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Summary: Latent viral reservoirs (VRs) represent a main barrier to HIV cure. Thus, developing new approaches that can purge and eliminate VRs paves the path toward achieving an HIV-1 cure. APG-1387, a bivalent SMAC mimetic (SM), efficiently reactivates latent HIV expression in T cell line models and enhances active caspase 3 expression, a condition that typically leads to apoptosis. In primary CD4+ T cells infected with a dual reporter-encoded HIV, APG-1387 decreases latently infected cells without a notable effect on productively infected cells. In virally suppressed humanized (hu)-BLT mice, APG-1387 augments cell-associated viral RNA and potently reduces HIV DNA-containing cells without modulating T cell activation or proliferation. Upon antiretroviral therapy (ART) interruption, HIV rebound was decreased in APG-1387-treated humanized mice (hu-mice), and the viremia maintained at levels below that of pre-ART. Thus, the ability of APG-1387 to affect VRs and decrease viral rebound highlights the potential of bivalent SMs in HIV cure strategies.

Purpose The Health state descriptive system includes standardized self-administered instruments for measuring Health-Related Quality of Life (HRQoL) respectively among adolescents, and children. The objectives of the current study were: (1) to translate and adapt the pediatric-adolescent version 16D and 17D from English into French (Canada), (2) to demonstrate their feasibility in pediatric conditions. Methods The translation methodology combined forward and back translations, and cognitive debriefing with eight adolescents and eight children. Four bilingual translators were involved in the process. We administered the translated versions to two clinical samples, being treated for Primary immunodeficiency (PID, n = 48, aged 14.1 years, 20 girls), and having recovered from pediatric Acute Lymphoblastic Leukemia (ALL, n = 153, aged 14.7 years, 77 girls). Results Cognitive debriefing indicated that that the instructions, items, and response options were clear, easy to understand, and easy to answer. Adjustments were made for clarity. Translated versions were highly usable (measurement completion >90%). HRQoL levels were high for both samples (range 0.85–0.96). Participants reported lower levels if they were adolescents, particularly if they were girls. Older boys with PID reported a lower HRQoL than their counterparts with a history of ALL. PID and ALL patients mainly reported issues with discomfort and pain, concentration/learning, physical appearance, and psychological distress and sleeping, although to a different degree. Conclusion The French-language versions of the 16D and 17D are easy to administer and may be used to identify problematic domains. Greater availability of translated versions of short evaluation tools may facilitate broader uptake of screening practices in pediatric care.

Abstract: Acute megakaryoblastic leukemia (AMKL) represents ∼10% of pediatric acute myeloid leukemia cases and typically affects young children (

Summary: Plasmacytoid dendritic cells (plasmacytoid DC, pDC) are major IFN-I producers and have been shown to be affected by HIV through ill-defined mechanisms. In this study, we directly assess the role of pDC in early infection, evaluating whether modulating their abundance can alter viral replication. First, HIV infection of humanized mice induces systemic depletion of pDC, and in the presence of soluble FMS-like tyrosine kinase 3 ligand (Flt3L), pDC levels remain elevated. Flt3L significantly delays the onset of viremia and reduces viral replication via a process that is dependent on pDC and mediated through an enhanced early IFN-I response. pDC from Flt3L-treated mice are more prone to express IFN-α following TLR7 stimulation, but this propensity is gradually decreased during infection. In conclusion, maintaining pDC levels and function is key to effective early viral control, and in this context, these findings provide practical insights for anti-HIV strategies and vaccine design. : Plasmacytoid DC (pDC) are vital for a host’s early antiviral responses. Pham et al. demonstrate that HIV infection of hu-mice induces widespread depletion of pDC and impairs their ability to make IFN-α. Flt3L treatment expands pDC and suppresses HIV replication through early enhancement of IFN-I responses. Keywords: FLT3L, pDCs, acute HIV infection, TLR7 stimulation, IFN-I, antiviral response, pDC dysfunction, hu-mice

OBJECTIVE In Lebanon, HIV prevalence among key populations such as men who have sex with men is high at 12%, warranting a need for targeted healthcare efforts. Pre-exposure prophylaxis (PrEP) is an effective prevention measure, yet global challenges persist, including limited awareness of PrEP among healthcare professionals. This study investigates PrEP awareness within the Lebanese medical community. METHODS A survey targeted 201 participants from the Saint Joseph University of Beirut, Faculty of Medicine, comprising students, residents, and physicians. Analyses, including chi-square tests, mid- P exact test, and point-biserial correlation, assessed PrEP knowledge and perceptions. RESULTS Significant disparities in PrEP awareness were noted among medical students, residents, and physicians, revealing misconceptions about its purpose, administration, and effectiveness. Positive correlations between age and awareness among medical students suggest evolving awareness during medical education. Residents exhibited higher awareness compared to physicians, emphasizing the impact of recent training. No significant correlation based on specialty was found among physicians, indicating the need for uniform PrEP education across all medical fields. CONCLUSION Addressing PrEP awareness gaps among medical professionals is crucial for effective HIV prevention in Lebanon, necessitating tailored educational strategies integrated into medical curricula and ongoing professional development.

