Magnesium sensing via LFA-1 regulates CD8+ T cell effector function.

The relevance of extracellular magnesium in cellular immunity remains largely unknown. Here, we show that the co-stimulatory cell-surface molecule LFA-1 requires magnesium to adopt its active conformation on CD8+ T cells, thereby augmenting calcium flux, signal transduction, metabolic reprogramming, immune synapse formation, and, as a consequence, specific cytotoxicity. Accordingly, magnesium-sufficiency sensed via LFA-1 translated to the superior performance of pathogen- and tumor-specific T cells, enhanced effectiveness of bi-specific T cell engaging antibodies, and improved CAR T cell function. Clinically, low serum magnesium levels were associated with more rapid disease progression and shorter overall survival in CAR T cell and immune checkpoint antibody-treated patients. LFA-1 thus directly incorporates information on the composition of the microenvironment as a determinant of outside-in signaling activity. These findings conceptually link co-stimulation and nutrient sensing and point to the magnesium-LFA-1 axis as a therapeutically amenable biologic system.

Comparison of the oncolytic activity of a replication-competent and a replication-deficient herpes simplex virus 1.

In 2015, the oncolytic herpes simplex virus 1 (HSV-1) T-VEC (talimogene laherparepvec) was approved for intratumoral injection in non-resectable malignant melanoma. To determine whether viral replication is required for oncolytic activity, we compared replication-deficient HSV-1 d106S with replication-competent T-VEC. High infectious doses of HSV-1 d106S killed melanoma (n = 10), head-and-neck squamous cell carcinoma (n = 11), and chondrosarcoma cell lines (n = 2) significantly faster than T-VEC as measured by MTT metabolic activity, while low doses of T-VEC were more effective over time. HSV-1 d106S and, to a lesser extent T-VEC, triggered caspase-dependent early apoptosis as shown by pan-caspase inhibition and specific induction of caspases 3/7, 8, and 9. HSV-1 d106S induced a higher ratio of apoptosis-inducing infected cell protein (ICP) 0 to apoptosis-blocking ICP6 than T-VEC. T-VEC was oncolytic for an extended period of time as viral replication continued, which could be partially blocked by the antiviral drug aciclovir. High doses of T-VEC, but not HSV-1 d106S, increased interferon-ß mRNA as part of the intrinsic immune response. When markers of immunogenic cell death were assessed, ATP was released more efficiently in the context of T-VEC than HSV-1 d106S infection, whereas HMGB1 was induced comparatively well. Overall, the early oncolytic effect on three different tumour entities was stronger with the non-replicative strain, while the replication-competent virus elicited a stronger innate immune response and more pronounced immunogenic cell death.

Feasibility of oncology clinical trial-embedded evaluation of social determinants of health.

Social determinants of health (SDoH) are associated with stark disparities in cancer outcomes, but systematic SDoH data collection is virtually absent from oncology clinical trials. Trial-based SDoH data are essential to ensure representation of marginalized populations, contextualize outcome disparities, and identify health-equity intervention opportunities. We report the feasibility of a pediatric oncology multicenter therapeutic trial-embedded SDoH investigation. Among 448 trial participants, 392 (87.5%) opted-in to the embedded SDoH study; 375 (95.7%) completed baseline surveys, with high longitudinal response rates (88.9-93.1%) over 24 months. Trial-embedded SDoH data collection is feasible and acceptable and must be consistently included within future oncology trials.

CRISPR-Cas9 Mediated TSPO Gene Knockout alters Respiration and Cellular Metabolism in Human Primary Microglia Cells.

