Dual targeting of CD19 and CD22 with bicistronic CAR-T cells in patients with relapsed/refractory large B-cell lymphoma

Relapse after CD19-directed chimeric antigen receptor T-cell (CAR-T) therapy for large B-cell lymphoma (LBCL) is commonly ascribed to antigen loss or CAR-T exhaustion. Multiantigen targeting and programmed cell death protein-1 blockade are rational approaches to prevent relapse. Here, we test CD19/22 dual-targeting CAR-T (AUTO3) plus pembrolizumab in relapsed/refractory LBCL (NCT03289455). End points include toxicity (primary) and response rates (secondary). Fifty-two patients received AUTO3 and 48/52 received pembrolizumab. Median age was 59 years (range, 27-83), 46/52 had stage III/ IV disease and median follow-up was 21.6 months. AUTO3 was safe; grade 1-2 and grade 3 cytokine release syndrome affected 18/52 (34.6%) and 1/52 (1.9%) patients, neurotoxicity arose in 4 patients (2/4, grade 3-4), and hemophagocytic lymphohistiocytosis affected 2 patients. Outpatient administration was tested in 20 patients, saving a median of 14 hospital days per patient. Overall response rates were 66% (48.9%, complete response [CR]; 17%, partial response). Median duration of remission (DOR) for CR patients was not reached and for all responding patients was 8.3 months (95% confidence interval [CI]: 3.0-not evaluable). 54.4% (CI: 32.8-71.7) of CR patients and 42.6% of all responding patients were projected to remain progression-free at ≥12 months. AUTO3 ± pembrolizumab for relapsed/refractory LBCL was safe and delivered durable remissions in 54.4% of complete responders, associated with robust CAR-T expansion. Neither dual-targeting CAR-T nor pembrolizumab prevented relapse in a significant proportion of patients, and future developments include next-generation-AUTO3, engineered for superior expansion in vivo, and selection of CAR binders active at low antigen densities.

Dissecting the early steps of MLL induced leukaemogenic transformation using a mouse model of AML

Leukaemogenic mutations commonly disrupt cellular differentiation and/or enhance proliferation, thus perturbing the regulatory programs that control self-renewal and differentiation of stem and progenitor cells. Translocations involving the Mll1 (Kmt2a) gene generate powerful oncogenic fusion proteins, predominantly affecting infant and paediatric AML and ALL patients. The early stages of leukaemogenic transformation are typically inaccessible from human patients and conventional mouse models. Here, we take advantage of cells conditionally blocked at the multipotent haematopoietic progenitor stage to develop a MLL-r model capturing early cellular and molecular consequences of MLL-ENL expression based on a clear clonal relationship between parental and leukaemic cells. Through a combination of scRNA-seq, ATAC-seq and genome-scale CRISPR-Cas9 screening, we identify pathways and genes likely to drive the early phases of leukaemogenesis. Finally, we demonstrate the broad utility of using matched parental and transformed cells for small molecule inhibitor studies by validating both previously known and other potential therapeutic targets.

RNA Nanotherapeutics for the Amelioration of Astroglial Reactivity

In response to injuries to the CNS, astrocytes enter a reactive state known as astrogliosis, which is believed to be deleterious in some contexts. Activated astrocytes overexpress intermediate filaments including glial fibrillary acidic protein (GFAP) and vimentin (Vim), resulting in entangled cells that inhibit neurite growth and functional recovery. Reactive astrocytes also secrete inflammatory molecules such as Lipocalin 2 (Lcn2), which perpetuate reactivity and adversely affect other cells of the CNS. Herein, we report proof-of-concept use of the packaging RNA (pRNA)-derived three-way junction (3WJ) motif as a platform for the delivery of siRNAs to downregulate such reactivity-associated genes. In vitro, siRNA-3WJs induced a significant knockdown of Gfap, Vim, and Lcn2 in a model of astroglial activation, with a concomitant reduction in protein expression. Knockdown of Lcn2 also led to reduced protein secretion from reactive astroglial cells, significantly impeding the perpetuation of inflammation in otherwise quiescent astrocytes. Intralesional injection of anti-Lcn2-3WJs in mice with contusion spinal cord injury led to knockdown of Lcn2 at mRNA and protein levels in vivo. Our results provide evidence for siRNA-3WJs as a promising platform for ameliorating astroglial reactivity, with significant potential for further functionalization and adaptation for therapeutic applications in the CNS.