Background Allogeneic hematopoietic stem cell transplantation (HSCT) remains the standard of care for chemotherapy-refractory leukemia patients, but cure rates are still dismal. To prevent leukemia relapse following HSCT, we aim to improve the early graft-versus-leukemia effect mediated by natural killer (NK) cells. Our approach is based on the adoptive transfer of Therapeutic Inducers of Natural Killer cell Killing (ThINKK). ThINKK are expanded and differentiated from HSC, and exhibit blood plasmacytoid dendritic cell (pDC) features. We previously demonstrated that ThINKK stimulate NK cells and control acute lymphoblastic leukemia (ALL) development in a preclinical mouse model of HSCT for ALL. Here, we assessed the cellular identity of ThINKK and investigated their potential to activate allogeneic T cells. We finally evaluated the effect of immunosuppressive drugs on ThINKK-NK cell interaction.Methods ThINKK cellular identity was explored using single-cell RNA sequencing and flow cytometry. Their T-cell activating potential was investigated by coculture of allogeneic T cells and antigen-presenting cells in the presence or the absence of ThINKK. A preclinical human-to-mouse xenograft model was used to evaluate the impact of ThINKK injections on graft-versus-host disease (GvHD). Finally, the effect of immunosuppressive drugs on ThINKK-induced NK cell cytotoxicity against ALL cells was tested.Results The large majority of ThINKK shared the key characteristics of canonical blood pDC, including potent type-I interferon (IFN) production following Toll-like receptor stimulation. A minor subset expressed some, although not all, markers of other dendritic cell populations. Importantly, while ThINKK were not killed by allogeneic T or NK cells, they did not increase T cell proliferation induced by antigen-presenting cells nor worsened GvHD in vivo. Finally, tacrolimus, sirolimus or mycophenolate did not decrease ThINKK-induced NK cell activation and cytotoxicity.Conclusion Our results indicate that ThINKK are type I IFN producing cells with low T cell activation capacity. Therefore, ThINKK adoptive immunotherapy is not expected to increase the risk of GvHD after allogeneic HSCT. Furthermore, our data predict that the use of tacrolimus, sirolimus or mycophenolate as anti-GvHD prophylaxis regimen will not decrease ThINKK therapeutic efficacy. Collectively, these preclinical data support the testing of ThINKK immunotherapy in a phase I clinical trial.

Abstract Neuroblastoma, the most common type of pediatric extracranial solid tumor, causes 10% of childhood cancer deaths. Despite intensive multimodal treatment, the outcomes of high-risk neuroblastoma remain poor. We urgently need to develop new therapies with safe long-term toxicity profiles for rapid testing in clinical trials. Drug repurposing is a promising approach to meet these needs. Here, we investigated disulfiram, a safe and successful chronic alcoholism treatment with known anticancer and epigenetic effects. Disulfiram efficiently induced cell cycle arrest and decreased the viability of six human neuroblastoma cell lines at half-maximal inhibitory concentrations up to 20 times lower than its peak clinical plasma level in patients treated for chronic alcoholism. Disulfiram shifted neuroblastoma transcriptome, decreasing MYCN levels and activating neuronal differentiation. Consistently, disulfiram significantly reduced the protein level of lysine acetyltransferase 2A (KAT2A), drastically reducing acetylation of its target residues on histone H3. To investigate disulfiram’s anticancer effects in an in vivo model of high-risk neuroblastoma, we developed a disulfiram-loaded emulsion to deliver the highly liposoluble drug. Treatment with the emulsion significantly delayed neuroblastoma progression in mice. These results identify KAT2A as a novel target of disulfiram, which directly impacts neuroblastoma epigenetics and is a promising candidate for repurposing to treat pediatric neuroblastoma.

Summary: Macrophages populate the embryo early in gestation, but their role in development is not well defined. In particular, specification and function of macrophages in intestinal development remain little explored. To study this event in the human developmental context, we derived and combined human intestinal organoid and macrophages from pluripotent stem cells. Macrophages migrate into the organoid, proliferate, and occupy the emerging microanatomical niches of epithelial crypts and ganglia. They also acquire a transcriptomic profile similar to that of fetal intestinal macrophages and display tissue macrophage behaviors, such as recruitment to tissue injury. Using this model, we show that macrophages reduce glycolysis in mesenchymal cells and limit tissue growth without affecting tissue architecture, in contrast to the pro-growth effect of enteric neurons. In short, we engineered an intestinal tissue model populated with macrophages, and we suggest that resident macrophages contribute to the regulation of metabolism and growth of the developing intestine.

