BACKGROUND: Illness resulting from influenza is a global health problem that has significant adverse socioeconomic impact. Although various strategies such as flu vaccination have beneficial effects, the risk of this illness has not been eliminated. The use of botanicals may provide a complementary approach by enhancement of the host antiviral immune response.
OBJECTIVE: Generate preclinical data using rodent models to determine the most effective utility of a Limnospira (formerly Arthrospira)-derived oral supplement (Immulina®) for enhancing host immunity to improve antiviral resilience.
METHODS: Two non-lethal mouse models (prophylactic and therapeutic) were used to evaluate the impact of Immulina® on increasing host resilience against experimental influenza infection.
METHODS: Mice were fed Immulina® only for the 2 weeks prior to viral infection (prophylactic regime) or starting 3 days post-viral infection (at the onset of symptoms, therapeutic design). Three doses of Immulina® were evaluated in each model using both female and male mice.
RESULTS: Significant protective effect of Immulina® against viral illness was observed in the prophylactic model (improved clinical scores, less body weight loss, decreased lung/body weight ratio, lower lung viral load, and increased lung IFN-γ and IL-6). Substantially less (minimal) protective effect was observed in the therapeutic model.
CONCLUSIONS: This study demonstrates that Immulina® exerts a protective effect against influenza illness when administered using a prophylactic regime and may not be effective if given after the onset of symptoms. The results will help to optimally design future clinical trials.

We have developed an automated sensing system for the repeated detection of a specific microRNA (miRNA) of the influenza A (H1N1) virus. In this work, magnetic particles functionalized with DNAs, target miRNAs, and alkaline phosphate (ALP) enzymes formed sandwich structures. These particles were trapped on nickel (Ni) patterns of our sensor chip by an external magnetic field. Then, additional electrical signals from electrochemical markers generated by ALP enzymes were measured using the sensor, enabling the highly sensitive detection of target miRNA. The magnetic particles used on the sensor were easily removed by applying the opposite direction of external magnetic fields, which allowed us to repeat sensing measurements. As a proof of concept, we demonstrated the detection of miRNA-1254, one of the biomarkers for the H1N1 virus, with a high sensitivity down to 1 aM in real time. Moreover, our sensor could selectively detect the target from other miRNA samples. Importantly, our sensor chip showed reliable electrical signals even after six repeated miRNA sensing measurements. Furthermore, we achieved technical advances to utilize our sensor platform as part of an automated sensing system. In this regard, our reusable sensing platform could be utilized for versatile applications in the field of miRNA detection and basic research.

BACKGROUND: Immulina®, a dietary supplement derived from Limnospira (formerly Arthrospira), is being investigated as a potential agent to increase antiviral resilience. In our recently published manuscript, we described the effects of Immulina® on influenza when taken daily, beginning before infection (prophylaxis) or after the onset of clinical symptoms of viral illness (therapeutic). However, the benefit of Immulina® in infected individuals before the manifestation of any symptoms (prodromal) has not been investigated yet.
OBJECTIVE: To evaluate Immulina®\'s potential use to increase the host antiviral immune response using a prodromal therapy regime.
METHODS: The efficacy of Immulina® extract was evaluated in rodents using a prodromal protocol (test material administered prior to the emergence of viral illness symptoms).
METHODS: Immulina® (25, 50 and 100 mg/kg body weight) was orally administered to both genders of mice, 2 h following influenza A viral infection, and continued daily for 14 days.
RESULTS: Compared to the infected control mice, animals fed Immulina® exhibited statistically significant reduction in the emergence of various physical symptoms of viral-induced illness and decreased viral RNA levels. The effects are likely mediated through the host immune system since the level of various cytokines (IL-6 and IFN-γ) were significantly increased in lung tissue.
CONCLUSIONS: This study, together with our previous paper, indicate that Immulina® was most effective at enhancing immune antiviral resilience if administered before or soon after initial infection. The data generated can be used to guide additional research using human subjects.