Dysregulation of haematopoietic stem cell regulatory programs in acute myeloid leukaemia

Haematopoietic stem cells (HSC) are situated at the apex of the haematopoietic differentiation hierarchy, ensuring the life-long supply of mature haematopoietic cells and forming a reservoir to replenish the haematopoietic system in case of emergency such as acute blood loss. To maintain a balanced production of all mature lineages and at the same time secure a stem cell reservoir, intricate regulatory programs have evolved to control multi-lineage differentiation and self-renewal in haematopoietic stem and progenitor cells (HSPCs). Leukaemogenic mutations commonly disrupt these regulatory programs causing a block in differentiation with simultaneous enhancement of proliferation. Here, we briefly summarize key aspects of HSPC regulatory programs, and then focus on their disruption by leukaemogenic fusion genes containing the mixed lineage leukaemia (MLL) gene. Using MLL as an example, we explore important questions of wider significance that are still under debate, including the importance of cell of origin, to what extent leukaemia oncogenes impose specific regulatory programs and the relevance of leukaemia stem cells for disease development and prognosis. Finally, we suggest that disruption of stem cell regulatory programs is likely to play an important role in many other pathologies including ageing-associated regenerative failure.

An experimentally validated network of nine haematopoietic transcription factors reveals mechanisms of cell state stability

Transcription factor (TF) networks determine cell-type identity by establishing and maintaining lineage-specific expression profiles, yet reconstruction of mammalian regulatory network models has been hampered by a lack of comprehensive functional validation of regulatory interactions. Here, we report comprehensive ChIP-Seq, transgenic and reporter gene experimental data that have allowed us to construct an experimentally validated regulatory network model for haematopoietic stem/progenitor cells (HSPCs). Model simulation coupled with subsequent experimental validation using single cell expression profiling revealed potential mechanisms for cell state stabilisation, and also how a leukaemogenic TF fusion protein perturbs key HSPC regulators. The approach presented here should help to improve our understanding of both normal physiological and disease processes.

Genome-scale definition of the transcriptional programme associated with compromised PU.1 activity in acute myeloid leukaemia

Transcriptional dysregulation is associated with haematological malignancy. Although mutations of the key haematopoietic transcription factor PU.1 are rare in human acute myeloid leukaemia (AML), they are common in murine models of radiation-induced AML, and PU.1 downregulation and/or dysfunction has been described in human AML patients carrying the fusion oncogenes RUNX1-ETO and PML-RARA. To study the transcriptional programmes associated with compromised PU.1 activity, we adapted a Pu.1-mutated murine AML cell line with an inducible wild-type PU.1. PU.1 induction caused transition from leukaemia phenotype to monocytic differentiation. Global binding maps for PU.1, CEBPA and the histone mark H3K27Ac with and without PU.1 induction showed that mutant PU.1 retains DNA-binding ability, but the induction of wild-type protein dramatically increases both the number and the height of PU.1-binding peaks. Correlating chromatin immunoprecipitation (ChIP) Seq with gene expression data, we found that PU.1 recruitment coupled with increased histone acetylation induces gene expression and activates a monocyte/macrophage transcriptional programme. PU.1 induction also caused the reorganisation of a subgroup of CEBPA binding peaks. Finally, we show that the PU.1 target gene set defined in our model allows the stratification of primary human AML samples, shedding light on both known and novel AML subtypes that may be driven by PU.1 dysfunction.

Outcomes of percutaneous tracheostomy

AIM

Percutaneous dilatational tracheostomy (PDT) is one of the most commonly performed procedures in critically ill patients receiving mechanical ventilation. Although many papers have compared different PDT techniques, few records on the outcome of tracheostomized patients after intensive care unit (ICU) discharge are available.

METHODS

Prospective observational study to evaluate efficacy, safety and long-term consequences of PDT performed over a 6-year period (January 2002-December 2007) in a combined medical/surgical ICU in Rho, Milan, Italy. A total of 181 patients were subjected to PDT, 26.5% with the Ciaglia technique and 73.5% with the Percu-twist technique.

