Bulut Yurtsever

Dr. Bulut Yurtsever

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 June 2020 in TURKISH JOURNAL OF BIOLOGY
Verified
Journal Article
Open access
CIHAN TASTANCIHAN TASTAN
CIHAN TASTAN
BYBulut Yurtsever
Bulut Yurtsever
GKGözde Sir Karakuş
Gözde Sir Karakuş
DKDerya Di̇lEk Kançaği
Derya Di̇lEk Kançaği
SDSevda Demir
Sevda Demir
EOErcüment Ovali
Ercüment Ovali
The novel coronavirus pneumonia, which was named later as coronavirus disease 2019 (COVID-19), is caused by the severe acute respiratory syndrome coronavirus 2, namely SARS-CoV-2. It is a positive-strand RNA virus that is the seventh coronavirus known to infect humans. The COVID-19 outbreak presents enormous challenges for global health behind the pandemic outbreak. The first diagnosed patient in Turkey has been reported by the Republic of Turkey Ministry of Health on March 11, 2020. In May, over 150,000 cases in Turkey, and 5.5 million cases around the world have been declared. Due to the urgent need for a vaccine and antiviral drug, isolation of the virus is crucial. Here, we report 1 of the first isolation and characterization studies of SARS-CoV-2 from nasopharyngeal and oropharyngeal specimens of diagnosed patients in Turkey. This study provides an isolation and replication methodology,and cell culture tropism of the virus that will be available to the research communities.

1 January 2020 in Turkish Journal of Hematology
Verified
Journal Article
Open access
CIHAN TASTANCIHAN TASTAN
CIHAN TASTAN
DKDerya Dilek Kançağı
Derya Dilek Kançağı
RTRaife Dilek Turan
Raife Dilek Turan
BYBulut Yurtsever
Bulut Yurtsever
DÇDidem Çakırsoy
Didem Çakırsoy
EOErcüment Ovalı
Ercüment Ovalı
Objective: Relapsed and refractory CD19-positive B-cell acute lymphoblastic leukemia (ALL) and non-Hodgkin lymphoma (NHL) are the focus of studies on hematological cancers. Treatment of these malignancies has undergone recent transformation with the development of new gene therapy and molecular biology techniques, which are safer and well-tolerated therapeutic approaches. The CD19 antigen is the most studied therapeutic target in these hematological cancers. This study reports the results of clinical-grade production, quality control, and in vivo efficacy processes of ISIKOK-19 cells as the first academic clinical trial of CAR-T cells targeting CD19-expressing B cells in relapsed/refractory ALL and NHL patients in Turkey. Materials and Methods: We used a lentiviral vector encoding the CD19 antigen-specific antibody head (FMC63) conjugated with the CD8-CD28-CD3 zeta; sequence as a chimeric antigen receptor (CAR) along with a truncated form of EGFR (EGFRt) on human T-lymphocytes (CAR-T). We preclinically assessed the efficacy and safety of the manufactured CAR-T cells, namely ISIKOK-19, from both healthy donors' and ALL/NHL patients' peripheral blood mononuclear cells. Results: We showed significant enhancement of CAR lentivirus transduction efficacy in T-cells using BX-795, an inhibitor of the signaling molecule TBK1/IKK epsilon, in order to cut the cost of CAR-T cell production. In addition, ISIKOK-19 cells demonstrated a significantly high level of cytotoxicity specifically against a CD19+ B-lymphocyte cancer model, RAJI cells, in NOD/SCID mice. Conclusion: This is the first report of preclinical assessment of efficacy and safety analysis of CAR-T cells (ISIKOK-19) targeting CD19-expressing B cells in relapsed/refractory ALL and NHL patients in Turkey.

