to induce widespread transcriptional gene expression modulation in the donor lung. In a future vision, dedicated organ repair and engineering centers will use gene editing and epigenetic engineering, to not only increase the donor organ pool, but to create superior organs that will function better and longer in the recipient.

Gene Therapy: Will the Promise of Optimizing Lung Allografts Become Reality?

Lung transplantation is the definitive therapy for patients living with end-stage lung disease. Despite significant progress made in the field, graft survival remains the lowest of all solid organ transplants. Additionally, the lung has among the lowest of organ utilization rates-among eligible donors, only 22% of lungs from multi-organ donors were transplanted in 2019. Novel strategies are needed to rehabilitate marginal organs and improve graft survival. Gene therapy is one promising strategy in optimizing donor allografts. Over-expression or inhibition of specific genes can be achieved to target various pathways of graft injury, including ischemic-reperfusion injuries, humoral or cellular rejection, and chronic lung allograft dysfunction. Experiments in animal models have historically utilized adenovirus-based vectors and the majority of literature in lung transplantation has focused on overexpression of IL-10. Although several strategies were shown to prevent rejection and prolong graft survival in preclinical models, none have led to clinical translation. The past decade has seen a renaissance in the field of gene therapy and two AAV-based in vivo gene therapies are now FDA-approved for clinical use. Concurrently, normothermic ex vivo machine perfusion technology has emerged as an alternative to traditional static cold storage. This preservation method keeps organs physiologically active during storage and thus potentially offers a platform for gene therapy. This review will explore the advantages and disadvantages of various gene therapy modalities, review various candidate genes implicated in various stages of allograft injury and summarize the recent efforts in optimizing donor lungs using gene therapy.

Hemorrhage-induced interleukin-1 receptor pathway in lung is suppressed by 3,5-bis(2-fluorobenzylidene)-4-piperidone in a rat model of hypovolemic shock

Severe blood loss in victims of trauma creates an exaggerated inflammatory background that contributes to the development of intravascular coagulopathy and multiple organ dysfunction syndrome. We hypothesized that treatment with diphenyldifluoroketone EF24, an inhibitor of nuclear factor kappa-B, would have salutary effects in hemorrhagic shock. The objective of this study was to investigate the effect of EF24 on the expression of the interleukin-1 receptor (IL-1R) superfamily in a rat model of hypovolemic shock. Hypovolemia was induced by gradually withdrawing approximately 50% of circulating blood, and EF24 was administered intraperitoneally (0.2 mg/kg) in 50 μL of saline. After 6 h of shock, lung tissue was probed immunohistochemically and by immunoblotting to study the expression of Toll-like receptor 4 (TLR4), IL-1R, suppression of tumorigenicity 2 (ST2), and single immunoglobulin IL-1R-related (SIGIRR). The tissue-associated pro-inflammatory cytokines, tumor necrosis factor alpha (TNF-α) and IL-6, were measured by enzyme-linked immunosorbent assay. We observed a reduction in immunoreactive TLR4 and IL-1R1 in lung tissue of rats treated with EF24. Simultaneously, the pulmonary expression of ST2 and SIGIRR (the putative down-regulators of the pro-inflammatory IL-1R pathway) was increased in EF24-treated hemorrhaged rats. The concentration of hemorrhage-induced TNF-α and IL-6 in lung tissue homogenates was also reduced by EF24 treatment. These results confirm our previous in vitro observations in lipopolysaccharide-stimulated dendritic cells that EF24 beneficially modulates the IL-1R pathway and suggest that it could be investigated as an adjunct therapeutic in managing inflammation associated with hemorrhagic shock.

Update on donor assessment, resuscitation, and acceptance criteria, including novel techniques--non-heart-beating donor lung retrieval and ex vivo donor lung perfusion

The shortage of adequate organ donors remains a great challenge in clinical lung transplantation. With increasing experience in the medical management and surgical technique of lung transplantation, gradual expansion of the criteria for lung donor selection has occurred with beneficial effects on the donor pool. Interest in donation after cardiac death also is increasing as the gap increases between donors and the needs of listed patients. Successful use of these new sources of lungs depends on the accurate assessment and prediction of transplanted lung function. Promising techniques for lung assessment and diagnostics include investigating key genes associated with graft failure or good graft performance using molecular approaches, and ex vivo evaluation. Further studies are needed to answer remaining questions about the best technique and solution to reperfuse human lungs for several hours without edema formation. As the predictive ability to discern good from injured donor lungs improves, strategies to repair donor lungs become increasingly important. Prolonged normothermic EVLP seems to be a platform on which many reparative strategies can be realized. With these new methods for assessing and resuscitating lungs accurately, it is hoped that inroads will be made toward providing every listed patient a chance for successful lung transplantation.

Is late diagnosis of lung cancer inevitable? Interview study of patients' recollections of symptoms before diagnosis

BACKGROUND

A study was undertaken to explore the pathway to diagnosis among a group of patients recently diagnosed with lung cancer.

METHODS

A directed interview study triangulating patients' accounts with hospital and GP records was performed with 22 men and women recently diagnosed with lung cancer at two cancer centres in the south and north of England. The main outcome measures were the symptoms leading up to a diagnosis of lung cancer and patient and GP responses before diagnosis.

RESULTS

Patients recalled having new symptoms for many months, typically over the year before their diagnosis, irrespective of their disease stage once diagnosed. Chest symptoms (cough, breathing changes, and pain in the chest) were common, as were systemic symptoms (fatigue/lethargy, weight loss and eating changes). Although symptoms were reported as being marked changes in health, these were not in the main (with the exception of haemoptysis) interpreted as serious by patients at the time and not acted on. Once the trigger for action occurred (the event that took patients to their GP or elsewhere in the healthcare system), events were relatively speedy and were faster for patients who presented via their GP than via other routes. Patients' beliefs about health changes that may indicate lung cancer appeared to have played a part in delay in diagnosis.

CONCLUSION

Further investigation of the factors influencing the timing of diagnosis in lung cancer is warranted since it appears that patients did not readily attend GP surgeries with symptoms. Insight into patients' perspectives on their experience before diagnosis may help medical carers to recognise patients with lung cancer more easily so that they can refer them for diagnosis and treatment. Encouragement to present early with signs of lung cancer should be considered alongside other efforts to speed up diagnosis and treatment.