Biology subjects

Yalcin, K.

Publications and source records attributed to Yalcin, K..

4 recordsLinked to original sources

bioRxiv2026

Multicellular Spatial Programs Define the Histopathological Architecture of Meningioma

Tumors are often described by cell types or gradients, but the organizing units of tumor tissue remain unclear. Using meningiomas, which show marked morphologic diversity despite constrained and recurrent genetics, we identify reproducible multicellular spatial molecular programs (SMPs) characterized by recurring cell-type mixtures that combine in different proportions across tumors. We built a multi-omic atlas of 147 human meningiomas (1.6 million cells/spots), integrating scRNA-seq, Visium, CosMx-RNA, and CosMx-Protein. Across platforms, SMPs mapped onto canonical whorl-lobule architecture and defined a structured ecological landscape linking hypoxic, immune-evasive states to vascularized, matrix-remodeling, and mineralization-rich states. For translation, we developed MeningNet, a hybrid ConvNeXt-Vision Transformer that infers SMPs directly from hematoxylin-and-eosin sections. MeningNet generalized across an internal replication cohort and 465 external whole-slide images, recovering cross-platform inference and showing significant association with CNS-WHO grade. These findings establish meningioma architecture as a reproducible histopathological framework for inferring spatial molecular state from routine pathology.

Cancer Biology↗

bioRxiv2025

Non-invasive approach for endoluminal biopsy coupled with single-cell proteomics allows for immune characterization of intracranial aneurysms

The immune regulatory mechanisms driving the stability, growth, and rupture of intracranial aneurysms (IAs) remain incompletely understood. In this study, we employ endoluminal biopsy with single-cell proteomics to comprehensively profile the immune landscape of IAs across their pathologic states. Our findings reveal distinct immune signatures associated with aneurysm states. Stable, i.e. non-growing unruptured, IAs exhibit a balanced immune cell composition. Ruptured IAs are marked by significant neutrophil predominance. Notably, we highlight key immune markers in aneurysm instability, offering new insights into immune drivers of aneurysm progression. These findings provide a foundation for immune-targeted, non-invasive therapeutic strategies aimed at targeting IAs and preventing rupture.

physiology↗

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↗