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BACKGROUND: A major obstacle in translating the therapeutic potential of chimeric antigen receptor (CAR) T cells to children with central nervous system (CNS) tumors is the blood–brain barrier. To overcome this limitation, preclinical and clinical studies have supported the use of repeated, locoregional intracranial CAR T-cell delivery. However, there is limited literature available describing the process for the involvement of an investigational drug service (IDS) pharmacy, particularly in the setting of a children’s hospital with outpatient dosing for CNS tumors. OBJECTIVES: To describe Seattle Children’s Hospital’s experience in clinically producing CAR T cells and the implementation of IDS pharmacy practices used to deliver more than 300 intracranial CAR T-cell doses to children, as well as to share how we refined the processing techniques from CAR T-cell generation to the thawing of fractionated doses for intracranial delivery. METHODS: Autologous CD4+ and CD8+ T cells were collected and transduced to express HER2, EGFR, or B7-H3–specific CAR T cells. Cryopreserved CAR T cells were thawed by the IDS pharmacy before intracranial delivery to patients with recurrent/refractory CNS tumors or with diffuse intrinsic pontine glioma/diffuse midline glioma. RESULTS: The use of a thaw-and-dilute procedure for cryopreserved individual CAR T-cell doses provides reliable viability and is more efficient than typical thaw-and-wash protocols. Cell viability with the thaw-and-dilute protocol was approximately 75% and was always within 10% of the viability assessed at cryopreservation. Cell viability was preserved through 6 hours after thawing, which exceeded the 1-hour time frame from thawing to infusion. CONCLUSION: As the field of adoptive immunotherapy grows and continues to bring hope to patients with fatal CNS malignancies, it is critical to focus on improving the preparatory steps for CAR T-cell delivery. [ABSTRACT FROM AUTHOR]

Cells rely on activity-dependent protein-protein interactions to convey biological signals. For chimeric antigen receptor (CAR) T cells containing a 4-1BB costimulatory domain, receptor engagement is thought to stimulate the formation of protein complexes similar to those stimulated by T cell receptor (TCR)–mediated signaling, but the number and type of protein interaction–mediating binding domains differ between CARs and TCRs. Here, we performed coimmunoprecipitation mass spectrometry analysis of a second-generation, CD19-directed 4-1BB:ζ CAR (referred to as bbζCAR) and identified 128 proteins that increased their coassociation after target engagement. We compared activity-induced TCR and CAR signalosomes by quantitative multiplex coimmunoprecipitation and showed that bbζCAR engagement led to the activation of two modules of protein interactions, one similar to TCR signaling that was more weakly engaged by bbζCAR as compared with the TCR and one composed of TRAF signaling complexes that was not engaged by the TCR. Batch-to-batch and interindividual variations in production of the cytokine IL-2 correlated with differences in the magnitude of protein network activation. Future CAR T cell manufacturing protocols could measure, and eventually control, biological variation by monitoring these signalosome activation markers. Editor's summary: Chimeric antigen receptor (CAR) T cells are effective therapies against some cancers; however, a better understanding of their signaling pathways would help in enhancing their efficacy. Ritmeester-Loy et al. identified and quantified the protein-protein interactions induced by CAR stimulation in CAR T cells generated from healthy donors. As well as characterizing protein-protein interactions that were induced both by CARs and endogenous T cell receptors, the authors identified a set of protein-protein interactions specific to CARs. The extent of activation of CAR T cells varied from batch to batch but correlated with signaling strength, suggesting that variations in key signaling components may modulate CAR T cell performance. —John F. Foley [ABSTRACT FROM AUTHOR]

Purpose of Review: Correlative studies should leverage clinical trial frameworks to conduct biospecimen analyses that provide insight into the bioactivity of the intervention and facilitate iteration toward future trials that further improve patient outcomes. In pediatric cellular immunotherapy trials, correlative studies enable deeper understanding of T cell mobilization, durability of immune activation, patterns of toxicity, and early detection of treatment response. Here, we review the correlative science in adoptive cell therapy (ACT) for childhood central nervous system (CNS) tumors, with a focus on existing chimeric antigen receptor (CAR) and T cell receptor (TCR)-expressing T cell therapies. Recent Findings: We highlight long-standing and more recently understood challenges for effective alignment of correlative data and offer practical considerations for current and future approaches to multi-omic analysis of serial tumor, serum, and cerebrospinal fluid (CSF) biospecimens. We highlight the preliminary success in collecting serial cytokine and proteomics from patients with CNS tumors on ACT clinical trials. [ABSTRACT FROM AUTHOR]