ObjectivesThis study reports cases of systemic-onset juvenile idiopathic arthritis (sJIA) who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) at our center and reviews published outcomes of allo-HSCT in sJIA.MethodsWe present a case report of two patients with sJIA who underwent allo-HSCT at a tertiary pediatric hospital. Each patient’s disease course and allo-HSCT protocol/outcome are described. Outcomes of published cases of allo-HSCT in sJIA were compared to our experience.ResultsTwo patients with sJIA had allo-HSCT. Both failed multiple lines of disease-modifying anti-rheumatic drugs and experienced severe disease/treatment-related complications. Despite post-HSCT complications, both recovered without sequelae. Five years post-HSCT, patient 1 is in complete remission (CR) and is off medications. Patient 2 was in CR until 11 months post-HSCT after which he developed three disease flares. At 4 years post-HSCT he is currently in CR on Adalimumab monotherapy. Engraftment was excellent with a donor chimerism of 100% for patient 1 and 93% for patient 2. In the literature, the outcome of allo-HSCT is reported in 13 sJIA patients. When merging those with our 2 patients, 1/15 patients died and 13/14 achieved CR, of which 12 are off medications (median [range] follow-up: 2.2 [0.2–7.0] years). Extended follow-up data on 11 of the 13 reported sJIA patients showed that an additional 3 patients flared at 3, 4, and 10 years post-HSCT.ConclusionWe report two patients with severe/refractory sJIA who underwent successful allo-HSCT and achieved CR. Allo-HSCT is a potential curative option for severe/refractory sJIA. It should be considered only after failure of conventional sJIA treatments and when an HLA-matched donor is available in order to lower transplant-related mortality. The outcomes of reported sJIA patients who received allo-HSCT are encouraging but long-term follow-up data are needed to better characterized the risk–benefit ratio of this procedure.

IntroductionNatural Killer (NK) cells hold the potential to shift cell therapy from a complex autologous option to a universal off-the-shelf one. Although NK cells have demonstrated efficacy and safety in the treatment of leukemia, the limited efficacy of NK cell-based immunotherapies against solid tumors still represents a major hurdle. In the immunosuppressive tumor microenvironment (TME), inhibitory interactions between cancer and immune cells impair antitumoral immunity. KLRC1 gene encodes the NK cell inhibitory receptor NKG2A, which is a potent NK cell immune checkpoint. NKG2A specifically binds HLA-E, a non-classical HLA class I molecule frequently overexpressed in tumors, leading to the transmission of inhibitory signals that strongly impair NK cell function.MethodsTo restore NK cell cytotoxicity against HLA-E+ tumors, we have targeted the NKG2A/HLA-E immune checkpoint by using a CRISPR-mediated KLRC1 gene editing.ResultsKLRC1 knockout resulted in a reduction of 81% of NKG2A+ cell frequency in ex vivo expanded human NK cells post-cell sorting. In vitro, the overexpression of HLA-E by tumor cells significantly inhibited wild-type (WT) NK cell cytotoxicity with p-values ranging from 0.0071 to 0.0473 depending on tumor cell lines. In contrast, KLRC1KO NK cells exhibited significantly higher cytotoxicity when compared to WT NK cells against four different HLA-E+ solid tumor cell lines, with p-values ranging from

Objectives: Invasive aspergillosis is a threat for immunocompromised patients. We present a case series of aggressive cerebral vasculitis caused by Aspergillus spp. infection in immunocompromised patients. Methods: We present a retrospective case series of three autopsy-proven invasive cerebral aspergillosis with diffuse vasculitis affecting large caliber cerebral vessels. Results: Three patients were immunosuppressed: one on rituximab, one on corticosteroids, and one with a renal transplant. Two of these patients were diagnosed with cerebral aspergillosis on postmortem. Conclusion: Aspergillus cerebral vasculitis is a rare form of invasive aspergillosis that should be considered in an immunocompromised individual with suggestive lesions on imaging. It should be suspected as a possible cause of aseptic neutrophil meningitis.

