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H3K27M-mutant diffuse midline gliomas (DMGs) express high levels of the disialoganglioside GD2 (ref. 1 ). Chimeric antigen receptor-modified T cells targeting GD2 (GD2-CART) eradicated DMGs in preclinical models 2 . Arm A of Phase I trial no. NCT04196413 (ref.  3 ) administered one intravenous (IV) dose of autologous GD2-CART to patients with H3K27M-mutant pontine (DIPG) or spinal DMG (sDMG) at two dose levels (DL1, 1 × 10 6  kg - 1 ; DL2, 3 × 10 6  kg -1 ) following lymphodepleting chemotherapy. Patients with clinical or imaging benefit were eligible for subsequent intracerebroventricular (ICV) intracranial infusions (10-30 × 10 6 GD2-CART). Primary objectives were manufacturing feasibility, tolerability and the identification of maximally tolerated IV dose. Secondary objectives included preliminary assessments of benefit. Thirteen patients enroled, with 11 receiving IV GD2-CART on study (n = 3 DL1 (3 DIPG); n = 8 DL2 (6 DIPG, 2 sDMG)). GD2-CART manufacture was successful for all patients. No dose-limiting toxicities occurred on DL1, but three patients experienced dose-limiting cytokine release syndrome on DL2, establishing DL1 as the maximally tolerated IV dose. Nine patients received ICV infusions, with no dose-limiting toxicities. All patients exhibited tumour inflammation-associated neurotoxicity, safely managed with intensive monitoring and care. Four patients demonstrated major volumetric tumour reductions (52, 54, 91 and 100%), with a further three patients exhibiting smaller reductions. One patient exhibited a complete response ongoing for over 30 months since enrolment. Nine patients demonstrated neurological benefit, as measured by a protocol-directed clinical improvement score. Sequential IV, followed by ICV GD2-CART, induced tumour regressions and neurological improvements in patients with DIPG and those with sDMG., Competing Interests: Competing interests M.M., R.M. and C. Mackall are coinventors on a patent for the use of GD2-CAR T cells in regard to H2K27M gliomas, coordinated through Stanford University. C. Mackall is a coinventor on patents for the use of dasatinib and other small molecules to modulate CAR function and control CAR-associated toxicity, and on several patents related to CAR T cell therapies. C. Mackall holds equity in CARGO Therapeutics, Link Cell Therapies and GBM Newco, which are developing CAR-based therapies, and consults for CARGO, Link, Immatics, Ensoma, GBM NewCo and Red Tree Capital. She receives research funding from Lyell and Tune Therapeutics. R.M. is a cofounder of, and holds equity in, Link Cell Therapies and CARGO Therapeutics, and is a consultant for Lyell Immunopharma, NKarta, Arovella Pharmaceuticals, Innervate Radiopharmaceuticals, Aptorum Group, Gadeta, FATE Therapeutics (Data and Safety Monitoring Board) and Waypoint Bio. S.A.F. holds several patents in the field of cellular immunotherapy. V.B. is an investor and Director at Umoja Biopharma and Arsenal Bio. S.P.R. holds equity in Lyell Immunopharma. M.M. holds equity in MapLight Therapeutics and CARGO Therapeutics. The other authors declare no competing interests., (© 2024. The Author(s).)

Copy-number variants (CNVs) have been implicated in a variety of neuropsychiatric and cognitive phenotypes. We found that deleterious CNVs are less prevalent in non-European ancestry groups than they are in European ancestry groups of both the UK Biobank (UKBB) and a US replication cohort (SPARK). We also identified specific recurrent CNVs that consistently differ in frequency across ancestry groups in both the UKBB and SPARK. These ancestry-related differences in CNV prevalence present in both an unselected community population and a family cohort enriched with individuals diagnosed with autism spectrum disorder (ASD) strongly suggest that genetic ancestry should be considered when probing associations between CNVs and health outcomes., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Importance: Functional brain networks are associated with both behavior and genetic factors. To uncover clinically translatable mechanisms of psychopathology, it is critical to define how the spatial organization of these networks relates to genetic risk during development., Objective: To determine the relationship between transdiagnostic polygenic risk scores (PRSs), personalized functional brain networks (PFNs), and overall psychopathology (p-factor) during early adolescence., Design: The Adolescent Brain Cognitive Development (ABCD) Study is an ongoing longitudinal cohort study of 21 collection sites across the United States. Here, we conduct a cross-sectional analysis of ABCD baseline data, collected 2017-2018., Setting: The ABCD Study ® is a multi-site community-based study., Participants: The sample is largely recruited through school systems. Exclusion criteria included severe sensory, intellectual, medical, or neurological issues that interfere with protocol and scanner contraindications. Split-half subsets were used for cross-validation, matched on age, ethnicity, family structure, handedness, parental education, site, sex, and anesthesia exposure., Exposures: Polygenic risk scores of transdiagnostic genetic factors F1 (PRS-F1) and F2 (PRS-F2) derived from adults in Psychiatric Genomic Consortium and UK Biobanks datasets. PRS-F1 indexes liability for common psychiatric symptoms and disorders related to mood disturbance; PRS-F2 indexes liability for rarer forms of mental illness characterized by mania and psychosis., Main Outcomes and Measures: (1) P-factor derived from bifactor models of youth- and parent-reported mental health assessments. (2) Person-specific functional brain network topography derived from functional magnetic resonance imaging (fMRI) scans., Results: Total participants included 11,873 youths ages 9-10 years old; 5,678 (47.8%) were female, and the mean (SD) age was 9.92 (0.62) years. PFN topography was found to be heritable ( N =7,459, 57.06% of vertices h 2 p FDR <0.05, mean h 2 =0.35). PRS-F1 was associated with p-factor ( N =5,815, r =0.12, 95% CI [0.09-0.15], p<0.001). Interindividual differences in functional network topography were associated with p-factor ( N =7,459, mean r =0.12), PRS-F1 ( N =3,982, mean r =0.05), and PRS-F2 ( N =3,982, mean r =0.08). Cortical maps of p-factor and PRS-F1 regression coefficients were highly correlated ( r =0.7, p =0.003)., Conclusions and Relevance: Polygenic risk for transdiagnostic adulthood psychopathology is associated with both p-factor and heritable PFN topography during early adolescence. These results advance our understanding of the developmental drivers of psychopathology.

H3K27M-mutant diffuse midline gliomas (DMGs) express high levels of the GD2 disialoganglioside and chimeric antigen receptor modified T-cells targeting GD2 (GD2-CART) eradicate DMGs in preclinical models. Arm A of the Phase I trial NCT04196413 administered one IV dose of autologous GD2-CART to patients with H3K27M-mutant pontine (DIPG) or spinal (sDMG) diffuse midline glioma at two dose levels (DL1=1e6/kg; DL2=3e6/kg) following lymphodepleting (LD) chemotherapy. Patients with clinical or imaging benefit were eligible for subsequent intracerebroventricular (ICV) GD2-CART infusions (10-30e6 GD2-CART). Primary objectives were manufacturing feasibility, tolerability, and identification of a maximally tolerated dose of IV GD2-CART. Secondary objectives included preliminary assessments of benefit. Thirteen patients enrolled and 11 received IV GD2-CART on study [n=3 DL1(3 DIPG); n=8 DL2(6 DIPG/2 sDMG). GD2-CART manufacturing was successful for all patients. No dose-limiting toxicities (DLTs) occurred on DL1, but three patients experienced DLT on DL2 due to grade 4 cytokine release syndrome (CRS). Nine patients received ICV infusions, which were not associated with DLTs. All patients exhibited tumor inflammation-associated neurotoxicity (TIAN). Four patients demonstrated major volumetric tumor reductions (52%, 54%, 91% and 100%). One patient exhibited a complete response ongoing for >30 months since enrollment. Eight patients demonstrated neurological benefit based upon a protocol-directed Clinical Improvement Score. Sequential IV followed by ICV GD2-CART induced tumor regressions and neurological improvements in patients with DIPG and sDMG. DL1 was established as the maximally tolerated IV GD2-CART dose. Neurotoxicity was safely managed with intensive monitoring and close adherence to a management algorithm.

