About

Saba Ghassemi, PhD, is a Research Assistant Professor of Pathology and Laboratory Medicine at the University of Pennsylvania's Perelman School of Medicine. His research expertise includes CAR-T cell manufacturing, T cell activation, proliferation, and differentiation, as well as gene transfer techniques using lentiviral, retroviral, and mRNA-based methods. He is involved in developing nano-engineered cell culture platforms and microfluidics for immunotherapy applications. His work focuses on advancing immunotherapy strategies, particularly in the context of CAR T cell therapy, with an emphasis on improving efficacy and understanding the underlying biological mechanisms. Dr. Ghassemi's contributions include the development of mechanostimulatory platforms for CAR T cell immunotherapy, bioengineered preclinical trial-on-chip models for leukemia, and genetic modification techniques to enhance CAR T cell efficacy in solid tumors. His research aims to optimize cell manufacturing processes and enhance the therapeutic potential of cellular immunotherapies.

Research topics

• Biology
• Immunology
• Cancer research
• Cell biology
• Chemistry

Selected publications

• Biogenic Selenium Nanoparticles Potentiate Anti-Mesothelin CAR-T Cell Therapy in a Syngeneic TNBC Model

  Transplantation and Cellular Therapy · 2026-01-18

  article
  PublisherDOI

• Single-day nonactivated IL-18-armed CAR T cells establish a durable, stemlike state with enhanced persistence

  Blood · 2026-04-16

  articleSenior author

  Chimeric antigen receptor (CAR) T-cell therapies have transformed the treatment of B-cell malignancies, yet challenges including manufacturing delays, T-cell exhaustion, and limited persistence impede broader clinical success. Here, we report the single day production of non-activated CAR T-cells engineered to secrete interleukin-18 (IL-18), a pro-inflammatory cytokine that enhances T-cell function. These non-activated CART-IL18 cells exhibit robust anti-tumor efficacy across xenograft models of lymphoma, leukemia, and pancreatic cancer. IL-18 expression enhances the functional advantages of naïve-like non-activated CAR T-cells, resulting in improved persistence, metabolic fitness, and resistance to exhaustion. Single-cell transcriptomic analysis revealed upregulation of IL7R, KLF2, and MCL1, alongside suppression of inhibitory checkpoint genes such as PDCD1, TOX, and HAVCR2. Metabolomic profiling demonstrated enhanced mitochondrial bioenergetics, with increased spare respiratory capacity and accumulation of α-ketoglutarate, malate, and spermine. Functional in vitro and in vivo profiling demonstrated enhanced per-cell cytotoxicity and in vivo durability. We complemented these studies with single-cell transcriptomic and metabolomic analyses to define CAR T-cell biological states beyond what is captured by xenograft tumor clearance. This IL-18-enhanced, activation-free CAR T product offers a clinically actionable platform with the potential to reduce vein-to-vein time while improving product potency and persistence, providing a rationale for clinical testing in patients with tumors refractory to standard CAR T.

  PublisherDOI

• Abstract 4272: Glutamic-oxaloacetic transaminase 2 (GOT2) as a dual-functional enhancer for CAR-T cell metabolic fitness

