Peptide delivery of a multivalent mRNA SARS-CoV-2 vaccine.

Lipid nanoparticles (LNP) have been instrumental in the success of mRNA vaccines and have opened up the field to a new wave of therapeutics. However, what is ahead beyond the LNP? The approach herein used a nanoparticle containing a blend of Spike, Membrane and Envelope antigens complexed for the first time with the RALA peptide (RALA-SME). The physicochemical characteristics and functionality of RALA-SME were assessed. With >99% encapsulation, RALA-SME was administered via intradermal injection in vivo, and all three antigen-specific IgG antibodies were highly significant. The IgG2a:IgG1 ratio were all >1.2, indicating a robust TH1 response, and this was further confirmed with the T-Cell response in mice. A complete safety panel of markers from mice were all within normal range, supported by safety data in hamsters. Vaccination of Syrian Golden hamsters with RALA-SME derivatives produced functional antibodies capable of neutralising SARS-CoV-2 from both Wuhan-Hu-1 and Omicron BA.1 lineages after two doses. Antibody levels increased over the study period and provided protection from disease-specific weight loss, with inhibition of viral migration down the respiratory tract. This peptide technology enables the flexibility to interchange and add antigens as required, which is essential for the next generation of adaptable mRNA vaccines.

BRD7, a subunit of SWI/SNF complexes, binds directly to BRCA1 and regulates BRCA1-dependent transcription.

We carried out a yeast two-hybrid screen using a BRCA1 bait composed of amino acids 1 to 1142 and identified BRD7 as a novel binding partner of BRCA1. This interaction was confirmed by coimmunoprecipitation of endogenous BRCA1 and BRD7 in T47D and HEK-293 cells. BRD7 is a bromodomain containing protein, which is a subunit of PBAF-specific Swi/Snf chromatin remodeling complexes. To determine the functional consequences of the BRCA1-BRD7 interaction, we investigated the role of BRD7 in BRCA1-dependent transcription using microarray-based expression profiling. We found that a variety of targets were coordinately regulated by BRCA1 and BRD7, such as estrogen receptor alpha (ERalpha). Depletion of BRD7 or BRCA1 in either T47D or MCF7 cells resulted in loss of expression of ERalpha at both the mRNA and protein level, and this loss of ERalpha was reflected in resistance to the antiestrogen drug fulvestrant. We show that BRD7 is present, along with BRCA1 and Oct-1, on the ESR1 promoter (the gene which encodes ERalpha). Depletion of BRD7 prevented the recruitment of BRCA1 and Oct-1 to the ESR1 promoter; however, it had no effect on the recruitment of the other Swi/Snf subunits BRG1, BAF155, and BAF57 or on RNA polymerase II recruitment. These results support a model whereby the regulation of ERalpha transcription by BRD7 is mediated by its recruitment of BRCA1 and Oct-1 to the ESR1 promoter.

Staphylococcus aureus enterotoxins induce IL-8 secretion by human nasal epithelial cells.

BACKGROUND: Staphylococcus aureus produces a set of proteins which act both as superantigens and toxins. Although their mode of action as superantigens is well understood, little is known about their effects on airway epithelial cells. METHODS: To investigate this problem, primary nasal epithelial cells derived from normal and asthmatic subjects were stimulated with staphylococcal enterotoxin A and B (SEA and SEB) and secreted (supernatants) and cell-associated (cell lysates) IL-8, TNF-alpha, RANTES and eotaxin were determined by specific ELISAs. RESULTS: Non-toxic concentrations of SEA and SEB (0.01 microg/ml and 1.0 microg/ml) induced IL-8 secretion after 24 h of culture. Pre-treatment of the cells with IFN-gamma (50 IU/ml) resulted in a further increase of IL-8 secretion. In cells from healthy donors pretreated with IFN-gamma, SEA at 1.0 mug/ml induced release of 1009 pg/ml IL-8 (733.0-1216 pg/ml, median (range)) while in cells from asthmatic donors the same treatment induced significantly higher IL-8 secretion - 1550 pg/ml (1168.0-2000.0 pg/ml p = 0.04). Normal cells pre-treated with IFN-gamma and then cultured with SEB at 1.0 mug/ml released 904.6 pg/ml IL-8 (666.5-1169.0 pg/ml). Cells from asthmatics treated in the same way produced significantly higher amounts of IL-8--1665.0 pg/ml (1168.0-2000.0 pg/ml, p = 0.01). Blocking antibodies to MHC class II molecules added to cultures stimulated with SEA and SEB, reduced IL-8 secretion by about 40% in IFN-gamma unstimulated cultures and 75% in IFN-gamma stimulated cultures. No secretion of TNF-alpha, RANTES and eotaxin was noted. CONCLUSION: Staphylococcal enterotoxins may have a role in the pathogenesis of asthma.