Chimeric antigen receptor (CAR) T cells targeting CD22 (CD22-CAR) provide a therapeutic option for patients with CD22 + malignancies with progression after CD19-directed therapies. Using on-site, automated, closed-loop manufacturing, we conducted parallel Phase 1b clinical trials investigating a humanized CD22-CAR with 41BB costimulatory domain in children and adults with heavily treated, relapsed/refractory (r/r) B-ALL. Of 19 patients enrolled, 18 had successful CD22-CAR manufacturing, and 16 patients were infused. High grade (3-4) cytokine release syndrome (CRS) and immune effector-cell-associated neurotoxicity syndrome (ICANS) each occurred in only one patient; however, three patients experienced immune-effector-cell-associated hemophagocytic lymphohistiocytosis-like syndrome (IEC-HS). Twelve of 16 patients (75%) achieved CR with an overall 56% MRD-negative CR rate. Duration of response was overall limited (median 77 days), and CD22 expression was downregulated in 4/12 (33%) available samples at relapse. In summary, we demonstrate that closed-loop manufacturing of CD22-CAR T cells is feasible and is associated with a favorable safety profile and high CR rates in pediatric and adult r/r B-ALL, a cohort with limited CD22-CAR reporting., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the treatment of B cell malignancies, with multiple CAR T cell products approved for numerous indications by regulatory agencies worldwide. However, significant work remains to be done to enhance these treatments. In March 2023, a group of experts in CAR T cell therapy assembled at the National Institutes of Health in Bethesda, Maryland at the Insights in Pediatric CAR T Cell Immunotherapy: Recent Advances and Future Directions (INSPIRED) Symposium to identify key areas for research for the coming years. In session 4B, correlative studies to be incorporated into future clinical trials and real-world settings were discussed. Active areas of research identified included (1) optimizing CAR T cell product manufacturing; (2) ensuring adequate lymphodepletion prior to CAR T cell administration; (3) overcoming immunoregulatory cells and tumor stroma present in the tumor microenvironment, particularly in solid tumors; (4) understanding tumor intrinsic properties that lead to CAR T cell immunotherapy resistance; and (5) uncovering biomarkers predictive of treatment resistance, treatment durability, or immune-related adverse events. Here we review the results of previously published clinical trials and real-world studies to summarize what is currently known about each of these topics. We then outline priorities for future research that we believe will be important for improving our understanding of CAR T cell therapy and ultimately leading to better outcomes for patients., (Copyright © 2023 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Introduction: Mediport use as a clinical option for the administration of chimeric antigen receptor T cell (CAR T cell) therapy in patients with B-cell malignancies has yet to be standardized. Concern for mediport dislodgement, cell infiltration, and ineffective therapy delivery to systemic circulation has resulted in variable practice with intravenous administration of CAR T cell therapy. With CAR T cell commercialization, it is important to establish practice standards for CAR T cell delivery. We conducted a study to establish usage patterns of mediports in the clinical setting and provide a standard of care recommendation for mediport use as an acceptable form of access for CAR T cell infusions., Methods: In this retrospective cohort study, data on mediport use and infiltration rate was collected from a survey across 34 medical centers in the Pediatric Real-World CAR Consortium, capturing 504 CAR T cell infusion routes across 489 patients. Data represents the largest, and to our knowledge sole, report on clinical CAR T cell infusion practice patterns since FDA approval and CAR T cell commercialization in 2017., Results: Across 34 sites, all reported tunneled central venous catheters, including Broviac ® and Hickman ® catheters, as accepted standard venous options for CAR T cell infusion. Use of mediports as a standard clinical practice was reported in 29 of 34 sites (85%). Of 489 evaluable patients with reported route of CAR T cell infusion, 184 patients were infused using mediports, with no reported incidences of CAR T cell infiltration., Discussion/conclusion: Based on current clinical practice, mediports are a commonly utilized form of access for CAR T cell therapy administration. These findings support the safe practice of mediport usage as an accepted standard line option for CAR T cell infusion., Competing Interests: JR has consulted for Novartis. CBo has patents pending on the use of engineered cellular therapies for cancer, and has research support provided by BMS, Merck, and Kiadis pharma. CC has served as the C.M.C. reports honorarium for advisory boards from Bayer, Elephas, Nektar Therapeutics, Novartis and WiCell Research Institute, all of whom had no input in the study design, analysis, manuscript preparation or decision to submit for publication. VH has grant funding from Servier. TL has consulted for Advanced Microbubbles, AI Therapeutics, Bayer, GentiBio, Jazz Pharmaceuticals, MassiveBio, Menarini, Novartis, Pyramid Biosciences, and Treeline Bio. VF has consulted for Adaptimmune. LS served on advisory board for Novartis and CARGO therapeutics. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Eylon, Prabhu, John, King, Bhatt, Curran, Erickson, Karras, Phillips, Satwani, Hermiston, Southworth, Baumeister, Talano, MacMillan, Rossoff, Bonifant, Myers, Rouce, Toner, Driscoll, Katsanis, Salzberg, Schiff, De Oliveira, Capitini, Pacenta, Pfeiffer, Shah, Huynh, Skiles, Fraint, McNerney, Quigg, Krueger, Ligon, Fabrizio, Baggott, Laetsch and Schultz.)

Background: Tisagenlecleucel was approved by the Food and Drug Administration (FDA) in 2017 for refractory B-cell acute lymphoblastic leukemia (B-ALL) and B-ALL in ≥2nd relapse. Outcomes of patients receiving commercial tisagenlecleucel upon 1st relapse have yet to be established. We aimed to report real-world tisagenlecleucel utilisation patterns and outcomes across indications, specifically including patients treated in 1st relapse, an indication omitted from formal FDA approval., Methods: We conducted a retrospective analysis of real-world tisagenlecleucel utilisation patterns across 185 children and young adults treated between August 30, 2017 and March 6, 2020 from centres participating in the Pediatric Real-World CAR Consortium (PRWCC), within the United States. We described definitions of refractory B-ALL used in the real-world setting and categorised patients by reported Chimeric Antigen Receptor (CAR) T-cell indication, including refractory, 1st relapse and ≥2nd relapse B-ALL. We analysed baseline patient characteristics and post-tisagenlecleucel outcomes across defined cohorts., Findings: Thirty-six percent (n = 67) of our cohort received tisagenlecleucel following 1st relapse. Of 66 evaluable patients, 56 (85%, 95% CI 74-92%) achieved morphologic complete response. Overall-survival (OS) and event-free survival (EFS) at 1-year were 69%, (95% CI 58-82%) and 49%, (95% CI 37-64%), respectively, with survival outcomes statistically comparable to remaining patients (OS; p = 0.14 , EFS; p = 0.39 ). Notably, toxicity was increased in this cohort, warranting further study. Interestingly, of 30 patients treated for upfront refractory disease, 23 (77%, 95% CI 58-90%) had flow cytometry and/or next-generation sequencing (NGS) minimum residual disease (MRD)-only disease at the end of induction, not meeting the historic morphologic definition of refractory., Interpretation: Our findings suggested that tisagenlecleucel response and survival rates overlap across patients treated with upfront refractory B-ALL, B-ALL ≥2nd relapse and B-ALL in 1st relapse. We additionally highlighted that definitions of refractory B-ALL are evolving beyond morphologic measures of residual disease., Funding: St. Baldrick's/Stand Up 2 Cancer, Parker Institute for Cancer Immunotherapy, Virginia and D.K. Ludwig Fund for Cancer Research., Competing Interests: V.B. serves on the boards of ArsenalBio and Umoja Biopharma and consults or holds stock in Zafrens and Treeline Biosciences which are developing therapies for cancer treatment and Illumina, Invitae, Pacific Biosciences, and Guardant who are developing oncology NGS tests. C.L.M. is an inventor on several patents related to CAR T-cell therapies. C.L.M. is a cofounder of Lyell Immunopharma, CARGO Therapeutics and Link Cell Therapies, which are developing CAR-based therapies, and consults for Lyell, CARGO, Link, Ensoma, Mammoth, Immatics, Apricity, Glaxo Smith Klein, Nektar, Legend and Bristol Myers Squibb. C.L.M receives royalties for CD-22 CAR licensing from NIH, has had grant/contract funding from St. Baldrick’s Foundation, NIH, CIRM, Parker, Tune therapeutics, Lyell Immunopharma, Ludwig Institute, Emerson Collective, Department of Defense and Goldhirsh-Yellin Foundation. She is a member of the Board of Directors of CARGO Therapeutics and Link Cell Therapies and owns stocks in Lyell Immunopharma, CARGO Therapeutics, Link Cell Therapies, Ensoma, Mammoth and Apricity. T.W.L. served on advisory boards or consults for Novartis, Bayer, Aptitude Health, Jumo Health, Massive Bio, Medscape, AI Therapeutics, Jazz Pharmaceuticals, GentiBio, Menarini, Pyramid Biosciences, Targeted Oncology, Treeline Biosciences. He owns stocks/other ownership interest in advanced microbubbles. T.W.L. received research funding from Lily, Roche/Genentech, Taiho Oncology, Advanced Accelerator Applications/Novartis, Bristol-Myers Squibb, BioAtla, Pfizer, Bayer and Turning Point Therapeutics. G.D.M. received funding for medical writing from Novartis. C.L.P. served on an advisory board for Novartis. L.S. served on an advisory board for Novartis. H.S. served on an advisory board for Novartis. M.H. served on editorial advisory board for Novartis and Sobi Pharmaceuticals and is the Vice Chair for COG NHL committee and COG NHL Biology Committee. V.F. consulted for Adaptimmune. S.P. is supported by the UCSF-Stanford CERSI grant UOI FD005978 from the FDA. P.S. served on advisory board for Sobi Pharmaceuticals. A.K. received COG support for meeting attendance. K.J.C. received grant support for an investigator-initiated trial and sat on advisory boards for Novartis and Atara Biotherapeutics. M.R.V. consults for Novartis, Sanofi, Qihan, Forge, Takada and Equillium. M.R.V. has a provisional patent describing methods of producing and using immunotherapy for cancer. M.R.V.participates on the safety monitoring/advisory board for FBX-101 and owns stocks/options for Fate therapeutics., (© 2023 The Authors.)

