A quadrivalent recombinant influenza Hemagglutinin vaccine induced strong protective immune responses in animal models.

Globally, influenza poses a substantial threat to public health, serving as a major contributor to both morbidity and mortality. The current vaccines for seasonal influenza are not optimal. A novel recombinant hemagglutinin (rHA) protein-based quadrivalent seasonal influenza vaccine, SCVC101, has been developed. SCVC101-S contains standard dose protein (15µg of rHA per virus strain) and an oil-in-water adjuvant, CD-A, which enhances the immunogenicity and cross-protection of the vaccine. Preclinical studies in mice, rats, and rhesus macaques demonstrate that SCVC101-S induces robust humoral and cellular immune responses, surpassing those induced by commercially available vaccines. Notably, a single injection with SCVC101-S can induce a strong immune response in macaques, suggesting the potential for a standard-dose vaccination with a recombinant protein influenza vaccine. Furthermore, SCVC101-S induces cross-protection immune responses against heterologous viral strains, indicating broader protection than current vaccines. In conclusion, SCVC101-S has demonstrated safety and efficacy in preclinical settings and warrants further investigation in human clinical trials. Its potential as a valuable addition to the vaccines against seasonal influenza, particularly for the elderly population, is promising.

Immunization with a Prefusion SARS-CoV-2 Spike Protein Vaccine (RBMRNA-176) Protects against Viral Challenge in Mice and Nonhuman Primates.

There is an urgent need for a broad-spectrum and protective vaccine due to the emergence and rapid spreading of more contagious SARS-CoV-2 strains. We report the development of RBMRNA-176, a pseudouridine (Ψ) nucleoside-modified mRNA-LNP vaccine encoding pre-fusion stabilized trimeric SARS-CoV-2 spike protein ectodomain, and evaluate its immunogenicity and protection against virus challenge in mice and nonhuman primates. A prime-boost immunization with RBMRNA-176 at intervals of 21 days resulted in high IgG titers (over 1:819,000 endpoint dilution) and a CD4+ Th1-biased immune response in mice. RBMRNA-176 vaccination induced pseudovirus-neutralizing antibodies with IC50 ranging from 1:1020 to 1:2894 against SARS-CoV-2 spike pseudotyped wild-type and variant viruses, including Alpha, Beta, Gamma, and Kappa. Moreover, significant control of viral replication and histopathology in lungs was observed in vaccinated mice. In nonhuman primates, a boost given by RBMRNA-176 on day 21 after the prime induced a persistent and sustained IgG response. RBMRNA-176 vaccination also protected macaques against upper and lower respiratory tract infection, as well as lung injury. Altogether, these findings support RBMRNA-176 as a vaccine candidate for prevention of COVID-19.

Enhanced analgesic effects of nefopam in combination with acetaminophen in rodents.

Nefopam, an analgesic drug, effectively elicits antinociception in the majority of noxious and thermal models in rodents. Acetaminophen is among the most commonly used analgesic and antipyretic drugs worldwide, either on prescription or over the counter. The present study aimed to investigate the analgesic activity of nefopam combined with acetaminophen, which was expected to maximize the potency of analgesia and decrease the dose of nefopam required. Three series of experiments, namely acetic acid-induced writhing tests in mice, hot plate tests in mice and tail flick tests in rats, were used to evaluate the analgesic effect. Initially, an optimum proportion of the two drugs, 3.5 mg/kg nefopam (N) + 60 mg/kg acetaminophen (A), was determined by orthogonal array design based on writhing response number. Subsequently, combinations of N and A (1.75 N + 30 A, 3.5 N + 60 A and 7.0 N + 120 A mg/kg) were determined to elicit antinociception in the writhing test (P<0.01 vs. normal saline control) in a dose-dependent manner. In the hot plate test, hot plate latencies up to 60 min after drug treatment were observed. The combination of 7.0 N + 120 A mg/kg exerted a greater cumulative antinociceptive effect throughout the observation period, with an area under the curve value of 1,156.95±199.30 area units (AU), compared with that achieved by 7.0 N mg/kg alone (632.12±62.38 AU). Furthermore, both monotherapy and compound therapy exhibited antinociception dose-dependently in the tail-flick test. However, a combination of 5.0 N + 84 A mg/kg exerted greater analgesic effect compared with 5.0 N mg/kg alone. The data obtained demonstrate that acetaminophen may enhance the antinociceptive activity of nefopam. Thus, coadministration of nefopam with acetaminophen warrants clinical evaluation.

External application of NF-κB inhibitor DHMEQ suppresses development of atopic dermatitis-like lesions induced with DNCB/OX in BALB/c mice.

