Eleftherios Athanasopoulos

Mr. Eleftherios Athanasopoulos


Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

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

Representative Publications

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25 October 2024 in Vaccines
Verified
Journal Article
Open access
PDF file
PDPanagiotis Theodorou Diamantopoulos
Panagiotis Theodorou Diamantopoulos
CKChristina-Nefeli Kontandreopoulou
Christina-Nefeli Kontandreopoulou
CSChristos Stafylidis
Christos Stafylidis
DVDimitra Vlachopoulou
Dimitra Vlachopoulou
SSStavroula Smilakou
Stavroula Smilakou
VLVasililki T. Labropoulou
Vasililki T. Labropoulou
Background/objectives: Patients with chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) are susceptible to viral infections, including varicella-zoster virus (VZV) reactivation due to both disease-related and treatment-induced immunosuppression. The recombinant adjuvanted herpes zoster vaccine (RZV) has shown high efficacy in immunocompetent adults, but immunogenicity data in CLL and MM patients are limited. This study evaluates the immunogenicity and safety of RZV in this population. Methods: Patients with CLL and MM vaccinated with RZV (administered in two doses at least one month apart) were included in the study. Pre- and post-vaccination anti-VZV IgM and IgG antibody levels were measured to assess immunogenicity, and adverse events (AEs) were captured for safety evaluation. Results: Seventy-eight patients received both vaccine doses, and 71 had post-vaccination samples. Most of the patients were IgM seronegative and IgG seropositive before vaccination. Pre-vaccination IgG levels were higher in CLL patients compared to MM patients (p = 0.001), while post-vaccination IgG levels significantly increased in both CLL (p < 0.0001) and MM (p < 0.0001) patients. In actively treated CLL patients, pre-vaccination IgG levels were significantly lower than in not actively treated patients (p = 0.002). Post-vaccination IgG levels were lower in MM patients receiving antiviral prophylaxis concurrently with the vaccination (p = 0.013). AEs were reported in 49.4% of patients after the first dose and 48.7% after the second dose, mostly mild (local or low-grade systemic). One case of immune thrombocytopenia was noted. Conclusions: RZV demonstrated strong immunogenicity and acceptable safety in CLL and MM patients, significantly boosting IgG levels, even in actively treated or heavily pretreated patients.

17 September 2024 in Preprints.org
Verified
Preprint
Open access
PDF file
PDPanagiotis Theodorou Diamantopoulos
Panagiotis Theodorou Diamantopoulos
CSChristos Stafylidis
Christos Stafylidis
VLVasililki T. Labropoulou
Vasililki T. Labropoulou
CKChristina-Nefeli Kontandreopoulou
Christina-Nefeli Kontandreopoulou
DVDimitra Vlachopoulou
Dimitra Vlachopoulou
MMMarina Mantzourani
Marina Mantzourani
Introduction: Patients with chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) are susceptible to viral infections, including varicella-zoster virus (VZV) reactivation due to both disease-related and treatment-induced immunosuppression. The recombinant adjuvanted herpes zoster vaccine (RZV) has shown high efficacy in immunocompetent adults, but immunogenicity data in CLL and MM patients is limited. This study evaluates the immunogenicity and safety of RZV in this population. Methods: Patients with CLL and MM vaccinated with RZV (administered in two doses at least one month apart) were included in the study. Pre- and post-vaccination anti-VZV IgM and IgG antibody levels were measured to assess immunogenicity, and adverse events (AEs) were captured for safety evaluation. Results: Seventy-eight patients received both vaccine doses, and 71 had post-vaccination samples. Most of the patients were IgM seronegative and IgG seropositive before vaccination. Pre-vaccination IgG levels were higher in CLL compared to MM patients (p=0.001), while post-vaccination IgG levels significantly increased in both CLL (p<0.0001) and MM (p<0.0001) patients. In actively treated CLL patients, the pre-vaccination IgG levels were significantly lower than in not actively treated patients (p=0.002). Post-vaccination IgG levels were lower in MM patients receiving antiviral prophylaxis concurrently with the vaccination (p=0.013). AEs were reported in 49.4% after the first dose and 48.7% after the second dose, mostly mild (local or low-grade systemic). One case of immune thrombocytopenia was noted. Conclusion: RZV demonstrated strong immunogenicity and acceptable safety in CLL and MM patients, significantly boosting IgG levels, even in actively treated or heavily pretreated patients.

9 April 2026 in Cells
Verified
Journal Article
Open access
PDF file
EAEleftherios Athanasopoulos
Eleftherios Athanasopoulos
CGChrysostomi Gialeli
Chrysostomi Gialeli
ANAngeliki Natsiou
Angeliki Natsiou
DMDimitra Manou
Dimitra Manou
VLVasililki T. Labropoulou
Vasililki T. Labropoulou
ATAchilleas D. Theocharis
Achilleas D. Theocharis
Serglycin (SRGN) has been found overexpressed and secreted in glioblastoma (GBM), associated with tumorigenic signaling and poor prognosis. In this study, we aimed to elucidate the involvement of SRGN in the unfolded protein response (UPR), an oncogenic signaling pathway implicated in protein recycling and cell fate. Herein, we developed stably transduced LN-18shSCR GBM cells, expressing high levels of SRGN, and SRGN-depleted LN-18shSRGN cells. We observed significantly attenuated expression and activity of all UPR mediators upon SRGN suppression, in particular PERK, IRE1, ATF6 and downstream effectors. SRGN-expressing cells possessed a constitutively active UPR, as indicated by its active phosphorylation status and accumulated pool of nuclear ATF4 in LN-18shSCR cells. Constitutive activation of the caspase-dependent apoptotic pathway was apparent in LN-18shSRGN cells. Induction of endoplasmic reticulum (ER) stress pointed out that LN-18shSRGN cells were predisposed to ER stress-associated cell death, whereas LN-18shSCR cells activated adaptive UPR signaling and displayed resistance to apoptosis. The evaluation of TLRs, TNFRs, ILs and NF-kB also underscored that SRGN is essential for their expression and active inflammatory signaling. We concluded that SRGN-expressing cells acquire a pro-survival UPR mechanism, highlighting the novel regulatory role of SRGN in the adaptation and survival of GBM cells.

Verified
Journal Article
Open access
PDF file
EAEleftherios Athanasopoulos
Eleftherios Athanasopoulos
VLVasililki T. Labropoulou
Vasililki T. Labropoulou
ATAchilleas D. Theocharis
Achilleas D. Theocharis
The inflammatory response possesses a central role in human pathophysiology, regulating the tissue microenvironment and cell signaling. Inflammation occurs either as a symptom of homeostasis disturbance or as a driver for determining cell fate. In this context, cells recruit secreted cytokines, chemokines and intracellular mediators, in cooperation with their surrounding cellular components, to integrate inflammatory stimuli. The extracellular matrix (ECM) acts as a scaffold for shaping tissue structure and simultaneously undergoes continuous remodeling to provide a dynamic network for intercellular communication. Serglycin (SRGN) is the only known intracellular and extracellular proteoglycan, implicated in the formation of secretory vesicles and ECM reorganization. The regulatory roles of SRGN in the bioavailability of secreted factors, as well as SRGN pleiotropic interactions within the ECM, as well as with cell surface receptors, have emerged to beessential for inflammatory diseases and tumor progression. Its overexpression and excessive secretion, alongside its contribution to cell signaling, highlight the potential diagnostic and therapeutic aspects of SRGN in human diseases.