Chimeric antigen receptor (CAR) T cell therapy (CAR-T) targeting the CD19 antigen on B cell acute lymphoblastic leukemia (B-ALL) has transitioned from a highly investigational therapy with limited access to a commercial therapy with established toxicities, response and survival rates, and access in numerous countries. With more than a decade of clinical study and 5 years of commercial access, data showing associations with success and failure have emerged. To address functional limitations of CAR-T and overcome constrained sample sizes when studying single-trial or single-center data, collaborative groups, including the Pediatric Real World CAR Consortium, the CAR-Multicenter Analysis, the Center for International Blood and Marrow Transplant Research, and the International BFM Study Group, among others, have been retrospectively interrogating the amassed clinical experience. The high patient numbers and varied clinical experiences compiled by these groups have defined clinical variables impacting CAR-T outcomes. Here we review published CAR-T trials and consortium/collaborative outcomes to establish variables associated with optimal response to CAR-T in children and young adults with B-ALL. We focus on findings with clinical relevance that have emerged, including data implicating pretreatment disease burden, presence of extramedullary disease, nonresponse to prior CD19 antigen targeting (blinatumomab therapy), CAR T cell dose, and fludarabine pharmacokinetics as factors impacting post-CAR-T survival. Additionally, we address the role of collaborative efforts going forward in guiding clinical practice evolution and further optimizing post-CAR-T outcomes., (Copyright © 2023 The American Society for Transplantation and Cellular Therapy. All rights reserved.)

Background: Our understanding of the impact of copy number variants (CNVs) on psychopathology and their joint influence with polygenic risk scores (PRSs) remains limited., Methods: The UK Biobank recruited 502,534 individuals ages 37 to 73 years living in the United Kingdom between 2006 and 2010. After quality control, genotype data from 459,855 individuals were available for CNV calling. A total of 61 commonly studied recurrent neuropsychiatric CNVs were selected for analyses and examined individually and in aggregate (any CNV, deletion, or duplication). CNV risk scores were used to quantify intolerance of CNVs to haploinsufficiency. Major depressive disorder and generalized anxiety disorder PRSs were generated for White British individuals (N = 408,870). Mood/anxiety factor scores were generated using item-level questionnaire data (N = 501,289)., Results: CNV carriers showed higher mood/anxiety scores than noncarriers, with the largest effects seen for intolerant deletions. A total of 11 individual deletions and 8 duplications were associated with higher mood/anxiety. Carriers of the 9p24.3 (DMRT1) duplication showed lower mood/anxiety. Associations remained significant for most CNVs when excluding individuals with psychiatric diagnoses. Nominally significant CNV × PRS interactions provided preliminary evidence that associations between select individual CNVs, but not CNVs in aggregate, and mood/anxiety may be modulated by PRSs., Conclusions: CNVs associated with risk for psychiatric disorders showed small to large effects on dimensional mood/anxiety scores in a general population cohort, even when excluding individuals with psychiatric diagnoses. CNV × PRS interactions showed that associations between select CNVs and mood/anxiety may be modulated by PRSs., (Copyright © 2023 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Objective: Copy number variants (CNVs) are well-known genetic pleiotropic risk factors for multiple neurodevelopmental and psychiatric disorders (NPDs), including autism (ASD) and schizophrenia. Little is known about how different CNVs conferring risk for the same condition may affect subcortical brain structures and how these alterations relate to the level of disease risk conferred by CNVs. To fill this gap, the authors investigated gross volume, vertex-level thickness, and surface maps of subcortical structures in 11 CNVs and six NPDs., Methods: Subcortical structures were characterized using harmonized ENIGMA protocols in 675 CNV carriers (CNVs at 1q21.1, TAR, 13q12.12, 15q11.2, 16p11.2, 16p13.11, and 22q11.2; age range, 6-80 years; 340 males) and 782 control subjects (age range, 6-80 years; 387 males) as well as ENIGMA summary statistics for ASD, schizophrenia, attention deficit hyperactivity disorder, obsessive-compulsive disorder, bipolar disorder, and major depression., Results: All CNVs showed alterations in at least one subcortical measure. Each structure was affected by at least two CNVs, and the hippocampus and amygdala were affected by five. Shape analyses detected subregional alterations that were averaged out in volume analyses. A common latent dimension was identified, characterized by opposing effects on the hippocampus/amygdala and putamen/pallidum, across CNVs and across NPDs. Effect sizes of CNVs on subcortical volume, thickness, and local surface area were correlated with their previously reported effect sizes on cognition and risk for ASD and schizophrenia., Conclusions: The findings demonstrate that subcortical alterations associated with CNVs show varying levels of similarities with those associated with neuropsychiatric conditions, as well distinct effects, with some CNVs clustering with adult-onset conditions and others with ASD. These findings provide insight into the long-standing questions of why CNVs at different genomic loci increase the risk for the same NPD and why a single CNV increases the risk for a diverse set of NPDs., Competing Interests: Dr. van den Bree, Dr. Owen, and Dr. Hall have received grants from Takeda Pharmaceuticals. Dr. Owen has received a grant from Akrivia Health. Dr. Ching and Dr. Thompson have received a research grant from Biogen. Dr. Gutman is employed by and holds stock in Natera. The other authors report no financial relationships with commercial interests.

Chimeric antigen receptor-associated hemophagocytic lymphohistiocytosis (HLH)-like toxicities (LTs) involving hyperferritinemia, multiorgan dysfunction, coagulopathy, and/or hemophagocytosis are described as occurring in a subset of patients with cytokine release syndrome (CRS). Case series report poor outcomes for those with B-cell acute lymphoblastic leukemia (B-ALL) who develop HLH-LTs, although larger outcomes analyses of children and young adults (CAYAs) with B-ALL who develop these toxicities after the administration of commercially available tisagenlecleucel are not described. Using a multi-institutional database of 185 CAYAs with B-ALL, we conducted a retrospective cohort study including groups that developed HLH-LTs, high-grade (HG) CRS without HLH-LTs, or no to low-grade (NLG) CRS without HLH-LTs. Primary objectives included characterizing the incidence, outcomes, and preinfusion factors associated with HLH-LTs. Among 185 CAYAs infused with tisagenlecleucel, 26 (14.1%) met the criteria for HLH-LTs. One-year overall survival and relapse-free survival were 25.7% and 4.7%, respectively, in those with HLH-LTs compared with 80.1% and 57.6%, respectively, in those without. In multivariable analysis for death, meeting criteria for HLH-LTs carried a hazard ratio of 4.61 (95% confidence interval, 2.41-8.83), controlling for disease burden, age, and sex. Patients who developed HLH-LTs had higher pretisagenlecleucel disease burden, ferritin, and C-reactive protein levels and lower platelet and absolute neutrophil counts than patients with HG- or NLG-CRS without HLH-LTs. Overall, CAYAs with B-ALL who developed HLH-LTs after tisagenlecleucel experienced high rates of relapse and nonrelapse mortality, indicating the urgent need for further investigations into prevention and optimal management of patients who develop HLH-LTs after tisagenlecleucel., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Pleiotropy occurs when a genetic variant influences more than one trait. This is a key property of the genomic architecture of psychiatric disorders and has been observed for rare and common genomic variants. It is reasonable to hypothesize that the microscale genetic overlap (pleiotropy) across psychiatric conditions and cognitive traits may lead to similar overlaps at the macroscale brain level such as large-scale brain functional networks. We took advantage of brain connectivity, measured by resting-state functional MRI to measure the effects of pleiotropy on large-scale brain networks, a putative step from genes to behaviour. We processed nine resting-state functional MRI datasets including 32 726 individuals and computed connectome-wide profiles of seven neuropsychiatric copy-number-variants, five polygenic scores, neuroticism and fluid intelligence as well as four idiopathic psychiatric conditions. Nine out of 19 pairs of conditions and traits showed significant functional connectivity correlations (rFunctional connectivity), which could be explained by previously published levels of genomic (rGenetic) and transcriptomic (rTranscriptomic) correlations with moderate to high concordance: rGenetic-rFunctional connectivity = 0.71 [0.40-0.87] and rTranscriptomic-rFunctional connectivity = 0.83 [0.52; 0.94]. Extending this analysis to functional connectivity profiles associated with rare and common genetic risk showed that 30 out of 136 pairs of connectivity profiles were correlated above chance. These similarities between genetic risks and psychiatric disorders at the connectivity level were mainly driven by the overconnectivity of the thalamus and the somatomotor networks. Our findings suggest a substantial genetic component for shared connectivity profiles across conditions and traits, opening avenues to delineate general mechanisms-amenable to intervention-across psychiatric conditions and genetic risks., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Remarkable complete response rates have been shown with tisagenlecleucel, a chimeric antigen receptor (CAR) T-cell therapy targeting CD19, in patients up to age 26 years with refractory/relapsed B-cell acute lymphoblastic leukemia; it is US Food and Drug Administration approved for this indication. Currently, patients receive a single dose of tisagenlecleucel across a wide dose range of 0.2 to 5.0 × 106 and 0.1 to 2.5 × 108 CAR T cells per kg for patients ≤50 and >50 kg, respectively. The effect of cell dose on survival and remission is not yet well established. Our primary goal was to determine if CAR T-cell dose affects overall survival (OS), event-free survival (EFS), or relapse-free-survival (RFS) in tisagenlecleucel recipients. Retrospective data were collected from Pediatric Real World CAR Consortium member institutions and included 185 patients infused with commercial tisagenlecleucel. The median dose of viable transduced CAR T cells was 1.7 × 106 CAR T cells per kg. To assess the impact of cell dose, we divided responders into dose quartiles: 0.134 to 1.300 × 106 (n = 48 [27%]), 1.301 to 1.700 × 106 (n = 46 [26%]), 1.701 to 2.400 × 106 (n = 43 [24%]), and 2.401 to 5.100 × 106 (n = 43 [24%]). OS, EFS, and RFS were improved in patients who received higher doses of tisagenlecleucel (P = .031, .0079, and .0045, respectively). Higher doses of tisagenlecleucel were not associated with increased toxicity. Because the current tisagenlecleucel package insert dose range remains broad, this work has implications in regard to targeting higher cell doses, within the approved dose range, to optimize patients' potential for long-standing remission., (Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Purpose: Nonresponse and relapse after CD19-chimeric antigen receptor (CAR) T-cell therapy continue to challenge survival outcomes. Phase II landmark data from the ELIANA trial demonstrated nonresponse and relapse rates of 14.5% and 28%, respectively, whereas use in the real-world setting showed nonresponse and relapse rates of 15% and 37%. Outcome analyses describing fate after post-CAR nonresponse and relapse remain limited. Here, we aim to establish survival outcomes after nonresponse and both CD19+ and CD19- relapses and explore treatment variables associated with inferior survival., Methods: We conducted a retrospective multi-institutional study of 80 children and young adults with B-cell acute lymphoblastic leukemia experiencing nonresponse (n = 23) or relapse (n = 57) after tisagenlecleucel. We analyze associations between baseline characteristics and these outcomes and establish survival rates and salvage approaches., Results: The overall survival (OS) at 12 months was 19% across nonresponders (n = 23; 95% CI, 7 to 50). Ninety-five percent of patients with nonresponse had high preinfusion disease burden. Among 156 morphologic responders, the cumulative incidence of relapse was 37% (95% CI, 30 to 47) at 12 months (CD19+; 21% [15 to 29], CD19-; 16% [11 to 24], median follow-up; 380 days). Across 57 patients experiencing relapse, the OS was 52% (95% CI, 38 to 71) at 12 months after time of relapse. Notably, CD19- relapse was associated with significantly decreased OS as compared with patients who relapsed with conserved CD19 expression (CD19- 12-month OS; 30% [14 to 66], CD19+ 12-month OS; 68% [49 to 92], P = .0068). Inotuzumab, CAR reinfusion, and chemotherapy were used as postrelapse salvage therapy with greatest frequency, yet high variability in treatment sequencing and responses limits efficacy analysis across salvage approaches., Conclusion: We describe poor survival across patients experiencing nonresponse to tisagenlecleucel. In the post-tisagenlecleucel relapse setting, patients can be salvaged; however, CD19- relapse is distinctly associated with decreased survival outcomes.