CONTEXT: Dehydroxymethylepoxyquinomicin (DHMEQ) which is originally developed as an analog of antibiotic epoxyquinomicin C is a specific and potent inhibitor of NF-κB and has been shown to possess promising potential as an anti-inflammatory and anti-tumor agent. OBJECTIVE: This study examines DHMEQ's effect on therapeutic potential for atopic dermatitis (AD)-like lesions. MATERIALS AND METHODS: AD lesions were chronically induced by the repetitive and alternative application of 2,4-dinitrochlorobenzene (DNCB) and oxazolone (OX) on ears in BALB/c mice. The mice were then externally treated with DHMEQ ointment. Macroscopic and microscopic changes of the skin lesions were observed and recorded. RESULTS: DHMEQ inhibited ear swelling and relieved clinical symptoms of the AD-like lesions induced by DNCB/OX in BALB/c mice. Histopathology examination illustrated that it significantly decreased DNCB/OX-induced epidermal thickness, the infiltration of inflammatory cells, and the count of mast cell. The elevated level of immunoglobulin E (IgE) in serum and the mRNA levels of interferon γ (IFN-γ), interleukin 4 (IL-4) and IL-13 in the ear tissues, were also suppressed by DHMEQ. DISCUSSION AND CONCLUSION: This study indicated that DHMEQ would be useful for the treatment of AD.

Stimulated CB1 Cannabinoid Receptor Inducing Ischemic Tolerance and Protecting Neuron from Cerebral Ischemia.

BACKGROUND: It is reported that endogenous cannabinoids can cause vasodilation and bradycardia. They have anti-inflammatory effect and protect endothelial cells from injury, therefore they have potential application prospect in the prevention of cardio-cerebrovascular diseases. However, the mechanisms of the neuroprotection mediated by cannabinoid 1 receptors (CB1Rs) have not been uncovered in detail. METHODS: Nearly one hundred of new publications relevant to the theme are almost selected from Pubmed. The advanced details associated with the involvement of CB1R in cerebral ischemia as well as cerebral ischemic tolerance are reviewed. RESULTS: Anandamide system is mainly made up of cannabinoid receptors, their endogenous ligands and some related enzymes. The activation of the system mediates various molecular events so that plays a crucial role in the neuroprotection of cerebral ischemia. Increasing evidences suggest that CB1R is one of key molecules that mediate cerebral ischemia and cerebral ischemia tolerance. It is likely to provide an appropriate antioxidant balance by increasing endogenous free radical scavengers and helpful to exert the neuroprotective effects. Moreover, MAPKs, including ERK1/2, c-Jun Nterminal kinase (JNK) and p38MAPK can be recruited and stimulated through a complex signaling networks mediated by CB1R. Considerable evidences have indicated that CB1R was a crucial regulator for ERK1/2 signaling pathway. It is known that PI3K/Akt is a classical signaling pathway and its activation exerts neuroprotective effect via significant promoting cell survival. Glycogen synthase kinase-3ß (GSK-3ß) is an important downstream target of p-Akt. The PI3K/Akt/GSK-3ß signaling pathway mediated by CB1Rs takes an important part in cerebral ischemic injury. PKC and CB1R are found to be abundantly co-expressed in presynaptic nerve endings of brain. There are considerable reports that different PKC isozymes played vital roles respectively in cerebral ischemic injury and preconditioning. The CB1R -mediated activation of PKCε can effectively stimulate ischemic tolerance. CONCLUSION: CB1R played an important part via several signaling pathways in the protection from ischemic stroke and in ischemic tolerance. The involved molecular signaling pathways include ERK1/2, PI3K/Akt/GSK-3ß and the translocation and activation of PKCε. With the intimate association between CB1R and neuron injuries, to target the receptor will exert neuroprotective effects on cerebral ischemia, which provides wide foreground for a novel therapy target.

Suppression of the increasing level of acetylcholine-stimulated intracellular Ca2+ in guinea pig airway smooth muscle cells by mabuterol.

The present study aimed to establish an effective method for the in vitro culture of guinea pig airway smooth muscle (ASM) cells, and also investigate the suppressive effect of mabuterol hydrochloride (Mab) on the increased level of intracellular Ca2+ in ASM cells induced with acetylcholine (Ach). Two different methods, i.e. with or without collagenase to pretreat tracheal tissues, were applied to the manufacture of ASM cells. Cell viability was determined with the 3-(4,5-dimethylthinazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Immunocytochemistry and immunofluorescence were used for the identification of ASM cells. Different concentration levels (10-3, 10-4, 10-5, 10-6 and 10-7 mmol/l) of Mab were administered 5 min before Ach (10-4 M) treatment, respectively. The Ca2+ fluorescent probe, Fura-2/AM or Fluo-3/AM were applied to the inspection of Ca2+ fluorescent intensity with Varioskan Flash, immunocytometry systems and an inverted system microscope, respectively. The results showed that the fresh method, in which isolated tracheal tissues were previously treated with collagenase for 20 min, was more advantageous for the preparation of guinea pig ASM cells compared to when the enzyme was not used. The time for the ASM cells to initially migrate out of the 'tissue blocks' and the culture having to be generated due to the thick cell density was significantly less. On identification with immunocytochemistry or immunofluorescent staining, >95% of the cells were ASM cells. Mab (10-3-10-7 mmol/l) significantly suppressed the elevation of intracellular Ca2+ induced by Ach in a concentration-dependent manner. The inhibitory rates of intracellular Ca2+ by different concentrations of Mab, from low to high, were 14.93, 24.73, 40.06, 48.54 and 57.13%, respectively, when Varioskan Flash was used for determination. In conclusion, this novel method has a shorter harvesting period for ASM cells. Mab can suppress the increasing level of intracellular Ca2+ induced by Ach in guinea pig ASM cells. Further investigation into the precise mechanisms of action is required.