Biology subjects

Arbab, A. S.

Publications and source records attributed to Arbab, A. S..

8 recordsLinked to original sources

bioRxiv2025

Adoptive Transfer of ILC2s into the Brain Reveals Tumor Homing in Glioblastoma: A Proof-of-Concept for Cellular Therapy

Glioblastoma (GBM) is an aggressive brain tumor with limited treatment options and poor immune cell infiltration. Cellular immunotherapies have transformed cancer treatment but remain largely ineffective against GBM due to the restrictive blood-brain barrier (BBB) and its profoundly immunosuppressive microenvironment. Innate lymphoid cells type 2 (ILC2s) have recently emerged as potential candidates for cellular immunotherapy because of their regenerative and immunomodulatory functions. Here, we provide the first in vivo evidence that systemically administered ILC2s can cross the BBB and home to glioblastoma. Bone marrow-derived ILC2s from C57BL/6 mice were labeled with CFSE and intravenously transferred into hosts bearing orthotopic, luciferase-expressing GL261 tumors. Fluorescence imaging and flow cytometry analyses indicated that transferred ILC2s successfully entered the brain, localized within tumor tissue, and were also detected in meninges and peripheral organs. Although no measurable reduction in tumor growth was observed, these findings support a proof-of-concept for adoptive ILC2 transfer as a feasible approach for targeting CNS tumors and exploring their immunomodulatory potential in GBM.

immunology↗

bioRxiv2025

Cannabidiol as a Prophylactic Agent Against Glioblastoma Growth: A Preclinical Investigation

PurposeGlioblastoma (GBM) is one of the most aggressive brain tumors, with limited treatment options and poor outcomes due to frequent relapse after surgery. This study aims to investigate whether pretreatment with inhaled cannabidiol (CBD) can inhibit GBM growth in a preclinical murine model. Specifically, we hypothesize that CBD pretreatment may reduce tumor progression and modulate the tumor microenvironment. MethodsC57BL/6 mice were pretreated with inhaled CBD for either 3 or 14 days, or a placebo, followed by intracranial implantation of glioblastoma cells. Tumor growth, immune checkpoint expression (IDO, PD-L1), and key biomarkers (MGMT, Ki67) were assessed to determine the impact of CBD pretreatment on tumor progression and the immune microenvironment. ResultsThe 14-day CBD pretreatment significantly reduced tumor growth compared to both the placebo and 3-day CBD groups. Additionally, this group showed lower expression of immune checkpoints (IDO, PD-L1) and reduced levels of MGMT and Ki67, suggesting enhanced tumor suppression. These results indicate that prolonged CBD pretreatment modulates the tumor microenvironment and may improve tumor control and reduce relapse risk. ConclusionThis study demonstrates that inhaled CBD pretreatment significantly inhibits GBM growth in a preclinical model. CBDs ability to reduce immune checkpoint expression and key biomarkers associated with tumor progression suggests that it could be an effective strategy for enhancing the efficacy of GBM therapies and potentially improving post-surgical outcomes. Further research is required to investigate its clinical potential and mechanisms of action.

cancer biology↗

bioRxiv2021

Pulsed Focal ultrasound as a non-invasive method to deliver exosomes in the brain/stroke

Exosomes, a component of extracellular vesicles are shown to carry important small RNAs, mRNAs, protein, and bioactive lipid from parent cells and are found in most biological fluids. Investigators have demonstrated the importance of mesenchymal stem cells (MSCs) derived exosomes in repairing stroke lesions. However, exosomes from endothelial progenitor cells (EPCs) have not been tested in any stroke model nor has there been an evaluation of whether these exosomes target/home to areas of pathology. Targeted delivery of IV administered exosomes has been a great challenge and a targeted delivery system is lacking to deliver naive (unmodified) exosomes from EPCs to the site of interest. Pulsed focused ultrasound (pFUS) is being used for therapeutic and experimental purposes. There has not been any report showing the use of pulsed low-intensity pFUS to deliver exosomes to the site of interest in models of stroke. In this proof of principle study, we have shown different parameters of pFUS to deliver exosomes in the intact and stroke brain with or without IV administration of nanobubbles. The study results showed that administration of nanobubbles is detrimental to the brain structures (micro bleeding and white matter destruction) at peak negative pressure (PNP) of >0.25 MPa, despite enhanced delivery of IV administered exosomes. However, without nanobubbles, pFUS PNP = 1 to 2 MPa enhances the delivery of exosomes in the stroke area without altering the brain structures.

neuroscience↗

bioRxiv2020

The critical immunosuppressive effect of MDSC-derived exosomes in the tumor microenvironment.

Myeloid-derived suppressor cells (MDSCs) are an indispensable component of the tumor microenvironment (TME), and our perception regarding the role of MDSCs in tumor promotion is attaining extra layer of intricacy in every study. In conjunction with MDSCs immunosuppressive and anti-tumor immunity, they candidly facilitate tumor growth, differentiation, and metastasis in several ways that yet to be explored. Alike any other cell types, MDSCs also release a tremendous amount of exosomes or nanovesicles of endosomal origin and partake in intercellular communications by dispatching biological macromolecules. There has not been any experimental study done to characterize the role of MDSCs derived exosomes (MDSC exo) in the modulation of TME. In this study, we isolated MDSC exo and demonstrated that they carry a significant amount of proteins that play an indispensable role in tumor growth, invasion, angiogenesis, and immunomodulation. We observed higher yield and more substantial immunosuppressive potential of exosomes isolated from MDSCs in the primary tumor area than those are in the spleen or bone marrow. Our in vitro data suggest that MDSC exo are capable of hyper activating or exhausting CD8 T-cells and induce reactive oxygen species production that elicits activation-induced cell death. We confirmed the depletion of CD8 T-cells in vivo by treating the mice with MDSC exo. We also observed a reduction in pro-inflammatory M1-macrophages in the spleen of those animals. Our results indicate that immunosuppressive and tumor-promoting functions of MDSC are also implemented by MDSC-derived exosomes which would open up a new avenue of MDSC research and MDSC-targeted therapy.