Background: Polygenicity and genetic heterogeneity pose great challenges for studying psychiatric conditions. Genetically informed approaches have been implemented in neuroimaging studies to address this issue. However, the effects on functional connectivity of rare and common genetic risks for psychiatric disorders are largely unknown. Our objectives were to estimate and compare the effect sizes on brain connectivity of psychiatric genomic risk factors with various levels of complexity: oligogenic copy number variants (CNVs), multigenic CNVs, and polygenic risk scores (PRSs) as well as idiopathic psychiatric conditions and traits., Methods: Resting-state functional magnetic resonance imaging data were processed using the same pipeline across 9 datasets. Twenty-nine connectome-wide association studies were performed to characterize the effects of 15 CNVs (1003 carriers), 7 PRSs, 4 idiopathic psychiatric conditions (1022 individuals with autism, schizophrenia, bipolar conditions, or attention-deficit/hyperactivity disorder), and 2 traits (31,424 unaffected control subjects)., Results: Effect sizes on connectivity were largest for psychiatric CNVs (estimates: 0.2-0.65 z score), followed by psychiatric conditions (0.15-0.42), neuroticism and fluid intelligence (0.02-0.03), and PRSs (0.01-0.02). Effect sizes of CNVs on connectivity were correlated to their effects on cognition and risk for disease (r = 0.9, p = 5.93 × 10 -6 ). However, effect sizes of CNVs adjusted for the number of genes significantly decreased from small oligogenic to large multigenic CNVs (r = -0.88, p = 8.78 × 10 -6 ). PRSs had disproportionately low effect sizes on connectivity compared with CNVs conferring similar risk for disease., Conclusions: Heterogeneity and polygenicity affect our ability to detect brain connectivity alterations underlying psychiatric manifestations., (Copyright © 2022 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Classic Hodgkin lymphoma (CHL) patients may infrequently present with a prior or recurrent disease with discordant histology resembling non-Hodgkin lymphomas. These include primary mediastinal large B-cell lymphoma (PMBL), diffuse large B-cell lymphoma (DLBCL), or mediastinal gray-zone lymphoma (MGZL). Such patients are often refractory to standard therapy and their diagnosis is hampered by significant morphologic and immunophenotypic overlap and insufficient molecular data. Among 509 CHL patients seen at an academic medical center, 6 patients had a prior or subsequent diagnosis different from CHL. Paired tissue samples were evaluated by targeted mutational analysis using a 164-gene panel. Our findings show multiple shared variants indicative of a clonal relationship between the CHL and the PMBL, DLBCL, or MGZL diagnoses. Most frequent mutated genes included TNFAIP3 (4 of 6, 66.7%), STAT6 (3 or 6, 50%), ARID1A (3 of 6, 50%), and XPO1 (3 of 5, 60%). Three patients showed the same oncogenic variant within the XPO1 gene (E571K), and mutations in TNFAIP3 and B2M were observed in 2 of the 5 patients with shared variants. In addition, differences in the mutation profile between the lymphoma pairs were also observed, which could represent clonal evolution. Mutational profiling could be of benefit in patients with recurrent/refractory disease with discordant histology, where the clonal relationship could be helpful to inform and guide therapeutic decisions. These findings provide further evidence of a true biological continuum surrounding CHL, PMBL, DLBCL, and MGZL and shed light on underlying genetic events and their clinical impact., Competing Interests: Conflicts of Interest and Source of Funding: Institutional seed funds supported this study. The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Suicidal ideation and attempts in youth are a growing health concern, and more data are needed regarding their biological underpinnings. Asthma is a common chronic inflammatory disorder in youth and has been associated with suicidal ideation and attempts in adolescent and adult populations, but data in younger children and early adolescents are lacking. We wished to study associations of asthma with childhood suicidality considering asthma's potential as a clinically relevant model for childhood chronic immune dysregulation., Methods: Using data from the Adolescent Brain Cognitive Development (ABCD) Study ( n = 11,876, 47.8% female, mean age 9.9 years at baseline assessment and 12.0 years at two-year follow-up), we assessed associations between asthma and suicidal ideation and attempts through baseline to two-year follow-up., Results: Asthma history as defined by parent report ( n = 2282, 19.2% of study population) was associated with suicide attempts (SA) (odds ratio (OR) = 1.44, p = 0.01), and this association remained significant even when controlling for demographics, socioeconomic factors, and environmental factors (OR = 1.46, p = 0.028). History of asthma attacks was associated with both suicidal ideation (SI) and SA when controlling for demographics, socioeconomic factors, and environmental factors (OR = 1.27, p = 0.042; OR = 1.83, p = 0.004, respectively). The association of asthma attack with SA remained significant when controlling for self-reported psychopathology (OR = 1.92, p = 0.004). The total number of asthma attacks was associated with both SI and SA (OR = 1.03, p = 0.043; OR = 1.06, p = 0.05, respectively)., Conclusions: Findings suggest an association between asthma and suicidality in early adolescence. Further research is needed to investigate mechanisms underlying this relationship.

Background: Adolescent suicide is a major health problem in the US marked by a recent increase in risk of suicidal behavior among Black/African American youth. While genetic factors partly account for familial transmission of suicidal behavior, it is not clear whether polygenic risk scores of suicide attempt can contribute to suicide risk classification., Objectives: To evaluate the contribution of a polygenic risk score for suicide attempt (PRS-SA) in explaining variance in suicide attempt by early adolescence., Methods: We studied N = 5,214 non-related youth of African and European genetic ancestry from the Adolescent Brain Cognitive Development (ABCD) Study (ages 8.9-13.8 years) who were evaluated between 2016 and 2021. Regression models tested associations between PRS-SA and parental history of suicide attempt/death with youth-reported suicide attempt. Covariates included age and sex., Results: Over three waves of assessments, 182 youth (3.5%) reported a past suicide attempt, with Black youth reporting significantly more suicide attempts than their White counterparts (6.1 vs. 2.8%, p < 0.001). PRS-SA was associated with suicide attempt [odds ratio (OR) = 1.3, 95% confidence interval (CI) 1.1-1.5, p = 0.001]. Parental history of suicide attempt/death was also associated with youth suicide attempt (OR = 3.1, 95% CI, 2.0-4.7, p < 0.001). PRS-SA remained significantly associated with suicide attempt even when accounting for parental history (OR = 1.29, 95% CI = 1.1-1.5, p = 0.002). In European ancestry youth ( n = 4,128), inclusion of PRS-SA in models containing parental history explained more variance in suicide attempt compared to models that included only parental history (Δ R 2 = 0.7%, p = 0.009)., Conclusions: Findings suggest that PRS-SA may be useful for youth suicide risk classification in addition to established risk factors., Competing Interests: RB serves on the scientific board and receives consulting fees from “Taliaz Health” and “Zynerba Pharmaceuticals” and reports stock ownership in “Taliaz Health”, with no conflict of interest relevant to this work. EV's spouse is a shareholder and executive in ‘Kidas’, with no conflict of interest relevant to this work. In the past 3 years, ND has been a consultant for Sunovion Pharmaceuticals and is on the scientific advisory board for Sentio Solutions and Circular Genomics for unrelated work. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Barzilay, Visoki, Schultz, Warrier, Daskalakis and Almasy.)