  Cancer Research · 2026-04-03

  article

  Abstract CAR-T cell therapy has transformed the treatment landscape for hematologic malignancies, yet its efficacy in solid tumors remains challenged. Aspartate is one of the most critically depleted metabolites in the solid tumor microenvironment; its deficiency impairs T cell proliferation, redox balance, and mitochondrial fitness. GOT2, a mitochondrial enzyme in the malate-aspartate shuttle, plays a critical role in T cell metabolism, as it catalyzes the conversion of oxaloacetate to aspartate. In doing so, GOT2 also helps maintain redox balance and energy production. In addition to its canonical role in aspartate biosynthesis, recent studies in cancer cells suggest that GOT2 regulates fatty acid metabolism through the activation of the transcription factor PPARδ. In T cells, PPARδ is shown to regulate the formation of central memory phenotype and long-term survival. In this study, we examined whether GOT2 overexpression enhances CAR-T cell metabolic fitness and antitumor activity. We found that GOT2-overexpressing CAR-T cells (CART19-GOT2) exhibit superior cytolytic function in both in vitro hypoxic conditions and in vivo tumor models. In xenograft models of NALM6 leukemia, CART19-GOT2 was able to sustain tumor control and prevented regrowth even after rechallenge. Compared to standard CART19 cells, CART19-GOT2 show enhanced mitochondrial respiration and spare respiratory capacity, indicating better mitochondrial fitness. GOT2 overexpression also elevated intracellular aspartate levels in CAR-T cells in normal growth conditions and under hypoxic stress. Using isotypically labeled nutrients as tracers, we found that aspartate is replenished through a cooperative interplay of fuels in primary human T cells, with glutamine serving as the preferred substrate. Collectively, these findings indicate that GOT2 overexpression is a promising strategy for metabolic enhancement of CAR-T cells for solid tumor immunotherapy. Citation Format: Xiangyi Fang, Shadab Kazmi, Andre Kelly, Xiaoling Jin, Alison Jaccard, Nathaniel W. Snyder, Alexander A. Shestov, Saba Ghassemi, Roddy S. O'Connor. Glutamic-oxaloacetic transaminase 2 (GOT2) as a dual-functional enhancer for CAR-T cell metabolic fitness [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 4272.

  PublisherDOI

• Piezo1-mediated mechano-energetics regulate CAR T cell function

  Research Square · 2025-10-23 · 1 citations

  preprintOpen access
  PublisherOA PDFDOI

• Glucose transporter 5 enhances CAR-T cell metabolic function and serial killing

  Blood · 2025-11-03

  article

  Abstract Physiologic serum fructose levels range from 20-150. In the context of AML, fructose accumulates in the bone marrow, reaching concentrations of 2mM, 5mM and in some reports 8mM. Implicit in this observation is that fructose is produced by cells present in the bone marrow and diffuses into the larger blood volume of the periphery. Transmembrane flux of glucose and/or fructose is facilitated by glucose transporters (GLUT) that play a vital role in T cell metabolic reprogramming and anti-tumour function. GLUTs display preferential selectivity for carbohydrate macronutrients including glucose, galactose, and fructose. GLUT5, which selectively transports fructose over glucose, has never been explored as a genetic engineering strategy to enhance CAR-T cell serial killing and durable anti-tumor function in fructose-rich tumour environments. Here, we demonstrate that the expression of wild-type GLUT5 restores T cell metabolic fitness in glucose-free, high fructose conditions. We find that GLUT5 supports maximal glycolytic capacity, expedites ATP replenishments, and rescues IL-2 production by using fructose as the primary nutrient source. Using steady state tracer technology, we show that 13C6 fructose supports glycolytic reprogramming and TCA anaplerosis in CAR-T cells undergoing log phase expansion. In cytotoxicity assays, GLUT5 rescues T cell cytolytic function in glucose-free medium. The fructose/GLUT5 metabolic axis also supports maximal migratory velocity, which provides mechanistic insight into why GLUT5-expressing CAR-Ts have superior effector function as they undergo “hit-and-run” serial killing. Our findings have immediate translational relevance as GLUT5 confers a competitive edge in a fructose-enriched milieu, and is a novel approach to overcome glucose depletion in hostile tumour microenvironments (TMEs). Importantly, the source of fructose production has not been described. As sorbitol dehydrogenase (encoded by SORD) synthesizes fructose at the end of the polyol pathway, we profiled SORD abundance in human bone marrow using single cell transcriptomic data generated from the anti-CD123-CAR-T cell clinical trial (NCT04106076) performed at the University of Pennsylvania. UMAP visualization revealed SORD expression in AML blasts (CD33+ and CD34+). This was expected as they account for 20-80% of all the cells in the leukemic bone marrow. We found that the highest SORD transcript levels were mapped to a non-AML cell population. These cells are haematopoietic in origin (CD45/PTPRC+ cells). Interestingly, data from The Human Protein Atlas reveals that naive B cells express high levels of GLUT5 which could facilitate diffusion of fructose across the surface (Fig. S1B). scRNA seq data also indicated high Glut5 and GAPDH as well as LDHA in tumor cells which suggests that Glut5 is fueling glycolysis and the rapid growth of tumor cells These findings imply that Glut5 could be a target for cancer treatment. We recognize that AML blasts and CD123-CAR-T cells engineered to express GLUT5 may compete for fructose in the bone marrow. As GLUT8 also displays high affinity for fructose, it emerges as an important candidate to inspire similar approaches. Intuitively, select inhibitors of GLUT5 such as MSNBA (N-[4-(methylsulfonyl)-2-nitrophenyl]-1,3-benzodioxol-5-amine; Ki of 3.2 ± 0.4 μM) can be combined with GLUT8-expressing CAR-T cells to bypass competition for fructose in AML. In a subset of patients Glut1 is high (SLC2A1) and these tumor cells do not express high levels of GAPDH or LDHA. These data suggest that the complete oxidation of glucose in the mitochondria maybe supporting the growth of AML blasts; positioning the complex 1 inhibitor metformin as an important candidate along with standard therapy. In summary, we show that T cell dependency on glucose can be mitigated by facilitating the metabolism of fructose, a closely related functional isomer of glucose. Our findings provide an important advance in the clinical applications of CAR-T cell therapy against AML, and potentially other tumors where fructose is abundant. Expressing glucose transporters to optimize fuel selection, expedite ATP replenishment, support cytokine production, and bolster anti-tumour function has been fraught with challenges. Here, we show that GLUT5 is an ideal candidate with immediate translational relevance, including CAR-Ts against AML.

