Biology subjects

Biondi, A.

Publications and source records attributed to Biondi, A..

7 recordsLinked to original sources

bioRxiv2026

A humanized ossicle platform for real-time tracking and preclinical assessment of CAR-based immunotherapies in acute myeloid leukemia

Preclinical evaluation of chimeric antigen receptor (CAR)-T therapies for acute myeloid leukemia (AML) is limited by the lack of models that faithfully recapitulate the human bone marrow (BM) niche. Here, we implemented a humanized ossicle-based AML model that enables simultaneous engraftment of leukemic blasts and longitudinal assessment of responses to CAR-based immunotherapies. Intravenous or intra-ossicle injection of AML blasts produced robust, reproducible disease mimicking features of human AML within its microenvironment. To monitor tumor burden and immune effector cells in real-time, we developed a dual bioluminescence system using distinct luciferases in AML and CAR-T cells. This approach allowed non-invasive longitudinal tracking of CAR-T cell localization, expansion, persistence, and leukemic clearance within the ossicle. Overall, our model provides a powerful platform to study CAR-T cell behavior within a human BM niche and, for the first time, allows simultaneous longitudinal visualization of leukemic burden and CAR-T cell dynamics in a physiologically relevant ossicle-based AML model. TeaserHumanized ossicles combined with dual BLI enable tracking of AML progression and CAR-T cell dynamics in a human stromal niche.

Cell Biology↗

bioRxiv2026

Differential TIM-3 glycosylation enables specific dual targeting CAR-T therapy in acute myeloid leukemia

Chimeric Antigen Receptor (CAR) therapy for Acute Myeloid Leukemia (AML) is hindered by disease heterogeneity, antigen overlap with normal hematopoiesis, and the persistence of leukemic stem cells (LSCs). To overcome these barriers, we employed the IF-BETTER strategy to simultaneously target CD33 and the LSC-associated marker TIM-3 by pairing a second-generation CAR with a Cytokine-Costimulatory Receptor (CCR) in two dual CAR configurations (CD33.CAR/TIM-3.CCR and TIM-3.CAR/CD33.CCR). Both constructs displayed potent antigen-restricted cytotoxicity against AML cell lines and primary blasts, achieving leukemia clearance, while sparing normal immune and hematopoietic cells. Mechanistic studies revealed that the TIM-3.CAR single-chain fragment variable (scFv) recognizes a protein-proximal epitope whose interaction is selectively enhanced by AML-specific hyper-fucosylated and hyper-sialylated N-glycans. Fucosylation blockade reduced TIM-3.CAR avidity and cytotoxicity, confirming a glycosylation-modulated interaction. Integrating this glycosylation-tolerant TIM-3 scFv into a dual CAR framework enables selective targeting of AML cells, providing a rational strategy for safer and more effective AML-directed immunotherapy.

immunology↗

bioRxiv2024

Acquisition of an immunosuppressive microenvironment after CAR-T therapy drives T-cell dysfunction and resistance

Chimeric antigen receptor (CAR) T cells targeting CD19 induce durable responses in B-cell acute lymphoblastic leukemia (B-ALL). However, the contribution of the tumor microenvironment to the therapeutic response after CAR-T cell treatment remains incompletely understood. We performed single-cell RNA sequencing and spectral flow cytometry-based analyses of bone marrow-resident immune cells from B-ALL patients before and after CAR T-cell treatment. We observed profound changes in the microenvironment in response to CAR T cell-mediated inflammation, including an increase in myeloid cells. Significant induction of the IFN response, hypoxia, and TGF-{beta}-signaling was associated with expansion of myeloid-derived suppressor cells (MDSCs) and endogenous exhausted CD8+ T cells. PD1 expression in endogenous T cells post-treatment was associated with a lack of durable response in the cohort of patients analyzed. Further, we revealed that HIF1, VEGF, and TGFBR2 are key players in the intercellular communication between CAR T cells and the immune niche, driving widespread T-cell dysfunction. Infusion of anti-CD19 CAR T cells led to increased accumulation of human MDSCs, exacerbation of a hypoxic environment and T-cell exhaustion in HSPC-humanized mice bearing a human tumor. In conclusion, CAR T-cell-mediated myeloid activation is associated with pathways of immune dysregulation that may antagonize the effects of therapy. Key pointsO_LIThe tumor immune context post-treatment affects CAR T-cell fate and endogenous immunity in B-cell acute lymphoblastic leukemia. C_LIO_LIIFN response, hypoxia, and TGF-{beta}-signaling result in endogenous T-cell exhaustion and compromise CAR T-cell efficacy. C_LI

immunology↗

bioRxiv2022

Activation of prefrontal cortex and striatal regions in rats after shifting between rules in a T-maze