RESULTS

The main endpoints that were examined were complications related to PDT and the final outcome of tracheostomized patients. Early complications included minor bleeding in 4 patients, stomal infection in 8 patients, and the occurrence of hypoxic/desaturation events during the procedure in 3 cases. Late complications included: tracheal stenosis in a single case, recurrent stomal granuloma in 2 cases, and tracheal mucosa injury caused by the endotracheal tube cuff in 3 patients. All patients who were decannulated late underwent bronchoscopic follow-up at 3, 6 and 12 months. Hospital discharge: of the 137 patients alive at the time of discharge from the hospital, 115 were decannulated (40 early decannulation, 75 late decannulation). In total, 22 patients were never decannulated (14 breathed spontaneously whereas 8 needed ventilator support). In the group of patients that were decannulated late, the mortality rate at 1 year was 20.6%.

CONCLUSIONS

PDT-related early complications without clinical consequences were observed. Conversely, late complications were infrequent but had significant clinical implications. Although late decannulation is the major risk for complications, in 83.9% of cases tracheostomy is only a temporary measure.

[Cornea donation: role of the local coordinator in monitoring and implementation]

BACKGROUND

In order to contribute to the dissemination of an organ and tissue donation culture, the authors report the results of a retrospective investigation into the donation of corneas for transplantation relative to the period from January 1997 to December 2001 at a leading hospital in the Milan area.

METHODS

All cases of intra-hospital death (n=2137) were considered. The adoption of a selection protocol for potential donors, in accordance with the indications of the North Italy Transplant program, and constant monitoring on the part of the local coordinator, led to the collection of 348 corneal flaps using the procedure whereby all deaths have to be notified to the Health Department.

RESULTS

Over this period, the donors/deaths ratio increased from 2.1 to 17.6%, while the collection index (real donors/potential donors including those wrongly excluded) increased from 40.8% in 1999-2000 to 67.8% in 2001. Most involved in the donor selection activity were the intensive care centres with an increase for Resuscitation of 12.7% and for First Aid of 33%, to a lesser extent non-intensive centres (increase of 11.2%). The causes of exclusion from cornea collection in the last three-year period were clinical contraindications in 51.2% of cases (sepsis, blood transfusions, diseases of the central nervous system of unknown aetiology), failure to activate the procedures in 17.4% of cases, opposition in 17%, unsuitability of the corneal tissues in 11.3%, inadequate age in 3%.

CONCLUSIONS

The results obtained indicate good prospects for technical implementation and for the development of a donation culture in respect of other organs and tissues.

[Initial epidemiological data on the clinical effects in health workers employed in the manual lifting of patients in wards]

An investigation was carried out by teams from various centres coordinated by the EPM (Ergonomics of Posture and Movement) Research Unit on 54 different hospitals in various regions of northern and central Italy. The teams examined a total of 3341 health workers whose job involved manual handling of patients (553 male and 2788 females, 1568 working in hospitals and 1773 in geriatric residences). Numerous meetings were held to ensure that the methods of assessing the exposure indexes and spinal impairment were identical in the various teams. The final data were processed centrally at the EPM Research Unit. The sample analyzed may be considered as representative of the situation in hospitals in Italy, at least for northern and central Italy. The mean age was 36 years, mean length of service in the department 6 years and mean length of job duration not exceeding 10 years; staff turnover was high. Physical examination revealed that 8.4% of the workers had had at least one episode of acute low back pain in the previous 12 months: i.e., 4 times the values of the reference groups. Also in the case of clinical-functional spondyloarthropathies of the lumbosacral spine, in the females there was a significantly higher prevalence than in the reference groups. All disorders were more severe in sectors more at risk, i.e., old peoples homes, rehabilitation centres, orthopaedic and surgical departments, and in any case higher in old peoples homes and geriatric residences. The initial data concerning the ratio between presence of spinal disease and risk index were also positive.

[The management of the risk due to the manual lifting of patients in a hospital risk-management program]

Application of Law 626/94 in the health care area is still only partial and in many respects practically in the initial stages. This is due to a number of causes, including the special features of this sector and the extreme variability and diffusion of the risk factors involved. Assessment of risk, especially the newest ones (from manual patient handling to biological agents) involves considerable difficulties, also because the usual methods cannot be applied. The process of assessment and especially the management of risks in this sector is an extremely complex problem, and to address it requires the creation of an organized structure within the hospital consisting of a general manager, or a person delegated by the same, the medical director, the administrative director, the certified occupational physician, the director of prevention and protection. This management team must be flexible in character, draw up strategic plans according to priority criteria, periodically assess the state of advancement of the plans that will be carried out in phases. It is also necessary to ensure the active cooperation of worker safety representatives and of other experts who may be involved in the various topics addressed from time to time. The authors propose a method used in a three-year project, still under way, for the assessment of risk due to manual patient handling in a major Italian hospital; the data obtained from an assessment made in 58 wards were the following: about 60% of the wards showed a medium-high exposure level, 24% negligible exposure levels and 13.8% zero exposure due to the absence of disabled patients. On the basis of the initial data obtained from health surveillance programmes on a group of 431 exposed subjects, about 10% were judged fit with limitations due to spinal disorders. The main problems that have arisen (management, organisation, training, transfer of workers with limited job fitness, accreditation) are discussed. The method proposed for management of risk due to manual handling of patients is considered suitable for other risk factors, within the framework of a more far reaching programme for application of Law 626/94, as a means of permanent management of risk in a particularly complex working environment such as that of a hospital.