  PublisherDOI

• Field testing and finite element modelling of old metal railway bridges with corrosion impact analysis

  Structures · 2025-12-01

  articleOpen access1st authorCorresponding

  Bridges are vital to transport infrastructure and connectivity, but old bridges pose significant maintenance and possibly even safety concerns. Accurately assessing the structural health of old bridges requires an approach that accounts for both bridge conditions and detailed simulation. This paper describes field monitoring and associated numerical investigation to assess the impact of corrosion on the structural performance of two old steel railway bridges, with an emphasis on nonlinear behaviour. Measured structural accelerations (natural frequencies of 13.9 Hz for bridge 1 and 7.2 Hz for bridge 2) and deflections during train passage are used to verify the accuracy of finite element models of each bridge in capturing modal responses and deflection behaviour. Parametric analyses across multiple corrosion scenarios for both representative bridges showed that a uniform thickness loss of around 30 % resulted in only a 10–12 % decrease in natural frequency and a 40–73 % increase in deflection (less than 1.5 mm) but led to substantial stress increases of up to 60–180 %. This demonstrates that stress is significantly more sensitive to corrosion than global stiffness or frequency. Moreover, localised corrosion produced far greater stress amplification than uniform corrosion with comparable total mass loss, confirming its potential to cause local yielding even when global deflection remains within acceptable limits. The study establishes a validated framework combining field measurements with corrosion-sensitive FE modelling to quantify the impact of both uniform and localised corrosion on old bridges. The findings highlight the need to integrate global monitoring data with detailed local inspections and modelling to improve the accuracy of bridge condition assessment and long-term service life prediction.