Abstract Background Interleukin-27 (IL-27) can trigger both pro- and anti-inflammatory responses. This cytokine is elevated in the central nervous system (CNS) of multiple sclerosis (MS) patients, but how it influences neuroinflammatory processes remains unclear. As astrocytes express the receptor for IL-27, we sought to determine how these glial cells respond to this cytokine and whether such exposure alters their interactions with infiltrating activated T lymphocytes. To determine whether inflammation shapes the impact of IL-27, we compared the effects of this cytokine in non-inflamed and inflamed conditions induced by an IL-1β exposure. Main body Transcriptomic analysis of IL-27-exposed human astrocytes showed an upregulation of multiple immune genes. Human astrocytes increased the secretion of chemokines (CXCL9, CXCL10, and CXCL11) and the surface expression of proteins (PD-L1, HLA-E, and ICAM-1) following IL-27 exposure. To assess whether exposure of astrocytes to IL-27 influences the profile of activated T lymphocytes infiltrating the CNS, we used an astrocyte/T lymphocyte co-culture model. Activated human CD4+ or CD8+ T lymphocytes were co-cultured with astrocytes that have been either untreated or pre-exposed to IL‑27 or IL-1β. After 24 h, we analyzed T lymphocytes by flow cytometry for transcription factors and immune molecules. The contact with IL-27-exposed astrocytes increased the percentages of T-bet, Eomes, CD95, IL-18Rα, ICAM-1, and PD-L1 expressing CD4+ and CD8+ T lymphocytes and reduced the proportion of CXCR3-positive CD8+ T lymphocytes. Human CD8+ T lymphocytes co-cultured with human IL-27-treated astrocytes exhibited higher motility than when in contact with untreated astrocytes. These results suggested a preponderance of kinapse-like over synapse-like interactions between CD8+ T lymphocytes and IL-27-treated astrocytes. Finally, CD8+ T lymphocytes from MS patients showed higher motility in contact with IL-27-exposed astrocytes compared to healthy donors’ cells. Conclusion Our results establish that IL-27 alters the immune functions of human astrocytes and shapes the profile and motility of encountered T lymphocytes, especially CD8+ T lymphocytes from MS patients.

Summary: Neutralizing antibodies (NAbs) hold great promise for clinical interventions against SARS-CoV-2 variants of concern (VOCs). Understanding NAb epitope-dependent antiviral mechanisms is crucial for developing vaccines and therapeutics against VOCs. Here we characterized two potent NAbs, EH3 and EH8, isolated from an unvaccinated pediatric patient with exceptional plasma neutralization activity. EH3 and EH8 cross-neutralize the early VOCs and mediate strong Fc-dependent effector activity in vitro. Structural analyses of EH3 and EH8 in complex with the receptor-binding domain (RBD) revealed the molecular determinants of the epitope-driven protection and VOC evasion. While EH3 represents the prevalent IGHV3-53 NAb whose epitope substantially overlaps with the ACE2 binding site, EH8 recognizes a narrow epitope exposed in both RBD-up and RBD-down conformations. When tested in vivo, a single-dose prophylactic administration of EH3 fully protected stringent K18-hACE2 mice from lethal challenge with Delta VOC. Our study demonstrates that protective NAbs responses converge in pediatric and adult SARS-CoV-2 patients.

Acute lymphoblastic leukemia (ALL) is the most frequent cancer diagnosed in children. Despite the great progress achieved over the last 40 years, with cure rates now exceeding 85%, refractory or relapsed ALL still exhibit a dismal prognosis. This poor outcome reflects the lack of treatment options specifically targeting relapsed or refractory ALL. In order to address this gap, we performed whole-genome CRISPR/Cas drop-out screens on a panel of seven B-ALL cell lines. Our results demonstrate that while there was a significant overlap in gene essentiality between ALL cell lines and other cancer types survival of ALL cell lines was dependent on several unique metabolic pathways, including an exquisite sensitivity to GPX4 depletion and ferroptosis induction. Detailed molecular analysis of B-ALL cells suggest that they are primed to undergo ferroptosis as they exhibit high steady-state oxidative stress potential, a low buffering capacity, and a disabled GPX4-independent secondary lipid peroxidation detoxification pathway. Finally, we validated the sensitivity of BALL to ferroptosis induction using patient-derived B-ALL samples.

Objectives: To report available information in the literature regarding frequency, indications, types of antibiotic usage, duration, and their efficacy in Covid-19 infected patients. Methods: The search was conducted on April 30 and May 7, 2020, using Ovid database and Google search. Patients’ characteristics, clinical outcomes, as well as selected characteristics regarding antibiotic use (indication, class used, rates and types of bacterial secondary and co-infection, and duration of treatment) were analyzed. Results: Nineteen clinical studies reporting data from 2834 patients were included. Mean rate of antibiotic use was 74.0 % of cases. Half the studies reported occurrence of a bacterial co-infection or complication (10 studies). Amongst the latter, at least 17.6 % of patients who received antibiotics had secondary infections. Pooled data of 4 studies show that half of patients receiving antibiotics were not severe nor critical. Detailed data on antibiotic use lack in most articles. Conclusions: The present review found a major use of antibiotics amongst Covid-19 hospitalized patients, mainly in an empirical setting. There is no proven efficacy of this practice. Further research to determine relevant indications for antibiotic use in Covid-19 patients is critical in view of the significant mortality associated with secondary infections in these patients, and the rising antimicrobial resistance.