WT1 often presents on the surface of diffuse pleural mesotheliomas (DPMs) and is an ideal therapeutic target. Galinpepimut-S (GPS), a tetravalent, non-human leukocyte antigen-restricted, heteroclitic WT1-specific peptide vaccine was safe and effective in early phase clinical trials and upregulates T-cell suppressive programmed death-ligand 1 in the tumor microenvironment of other malignancies. A randomized phase 2 study of adjuvant GPS in patients with DPM trended toward improved median overall survival.
To further enhance immunogenicity, we combined GPS with nivolumab, an anti-PD1 monoclonal antibody, in an open-label, single-center phase 1 study, examining tolerability and immunogenicity in patients with previously treated DPM. We enrolled patients with progressive or recurrent DPM treated with at least one course of pemetrexed-based chemotherapy. Patients received two doses of GPS followed by six doses of GPS with intravenous nivolumab every 2 weeks, and up to six additional cycles until disease progression or unacceptable toxicity.
Ten patients were treated; 70% experienced mostly mild treatment-related adverse events; two experienced a grade 3 or higher adverse event. Three of the 10 patients (30%) reported vaccine-specific T-cell responses. There were no partial responses; three patients had prolonged stable disease with up to 17% decrease in tumor volume. Median progression-free survival was 3.9 months and the median overall survival was 7.4 months.
Coadministration of GPS and nivolumab reported a tolerable toxicity profile and induced immune responses in a subset of patients, but initial response and survival benefit were limited possibly owing to the small sample size.
© 2024 The Authors.

The regulation of inflammatory responses and pulmonary disease during SARS-CoV-2 infection is incompletely understood. Here we examine the roles of the prototypic pro- and anti-inflammatory cytokines IFNγ and IL-10 using the rhesus macaque model of mild COVID-19. We find that IFNγ drives the development of 18fluorodeoxyglucose (FDG)-avid lesions in the lungs as measured by PET/CT imaging but is not required for suppression of viral replication. In contrast, IL-10 limits the duration of acute pulmonary lesions, serum markers of inflammation and the magnitude of virus-specific T cell expansion but does not impair viral clearance. We also show that IL-10 induces the subsequent differentiation of virus-specific effector T cells into CD69+CD103+ tissue resident memory cells (Trm) in the airways and maintains Trm cells in nasal mucosal surfaces, highlighting an unexpected role for IL-10 in promoting airway memory T cells during SARS-CoV-2 infection of macaques.
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Immunization via the respiratory route is predicted to increase the effectiveness of a SARS-CoV-2 vaccine. Here, we evaluate the immunogenicity and protective efficacy of one or two doses of a live-attenuated murine pneumonia virus vector expressing SARS-CoV-2 prefusion-stabilized spike protein (MPV/S-2P), delivered intranasally/intratracheally to male rhesus macaques. A single dose of MPV/S-2P is highly immunogenic, and a second dose increases the magnitude and breadth of the mucosal and systemic anti-S antibody responses and increases levels of dimeric anti-S IgA in the airways. MPV/S-2P also induces S-specific CD4+ and CD8+ T-cells in the airways that differentiate into large populations of tissue-resident memory cells within a month after the boost. One dose induces substantial protection against SARS-CoV-2 challenge, and two doses of MPV/S-2P are fully protective against SARS-CoV-2 challenge virus replication in the airways. A prime/boost immunization with a mucosally-administered live-attenuated MPV vector could thus be highly effective in preventing SARS-CoV-2 infection and replication.
© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.

Outcomes for children with relapsed and refractory neuroblastoma are dismal. ENCIT-01 is our first-in-human experience in patients with relapsed and refractory neuroblastoma using chimeric antigen receptor (CAR) T cells targeting L1-CAM, an adhesion molecule that is overexpressed in neuroblastoma with limited normal tissue expression. This trial evaluated three different CAR constructs: a short spacer second-generation 4-1BB CAR (Arm A), a short spacer third-generation 4-1BB+CD28 CAR (Arm B) and a long spacer second-generation 4-1BB CAR (Arm C). Thirty-six patients were enrolled and 22 were treated (Arm A n=11, Arm B n=8 and Arm C n=3). Cytokine-release syndrome, skin rash and dose-limiting hyponatremia were recurrently encountered toxicities. Patterns of toxicity appeared at lower dose levels on Arm B and Arm C compared to Arm A, suggesting enhanced potency of the third generation and long spacer products. No objective responses were seen. Correlative analyses demonstrated CAR T cells infiltration into tumor and skin, with evidence of macrophage tumor infiltration. In addition, enhanced CD107a production in the third-generation products when compared to patient matched second generation product, potentially explaining the observation of toxicities at lower dose levels. While feasible to manufacture in a heavily pretreated population, additional engineering safety of L1CAM CAR T cells and/or strategies to target the immunosuppressive tumor microenvironment may be needed to prevent toxicity and provide durable anti-tumor effects.

Appendicitis is one of the most common causes of acute abdominal surgery in children. The clinical course of appendicitis ranges from simple to complex appendicitis. The mechanisms underlying the heterogeneity of appendicitis in children remain largely unclear. Dysregulated T cell responses play an important role in several inflammatory diseases of the intestine, but the extend of T cell dysregulation in appendicitis in children is less well known.
To characterize appendiceal T cells in simple and complex appendicitis we performed in-depth immunophenotyping of appendiceal-derived T cells by flow cytometry and correlated this to appendiceal-derived microbiota analyses of the same patient.
Appendix samples of twenty children with appendicitis (n = 8 simple, n = 12 complex) were collected. T cells in complex appendicitis displayed an increased differentiated phenotype compared to simple appendicitis, including a loss of both CD27 and CD28 by CD4+ T cells and to a lesser extent by CD8+ T cells. Frequencies of phenotypic tissue-resident memory CD69+CD4+ T cells and CD69+CD8+ T cells were decreased in children with complex compared to simple appendicitis, indicating disruption of local tissue-resident immune responses. In line with the increased differentiated phenotype, cytokine production of in particular IL-17A by CD4+ T cells was increased in children with complex compared to simple appendicitis. Furthermore, frequencies of IL-17A+ CD4+ T cells correlated with a dysregulation of the appendiceal microbiota in children with complex appendicitis.
In conclusion, disruption of local T cell responses, and enhanced pro-inflammatory Th17 responses correlating to changes in the appendiceal microbiota were observed in children with complex compared to simple appendicitis. Further studies are needed to decipher the role of a dysregulated network of microbiota and Th17 cells in the development of complex appendicitis in children.
Copyright © 2024 The, Schreurs, Drewniak, Bakx, de Meij, Budding, Poort, Cense, Heij, van Heurn, Gorter and Bunders.