Microneedle array delivered recombinant coronavirus vaccines: Immunogenicity and rapid translational development

Background: Coronaviruses pose a serious threat to global health as evidenced by Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and COVID-19. SARS Coronavirus (SARS-CoV), MERS Coronavirus (MERS-CoV), and the novel coronavirus, previously dubbed 2019-nCoV, and now officially named SARS-CoV-2, are the causative agents of the SARS, MERS, and COVID-19 disease outbreaks, respectively. Safe vaccines that rapidly induce potent and long-lasting virus-specific immune responses against these infectious agents are urgently needed

Assessment of Route of Administration and Dose Escalation for an Adenovirus-Based Influenza A Virus (H5N1) Vaccine in Chickens▿

Highly pathogenic avian influenza (HPAI) virus causes one of the most economically devastating poultry diseases. An HPAI vaccine to prevent the disease in commercial and backyard birds must be effective, safe, and inexpensive. Recently, we demonstrated the efficacy of an adenovirus-based H5N1 HPAI vaccine (Ad5.HA) in chickens. To further evaluate the potential of the Ad5.HA vaccine and its cost-effectiveness, studies to determine the minimal effective dose and optimal route of administration in chickens were performed. A dose as low as 107 viral particles (vp) of adenovirus-based H5N1 vaccine per chicken was sufficient to generate a robust humoral immune response, which correlated with the previously reported level of protection. Several routes of administration, including intratracheal, conjunctival, subcutaneous, and in ovo routes, were evaluated for optimal vaccine administration. However, only the subcutaneous route of immunization induced a satisfactory level of influenza virus-specific antibodies. Importantly, these studies established that the vaccine-induced immunity was cross-reactive against an H5N1 strain from a different clade, emphasizing the potential of cross-protection. Our results suggest that the Ad5.HA HPAI vaccine is safe and effective, with the potential of cross-clade protection. The ease of manufacturing and cost-effectiveness make Ad5.HA an excellent avian influenza vaccine candidate with the ability to protect poultry from HPAI virus infection. Considering the limitations of the influenza vaccine technology currently used for poultry applications, any effort aimed at overcoming those limitations is highly significant

Bid-Independent Mitochondrial Activation in Tumor Necrosis Factor Alpha-Induced Apoptosis and Liver Injury

The death receptor apoptosis pathway is intimately connected with the mitochondrial apoptosis pathway. Bid is a BH3-only pro-death Bcl-2 family protein and is the major molecule linking the two pathways. Bid-mediated mitochondrial activation occurs early and is responsible for the prompt progress of tumor necrosis factor alpha (TNF-α)-induced apoptosis. However, in both cultured cells and animal models of TNF-α-induced injury, later-phase Bid-independent mitochondrial activation could be demonstrated. Consequently, bid-deficient mice are still susceptible to endotoxin-induced liver injury and mortality. Notably, embryonic hepatocyte apoptosis and lethality caused by TNF-α in the absence of p65relA cannot be rescued by the simultaneous deletion of bid. Further studies indicate that multiple mechanisms including reactive oxygen species, JNK, and permeability transition are critically involved in Bid-independent mitochondrial activation. Inhibition of these events suppresses TNF-α-induced mitochondrial activation and apoptosis in bid-deficient cells. These findings thus indicate that there are at least two sets of mechanisms of mitochondrial activation upon TNF-α stimulation. While the Bid-mediated mechanism is rapid and potent, the Bid-independent mechanism progresses gradually and involves multiple players. The critical involvement of Bid-independent mitochondrial activation in TNF-α-induced apoptosis demands the intervention of TNF-α-mediated tissue injury via multiple avenues

Multiple antigen-engineered DC vaccines with or without IFNα to promote antitumor immunity in melanoma

Abstract Background Cancer vaccines are designed to promote systemic antitumor immunity and tumor eradication. Cancer vaccination may be more efficacious in combination with additional interventions that may build on or amplify their effects. Methods Based on our previous clinical and in vitro studies, we designed an antigen-engineered DC vaccine trial to promote a polyclonal CD8+ and CD4+ T cell response against three shared melanoma antigens. The 35 vaccine recipients were then randomized to receive one month of high-dose IFNα or observation. Results The resulting clinical outcomes were 2 partial responses, 8 stable disease and 14 progressive disease among patients with measurable disease using RECIST 1.1, and, of 11 surgically treated patients with no evidence of disease (NED), 4 remain NED at a median follow-up of 3 years. The majority of vaccinated patients showed an increase in vaccine antigen-specific CD8+ and CD4+ T cell responses. The addition of IFNα did not appear to improve immune or clinical responses in this trial. Examination of the DC vaccine profiles showed that IL-12p70 secretion did not correlate with immune or clinical responses. In depth immune biomarker studies support the importance of circulating Treg and MDSC for development of antigen-specific T cell responses, and of circulating CD8+ and CD4+ T cell subsets in clinical responses. Conclusions DC vaccines are a safe and reliable platform for promoting antitumor immunity. This combination with one month of high dose IFNα did not improve outcomes. Immune biomarker analysis in the blood identified several predictive and prognostic biomarkers for further analysis, including MDSC. Trial registration NCT01622933

Role of Toll-Like Receptors in Changes in Gene Expression and NF-κB Activation in Mouse Hepatocytes Stimulated with Lipopolysaccharide

The liver is an important site of host-microbe interaction. Although hepatocytes have been reported to be responsive to lipopolysaccharide (LPS), the global gene expression changes by LPS and mechanism(s) by which LPS stimulates cultured hepatocytes remain uncertain. Cultures of primary mouse hepatocytes were incubated with LPS to assess its effects on the global gene expression, hepatic transcription factors, and mitogen-activated protein (MAP) kinase activation. DNA microarray analysis indicated that LPS modulates the selective expression of more than 80 genes and expressed sequence tags. We have shown previously that hepatocytes express CD14, which is required both for uptake and responsiveness to LPS. In other cells, responsiveness to microbial products requires expression of Toll-like receptors (TLR) and their associated accessory molecules. Hepatocytes expressed TLR1 through TLR9 as well as MyD88 and MD-2 transcripts, as shown by reverse transcriptase PCR analysis, indicating that hepatocytes express all known microbe recognition molecules. The MAP kinase extracellular signal-regulated kinase 1/2 was phosphorylated in response to LPS in mouse hepatocytes, and the levels of phosphorylation were lower in hepatocytes from TLR4-null mice. NF-κB activation was reduced in TLR4-mutant or -null hepatocytes compared to control hepatocytes, and this defect was partially restored by adenoviral transduction of mouse TLR4. Thus, hepatocytes respond to nanogram concentrations of LPS through a TLR4 response pathway