Prefrontal cortical and striatal areas have been identified by inactivation or lesion studies to be required for behavioral flexibility, including selecting and processing of different types of information. In order to identify these networks activated selectively during acquisition of new reward contingency rules, rats were trained to discriminate orientations of bars presented in pseudo-random sequence on two video monitors positioned behind the goal sites on a T maze with return arms. A second group already trained in the visual discrimination task learned to alternate left and right goal arm visits in the same maze while ignoring the visual cues still being presented. In each experimental group, once the rats reached criterion performance, the brains were prepared after a 90 minute delay, for later processing for c-fos immunohistochemistry. While both groups extinguished a prior strategy and acquired a new rule, they differed by the identity of the strategies, and previous learning experience. Among the 28 forebrain areas examined, there were significant increases in the relative density of c-fos immunoreactive cell bodies after learning the second rule in prefrontal cortex cingulate, prelimbic and infralimbic areas, in dorsomedial striatum and the core of nucleus accumbens, in ventral subiculum, and the central nucleus of the amygdala. These largely correspond to structures anatomically identified by previous inactivation studies. The data suggest that this dynamic network may underlie reward-based selection for action, a type of cognitive flexibility.

neuroscience↗

bioRxiv2022

ImmunoTyper-SR: A Novel Computational Approach for Genotyping Immunoglobulin Heavy Chain Variable Genes using Short Read Data

Human immunoglobulin heavy chain (IGH) locus on chromosome 14 includes more than 40 functional copies of the variable gene (IGHV), which, together with the joining genes (IGHJ), diversity genes (IGHD), constant genes (IGHC) and immunoglobulin light chains, code for antibodies that identify and neutralize pathogenic invaders as a part of the adaptive immune system. Because of its highly repetitive sequence composition, the IGH locus has been particularly difficult to assemble or genotype through the use of standard short read sequencing technologies. Here we introduce ImmunoTyper-SR, an algorithmic method for genotype and CNV analysis of the germline IGHV genes using Illumina whole genome sequencing (WGS) data. ImmunoTyper-SR is based on a novel combinatorial optimization formulation that aims to minimize the total edit distance between reads and their assigned IGHV alleles from a given database, with constraints on the number and distribution of reads across each called allele. We have validated ImmunoTyper-SR on 12 individuals with Illumina WGS data from the 1000 Genomes Project, whose IGHV allele composition have been studied extensively through the use of long read and targeted sequencing platforms, as well as nine individuals from the NIAID COVID Consortium who have been subjected to WGS twice. We have then applied ImmunoTyper-SR on 585 samples from the NIAID COVID Consortium to investigate associations between distinct IGHV alleles and anti-type I IFN autoantibodies which have been linked to COVID-19 severity.

bioinformatics↗

bioRxiv2021

Maturation signatures of conventional dendritic cells in COVID-19 reflect direct viral sensing

Growing evidence suggests that conventional dendritic cells (cDCs) undergo aberrant maturation in COVID-19 and this negatively affects T cell activation. The presence of functional effector T cells in mild patients and dysfunctional T cells in severely ill patients suggests that adequate T cell responses are needed to limit disease severity. Therefore, understanding how cDCs cope with SARS-CoV-2 infections can help elucidate the mechanism of generation of protective immune responses. Here, we report that cDC2 subtypes exhibit similar infection-induced gene signatures with the up-regulation of interferon-stimulated genes and IL-6 signaling pathways. The main difference observed between DC2s and DC3s is the up-regulation of anti-apoptotic genes in DC3s, which explains their accumulation during infection. Furthermore, comparing cDCs between severe and mild patients, we find in the former a profound down-regulation of genes encoding molecules involved in antigen presentation, such as major histocompatibility complex class II (MHCII) molecules, {beta}2 microglobulin, TAP and costimulatory proteins, while an opposite trend is observed for proinflammatory molecules, such as complement and coagulation factors. Therefore, as the severity of the disease increases, cDC2s enhance their inflammatory properties and lose their main function, which is the antigen presentation capacity. In vitro, direct exposure of cDC2s to the virus recapitulates the type of activation observed in vivo. Our findings provide evidence that SARS-CoV-2 can interact directly with cDC2s and, by inducing the down-regulation of crucial molecules required for T cell activation, implements an efficient immune escape mechanism that correlates with disease severity.

immunology↗

bioRxiv2020

Lethal and sublethal effects of synthetic and bio-insecticides on Trichogramma brassicae parasitizing Tuta absoluta

The invasive tomato leaf miner (TLM), Tuta absoluta (Meyrick) is an invasive pest on tomatoes worldwide. The main control measure against the pest has been chemical insecticides, but the pest developed resistance to many chemical classes. So alternative methods, such as biological control agents, alone or combined to chemical compounds must be evaluated to validate their synergistic actions. In this study, both lethal (concentration-mortality response) and sublethal effects of three synthetic insecticides, the bioinsecticide spinosad, as well as the entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) Sorokin were studied on Trichogramma brassicae Bezdenko within T. absoluta eggs. To assess the sublethal effects, the lethal concentration 25% (LC25) of chlorantraniliprole, spinosad, abamectin and indoxacarb and LC50 value of M. anisopliae was sprayed on eggs and then offered at three time intervals to the parasitoids. Fertility and other life table parameters of the individuals emerged from treated eggs were estimated. The results showed that indoxacarb showed the highest deleterious sublethal effects on T. brassicae. On the other hand, M. anisopliae was the safest treatment to combine to Trichogramma with no significant effect on some parameters. The lowest LC50 value for T. brassicae was obtained for chlorantraniliprole followed by spinosad. Synergistic effect was observed when M. anisopliae and T. brassicae used together. Hence, this will be a promising integration against T. absoluta.

ecology↗