cancer biology↗

bioRxiv2020

Changes in the tumor microenvironment and treatment outcome in glioblastoma: A pilot study

Glioblastoma (GBM) is a hypervascular and aggressive primary malignant tumor of the central nervous system. Recent investigations showed that traditional therapies along with antiangiogenic therapies failed due to the development of post-therapy resistant and recurrent GBM. Our investigations show that there are changes in the cellular and metabolic compositions in the tumor microenvironment (TME). It can be said that tumor cell-directed therapies are ineffective and we need to rethink how to treat GBM. We hypothesize that the composition of TME-associated cells will be different based on the therapy and therapeutic agents, and TME-targeting therapy will be better to decrease recurrence and improve survival. Therefore, the purpose of this study is to determine the changes in the TME in respect of T-cell population, M1 and M2 macrophage polarization status, and MDSC population following different treatments in a syngeneic model of GBM. In addition to these parameters, tumor growth and survival were also studied following different treatments. The results showed that changes in the TME-associated cells were dependent on the therapeutic agents and the TME-targeting therapy improved the survival of the GBM bearing animals. The current GBM therapies should be revisited to add agents to prevent the accumulation of bone marrow-derived cells in the TME or to prevent the effect of immune-suppressive myeloid cells in causing alternative neovascularization, the revival of glioma stem cells, and recurrence. Instead of concurrent therapy, a sequential strategy would be best to target TME-associated cells.

cancer biology↗

bioRxiv2019

Generation of novel diagnostic and therapeutic exosomes to detect and deplete pro-tumorigenic M2-macrophages.

Given their pro-tumorigenic function and prevalence in most malignant tumors with lower survival, early detection and intervention of CD206-positive M2-macrophages may boost the clinical outcome. To determine in vivo distribution of M2-macrophages, we adopted 111In-oxine-based radiolabeling of the targeted exosomes. When injected these radiolabeled targeted exosomes into breast tumor-bearing mice, exosomes accumulated at the periphery of the primary tumor, metastatic foci in the lungs, spleen, and liver. Ex vivo quantification of radioactivity also showed similar distribution. Injected DiI dye-labeled exosomes into the same mice showed adherence of exosomes to the CD206-positive M2-macrophages on ex vivo fluorescent microscopy imaging. In addition, we utilized these engineered exosomes to carry the Fc portion of IgG2b with the intention of augmenting antibody-dependent cell-mediated cytotoxicity. We have auspiciously demonstrated that M2-macrophage targeting therapeutic exosomes deplete M2-macrophages both in vitro and in vivo, and reduce tumor burden increasing survival in a metastatic breast cancer model.

cancer biology↗

bioRxiv2019

Oncoprotein GT198 Vaccination Delays Tumor Growth in MMTV-PyMT Mice

Different effects of anticancer drugs between mouse and human have caused increasing concerns. A better understanding of cancer initiation between the two species is needed. We have previously identified an oncoprotein GT198 (PSMC3IP) in human breast cancer. In this report, we investigated GT198 in MMTV-PyMT mouse mammary gland tumors and found a reconcilable mechanism in human and mouse. Specifically, distinct tumor initiating stimuli in human and mouse result in a common GT198-mediated tumorigenic pathway in both species. Here we show, similar to human breast cancer even before a tumor appears, GT198 has overexpressed in mouse tumor stroma including pericyte stem cells, descendent adipocytes, fibroblasts, and myoepithelial cells. Using recombinant GT198 protein as an antigen, we vaccinated MMTV-PyMT mice and found that the GT198 vaccine delayed mouse tumor growth and reduced lung metastasis. The antitumor effects in vaccinated mice were linearly correlated with serum titers of GT198 antibody, which can recognize cell surface GT198 protein on viable tumor cells confirmed by FACS. Furthermore, tumor cells isolated from MMTV-PyMT mice were re-implanted into normal FVB/N mice, GT198+ tumor cells induced faster tumor growths than GT198- tumor cells. Together, this first study of GT198 vaccine in mouse showed its effectiveness in antitumor and anti-metastasis. The finding may accelerate future development of GT198 immunotherapy in human cancer. Our finding also indicates that even though distinct cancer-initiation stimuli exist between mouse and human, a common tumorigenic pathway mediated by oncoprotein GT198 is shared in both species.

cancer biology↗

bioRxiv2019

Differential in vivo biodistribution of 131I-labeled exosomes from diverse cellular origins and its implication in the theranostic application.

Exosomes are critical mediators of intercellular crosstalk and regulator of cellular/tumor microenvironment. Exosomes have great prospects for clinical application as theranostic and prognostic probe. Nevertheless, the advancement of the exosomes research has been thwarted by limited knowledge elucidating the most efficient isolation method and their in vivo trafficking. Here we have showed that combination of two size-based methods using 0.20 {micro}m syringe filter and 100k centrifuge membrane filter followed by ultracentrifugation method yields a greater number of uniform exosomes. We also demonstrated the visual representation and quantification of differential in vivo distribution of radioisotope 131I-labelled exosomes from diverse cellular origins, e.g., tumor cells with or without treatments (HET0016 and GW2580), myeloid-derived suppressor cells and endothelial progenitor cells. We also determined that the distribution was dependent on the protein/cytokine contents of the exosomes. The applied in vivo imaging modalities can be utilized to monitor disease progression, metastasis, and exosome-based targeted therapy. Abbreviations

cancer biology↗