The 18 kDa translocator protein (TSPO) is an evolutionary conserved cholesterol binding protein localized in the outer mitochondrial membrane. It has been implicated in the regulation of various cellular processes including oxidative stress, proliferation, apoptosis, and steroid hormone biosynthesis. Since the expression of TSPO in activated microglia is upregulated in various neuroinflammatory and neurodegenerative disorders, we set out to examine the role of TSPO in an immortalized human microglia C20 cell line. To this end, we performed a dual approach and used (i) lentiviral shRNA silencing to reduce TSPO expression, and (ii) the CRISPR/Cas9 technology to generate complete TSPO knockout microglia cell lines. Functional characterization of control and TSPO knockdown as well as knockout cells, revealed only low de novo steroidogenesis in C20 cells, which was not dependent on the level of TSPO expression or influenced by the treatment with TSPO-specific ligands. In contrast to TSPO knockdown C20 cells, which did not show altered mitochondrial function, the TSPO deficient knockout cells displayed a significantly decreased mitochondrial membrane potential and cytosolic Ca2+ levels, as well as reduced respiratory function. Performing the rescue experiment by lentiviral overexpression of TSPO in knockout cells, increased oxygen consumption and restored respiratory function. Our study provides further evidence for a significant role of TSPO in cellular and mitochondrial metabolism and demonstrates that different phenotypes of mitochondrial function are dependent on the level of TSPO expression.

Oral Mercaptopurine Adherence in Pediatric Acute Lymphoblastic Leukemia: A Survey Study From the Dana-Farber Cancer Institute Acute Lymphoblastic Leukemia Consortium.

Background: Oral chemotherapy nonadherence is a challenge in clinical oncology. During therapy for acute lymphoblastic leukemia (ALL), poor adherence to 6-mercaptopurine (6MP) increases relapse risk. Clinically significant nonadherence is reported in 30% of children treated for ALL on Children's Oncology Group (COG) trials. Whether nonadherence rates vary across regimens with different treatment schedules and modes of administration is unknown. Methods: We conducted an exploratory, cross-sectional survey study on parents of children (1-18 years) receiving continuation therapy on, or as per Dana-Farber Cancer Institute (DFCI) ALL Consortium Protocol 11-001. Treatment required weekly visits to the clinic and 14 days of oral 6MP every 3 weeks. Survey assessed self-reported sociodemographics, medication-taking, chemotherapy comprehension, and 6MP adherence; adherence survey items were developed from published surveys. Patients were grouped as nonadherent if they endorsed missing one 6MP dose during the last cycle, or more than one dose during prior cycles, for nonmedical reasons. Results: Sixty-two families completed the surveys, all of whom had evaluable adherence data. In total, 25% of patients met the study definition of nonadherence. Twenty-three percent reported that it was "not easy" to follow administration guidelines around the dairy intake and 57% requested more teaching and educational resources. Conclusion: Self-reported nonadherence to oral 6MP in the DFCI ALL Consortium is high, with rates similar to those observed in the COG. This suggests that the additional contact during weekly infusions on the DFCI is insufficient to address barriers affecting oral chemotherapy adherence.

Disparities in parental distress in a multicenter clinical trial for pediatric acute lymphoblastic leukemia.

BACKGROUND: Parent psychological distress during childhood cancer treatment has short- and long-term implications for parent, child, and family well-being. Identifying targetable predictors of parental distress is essential to inform interventions. We investigated the association between household material hardship (HMH), a modifiable poverty-exposure defined as housing, food, or utility insecurity, and severe psychological distress among parents of children aged 1-17 years with acute lymphoblastic leukemia (ALL) enrolled on the multicenter Dana-Farber ALL Consortium Trial 16-001. METHODS: This was a secondary analysis of parent-reported data. Parents completed an HMH survey within 32 days of clinical trial enrollment (T0) and again at 6 months into therapy (T1). The primary exposure was HMH at T0 and primary outcome was severe parental distress at T0 and T1, defined as a score greater than or equal to 13 on the Kessler-6 Psychological Distress Scale. Multivariable models were adjusted for ALL risk group and single parent status. RESULTS: Among 375 evaluable parents, one-third (32%; n = 120/375) reported HMH at T0. In multivariable analyses, T0 HMH was associated with over twice the odds of severe psychological distress at T0 and T1 HMH was associated with over 5 times the odds of severe distress at T1. CONCLUSIONS: Despite uniform clinical trial treatment of their children at well-resourced pediatric centers, HMH-exposed parents-compared with unexposed parents-experienced statistically significantly increased odds of severe psychological distress at the time of their child's leukemia diagnosis, which worsened 6 months into therapy. These data identify a high-risk parental population who may benefit from early psychosocial and HMH-targeted interventions to mitigate disparities in well-being.