[Chemical and physical characteristics and toxicology of man-made mineral fibers]

The evidence for the adverse health effects following exposure to asbestos (i.e. fibrogenic and carcinogenic effect) has prompted widespread removal of asbestos-containing materials and led to banning of asbestos internationally (in Italy, DPR 257/1992), resulting in the increased use of substitutes composed of both naturally occurring and synthetic materials, including man made mineral fibres (MMMFs) and man made organic fibres (MMOF). MMMFs represent a family of synthetic, inorganic vitreous substances derived primarily from glass, rock, slag, or clay. MMMFs are further divided into two categories: 1) man made vitreous fibres (MMVFs), further divided as follows: a) fibrous glass, including mainly continuous filament, special purpose fibres; and microfibres. The materials are typically composed of oxides of silicon, calcium, sodium, potassium, aluminum, and boron. b) Mineral wool, including glass wool, rock wool (derived from magma rock) and slag wool (made from molten slag produced in metallurgical processes such as the production of iron, steel, or copper). The main components of rock wool and slag wool are oxides of silicon, calcium, magnesium, aluminum, and iron. 2) Refractory/ceramic fibres, amorphous or partially crystalline materials made from kaolin clay or oxides of aluminum, silicon or other metal oxides (i.e. oxides of zirconium and yttrium). Less commonly, refractory fibres are also made from non-oxide refractory materials such as silicon carbide, silicon nitride, or boron nitride. Industrial production of MMVFs began in the second half of the 19th century, while ceramic fibres production began more recently, in the early 1970s. Major uses of MMMFs include thermal, acoustic and aerospace insulation, fire proofing, reinforcing material in plastics, cement and textile, optic fibres, air and liquid filtration, friction products, refractory coatings. Serious questions have been raised about health implications of MMMFs. Suspicion about the possible occurrence of adverse effects following exposure to MMMFs arises mainly from some similarities of MMMFs with asbestos (fibrous aspects, inhalability, chemical composition, free radical formation). The fibre characteristics that have been identified as crucial in influencing the pathogenesis of fibre-related adverse respiratory effects can be mainly divided into two groups: fibre dimension, and chemical composition and structure. Fibre dimension plays a determining role in conditioning penetration in the lung. In a broad sense, the term "respirable" means "capable of being carried by breath into the respiratory system". For regulatory purposes, "respirable fibres" (i.e. RFP) are defined in most countries following WHO criteria: length > 5 microns, diameter < 3 microns, length/diameter > 3. MMMFs are generally produced as fibres of diameter higher than asbestos, and too large in diameter to be respirable. Moreover, due to the production process, they are structurally amorphous. Since MMMFs have no crystalline domains, they also have no clearly defined structural faults and they fracture transversely, and randomly. Fragments that are too large to be taken up by macrophages can be resolved in the lung by a leaching--or dissolution--process which leads to a progressive reduction of particle length. In contrast, when abraded, asbestos tends to split longitudinally into new, fine, straight fibres: these fibrils are of much smaller diameter, more respirable, and consequently more hazardous than parent fibres. Fibre chemical composition plays a determining role in conditioning the higher or lower biological activity, durability, biopersistence, and biodegradability. The term "biological activity" means reactivity or ability to interact (possibly due to formation of active oxygen species, identified as a crucial step in the mechanism of action) with biological structures and tissues. Fibre "durability" is strictly related to its solubility. It can be defined as the ability to resist

[Cognitive evaluation of patients with temporal epilepsy, candidates for surgery]

We provide a short overview on selected aspects of the neuropsychology of patients with temporal lobe epilepsy candidate to surgery. The possible impairment of verbal and non verbal memory is treated in particular. We also present the neuropsychological test battery that we use for the cognitive assessment of such patients before surgery and in the follow-up phase.