We recently provided mass spectrometric, H/D labeling, and computational evidence of pyranose to furanose N -acetylated ion isomerization reactions that occurred prior to glycosidic bond cleavage in both O- and N-linked glycosylated amino acid model systems (Guan et al. Phys. Chem. Chem. Phys. , 2021, 23, 23256-23266). These reactions occurred irrespective of the glycosidic linkage stereochemistry (α or β) and the N -acetylated hexose structure (GlcNAc or GalNAc). In the present article, we test the generality of the preceding findings by examining threonyl α-GalNAc-glycosylated peptides. We utilize computational chemistry to compare the various dissociation and isomerization pathways accessible with collisional activation. We then interrogate the structure(s) of the resulting charged glycan and peptide fragments with infrared "action" spectroscopy. Isomerization of the original pyranose, the protonated glycopeptide [AT(GalNAc)A+H] + , is predicted to be facile compared to direct dissociation, as is the glycosidic bond cleavage of the newly formed furanose form, i.e., furanose oxazolinium ion structures are predicted to predominate. IR action spectra for the m / z 204, C 8 H 14 N 1 O 5 + , glycan fragment population support this prediction. The IR action spectra of the complementary m / z 262 peptide fragment were assigned as a mixture of the lowest-energy structures of [ATA+H] + consistent with the literature. If general, the change to a furanose m / z 204 product ion structure fundamentally alters the ion population available for MS 3 dissociation and glycopeptide sequence identification.

Infants with B-cell acute lymphoblastic leukemia (B-ALL) have poor outcomes because of chemotherapy resistance leading to high relapse rates. Tisagenlecleucel, a CD19-directed chimeric antigen receptor T-cell (CART) therapy, is US Food and Drug Administration approved for relapsed or refractory B-ALL in patients ≤25 years; however, the safety and efficacy of this therapy in young patients is largely unknown because children <3 years of age were excluded from licensing studies. We retrospectively evaluated data from the Pediatric Real-World CAR Consortium to examine outcomes of patients with infant B-ALL who received tisagenlecleucel between 2017 and 2020 (n = 14). Sixty-four percent of patients (n = 9) achieved minimal residual disease-negative remission after CART and 50% of patients remain in remission at last follow-up. All patients with high disease burden at time of CART infusion (>M1 marrow) were refractory to this therapy (n = 5). Overall, tisagenlecleucel was tolerable in this population, with only 3 patients experiencing ≥grade 3 cytokine release syndrome. No neurotoxicity was reported. This is the largest report of tisagenlecleucel use in infant B-ALL and shows that this therapy is safe and can be effective in this population. Incorporating this novel immunotherapy into the treatment of infant B-ALL offers a promising therapy for a highly aggressive leukemia., (Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Importance: Psychiatric and cognitive phenotypes have been associated with a range of specific, rare copy number variants (CNVs). Moreover, IQ is strongly associated with CNV risk scores that model the predicted risk of CNVs across the genome. But the utility of CNV risk scores for psychiatric phenotypes has been sparsely examined., Objective: To determine how CNV risk scores, common genetic variation indexed by polygenic scores (PGSs), and environmental factors combine to associate with cognition and psychopathology in a community sample., Design, Setting, and Participants: The Philadelphia Neurodevelopmental Cohort is a community-based study examining genetics, psychopathology, neurocognition, and neuroimaging. Participants were recruited through the Children's Hospital of Philadelphia pediatric network. Participants with stable health and fluency in English underwent genotypic and phenotypic characterization from November 5, 2009, through December 30, 2011. Data were analyzed from January 1 through July 30, 2021., Exposures: The study examined (1) CNV risk scores derived from models of burden, predicted intolerance, and gene dosage sensitivity; (2) PGSs from genomewide association studies related to developmental outcomes; and (3) environmental factors, including trauma exposure and neighborhood socioeconomic status., Main Outcomes and Measures: The study examined (1) neurocognition, with the Penn Computerized Neurocognitive Battery; (2) psychopathology, with structured interviews based on the Schedule for Affective Disorders and Schizophrenia for School-Age Children; and (3) brain volume, with magnetic resonance imaging., Results: Participants included 9498 youths aged 8 to 21 years; 4906 (51.7%) were female, and the mean (SD) age was 14.2 (3.7) years. After quality control, 18 185 total CNVs greater than 50 kilobases (10 517 deletions and 7668 duplications) were identified in 7101 unrelated participants genotyped on Illumina arrays. In these participants, elevated CNV risk scores were associated with lower overall accuracy on cognitive tests (standardized β = 0.12; 95% CI, 0.10-0.14; P = 7.41 × 10-26); lower accuracy across a range of cognitive subdomains; increased overall psychopathology; increased psychosis-spectrum symptoms; and higher deviation from a normative developmental model of brain volume. Statistical models of developmental outcomes were significantly improved when CNV risk scores were combined with PGSs and environmental factors., Conclusions and Relevance: In this study, elevated CNV risk scores were associated with lower cognitive ability, higher psychopathology including psychosis-spectrum symptoms, and greater deviations from normative magnetic resonance imaging models of brain development. Together, these results represent a step toward synthesizing rare genetic, common genetic, and environmental factors to understand clinically relevant outcomes in youth.

