Biology subjects

Turan, R. D.

Publications and source records attributed to Turan, R. D..

5 recordsLinked to original sources

bioRxiv2023

Phytohemagglutinin-Activated CAR-T Cells: Prolonged Persistence and Enhanced Anti-Tumor Response in CD19-Specific Acute Lymphoblastic Leukemia

In recent times, chimeric antigen receptor (CAR)-T cell therapy has shown rapid advancements and gained clinical approval for use in cancer immunotherapy. CAR, a synthetic receptor integrated into autologous T cells, has yielded highly successful results in patients with leukemia. The significant potential of CAR-T cells has been validated through clinical trials in adult and pediatric cancer treatments. Our therapy developed specifically for CD19-specific Acute Lymphoblastic Leukemia (ALL) has shown promising results in in vitro and in vivo tests. To enhance the response against cancer, provide a bistimulatory effect, and increase stability, we designed two different CAR structures specific to CD19. These designs incorporate the CD28 and 41BB costimulatory domains. Through in vitro analysis, we evaluated the population ratios and cytotoxic activities of Central Memory T cells (TCM) and Stem Cell Memory T cells (TSCM) in CAR-T (CAR1928-T and CAR19BB-T) cells. Our initial design, CAR1928-T, produced an effective anti-tumor response. With our second design, CAR19BB-T, we not only achieved an anti-tumor effect but also conferred memory capabilities, leading to a comprehensive treatment approach. We demonstrated that CAR-T cells produced using Phytohemagglutinin (PHA) exhibited increased persistence in vitro and in vivo compared to anti-CD3 and anti-CD28 stimulation. The use of PHA to activate CAR19BB-T cells developed a long-lasting and effective CAR-T cell production method in vivo using cancerous animal models. CAR-T cell-treated mice survived tumor-free for up to 60 days, surpassing the survival of mice that received tumors only. Additionally, CAR19BB-T cell production with PHA remained stable over time. These results highlight a novel CAR-T cell production approach with a high-memory T cell profile capable of delaying or preventing cancer relapse. We optimized the method for the production of long-term and effective CAR-T cells and tested it in preclinical experiments. As a result, it was demonstrated that CAR-T cells generated with PHA, when administered as a co-stimulatory dose, can provide continuous proliferation and long-term persistence without compromising their anti-cancer efficacy. Preclinical studies have been completed to obtain valuable data for enhancing the long-term effectiveness of CAR-T therapy in clinical trials and transitioning to clinical applications.

immunology↗

bioRxiv2020

Gamma-irradiated SARS-CoV-2 vaccine candidate, OZG-38.61.3, confers protection from SARS-CoV-2 challenge in human ACEII-transgenic mice

The SARS-CoV-2 virus caused the most severe pandemic around the world, and vaccine development for urgent use became a crucial issue. Inactivated virus formulated vaccines such as Hepatitis A, oral polio vaccine, and smallpox proved to be reliable approaches for immunization for prolonged periods. During the pandemic, we produced an inactivated SARS-CoV-2 vaccine candidate, having the advantages of being manufactured rapidly and tested easily in comparison with recombinant vaccines. In this study, an inactivated virus vaccine that includes a gamma irradiation process for the inactivation as an alternative to classical chemical inactivation methods so that there is no extra purification required has been optimized. The vaccine candidate (OZG-38.61.3) was then applied in mice by employing the intradermal route, which decreased the requirement of a higher concentration of inactivated virus for proper immunization, unlike most of the classical inactivated vaccine treatments. Hence, the novelty of our vaccine candidate (OZG-38.61.3) is that it is a non-adjuvant added, gamma-irradiated, and intradermally applied inactive viral vaccine. Efficiency and safety dose (either 1013 or 1014 viral copy per dose) of OZG-38.61.3 was initially determined in Balb/c mice. This was followed by testing the immunogenicity and protective efficacy of OZG-38.61.3. Human ACE2-encoding transgenic mice were immunized and then infected with a dose of infective SARS-CoV-2 virus for the challenge test. Findings of this study show that vaccinated mice have lower SARS-CoV-2 viral copy number in oropharyngeal specimens along with humoral and cellular immune responses against the SARS-CoV-2, including the neutralizing antibodies similar to those shown in Balb/c mice without substantial toxicity. Subsequently, plans are being made for the commencement of Phase 1 clinical trial of the OZG-38.61.3 vaccine for the COVID-19 pandemic.

immunology↗

bioRxiv2020

Preliminary report of preclinical efficacy and safety analysis of gamma-irradiated inactivated SARS-CoV-2 vaccine candidates, SK-01 version 1 and OZG-3861 version 1