NK cells with tissue-resident traits shape response to immunotherapy by inducing adaptive antitumor immunity.

T cell-directed cancer immunotherapy often fails to generate lasting tumor control. Harnessing additional effectors of the immune response against tumors may strengthen the clinical benefit of immunotherapies. Here, we demonstrate that therapeutic targeting of the interferon-γ (IFN-γ)-interleukin-12 (IL-12) pathway relies on the ability of a population of natural killer (NK) cells with tissue-resident traits to orchestrate an antitumor microenvironment. In particular, we used an engineered adenoviral platform as a tool for intratumoral IL-12 immunotherapy (AdV5-IL-12) to generate adaptive antitumor immunity. Mechanistically, we demonstrate that AdV5-IL-12 is capable of inducing the expression of CC-chemokine ligand 5 (CCL5) in CD49a+ NK cells both in tumor mouse models and tumor specimens from patients with cancer. AdV5-IL-12 imposed CCL5-induced type I conventional dendritic cell (cDC1) infiltration and thus increased DC-CD8 T cell interactions. A similar observation was made for other IFN-γ-inducing therapies such as Programmed cell death 1 (PD-1) blockade. Conversely, failure to respond to IL-12 and PD-1 blockade in tumor models with low CD49a+ CXCR6+ NK cell infiltration could be overcome by intratumoral delivery of CCL5. Thus, therapeutic efficacy depends on the abundance of NK cells with tissue-resident traits and, specifically, their capacity to produce the DC chemoattractant CCL5. Our findings reveal a barrier for T cell-focused therapies and offer mechanistic insights into how T cell-NK cell-DC cross-talk can be enhanced to promote antitumor immunity and overcome resistance.

Whole-transcriptome analysis in acute lymphoblastic leukemia: a report from the DFCI ALL Consortium Protocol 16-001.

The molecular hallmark of childhood acute lymphoblastic leukemia (ALL) is characterized by recurrent, prognostic genetic alterations, many of which are cryptic by conventional cytogenetics. RNA sequencing (RNA-seq) is a powerful next-generation sequencing technology that can simultaneously identify cryptic gene rearrangements, sequence mutations and gene expression profiles in a single assay. We examined the feasibility and utility of incorporating RNA-seq into a prospective multicenter phase 3 clinical trial for children with newly diagnosed ALL. The Dana-Farber Cancer Institute ALL Consortium Protocol 16-001 enrolled 173 patients with ALL who consented to optional studies and had samples available for RNA-seq. RNA-seq identified at least 1 alteration in 157 patients (91%). Fusion detection was 100% concordant with results obtained from conventional cytogenetic analyses. An additional 56 gene fusions were identified by RNA-seq, many of which confer prognostic or therapeutic significance. Gene expression profiling enabled further molecular classification into the following B-cell ALL (B-ALL) subgroups: high hyperdiploid (n = 36), ETV6-RUNX1/-like (n = 31), TCF3-PBX1 (n = 7), KMT2A-rearranged (KMT2A-R; n = 5), intrachromosomal amplification of chromosome 21 (iAMP21) (n = 1), hypodiploid (n = 1), Philadelphia chromosome (Ph)-positive/Ph-like (n = 16), DUX4-R (n = 11), PAX5 alterations (PAX5 alt; n = 11), PAX5 P80R (n = 1), ZNF384-R (n = 4), NUTM1-R (n = 1), MEF2D-R (n = 1), and others (n = 10). RNA-seq identified 141 nonsynonymous mutations in 93 patients (54%); the most frequent were RAS-MAPK pathway mutations. Among 79 patients with both low-density array and RNA-seq data for the Philadelphia chromosome-like gene signature prediction, results were concordant in 74 patients (94%). In conclusion, RNA-seq identified several clinically relevant genetic alterations not detected by conventional methods, which supports the integration of this technology into front-line pediatric ALL trials. This trial was registered at www.clinicaltrials.gov as #NCT03020030.

Efficacy and Toxicity of Pegaspargase and Calaspargase Pegol in Childhood Acute Lymphoblastic Leukemia: Results of DFCI 11-001.

