Amr M. Saadeldin
A5115831995- CAR-T cell therapy research
- Nanowire Synthesis and Applications
- Immune Cell Function and Interaction
- Advancements in Semiconductor Devices and Circuit Design
- Immunotherapy and Immune Responses
Baylor College of Medicine
2025
Texas Children's Hospital
2025
Children's Cancer Center
2025
Chimeric antigen receptor T cells (CART) targeting CD19 through CD28.ζ signaling induce rapid lysis of leukemic blasts, contrasting with persistent tumor control exhibited by 4-1BB.ζ-CART. We reasoned that molecular dynamics at the CART immune synapse (CARIS) could explain differences in their rejection kinetics. observed CD28.ζ-CART engaged brief highly lethal CARIS and mastered serial killing, whereas 4-1BB.ζ-CART formed lengthy relied on robust expansion cooperative killing. analyzed...
Abstract The efficacy of CAR T-cells (CART) in solid tumors is limited by immune inhibition. In our study, we observed that effector cytokines mediated the upregulation PD-L1 immune-checkpoint primary glioblastoma (GBM). To offset inhibitory signal, engineered PD-1 checkpoint reversal receptors (CPR) with a CD28 or 41BB co-stimulatory endodomain and co-expressed them first-generation CD28-containing second-generation HER2-specific (CPR/CART) using bicistronic vectors. We found bipartite...
<p>Analysis of CAR immune synapse (CARIS) with HER2+ GBM cells.</p>
<p>Immunophenotype and immune-checkpoint receptor expression in patient-derived CPR/CART cells.</p>
<p>Expression of CAR/CPR on T cells and HER2/PD-L1 tumor cells.</p>
<p>Summary of CPR/CART design and characterization CARζ co-expressing CPR containing CD28 or 4-1BB signaling.</p>
<p>Assessment of PD-L1 expression and CARζ/CPR41BB cell cytotoxic function in osteosarcoma.</p>
<p>Immunophenotype and functional profile of CARζ/CPR41BB in comparison to CAR41BBζ cells.</p>
<p>Analysis of CAR immune synapse (CARIS) formation by CARζ/CPR41BB and CAR41BBζ cells with wild-type PD-L1 KO LN229-GBM cells.</p>
<p>Assessment of mitochondrial metabolism in CARζ/CPR41BB cells.</p>
<p>PD-L1 expression in GBM and PD-1 recruitment to the CARIS with GBM. <b>A,</b> Constitutive (UPN01) inducible (UPN06) surface of PD-L1 primary cells after 24–48 hours IFN-γ exposure. Representative results from two samples shown. UPN, unique patient number. <b>B,</b> median fluorescent intensity (MFI) on (<i>n</i> = 14) before at 48 (10 ng/mL) exposure; ***, <i>P</i> < 0.001, Wilcoxon signed-rank test. <b>C,</b>...
<div>Abstract<p>The efficacy of chimeric antigen receptor T cells (CART) in solid tumors is limited by immune inhibition. In our study, we observed that effector cytokines mediated the upregulation PD-L1 checkpoint primary glioblastoma. To offset inhibitory signal, engineered PD-1 reversal receptors (CPR) with a CD28 or 41BB costimulatory endodomain and coexpressed them first-generation CD28-containing second-generation HER2-specific CAR (CPR/CART) using bicistronic vectors. We...
<p>Dynamics of CARζ/CPR41BB T-cell activation and CARIS formation in comparison with CAR41BBζ cells. <b>A,</b> cells (<i>n</i> = 3 donors) demonstrated significantly lower IL-2 IFN-γ release compared at 24 hours coculture LN229-GBM cells, CAR28ζ consistently showing the higher Th1 cytokine production. Data are shown as mean ± SD. **, <i>P</i> < 0.000; ****, 0.0001; two-way ANOVA Tukey multiple comparisons test. <b>B,</b> Western blot...
<p>Metabolomic parameters of CARζ/CPR41BB cells in comparison with CAR41BBζ cells. <b>A,</b> OCR measurements resting (cultured media containing IL-7 and IL-15) (<i>n</i> = 3 donors; 200,000 T per well) under basal metabolic conditions after the addition mitochondrial inhibitors. <b>B,</b> Comparison maximal respiration between at baseline (day 0). <i>P</i> 0.059, Student two-tailed <i>t</i> test. <b>C,</b> Basal...
<p>Effect of decoupling signal 2 from the CAR on T-cell function. <b>A,</b> Illustration depicting bipartite activation through 1 delivery engaging HER2 antigen and binding CPR with PD-L1 (or PD-L2). <b>B,</b> Percent increase in IFN-γ production by CAR28ζ/CPR28 CARζ/CPR28 compared CAR28ζ cells (50,000 T cells/well) at 24 hours coculture autologous GBM (<i>n</i> = 5 patients). Effector (100,000 cells) to target ratio 1:1. **, <i>P</i>...
<p>Design and functional screening of PD-1<sub>TR</sub> CPR28 molecules. <b>A,</b> Schematic representation the bicistronic vectors encoding for HER2-CAR with truncated PD-1 (PD-1<sub>TR</sub>) or CPR28. The CPR28<sup>dimer</sup> included a membrane proximal extracellular cysteine residue (C141) required CD28 homodimerization, as indicated. <b>B,</b> Flow cytometry analysis showing coexpression CPR on T cells. CAR28ζ NT cells...
<p><i>In vivo</i> antitumor activity of locoregionally delivered CARζ/CPR41BB cells in an orthotopic GBM model. <b>A,</b> Experimental schema for <i>in functional testing a LN229-GBM xenograft Mice were injected with eGFP.FFluc-expressing tumor on day 0 and randomized to treatment groups 11. Treatment consisted two intracranial T-cell injections days 13 21. Tumors monitored by BLI. <b>B,</b> Comparison volumes between control after...
<p>Immunohistochemistry and histopathology findings in a metastatic osteosarcoma model after treatment with CARζ/CPR41BB cells.</p>
<p>PD-L1 expression in glioblastoma (GBM) cells and PD-1 upregulation CART.</p>
<p>In vivo function of systemically administered CARζ/CPR41BB cells in a metastatic osteosarcoma model.</p>
<p>Phenotypic and functional profile of CART receiving bipartite activation signals through CPR41BB costimulation. <b>A,</b><i>In vivo</i> screening CARζ CAR28ζ cells coexpressing CPR28 or against orthotopic xenografts HER2<sup>+</sup>PD-L1<sup>+</sup> U373-GBM in SCID mice (<i>n</i> = 5 per group). <b>B,</b> Fold change tumor burden after treatment relative to the volume before intratumoral injection T (day 0),...