Chimeric antigen receptor (CAR) T cells provide a therapeutic option in hematologic malignancies. However, treatment failure after initial response approaches 50%. In allogeneic hematopoietic cell transplantation, optimal fludarabine exposure improves immune reconstitution, resulting in lower nonrelapse mortality and increased survival. We hypothesized that optimal fludarabine exposure in lymphodepleting chemotherapy before CAR T-cell therapy would improve outcomes. In a retrospective analysis of patients with relapsed/refractory B-cell acute lymphoblastic leukemia undergoing CAR T-cell (tisagenlecleucel) infusion after cyclophosphamide/fludarabine lymphodepleting chemotherapy, we estimated fludarabine exposure as area under the curve (AUC; mg × h/L) using a validated population pharmacokinetic (PK) model. Fludarabine exposure was related to overall survival (OS), cumulative incidence of relapse (CIR), and a composite end point (loss of B-cell aplasia [BCA] or relapse). Eligible patients (n = 152) had a median age of 12.5 years (range, <1 to 26), response rate of 86% (n = 131 of 152), 12-month OS of 75.1% (95% confidence interval [CI], 67.6% to 82.6%), and 12-month CIR of 36.4% (95% CI, 27.5% to 45.2%). Optimal fludarabine exposure was determined as AUC ≥13.8 mg × h/L. In multivariable analyses, patients with AUC <13.8 mg × h/L had a 2.5-fold higher CIR (hazard ratio [HR], 2.45; 95% CI, 1.34-4.48; P = .005) and twofold higher risk of relapse or loss of BCA (HR, 1.96; 95% CI, 1.19-3.23; P = .01) compared with those with optimal fludarabine exposure. High preinfusion disease burden was also associated with increased risk of relapse (HR, 2.66; 95% CI, 1.45-4.87; P = .001) and death (HR, 4.77; 95% CI, 2.10-10.9; P < .001). Personalized PK-directed dosing to achieve optimal fludarabine exposure should be tested in prospective trials and, based on this analysis, may reduce disease relapse after CAR T-cell therapy., (© 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Purpose: Tisagenlecleucel is a CD19-specific chimeric antigen receptor T-cell therapy, US Food and Drug Administration-approved for children, adolescents, and young adults (CAYA) with relapsed and/or refractory (RR) B-cell acute lymphoblastic leukemia (B-ALL). The US Food and Drug Administration registration for tisagenlecleucel was based on a complete response (CR) rate of 81%, 12-month overall survival (OS) of 76%, and event-free survival (EFS) of 50%. We report clinical outcomes and analyze covariates of outcomes after commercial tisagenlecleucel., Methods: We conducted a retrospective, multi-institutional study of CAYA with RR B-ALL across 15 US institutions, who underwent leukapheresis shipment to Novartis for commercial tisagenlecleucel. A total of 200 patients were included in an intent-to-treat response analysis, and 185 infused patients were analyzed for survival and toxicity., Results: Intent-to-treat analysis demonstrates a 79% morphologic CR rate (95% CI, 72 to 84). The infused cohort had an 85% CR (95% CI, 79 to 89) and 12-month OS of 72% and EFS of 50%, with 335 days of median follow-up. Notably, 48% of patients had low-disease burden (< 5% bone marrow lymphoblasts, no CNS3, or other extramedullary disease), or undetectable disease, pretisagenlecleucel. Univariate and multivariate analyses associate high-disease burden (HB, ≥ 5% bone marrow lymphoblasts, CNS3, or non-CNS extramedullary) with inferior outcomes, with a 12-month OS of 58% and EFS of 31% compared with low-disease burden (OS; 85%, EFS; 70%) and undetectable disease (OS; 95%, EFS; 72%; P < .0001 for OS and EFS). Grade ≥ 3 cytokine release syndrome and neurotoxicity rates were 21% and 7% overall and 35% and 9% in patients with HB, respectively., Conclusion: Commercial tisagenlecleucel in CAYA RR B-ALL demonstrates efficacy and tolerability. This first analysis of commercial tisagenlecleucel stratified by disease burden identifies HB preinfusion to associate with inferior OS and EFS and increased toxicity., Competing Interests: Christine L. PhillipsConsulting or Advisory Role: NovartisTravel, Accommodations, Expenses: Novartis Heather E. StefanskiHonoraria: Novartis Steven P. MargossianConsulting or Advisory Role: NovartisTravel, Accommodations, Expenses: Novartis Michael R. VernerisStock and Other Ownership Interests: Fate TherapeuticsHonoraria: Novartis, Jazz PharmaceuticalsPatents, Royalties, Other Intellectual Property: patent to make innate lymphiod cells. It is not licensed. Gary Douglas MyersHonoraria: NovartisConsulting or Advisory Role: NovartisSpeakers' Bureau: NovartisResearch Funding: Novartis (Inst) Patrick A. BrownConsulting or Advisory Role: Novartis, Jazz Pharmaceuticals, Servier, Kite, a Gilead company Muna QayedConsulting or Advisory Role: Novartis, MesoblastTravel, Accommodations, Expenses: Novartis Michelle HermistonConsulting or Advisory Role: Novartis, SobiPatents, Royalties, Other Intellectual Property: Spouse has patents pending for platform technology with application to oncology, diagnostics, anti-infections and for anti-bleeding technology (I). Prakash SatwaniConsulting or Advisory Role: Mesoblast, TakedaSpeakers' Bureau: SobiOpen Payments Link: https://openpaymentsdata.cms.gov/physician/1047592 Rachel WilcoxResearch Funding: Novartis, AlloVirTravel, Accommodations, Expenses: Novartis Rayne H. RouceHonoraria: Novartis Pharmaceuticals UK Ltd, Kite/GileadResearch Funding: Tessa Therapeutics (Inst) Valentin V. BarsanLeadership: Tessera Therapeutics, NavioStock and Other Ownership Interests: Illumina, Natera, Pacific Biosciences, InVitaeConsulting or Advisory Role: Guardant Health Kevin J. CurranHonoraria: NovartisConsulting or Advisory Role: Novartis, MesoblastResearch Funding: Juno Therapeutics Crystal L. MackallLeadership: Syncopation Life SciencesStock and Other Ownership Interests: Lyell Immunopharma, Alimera Sciences, Vor Pharmaceuticals, Apricity Health, Syncopation Life Sciences, Ensoma, MammothConsulting or Advisory Role: Bryology, Vor Biopharma, Apricity Health, TPG, Alimera Sciences, PACT Pharma, Nektar, Lyell Immunopharma, NeoImmuneTech, Syncopation Life Sciences, Bristol Myers Squibb, Immatics, GlaxoSmithKline, Ensoma, MammothResearch Funding: Lyell ImmunopharmaPatents, Royalties, Other Intellectual Property: I am an inventor on numerous patents related to chimeric antigen receptor therapeutics and received royalties from NIH for the CD22-CAR patent licensed to Juno therapeutics.Travel, Accommodations, Expenses: NeoImmuneTech, Roche, NektarOther Relationship: Lyell Immunopharma, Syncopation Life Sciences Theodore W. LaetschConsulting or Advisory Role: Novartis, Bayer, Cellectis, Aptitude Health, Clinical Education Alliance, Deciphera, Jumo Health, Massive Bio, Med Learning Group, Medscape, Physicans' Education Resource, Y-mAbs TherapeuticsResearch Funding: Pfizer (Inst), Novartis (Inst), Bayer (Inst), AbbVie (Inst), Amgen (Inst), Atara Biotherapeutics (Inst), Bristol Myers Squibb (Inst), Lilly (Inst), Epizyme (Inst), GlaxoSmithKline (Inst), Janssen (Inst), Jubilant Pharmaceuticals (Inst), Novella Clinical (Inst), Servier (Inst), Foundation Medicine (Inst), Merck Sharp & Dohme (Inst)No other potential conflicts of interest were reported.

Diffuse intrinsic pontine glioma (DIPG) and other H3K27M-mutated diffuse midline gliomas (DMGs) are universally lethal paediatric tumours of the central nervous system 1 . We have previously shown that the disialoganglioside GD2 is highly expressed on H3K27M-mutated glioma cells and have demonstrated promising preclinical efficacy of GD2-directed chimeric antigen receptor (CAR) T cells 2 , providing the rationale for a first-in-human phase I clinical trial (NCT04196413). Because CAR T cell-induced brainstem inflammation can result in obstructive hydrocephalus, increased intracranial pressure and dangerous tissue shifts, neurocritical care precautions were incorporated. Here we present the clinical experience from the first four patients with H3K27M-mutated DIPG or spinal cord DMG treated with GD2-CAR T cells at dose level 1 (1 × 10 6 GD2-CAR T cells per kg administered intravenously). Patients who exhibited clinical benefit were eligible for subsequent GD2-CAR T cell infusions administered intracerebroventricularly 3 . Toxicity was largely related to the location of the tumour and was reversible with intensive supportive care. On-target, off-tumour toxicity was not observed. Three of four patients exhibited clinical and radiographic improvement. Pro-inflammatory cytokine levels were increased in the plasma and cerebrospinal fluid. Transcriptomic analyses of 65,598 single cells from CAR T cell products and cerebrospinal fluid elucidate heterogeneity in response between participants and administration routes. These early results underscore the promise of this therapeutic approach for patients with H3K27M-mutated DIPG or spinal cord DMG., (© 2022. The Author(s).)

Adoptive cellular therapy using chimeric antigen receptors (CARs) has revolutionized our treatment of relapsed B cell malignancies and is currently being integrated into standard therapy. The impact of selecting specific T cell subsets for CAR transduction remains under investigation. Previous studies demonstrated that effector T cells derived from naive, rather than central memory T cells mediate more potent antitumor effects. Here, we investigate a method to skew CAR transduction toward naive T cells without physical cell sorting. Viral-mediated CAR transduction requires ex vivo T cell activation, traditionally achieved using antibody-mediated strategies. CD81 is a T cell costimulatory molecule that when combined with CD3 and CD28 enhances naive T cell activation. We interrogate the effect of CD81 costimulation on resultant CAR transduction. We identify that upon CD81-mediated activation, naive T cells lose their identifying surface phenotype and switch to a memory phenotype. By prelabeling naive T cells and tracking them through T cell activation and CAR transduction, we document that CD81 costimulation enhanced naive T cell activation and resultantly generated a CAR T cell product enriched with naive-derived CAR T cells., Competing Interests: The authors declare no competing interest., (Copyright © 2022 the Author(s). Published by PNAS.)

Chimeric antigen receptor (CAR) T cells have transformed the therapeutic options for relapsed/refractory (R/R) B-cell acute lymphoblastic leukemia. Data for CAR therapy in extramedullary (EM) involvement are limited. Retrospective data were abstracted from the Pediatric Real World CAR Consortium (PRWCC) of 184 infused patients from 15 US institutions. Response (complete response) rate, overall survival (OS), relapse-free survival (RFS), and duration of B-cell aplasia (BCA) in patients referred for tisagenlecleucel with EM disease (both central nervous system (CNS)3 and non-CNS EM) were compared with bone marrow (BM) only. Patients with CNS disease were further stratified for comparison. Outcomes are reported on 55 patients with EM disease before CAR therapy (CNS3, n = 40; non-CNS EM, n = 15). The median age at infusion in the CNS cohort was 10 years (range, <1-25 years), and in the non-CNS EM cohort it was 13 years (range, 2-26 years). In patients with CNS disease, 88% (35 of 40) achieved a complete response vs only 66% (10 of 15) with non-CNS EM disease. Patients with CNS disease (both with and without BM involvement) had 24-month OS outcomes comparable to those of non-CNS EM or BM only (P = .41). There was no difference in 12-month RFS between CNS, non-CNS EM, or BM-only patients (P = .92). No increased toxicity was seen with CNS or non-CNS EM disease (P = .3). Active CNS disease at time of infusion did not affect outcomes. Isolated CNS disease trended toward improved OS compared with combined CNS and BM (P = .12). R/R EM disease can be effectively treated with tisagenlecleucel; toxicity, relapse, and survival rates are comparable to those of patients with BM-only disease. Outcomes for isolated CNS relapse are encouraging., (© 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Polygenic scores (PGS) are commonly evaluated in terms of their predictive accuracy at the population level by the proportion of phenotypic variance they explain. To be useful for precision medicine applications, they also need to be evaluated at the individual level when phenotypes are not necessarily already known. We investigated the stability of PGS in European American (EUR) and African American (AFR)-ancestry individuals from the Philadelphia Neurodevelopmental Cohort and the Adolescent Brain Cognitive Development study using different discovery genome-wide association study (GWAS) results for post-traumatic stress disorder (PTSD), type 2 diabetes (T2D), and height. We found that pairs of EUR-ancestry GWAS for the same trait had genetic correlations >0.92. However, PGS calculated from pairs of same-ancestry and different-ancestry GWAS had correlations that ranged from <0.01 to 0.74. PGS stability was greater for height than for PTSD or T2D. A series of height GWAS in the UK Biobank suggested that correlation between PGS is strongly dependent on the extent of sample overlap between the discovery GWAS. Focusing on the upper end of the PGS distribution, different discovery GWAS do not consistently identify the same individuals in the upper quantiles, with the best case being 60% of individuals above the 80th percentile of PGS overlapping from one height GWAS to another. The degree of overlap decreases sharply as higher quantiles, less heritable traits, and different-ancestry GWAS are considered. PGS computed from different discovery GWAS have only modest correlation at the individual level, underscoring the need to proceed cautiously with integrating PGS into precision medicine applications., Competing Interests: R.B. reports serving on the scientific board and owning stock in Taliaz Health, with no conflict of interest relevant to this work. The other authors declare no competing interests., (© 2022 The Authors.)