PURPOSE: Dana-Farber Cancer Institute Acute Lymphoblastic Leukemia (ALL) Consortium Protocol 11-001 assessed efficacy and toxicity of calaspargase pegol (calaspargase), a novel pegylated asparaginase formulation with longer half-life, compared with the standard formulation pegaspargase. METHODS: Patients age 1 to ≤ 21 years with newly diagnosed ALL or lymphoblastic lymphoma were randomly assigned to intravenous pegaspargase or calaspargase, 2,500 IU/m2/dose. Patients received one induction dose. Beginning week 7, pegaspargase was administered every 2 week for 15 doses and calaspargase every 3 week for 10 doses (30 weeks). Serum asparaginase activity (SAA) (≥ 0.1 IU/mL considered therapeutic) was assessed 4, 11, 18, and 25 days after the induction dose and before each postinduction dose. RESULTS: Between 2012 and 2015, 239 eligible patients enrolled (230 ALL, nine lymphoblastic lymphoma); 120 were assigned to pegaspargase and 119 to calaspargase. After the induction dose, SAA was ≥ 0.1 IU/mL in ≥ 95% of patients on both arms 18 days after dosing. At day 25, more patients had SAA ≥ 0.1 IU/mL with calaspargase (88% v 17%; P ˂ .001). Postinduction, median nadir SAAs were similar (≥ 1.0 IU/mL) for both arms. Of 230 evaluable patients, 99% of pegaspargase and 95% of calaspargase patients achieved complete remission (P = .12), with no difference in frequency of high end-induction minimal residual disease among evaluable patients with B acute lymphoblastic leukemia (B-ALL). There were no differences in frequencies of asparaginase allergy, pancreatitis, thrombosis, or hyperbilirubinemia. With 5.3 years median follow-up, 5-year event-free survival for pegaspargase was 84.9% (SE ± 3.4%) and 88.1% (± SE 3.0%) for calaspargase (P = .65). CONCLUSION: Every 3-week calaspargase had similar nadir SAA, toxicity, and survival outcomes compared with every 2-week pegaspargase. The high nadir SAA observed for both preparations suggest dosing strategies can be further optimized.

Randomized clinical trial of therapeutic exercise in subacute stroke.

BACKGROUND AND PURPOSE: Rehabilitation care after stroke is highly variable and increasingly shorter in duration. The effect of therapeutic exercise on impairments and functional limitations after stroke is not clear. The objective of this study was to determine whether a structured, progressive, physiologically based exercise program for subacute stroke produces gains greater than those attributable to spontaneous recovery and usual care. METHODS: This randomized, controlled, single-blind clinical trial was conducted in a metropolitan area and 17 participating healthcare institutions. We included persons with stroke who were living in the community. One hundred patients (mean age, 70 years; mean Orpington score, 3.4) consented and were randomized from a screened sample of 582. Ninety-two subjects completed the trial. Intervention was a structured, progressive, physiologically based, therapist-supervised, in-home program of thirty-six 90-minute sessions over 12 weeks targeting flexibility, strength, balance, endurance, and upper-extremity function. Main outcome measures were postintervention strength (ankle and knee isometric peak torque, grip strength), upper- and lower-extremity motor control (Fugl Meyer), balance (Berg and functional reach), endurance (peak aerobic capacity and exercise duration), upper-extremity function (Wolf Motor Function Test), and mobility (timed 10-m walk and 6-minute walk distance). RESULTS: In the intention-to-treat multivariate analysis of variance testing the overall effect, the intervention produced greater gains than usual care (Wilk's lambda=0.64, P=0.0056). Both intervention and usual care groups improved in strength, balance, upper- and lower-extremity motor control, upper-extremity function, and gait velocity. Gains for the intervention group exceeded those in the usual care group in balance, endurance, peak aerobic capacity, and mobility. Upper-extremity gains exceeded those in the usual care group only in patients with higher baseline function. CONCLUSIONS: This structured, progressive program of therapeutic exercise in persons who had completed acute rehabilitation services produced gains in endurance, balance, and mobility beyond those attributable to spontaneous recovery and usual care.