Because of the COVID-19 pandemic, in-person services for individuals with neurodevelopmental disabilities were disrupted globally, resulting in a transition to remote delivery of services and therapies. For individuals with neurogenetic conditions, reliance on nonclinical caregivers to facilitate all therapies and care was unprecedented. The study aimed to (1) describe caregivers' reported impact on their dependent's services, therapies, medical needs, and impact on themselves as a result of the COVID-19 pandemic and (2) assess the relationship between the extent of disruption of services and the degree of self-reported caregiver burden. Two online questionnaires were completed by caregivers participating in Simons Searchlight in April and May 2020. Surveys were completed by caregivers of children or dependent adults with neurodevelopmental genetic conditions in Simons Searchlight. Caregivers reported that the impact of the COVID-19 pandemic moderately or severely disrupted services, therapies, or medical supports. The majority of caregivers were responsible for providing some aspect of therapy. Caregivers reported "feeling stressed but able to deal with problems as they arise," and reported lower anxiety at follow-up. Caregivers reported that telehealth services were not meeting the needs of those with complex medical needs. Future surveys will assess if and how medical systems, educational programs, therapists, and caregivers adapt to the challenges arising during the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

Metastatic breast cancer is incurable. In order to improve patient survival, it is critical to develop a better understanding of the molecular mechanisms that regulate metastasis and the underlying process of cell motility. Here, we focus on the role of the adaptor molecule Breast Cancer Antiestrogen Resistance 3 (BCAR3) in cellular processes that contribute to cell motility, including protrusion, adhesion remodeling, and contractility. Previous work from our group showed that elevated BCAR3 protein levels enhance cell migration, while depletion of BCAR3 reduces the migratory and invasive capacities of breast cancer cells. In the current study, we show that BCAR3 is necessary for membrane protrusiveness, Rac1 activity, and adhesion disassembly in invasive breast cancer cells. We further demonstrate that, in the absence of BCAR3, RhoA-dependent signaling pathways appear to predominate, as evidenced by an increase in RhoA activity, ROCK-mediated phosphorylation of myosin light chain II, and large ROCK/mDia1-dependent focal adhesions. Taken together, these data establish that BCAR3 functions as a positive regulator of cytoskeletal remodeling and adhesion turnover in invasive breast cancer cells through its ability to influence the balance between Rac1 and RhoA signaling. Considering that BCAR3 protein levels are elevated in advanced breast cancer cell lines and enhance breast cancer cell motility, we propose that BCAR3 functions in the transition to advanced disease by triggering intracellular signaling events that are essential to the metastatic process. [ABSTRACT FROM AUTHOR]

Nonsmall cell lung cancer (NSCLC) is the major cause of lung cancer-related deaths in the United States. We are developing cell-based vaccines as a new approach for the treatment of NSCLC. NSCLC is broadly divided into 3 histologic subtypes: adenocarcinoma, squamous cell carcinoma and large cell carcinoma. Since these subtypes are derived from the same progenitor cells, we hypothesized that they share common tumor antigens, and vaccines that induce immune reactivity against 1 subtype may also induce immunity against other subtypes. Our vaccine strategy has focused on activating tumor-specific CD4 [ABSTRACT FROM AUTHOR]

Objective: Growing use of clinical exome sequencing (CES) has led to an increased burden of genomic education. Self-guided educational tools can minimize the educational burden for genetic counselors (GCs). The effectiveness of these tools must be evaluated.Methods: Parents of patients offered CES were randomized to watch educational videos before their visit or to receive routine care. Parents and GCs were surveyed about their experiences following the sessions. The responses of the video (n = 102) and no-video (n = 105) groups were compared.Results: GCs reported no significant differences between parents in the video and no-video groups on genetics knowledge or CES knowledge. In contrast, parents' scores on genetics knowledge questions were lower in the video than no-video group (p = 0.007). Most parents reported the videos were informative, and the groups did not differ in satisfaction with GCs or decisions to have CES.Conclusion: GCs and parents perceived the videos to be beneficial. However, lower scores on genetics knowledge questions highlight the need for careful development of educational tools.Practice Implications: Educational tools should be developed and assessed for effectiveness with the input of all stakeholders before widespread implementation. Better measures of the effectiveness of these educational tools are needed. [ABSTRACT FROM AUTHOR]