  PublisherDOI

• Bioengineered immunocompetent preclinical trial-on-chip tool enables screening of CAR T cell therapy for leukaemia

  Nature Biomedical Engineering · 2025-07-01 · 15 citations

  articleOpen access

  Chimeric antigen receptor (CAR) T cell immunotherapy is promising for treatment of blood cancers; however, clinical benefits remain unpredictable, necessitating development of optimal CAR T cell products. Unfortunately, current preclinical evaluation platforms are inadequate owing to their limited physiological relevance to humans. Here we engineer an organotypic immunocompetent chip that recapitulates microarchitectural and pathophysiological characteristics of human leukaemia bone marrow stromal and immune niches for CAR T cell therapy modelling. This leukaemia chip empowers real-time spatiotemporal monitoring of CAR T cell functionality, including T cell extravasation, recognition of leukaemia, immune activation, cytotoxicity and killing. We use our chip to model clinically observed heterogeneous responses such as remission, resistance and relapse under CAR T cell therapy and map factors that drive therapeutic success or failure. Finally, we demarcate functional performance of CAR T cells produced from different healthy donors and patients with cancer, with various CAR designs and protocols, systematically and multidimensionally. Together, our chip introduces an enabling '(pre-)clinical-trial-on-chip' tool for CAR T cell development, which may translate to personalized therapies and improved clinical decision-making.

  PublisherOA PDFDOI

• Metabolic conditioning for enhanced CAR T cell function

  Blood · 2025-11-03

  article

  Abstract Introduction Durable benefits in adoptive immunotherapies are often linked to metabolic reprogramming, differentiation states, and epigenetic remodeling. Previously, we showed that CAR design has a profound impact on T cell metabolism. Implicit in these earlier discoveries is that T cell metabolism is not fixed and can be dynamically modified to suit the target environment. Despite these advances, genetic targets and/or conditioning strategies to overcome metabolic conditions encountered in hostile environments are underdefined. Here, we developed an arginine conditioning strategy to enhance human CAR T cell metabolic fitness and sustain tumor control in several xenograft models of cancer. Methods To provide mechanistic insights into the value of arginine for CAR T cells, we expanded primary human CAR T cells in medium spiked with 5X arginine for 7 days. We tested anti-tumor function and persistence in our clinically validated Nalm6-xenograft model of leukemia. We examined differentiation status by flow cytometry as well as ATAC seq analyses. To understand how arginine conferred long-lasting efficacy, we screened histone modifications by ultra-high resolution mass spectrometry. We combined this with genomic metabolic modeling and a multimodal analyses including metabolomics, RNA seq, ATAC seq and machine-learning. We then validated the unique impact of arginine conditioning on methionine, glutamine, and branched chain amino acid metabolism via 13C tracer technology. Finally, we performed targeted LC-MS to examine the abundance of arginine and its related metabolites in responder vs nonresponder CAR T cell patients. Results We report that arginine promotes central memory differentiated T cells with enhanced mitochondrial volume. Arginine induces a strong epigenetic signature distinguished by methylation as well as acetylation of several histone proteins. S-adenosyl methionine (SAM) sits at the intersection of histone modification and polyamine biosynthesis. In novel insights, we propose that the fate of SAM is nutritionally-regulated via an arginine-mediated upregulation of ASS1. After its metabolism to ornithine, arginine can support polyamine synthesis (SAM dependent) or be metabolized by ASS1. As ASS1 is an ornithine-consuming enzyme, it deploys ornithine in the arginine-citrulline cycle. We propose that this intrinsic buffering role of ASS1 limits the commitment of ornithine to polyamine biosynthesis; sparing SAM for transmethylation. Importantly, this novel concept has never been described previously. Disproportionate increases in ornithine relative to SAM activate SAM production in the folate and methionine cycle. Modeling insights, RNA seq and ATAC-seq analyses highlight an important role for one carbon metabolism including induction of the synergistic gene pair MTHFD1L and SHMT2, as well as methionine synthase and the twin axis of methyl transferase enzymes MAT2A as well as MAT2B in the methionine cycle. Using a 13C metabolic tracer, we verify that arginine conditioning significantly enhances the replenishment of SAM via methionine. We show that the induction of cystathionine beta synthase (CBS) is a hallmark of arginine-treatment. We propose that CBS provides a relief valve for homocysteine, which facilitates high methionine cycle activity and SAM production. PRMTs are a family of proteins that catalyze the transfer of methyl groups to proteins including histones. We provide pharmacologic evidence that the benefits of arginine conditioning are regulated in part by PRMT3. We also identified that several arginine-related metabolites were elevated in the serum metabolome of “responder” patients CAR T cell treatment against lymphoma. Conclusions This study provides mechanistic insights into how arginine supports T cell anti-tumor function. Anchored to their epigenetic footprint, arginine-treated CAR T cells form progeny with enhanced mitochondrial fitness, lasting anti-tumor function in several models, and central memory differentiation in vivo. Our findings have immediate translational relevance as clinical outcomes depend on the cytolytic potency and metabolic fitness of the therapeutic product.

