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Gunay, G.

Publications and source records attributed to Gunay, G..

2 recordsLinked to original sources

Controllable membrane damage by tunable peptide aggregation with albumin

Aggregation of otherwise soluble proteins into amyloid structures is a hallmark of many disorders, such as Alzheimers and Parkinsons diseases. There is increasing evidence and acceptance that instead of ordered amyloid assemblies, the misfolded oligomer aggregations are the main toxic structures. However, there is no system to study the mechanism and kinetics of aggregation, distinguish between ordered structures and misfolded oligomers, and correlate the structures to their toxicity. The exact role of oligomer aggregation in the pathological process remains to be elucidated. Here, we use an engineered co-assembling oppositely charged amyloid-like peptide pair ([II]) to relate its aggregation to toxicity. The toxicity mechanism of [II] is through cell membrane damage and stress, as shown with YAP and eIF2 biomarkers, as in the amyloid protein-initiated diseases. Albumin is used to control the aggregation of [II], and so its toxicity. This study represents a molecular engineering strategy to study the aggregation process of amyloid-like structures in diseases. Understanding the nature of protein aggregation through engineered peptides paves the way for future designs and drug development applications.

bioengineering↗

Peptide Aggregation Induced Immunogenic Rupture (PAIIR)

Under the influence of stress and membrane damage, cells undergo immunogenic cell death (ICD), which involves the release of damage associated molecular patterns (DAMPs), natural adjuvants for enhancing an immune response. In the presence of an antigen, released DAMPs can determine the type and magnitude of the immune response, and therefore the longevity and efficacy of an antigen-specific immunity. In the last decade, the immune response effect of ICD has been shown, yet there is no tool that can induce controlled ICD with predictable results, regardless of the cell type. We designed a peptide-based tool, called [II], for controlled damage to cell membrane to induce ICD and DAMPs release. Herein we describe a series of experiments that determine that the mechanism of action of [II] includes a caspase-dependent ICD and subsequent release of immune stimulating DAMPs, on various cell types. Moreover, we tested the hypothesis that controlled DAMP release via [II] in vivo was associated with enhancement of antigen-specific adaptive immunity with influenza hemagglutinin (HA) subunit vaccine. HA and [II] showed significantly higher HA specific IgG1 and IgG2a antibodies, compared to HA-only immunized mice, while the peptide itself did not elicit antibodies. In this paper, we demonstrate the first peptide-aggregation induced immunogenic rupture (PAIIR) approach as vaccine adjuvants for increasing both humoral and cellular immunity. In consideration of its ability to enhance IgG2a responses that are associated with heterosubtypic influenza virus protection, PAIIR is a promising adjuvant to promote universal protection upon influenza HA vaccination.

bioengineering↗