Suicidal ideation and attempts (i.e., suicidality) are complex behaviors driven by environmental stress, genetic susceptibility, and their interaction. Preadolescent suicidality is a major health problem with rising rates, yet its underlying biology is understudied. Here we studied effects of genetic stress susceptibility, approximated by the polygenic risk score (PRS) for post-traumatic-stress-disorder (PTSD), on preadolescent suicidality in participants from the Adolescent Brain Cognitive Development (ABCD) Study®. We further evaluated PTSD-PRS effects on suicidality in the presence of environmental stressors that are established suicide risk factors. Analyses included both European and African ancestry participants using PRS calculated based on summary statistics from ancestry-specific genome-wide association studies. In European ancestry participants (N = 4,619, n = 378 suicidal), PTSD-PRS was associated with preadolescent suicidality (odds ratio [OR] = 1.12, 95%CI 1-1.25, p = 0.038). Results in African ancestry participants (N = 1,334, n = 130 suicidal) showed a similar direction but were not statistically significant (OR = 1.21, 95%CI 0.93-1.57, p = 0.153). Sensitivity analyses using non-psychiatric polygenic score for height and using cross-ancestry PTSD-PRS did not reveal any association with suicidality, supporting the specificity of the association of ancestry-specific PTSD-PRS with suicidality. Environmental stressors were robustly associated with suicidality across ancestries with moderate effect size for negative life events and family conflict (OR 1.27-1.6); and with large effect size (OR ∼ 4) for sexual-orientation discrimination. When combined with environmental factors, PTSD-PRS showed marginal additive effects in explaining variability in suicidality, with no evidence for G × E interaction. Results support use of cross-phenotype PRS, specifically stress-susceptibility, as a genetic marker for suicidality risk early in the lifespan., (© 2021 Published by Elsevier Inc.)

The use of radiotherapy as bridging therapy to chimeric antigen receptor T-cell therapy (CAR-T) in pre-B acute lymphoblastic leukemia (B-ALL) has been minimally explored. Here, we present a boy with B-ALL who relapsed after allogeneic bone marrow transplant with disseminated disease, including significant symptomatic cardiovascular and gastrointestinal (GI) involvement. The cardiac and GI leukemic infiltrates were successfully treated with bridging radiation therapy (BRT) prior to CAR-T infusion. Using this approach, he successfully tolerated CAR-T with no evidence of disease or sequelae on 3-month follow-up. This is the first reported case of safe and effective delivery of cardiac BRT in B-ALL., (© 2020 Wiley Periodicals LLC.)

Purpose: Immunomonitoring of chimeric antigen receptor (CAR) T cells relies primarily on their quantification in the peripheral blood, which inadequately quantifies their biodistribution and activation status in the tissues. Noninvasive molecular imaging of CAR T cells by PET is a promising approach with the ability to provide spatial, temporal, and functional information. Reported strategies rely on the incorporation of reporter transgenes or ex vivo biolabeling, significantly limiting the application of CAR T-cell molecular imaging. In this study, we assessed the ability of antibody-based PET (immunoPET) to noninvasively visualize CAR T cells., Experimental Design: After analyzing human CAR T cells in vitro and ex vivo from patient samples to identify candidate targets for immunoPET, we employed a syngeneic, orthotopic murine tumor model of lymphoma to assess the feasibility of in vivo tracking of CAR T cells by immunoPET using the 89 Zr-DFO-anti-ICOS tracer, which we have previously reported., Results: Analysis of human CD19-CAR T cells during activation identified the Inducible T-cell COStimulator (ICOS) as a potential target for immunoPET. In a preclinical tumor model, 89 Zr-DFO-ICOS mAb PET-CT imaging detected significantly higher signal in specific bone marrow-containing skeletal sites of CAR T-cell-treated mice compared with controls. Importantly, administration of ICOS-targeting antibodies at tracer doses did not interfere with CAR T-cell persistence and function., Conclusions: This study highlights the potential of ICOS-immunoPET imaging for monitoring of CAR T-cell therapy, a strategy readily applicable to both commercially available and investigational CAR T cells. See related commentary by Volpe et al., p. 911 ., (©2020 American Association for Cancer Research.)

Competing Interests: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Background: Malnutrition is common in pediatric heart failure and is associated with mortality. The effect of VAD support on malnutrition in children is unknown. We sought to compare the prevalence and severity of malnutrition at HT in children on VAD support vs OMT to inform decisions regarding support strategies., Methods: Retrospective chart review involving all patients <18 years who underwent HT at Stanford between 1/1/2011 and 3/1/2018. Malnutrition diagnosis and severity were defined by ASPEN guidelines using the lowest age-adjusted z-score for weight (WAZ), height (HAZ), and BMI (BMIZ) when the patient was euvolemic. Changes in z-scores from baseline to HT and across groups were analyzed., Results: A total of 104 patients (52 in each group) were included. Among all patients, WAZ (-0.9 vs 0.3, P < 0.001) and BMIZ (0 vs 0.6, P < 0.001) improved while HAZ (-0.9 vs -0.9, P = 0.4) did not. Compared to children on OMT, children on VAD experienced greater increases in WAZ (0.8 vs 0.3, P < 0.001) and BMIZ (0.7 vs 0.2, P < 0.003) at HT. The prevalence of moderate-to-severe malnutrition decreased in VAD patients (40% to 19%, P < 0.001) and increased in OMT patients (37% to 46%, P < 0.001), leading to a lower prevalence of moderate-to-severe malnutrition at HT (19% vs 46%, P = 0.003)., Conclusions: Malnutrition is common in pediatric HT candidates. Compared to children on OMT, children on VAD support had greater improvement in nutritional status while awaiting HT, and a lower prevalence of malnutrition at HT., (© 2019 Wiley Periodicals, Inc.)

In vitro cancer cultures, including three-dimensional organoids, typically contain exclusively neoplastic epithelium but require artificial reconstitution to recapitulate the tumor microenvironment (TME). The co-culture of primary tumor epithelia with endogenous, syngeneic tumor-infiltrating lymphocytes (TILs) as a cohesive unit has been particularly elusive. Here, an air-liquid interface (ALI) method propagated patient-derived organoids (PDOs) from >100 human biopsies or mouse tumors in syngeneic immunocompetent hosts as tumor epithelia with native embedded immune cells (T, B, NK, macrophages). Robust droplet-based, single-cell simultaneous determination of gene expression and immune repertoire indicated that PDO TILs accurately preserved the original tumor T cell receptor (TCR) spectrum. Crucially, human and murine PDOs successfully modeled immune checkpoint blockade (ICB) with anti-PD-1- and/or anti-PD-L1 expanding and activating tumor antigen-specific TILs and eliciting tumor cytotoxicity. Organoid-based propagation of primary tumor epithelium en bloc with endogenous immune stroma should enable immuno-oncology investigations within the TME and facilitate personalized immunotherapy testing., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals are at risk for prolonged hospitalisation after unifocalisation. Feeding problems after congenital heart surgery are associated with longer hospital stay. We sought to determine the impact of baseline, intra-operative, and postoperative factors on the need for feeding tube use at the time of discharge., Methods: We included patients with the aforementioned diagnosis undergoing unifocalisation from ages 3 months to 4 years from 2010 to 2016. We excluded patients with a pre-existing feeding tube. Patients discharged with an enteric tube were included in the feeding tube group. We compared the feeding tube group with the non-feeding-tube group by univariable and multi-variable logistic regression., Results: Of the 56 patients studied, 41% used tube feeding. Median age and weight z-score were similar in the two groups. A chromosome 22q11 deletion was associated with the need for a feeding tube (22q11 deletion in 39% versus 15%, p=0.05). Median cardiopulmonary bypass time in the feeding tube group was longer (335 versus 244 minutes, p=0.04). Prolonged duration of mechanical ventilation was associated with feeding tube use (48 versus 3%, p=0.001). On multi-variable analysis, prolonged mechanical ventilation was associated with feeding tube use (odds ratio 10.2, 95% confidence intervals 1.6; 63.8)., Conclusion: Among patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals who were feeding by mouth before surgery, prolonged mechanical ventilation after unifocalisation surgery was associated with feeding tube use at discharge. Anticipation of feeding problems in this population and earlier feeding tube placement may reduce hospital length of stay.