25 August 2022 in Turkish Journal of Hematology
Verified
Journal Article
Open access
EEEbru Erdoğan
Ebru Erdoğan
KYKoray Yalcin
Koray Yalcin
CHCansu Hemsinlioglu
Cansu Hemsinlioglu
ASAslıhan Sezgin
Aslıhan Sezgin
USUtku Seyis
Utku Seyis
EOErcüment Ovalı
Ercüment Ovalı
Objective: Chimeric antigen receptor T (CAR-T) cell therapies have already made an impact on the treatment of B-cell malignancies. Although CAR-T cell therapies are promising, there are concerns about commercial products regarding their affordability and sustainability. In this preliminary study, the results of the first production and clinical data of an academic CAR-T cell (ISIKOK-19) trial in Turkey are presented. Materials and Methods: A pilot clinical trial (NCT04206943) designed to assess the safety and feasibility of ISIKOK-19 T-cell therapy for patients with relapsed and refractory CD19+ tumors was conducted and participating patients received ISIKOK-19 infusions between October 2019 and July 2021. The production data of the first 8 patients and the clinical outcome of 7 patients who received ISIKOK-19 cell infusions are presented in this study. Results: Nine patients were enrolled in the trial [5 with acute lymphoblastic leukemia (ALL) and 4 with non-Hodgkin lymphoma (NHL)], but only 7 patients could receive treatment. Two of the 3 participating ALL patients and 3 of the 4 NHL patients had complete/partial response (overall response rate: 72%). Four patients (57%) had CAR-T-related toxicities (cytokine release syndrome, CAR-T-related encephalopathy syndrome, and pancytopenia). Two patients were unresponsive and had progressive disease following CAR-T therapy. Two patients with partial response had progressive disease during follow-up. Conclusion: Production efficacy and fulfillment of the criteria of quality control were satisfactory for academic production. Response rates and toxicity profiles were also acceptable for this heavily pretreated/refractory patient group. ISIKOK-19 cells appear to be a safe, economical, and efficient treatment option for CD19+ tumors. However, the findings of this study need to be supported by the currently ongoing ISIKOK-19 clinical trial.

28 October 2020 in bioRxiv
Verified
Preprint
Open access
PDF file
RTRaife Dilek Turan
Raife Dilek Turan
CIHAN TASTANCIHAN TASTAN
CIHAN TASTAN
DKDerya Dilek Kancagi
Derya Dilek Kancagi
BYBulut Yurtsever
Bulut Yurtsever
GKGozde Sir Karakus
Gozde Sir Karakus
GSGuldal Suyen
Guldal Suyen
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 10 13 or 10 14 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.

4 September 2020 in bioRxiv
Verified
Preprint
Open access
PDF file
GKGozde Sir Karakus
Gozde Sir Karakus
CIHAN TASTANCIHAN TASTAN
CIHAN TASTAN
DKDerya Dilek Kancagi
Derya Dilek Kancagi
BYBulut Yurtsever
Bulut Yurtsever
GTGamze Tumentemur
Gamze Tumentemur
EOErcument Ovali
Ercument Ovali
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.

24 April 2020 in bioRxiv
Verified
Preprint
Open access
PDF file
CIHAN TASTANCIHAN TASTAN
CIHAN TASTAN
BYBulut Yurtsever
Bulut Yurtsever
GSGozde Sir
Gozde Sir
DKDerya Dilek Kancagi
Derya Dilek Kancagi
SDSevda Demir
Sevda Demir
EOErcument Ovali
Ercument Ovali
The novel coronavirus pneumonia, which was named later as Coronavirus Disease 2019 (COVID-19), is caused by the Severe Acute Respiratory Syndrome Coronavirus 2, namely SARS-CoV-2. It is a positive-strand RNA virus that is the seventh coronavirus known to infect humans. The COVID-19 outbreak presents enormous challenges for global health behind the pandemic outbreak. The first diagnosed patient in Turkey has been reported by the Republic of Turkey Ministry of Health on March 11, 2020. Today, over ninety thousand cases in Turkey, and two million cases around the world have been declared. Due to the urgent need for vaccine and anti-viral drug, isolation of the virus is crucial. Here, we report one of the first isolation and characterization studies of SARS-CoV-2 from nasopharyngeal and oropharyngeal specimens of diagnosed patients in Turkey. This study provides an isolation and replication methodology, and cell culture tropism of the virus that will be available to the research communities. Article Summary: Scientists have isolated virus from Turkish COVID-19 patients. The isolation, propagation, and plaque and immune response assays of the virus described here will serve in following drug discovery and vaccine testing.