Streamlining the Fat: A Systematic Review of Active Closed Wash and Filtration in Autologous Fat Grafting After Breast Reconstruction.

While fat grafting in breast reconstruction continues to grow in popularity, the optimal technique remains elusive and outcomes are varied. This systematic review of available controlled studies utilizing active closed wash and filtration systems (ACWF) sought to examine differences in fat processing efficiency, aesthetic outcomes, and revision rates. A literature search was performed from inception to February 2022 following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) in Ovid MEDLINE (Wolters Kluwer, Alphen aan den Rijn, the Netherlands), Ovid Embase (Wolters Kluwer, Alphen aan den Rijn, the Netherlands), and Cochrane Library (Wiley, Hoboken, NJ). Studies were screened by 2 independent reviewers for eligibility using Covidence screening software. Bibliographies and citing references from selected articles were screened from Scopus (Elsevier, Amsterdam, the Netherlands). The search identified 3476 citations, with 6 studies included. Three studies demonstrated a significantly higher volume of graftable fat harvested in a significantly lower mean grafting time with ACWF than with their respective controls. With respect to adverse events, three studies reported significantly lower incidences of nodule or cyst formation with ACWF with respect to control. Two studies reported a significantly lower incidence of fat necrosis with ACWF vs control, with this trend upheld in 2 additional studies. Three studies reported significantly lower revision rates with ACWF with respect to control. No study reported inferiority with ACWF for any outcome of interest. These data suggest that ACWF yields higher fat volumes in less time than other common techniques, with decreased rates of suboptimal outcomes and revisions, thereby supporting active filtration as a safe and efficacious means of fat processing that may reduce operative times. Further large-scale, randomized trials are needed to definitively demonstrate the above trends.

Viral Mimicry of Interleukin-17A by SARS-CoV-2 ORF8.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection triggers cytokine-mediated inflammation, leading to a myriad of clinical presentations in COVID-19. The SARS-CoV-2 open reading frame 8 (ORF8) is a secreted and rapidly evolving glycoprotein. Patients infected with SARS-CoV-2 variants with ORF8 deleted are associated with mild disease outcomes, but the molecular mechanism behind this is unknown. Here, we report that SARS-CoV-2 ORF8 is a viral cytokine that is similar to but distinct from interleukin 17A (IL-17A) as it induces stronger and broader human IL-17 receptor (hIL-17R) signaling than IL-17A. ORF8 primarily targeted blood monocytes and induced the heterodimerization of hIL-17RA and hIL-17RC, triggering a robust inflammatory response. Transcriptome analysis revealed that besides its activation of the hIL-17R pathway, ORF8 upregulated gene expression for fibrosis signaling and coagulation dysregulation. A naturally occurring ORF8 L84S variant that was highly associated with mild COVID-19 showed reduced hIL-17RA binding and attenuated inflammatory responses. This study reveals how SARS-CoV-2 ORF8 by a viral mimicry of the IL-17 cytokine contributes to COVID-19 severe inflammation. IMPORTANCE Patients infected with SARS-CoV-2 variants lacking open reading frame 8 (ORF8) have been associated with milder infection and disease outcome, but the molecular mechanism behind how this viral accessory protein mediates disease pathogenesis is not yet known. In our study, we revealed that secreted ORF8 protein mimics host IL-17 to activate IL-17 receptors A and C (IL-17RA/C) and induces a significantly stronger inflammatory response than host IL-17A, providing molecular insights into the role of ORF8 in COVID-19 pathogenesis and serving as a potential therapeutic target.

Development of Spike Receptor-Binding Domain Nanoparticles as a Vaccine Candidate against SARS-CoV-2 Infection in Ferrets.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a causative agent of the CoV disease 2019 (COVID-19) pandemic, enters host cells via the interaction of its receptor-binding domain (RBD) of the spike protein with host angiotensin-converting enzyme 2 (ACE2). Therefore, the RBD is a promising vaccine target to induce protective immunity against SARS-CoV-2 infection. In this study, we report the development of an RBD protein-based vaccine candidate against SARS-CoV-2 using self-assembling Helicobacter pylori-bullfrog ferritin nanoparticles as an antigen delivery system. RBD-ferritin protein purified from mammalian cells efficiently assembled into 24-mer nanoparticles. Sixteen- to 20-month-old ferrets were vaccinated with RBD-ferritin nanoparticles (RBD nanoparticles) by intramuscular or intranasal inoculation. All vaccinated ferrets with RBD nanoparticles produced potent neutralizing antibodies against SARS-CoV-2. Strikingly, vaccinated ferrets demonstrated efficient protection from SARS-CoV-2 challenge, showing no fever, body weight loss, or clinical symptoms. Furthermore, vaccinated ferrets showed rapid clearance of infectious virus in nasal washes and lungs as well as of viral RNA in respiratory organs. This study demonstrates that spike RBD-nanoparticles are an effective protein vaccine candidate against SARS-CoV-2.