Publications by authors named "Penelope G Papayanni"

Background: Immunocompromised individuals are at major risk for severe infectious complications. This is particularly relevant in the context of allogeneic hematopoietic stem cell transplantation (allo-HCT) - a treatment modality that has proven curative for a range of malignant and nonmalignant hematological diseases. However, transplant-associated immune suppression leaves patients susceptible to infectious complications from viruses such as cytomegalovirus (CMV), adenovirus (AdV), Epstein-Barr virus (EBV), and BK virus (BKV).

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Reliable and sensitive characterization assays are important determinants of the successful clinical translation of immunotherapies. For the assessment of cytolytic potential, the chromium 51 (Cr) release assay has long been considered the gold standard for testing effector cells. However, attaining the approvals to access and use radioactive isotopes is becoming increasingly complex, while technical aspects [i.

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Respiratory syncytial virus (RSV)-associated viral infections are a major public health problem affecting the immunologically naïve/compromised populations. Given the RSV-associated morbidity and the limited treatment options, we sought to characterize the cellular immune response to RSV to develop a targeted T cell therapy for off-the-shelf administration to immunocompromised individuals. Here we report on the immunological profiling, as well as manufacturing, characterization and antiviral properties of these RSV-targeted T cells.

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Regulatory T-cell (Treg) immunotherapy has emerged as a promising and highly effective strategy to combat graft-versus-host disease (GvHD) after allogeneic hematopoietic cell transplantation (allo-HCT). Both naturally occurring Treg and induced Treg populations have been successfully evaluated in trials illustrating the feasibility, safety, and efficacy required for clinical translation. Using a non-mobilized leukapheresis, we have developed a good manufacturing practice (GMP)-compatible induced Treg product, termed iG-Tregs, that is enriched in cells expressing the potent immunosuppressive human leucocyte antigen-G molecule (HLA-G).

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We have attempted to explore further the involvement of complement components in the host COVID-19 (Coronavirus disease-19) immune responses by targeted genotyping of COVID-19 adult patients and analysis for missense coding Single Nucleotide Polymorphisms (coding SNPs) of genes encoding Alternative pathway (AP) components. We have identified a small group of common coding SNPs in Survivors and Deceased individuals, present in either relatively similar frequencies (CFH and CFI SNPs) or with stark differences in their relative abundance (C3 and CFB SNPs). In addition, we have identified several sporadic, potentially protective, coding SNPs of C3, CFB, CFD, CFH, CFHR1 and CFI in Survivors.

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Complement dysregulation has been documented in adults with COVID-19 and implicated in relevant pediatric inflammatory responses against SARS-CoV-2. We propose that signatures of complement missense coding SNPs associated with dysregulation could also be identified in children with multisystem inflammatory syndrome (MIS-C). We investigated 71 pediatric patients with RT-PCR validated SARS-CoV-2 hospitalized in pediatric COVID-19 care units (November 2020-March 2021) in three major groups.

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Article Synopsis
  • There is a need for better early prediction models for COVID-19 outcomes, specifically morbidity and mortality in hospital settings.
  • The study identified critical genetic variants related to the complement system that are linked to severe COVID-19 outcomes and developed a predictive artificial neural network (ANN) using these variants.
  • The ANN successfully predicted severe outcomes in nearly 90% of patients, highlighting the role of genetic factors in worsening COVID-19 conditions and confirming that these variants are associated with an impaired immune response.
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Background: Myeloid-derived suppressor cells (MDSCs) are implicated in the complex interplay involving graft-versus-leukemia (GVL) effects and graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HCT) in hematologic malignancies.

Methods: A review of literature through PubMed was undertaken to summarize the published evidence on the pathophysiology and clinical implications of MDSCs in allo-HCT. Literature sources published in English since 1978 were searched, using the terms Natural Suppressor (NS) cells, MDSCs, GVHD, and allo-HCT.

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Article Synopsis
  • - Recent studies indicate that excessive activation of the complement system plays a role in severe COVID-19, similar to a condition called thrombotic microangiopathy (TMA).
  • - Researchers analyzed genetic data from 97 COVID-19 patients and identified key genetic variants associated with severe illness, revealing that specific combinations of these variants correlated with ICU hospitalization.
  • - The study suggests that certain genetic profiles, particularly those involving ADAMTS13 and complement factors, could inform targeted treatments for severe COVID-19 patients, as well as uncover potential gender differences in these genetic variants.
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