COVID-19 outbreak caused by SARS-CoV-2 created an unprecedented health crisis since there is no vaccine for this novel virus. Therefore, SARS-CoV-2 vaccines have become crucial for reducing morbidity and mortality. In this study, in vitro and in vivo safety and efficacy analyzes of lyophilized vaccine candidates inactivated by gamma-irradiation were performed. The candidate vaccines in this study were OZG-3861 version 1 (V1), an inactivated SARS-CoV-2 virus vaccine, and SK-01 version 1 (V1), a GM-CSF adjuvant added vaccine. The candidate vaccines were applied intradermally to BALB/c mice to assess toxicity and immunogenicity. Preliminary results in vaccinated mice are reported in this study. Especially, the vaccine models containing GM-CSF caused significant antibody production with neutralization capacity in absence of the antibody-dependent enhancement feature, when considered in terms of T and B cell responses. Another important finding was that the presence of adjuvant was more important in T cell in comparison with B cell response. Vaccinated mice showed T cell response upon restimulation with whole inactivated SARS-CoV-2 or peptide pool. This study shows that the vaccines are effective and leads us to start the challenge test to investigate the gamma-irradiated inactivated vaccine candidates for infective SARS-CoV-2 virus in humanized ACE2+ mice.

immunology↗

bioRxiv2020

Development of Small Molecule MEIS Inhibitors that modulate HSC activity

Meis1, which belongs to TALE-type class of homeobox gene family, appeared as one of the key regulators of hematopoietic stem cell (HSC) self-renewal and a potential therapeutical target. However, small molecule inhibitors of MEIS1 remained unknown. This led us to develop inhibitors of MEIS1 that could modulate HSC activity. To this end, we have established a library of relevant homeobox family inhibitors and developed a high-throughput in silico screening strategy against homeodomain of MEIS proteins using the AutoDock Vina and PaDEL-ADV platform. We have screened over a million druggable small molecules in silico and selected putative MEIS inhibitors (MEISi) with no predicted cytotoxicity or cardiotoxicity. This was followed by in vitro validation of putative MEIS inhibitors using MEIS dependent luciferase reporter assays and analysis in the ex vivo HSC assays. We have shown that small molecules named MEISi-1 and MEISi-2 significantly inhibit MEIS-luciferase reporters in vitro and induce murine (LSKCD34low cells) and human (CD34+, CD133+, and ALDHhi cells) HSC self-renewal ex vivo. In addition, inhibition of MEIS proteins results in downregulation of Meis1 and MEIS1 target gene expression including Hif-1, Hif-2 and HSC quiescence modulators. MEIS inhibitors are effective in vivo as evident by induced HSC content in the murine bone marrow and downregulation of expression of MEIS target genes. These studies warrant identification of first-in-class MEIS inhibitors as potential pharmaceuticals to be utilized in modulation of HSC activity and bone marrow transplantation studies.

molecular biology↗

bioRxiv2018

c-Myc inhibition is critical for HSC expansion and Rad51 expression

c-Myc plays a major role in the maintenance of glycolytic metabolism and hematopoietic stem cell (HSC) quiescence. Targeting modulators of HSC quiescence and metabolism could lead to HSC cell cycle entry with concomitant expansion. Here we show that c-Myc inhibitor 10074-G5 treatment leads to 2-fold increase in murine LSKCD34low HSC compartment post 7 days. In addition, c-Myc inhibition increases CD34+ and CD133+ human HSC number. c-Myc inhibition leads to downregulation of glycolytic and cyclin-dependent kinase inhibitor (CDKI) gene expression ex vivo and in vivo. In addition, c-Myc inhibition upregulates major HDR modulator Rad51 expression in hematopoietic cells. Besides, c-Myc inhibition does not alter proliferation kinetics of endothelial cells, fibroblasts or adipose derived mesenchymal stem cells, however; it limits bone marrow derived mesenchymal stem cell proliferation. We further demonstrate that a cocktail of c-Myc inhibitor 10074-G5 along with tauroursodeoxycholic acid (TUDCA) and i-NOS inhibitor L-NIL provides a robust HSC maintenance and expansion ex vivo as evident by induction of all stem cell antigens analyzed. Intriguingly, the cocktail of c-Myc inhibitor 10074-G5, TUDCA and L-NIL improves HDR related gene expression. These findings provide tools to improve ex vivo HSC maintenance and expansion, autologous HSC transplantation and gene editing through modulation of HSC glycolytic and HDR pathways.\n\n\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=150 SRC=\"FIGDIR/small/403584_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (65K):\norg.highwire.dtl.DTLVardef@a34597org.highwire.dtl.DTLVardef@12dcc37org.highwire.dtl.DTLVardef@1ba68edorg.highwire.dtl.DTLVardef@13edbfd_HPS_FORMAT_FIGEXP M_FIG Graphical abstract\n\nC_FIG HighlightsO_LIc-Myc inhibition induces ex vivo murine and human hematopoietic stem and progenitor cell proliferation and in vivo murine HSC pool\nC_LIO_LIc-Myc inhibition downregulates CDKIs and glycolytic gene expression in hematopoietic cells\nC_LIO_LIc-Myc inhibition do not cause apparent changes to endothelial cells, fibroblasts, or AD-MSCs but it limits BM-MSC proliferation\nC_LIO_LIc-Myc inhibition along with TUDCA and L-NIL improves HSC maintenance and expansion as evident by induction of all HSC surface antigens analyzed\nC_LIO_LIc-Myc inhibition alone upregulates major HDR modulator Rad51 expression in hematopoietic cells\nC_LIO_LICocktail of c-Myc inhibitor 10074-G5, TUDCA and L-NIL improves HDR and S-phase related gene expression\nC_LI

cell biology↗