Immunopeptidomes promise novel surface markers as ideal immunotherapy targets, but their characterization by mass spectrometry (MS) remains challenging. Until recently, cell numbers exceeding 10 9 were needed to survey thousands of HLA ligands. Such limited analytical sensitivity has historically constrained the types of clinical specimens that can be evaluated to cell cultures or bulk tissues. Measuring immunopeptidomes from purified cell subpopulations would be preferable for many applications, particularly those evaluating rare, primary hematopoietic cell lineages. Here, we test the feasibility of immunopeptidome profiling from limited numbers of primary purified human regulatory T cells (T Reg ), conventional T cells (T conv ), and activated T cells. The combined T cell immunopeptide dataset reported here contains 13 804 unique HLA ligands derived from 5049 proteins. Of these, more than 700 HLA ligands were derived from 82 proteins that we exclusively identified from T Reg -enriched cells. This study 1) demonstrates that primary, lineage-enriched T cell subpopulations recovered from single donors are compatible with immunopeptidome analysis; 2) presents new T Reg -biased ligand candidates; and 3) supports immunopeptidome surveys' value for revealing T cell biology that may not be apparent from expression data alone. Taken together, these findings open up new avenues for targeting T Reg and abrogating their suppressive functions to treat cancer., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Purpose of Review: Building upon preclinical advances, we are uncovering immunotherapy strategies that are translating into improved outcomes in tumor subsets. Advanced pediatric solid tumors carry poor prognoses and resultant robust efforts to apply immunotherapy advances to pediatric solid tumors are in progress. Here, we discuss recent developments in the field using mAb and mAb-based therapies including checkpoint blockade and chimeric antigen receptors (CARs)., Recent Findings: The pediatric solid tumor mAb experience targeting the diganglioside, GD2, for patients with neuroblastoma has been the most compelling to date. GD2 and alternative antigen-specific mAbs are now being incorporated into antibody-drug conjugates, bispecific antibodies and CARs for treatment of solid tumors. CARs in pediatric solid tumors have not yet achieved comparative responses to the hematologic CAR experience; however, novel strategies such as bispecific targeting, intratumoral administration and improved understanding of T-cell biology may yield enhanced CAR-efficacy. Therapeutic effect using single-agent checkpoint blocking antibodies in pediatric solid tumors also remains limited to date. Combinatorial strategies continue to hold promise and the clinical effect in tumor subsets with high antigenic burden is being explored., Summary: Pediatric immunotherapy remains at early stages of translation, yet we anticipate that with advanced technology, we will achieve widespread, efficacious use of immunotherapy for pediatric solid tumors.

Tumor immunotherapy has had demonstrable efficacy in patients with cancer. The most promising results have been with T-cell-based therapies. These include adoptive cell transfer of tumor-infiltrating lymphocytes, genetically engineered T cells, and immune checkpoint inhibitor antibodies. In this review, we describe the different T-cell-based strategies currently in clinical trials and put their applications, present and future, into perspective., (©2015 American Association for Cancer Research.)

Prostate cancer is the leading cancer diagnosis and second leading cause of cancer-related mortality for men in the United States. Due to the increased prevalence of prostate cancer in men older than 50 years, men at risk for prostate cancer represent the same population of men who are at greatest risk for metabolic syndrome, diabetes mellitus, and coronary artery disease (CAD). In addition to risk factors for CAD that are applicable to the general population, men with prostate cancer can be at increased risk for CAD due to long-term androgen deprivation therapy (ADT) administered as treatment for prostate cancer. Men undergo ADT by medical (drug therapy) or surgical (castration) means. Luteinizing hormone-releasing hormone (LHRH) agonists are the primary drug therapies used for ADT. Commercially available LHRH agonists are goserelin, histrelin, leuprolide, and triptorelin. Body composition changes, hyperlipidemia, insulin resistance, metabolic syndrome, and acute coronary syndrome are all reported adverse effects of ADT, which are consequences of reduced levels of circulating testosterone. Metabolic and body composition changes associated with ADT arise within months of beginning medical ADT and persist after discontinuation of therapy. To better understand the increased risk of metabolic syndrome, diabetes, and heart disease in patients undergoing ADT for prostate cancer, we performed a MEDLINE search (1986-2008) to identify pertinent studies and reports. Additional citations were obtained from the articles retrieved from the literature search. We found that the increased risk for serious cardiovascular disease becomes evident within months of beginning ADT. Pharmacists should provide counseling to these patients on primary disease prevention. Men receiving ADT should be monitored routinely for signs and symptoms of metabolic syndrome, diabetes, and CAD. Healthy lifestyle practices should be encouraged, and physical therapy should be considered for these patients.

The authors of this prospective, single-case study evaluated the potential for functional recovery from chronic spinal cord injury (SCI). The patient was motor complete with minimal and transient sensory perception in the left hemibody. His condition was classified as C-2 American Spinal Injury Association (ASIA) Grade A and he had experienced no substantial recovery in the first 5 years after traumatic SCI. Clinical experience and evidence from the scientific literature suggest that further recovery would not take place. When the study began in 1999, the patient was tetraplegic and unable to breathe without assisted ventilation; his condition classification persisted as C-2 ASIA Grade A. Magnetic resonance imaging revealed severe injury at the C-2 level that had left a central fluid-filled cyst surrounded by a narrow donutlike rim of white matter. Five years after the injury a program known as "activity-based recovery" was instituted. The hypothesis was that patterned neural activity might stimulate the central nervous system to become more functional, as it does during development. Over a 3-year period (5-8 years after injury), the patient's condition improved from ASIA Grade A to ASIA Grade C, an improvement of two ASIA grades. Motor scores improved from 0/100 to 20/100, and sensory scores rose from 5-7/112 to 58-77/112. Using electromyography, the authors documented voluntary control over important muscle groups, including the right hemidiaphragm (C3-5), extensor carpi radialis (C-6), and vastus medialis (L2-4). Reversal of osteoporosis and an increase in muscle mass was associated with this recovery. Moreover, spasticity decreased, the incidence of medical complications fell dramatically, and the incidence of infections and use of antibiotic medications was reduced by over 90%. These improvements occurred despite the fact that less than 25 mm2 of tissue (approximately 25%) of the outer cord (presumably white matter) had survived at the injury level. The primary novelty of this report is the demonstration that substantial recovery of function (two ASIA grades) is possible in a patient with severe C-2 ASIA Grade A injury, long after the initial SCI. Less severely injured (lower injury level, clinically incomplete lesions) individuals might achieve even more meaningful recovery. The role of patterned neural activity in regeneration and recovery of function after SCI therefore appears a fruitful area for future investigation.

We investigated whether the long (approximately 30-s) or short (approximately 3-s) light stimuli that have been used during behavioral training would induce post-light potentiation (PLP) at the type B to A photoreceptor connections of the isolated nervous system of Hermissenda. We found that a single approximately 30-s light step induced PLP at these connections relative to both pre-light baseline and seawater control preparations, as did a series of nine short (approximately 3-s) light steps. In addition, a 30-s step of depolarization-elicited type B cell activity induced potentiation comparable to that induced by a approximately 30-s light step, indicating that light-elicited type B cell activity contributes to the induction of PLP. By contrast, even though a series of short (3-s) light steps induced potentiation, short steps of depolarization-evoked type B cell activity did not. Hence, light-evoked processes other than type B cell depolarization or activity (e.g., perhaps intracellular Ca2+ release) also contribute to the induction of PLP. Further results suggest that these other light-evoked processes interact nonadditively with type B cell activity to generate PLP. Some but not all instances of synaptic potentiation were accompanied by various changes in parameters of type B cell action potentials and afterhyperpolarizing potentials, suggesting diverse underlying mechanisms, including increases in neurotransmitter release. Given that the type A cells have been proposed to polysynaptically excite the motor neurons that drive phototaxis, a light-evoked potentiation of synaptic strength at the inhibitory type B to A photoreceptor connections may play a mechanistic role in light-elicited nonassociative learning.

We quantified synaptic depression at the type B to A photoreceptor connections of Hermissenda. Type B cell action potentials were evoked at interstimulus intervals (ISIs) of 0.3, 3 or 30 s and the resulting inhibitory postsynaptic potentials (IPSPs) were recorded in a type A cell. A progressive decline in IPSP amplitude occurred at all three ISIs. Synaptic depression was greater at shorter ISIs, as was the level of recovery 2 min after the stimulus series. The profound level of synaptic depression observed (79.0+/-3.2% at the 0.3 s ISI) implies that synaptic depression is an important control process in the neuronal circuitry that drives phototactic behavior.

Gamma-aminobutyric acid (GABA) is a prevalent neurotransmitter in both vertebrate and invertebrate systems. Here we report that, in addition to its usual inhibitory actions, GABA induced synaptic facilitation at type B to A photoreceptor connections of the marine mollusk Hermissenda when applied transiently to the isolated nervous system. Synaptic facilitation also occurred in response to mechanical stimulation of the GABAergic hair cells, which are normally activated by rotational unconditioned stimuli during behavioral training of the intact animal. This synaptic facilitation represents a novel form of GABA-induced neuromodulation which may contribute to learning-dependent suppression of phototaxis in Hermissenda.