  PublisherDOI

• Enhanced CAR T-Cell Therapy for Lymphoma after Previous Failure

  New England Journal of Medicine · 2025-05-07 · 84 citations

  article

  BACKGROUND: Chimeric antigen receptor (CAR) T cells targeting CD19 have transformed the treatment of B-cell cancers, but many patients do not have long-term remission. We designed an anti-CD19 enhanced (armored) CAR T-cell product (huCART19-IL18) that secretes interleukin-18 to enhance antitumor activity. METHODS: . RESULTS: A total of 21 patients received huCART19-IL18. Cytokine release syndrome occurred in 62% of the patients (47% with grade 1 or 2), and immune effector-cell-associated neurotoxicity syndrome occurred in 14% (all grade 1 or 2). No unexpected adverse events were observed. Robust CAR T-cell expansion was detected across all dose levels. At 3 months after infusion, a complete or partial response was seen in 81% of the patients (90% confidence interval [CI], 62 to 93) and a complete response in 52% (90% CI, 33 to 71). With a median follow-up of 17.5 months (range, 3 to 34), the median duration of response was 9.6 months (90% CI, 5.5 to not reached). CONCLUSIONS: In this small study, huCART19-IL18 had a safety profile consistent with other CAR T-cell treatments and showed promising efficacy at low cell doses in patients with lymphoma after the failure of previous anti-CD19 CAR T-cell therapy. (ClinicalTrials.gov number, NCT04684563.).

  PublisherDOI

• Innovative insights into micropile seismic response: Shaking table tests reveal critical dependencies and liquefaction mitigation

  Bulletin of Engineering Geology and the Environment · 2025-03-25 · 8 citations

  articleOpen access1st authorCorresponding

  Abstract This study presents a novel investigation into the seismic response of micropiles through shaking table tests, diverging from the predominant reliance on numerical analyses in assessing micropiles in liquefiable sites. Three models of shaking table tests were conducted using Iai scaling rules for physical modelling in 1-g conditions. The investigation reveals a significant dependency of micropile efficiency on the frequency of input motions. During the 2 Hz test, the entire model experienced liquefaction; however, in the 3 Hz test, there was a remarkable 29% reduction in excess pore water pressure. Additionally, the study explores the impacts of varying distances between micropiles and examines how liquefaction influences the induced peak accelerations at different depths within the soil media. Notably, recorded accelerations on the surface decreased by up to 76% in the free field tests during liquefaction. This comprehensive exploration advances our understanding of micropile behaviour under seismic conditions, offering valuable insights for soil improvement projects.

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Frequent coauthors

• Roddy S. O’Connor

  California University of Pennsylvania

  32 shared

• Michael C. Milone

  University of Pennsylvania

  22 shared

• Carl H. June

  Parker Institute for Cancer Immunotherapy

  19 shared

• Selene Nuñez-Cruz

  University of Pennsylvania

  13 shared

• James Hone

  Columbia University

  13 shared

• Michael P. Sheetz

  The University of Texas Medical Branch at Galveston

  13 shared

• Pere Roca‐Cusachs

  Institute for Bioengineering of Catalonia

  11 shared

• John Leferovich

  University of Pennsylvania

  10 shared

Labs

• Ghassemi Lab, Center for Cellular ImmunotherapiesPI