UNASSIGNED: Systematic evaluation of long-term outcomes in survivors of H1N1 is still lacking. This study aimed to characterize long-term outcomes of severe H1N1-induced pneumonia and acute respiratory distress syndrome (ARDS).
UNASSIGNED: This was a single-center, prospective, cohort study. Survivors were followed up for four times after discharge from intensive care unit (ICU) by lung high-resolution computed tomography (HRCT), pulmonary function assessment, 6-minute walk test (6MWT), and SF-36 instrument.
UNASSIGNED: A total of 60 survivors of H1N1-induced pneumonia and ARDS were followed up for four times. The carbon monoxide at single breath (DLCO) of predicted values and the 6MWT results didn\'t continue improving after 3 months. Health-related quality of life didn\'t change during the 12 months after ICU discharge. Reticulation or interlobular septal thickening on HRCT did not begin to improve significantly until the 12-month follow-up. The DLCO of predicted values showed negative correlation with the severity degree of primary disease and reticulation or interlobular septal thickening, and a positive correlation with physical functioning. The DLCO of predicted values and reticulation or interlobular septal thickening both correlated with the highest tidal volume during mechanical ventilation. Levels of fibrogenic cytokines had a positive correlation with reticulation or interlobular septal thickening.
UNASSIGNED: The improvements in pulmonary function and exercise capacity, imaging, and health-related quality of life had different time phase and impact on each other during 12 months of follow-up. Long-term outcomes of pulmonary fibrosis might be related to the lung injury and excessive lung fibroproliferation at the early stage during ICU admission.

BACKGROUND: The flowers of Trollius chinensis Bunge (Ranunculaceae) is a traditional Chinese medicine used to treat various inflammatory diseases, including upper respiratory infections, chronic tonsillitis, and pharyngitis. Recently, there has been growing research on the antiviral role of the flowers of T. chinensis Bunge. However, little is known about its anti-influenza virus effects and the underlying mechanisms.
OBJECTIVE: This study aims to evaluate the therapeutic effects of the crude extract from the flowers of T. chinensis Bunge (CEFTC) on mice infected with influenza virus. We further explored its mechanism by detecting the expression of vital proteins (TLR3, TBK1, TAK1, IKKα, IRF3, and IFN-β) related to TLR3 signaling pathway.
METHODS: Mice were infected with influenza A virus (H1N1) through the nasal cavity and were intragastrically administered CEFTC at the dose of 0.2 mg/g once daily. The therapeutic effects of CEFTC were evaluated by blood cell count, lung index, spleen index, alveolar lavage fluid testing, and HE staining. Network pharmacology analysis predicted the potential signaling pathway between the flowers of T. chinensis Bunge and pneumonia. The expression of TLR3, TBK1, TAK1, IKKα, IRF3, and IFN-β in lung tissues were examined by Western blot assay. In addition, the immunofluorescence assay was applied to assess the effect of CEFTC on the distribution of IRF3 and IFN-β between nuclei and cytoplasm.
RESULTS: Compared with the infected group, the lung index was markedly reduced, and the pathological damage of the lungs was also attenuated in the CEFTC treatment group. The network pharmacology analysis indicated that the NF-κB pathway was a potential signaling pathway in the flowers of T. chinensis Bunge for the treatment of pneumonia, TLR3, IRF3, and TBK1 were crucial targets associated with pneumonia. Western blot assay demonstrated that in the high-dose virus infected group, CEFTC reduced the expression of TLR3, TAK1, TBK1, and IRF3. Furthermore, CEFTC could increase the nuclear distribution of IRF3 in alveolar epithelial cells after virus infection.
CONCLUSIONS: These results suggested that different doses of influenza virus could cause varying infection symptoms in mice. Moreover, CEFTC could exert anti-influenza virus effects by regulating the expression of TLR3, IRF3, IFN-β, TAK1, and TBK1 in the TLR3 signaling pathway.

BACKGROUND: Inbred mice have several advantages, including genetic similarity to humans, a well-established gene manipulation system, and strong tolerance to inbreeding. However, inbred mice derived from a limited genetic pool have a small genetic diversity. Thus, the development of new inbred strains from wild mice is needed to overcome this limitation. Hence, in this study, we used a new strain of inbred mice called KWM/Hym. We sequenced the Mx1 gene to elucidate the genetic diversities of KWM/Hym mice and observed the biological alterations of the Mx1 protein upon influenza A infection.
RESULTS: The Mx1 gene in KWM/Hym mice had 2, 4, and 38 nucleotide substitutions compared to those in the Mx1 gene in A2G, CAST/EiJ, and Mus spretus mice, respectively. Moreover, the Mx1 protein in KWM/Hym mice had 2 and 25 amino acid substitutions compared to those in the Mx1 protein in CAST/EiJ and M. spretus mice, respectively. To elucidate the function of the Mx1 protein, we inoculated the influenza A virus (A/WSN/1933) in KWM/Hym mice. Nine days after infection, all infected KWM/Hym mice survived without any weight loss. Four days after infection, the lungs of the infected KWM/Hym mice showed mild alveolitis and loss of bronchiolar epithelium; however, the pulmonary viral titers of the infected KWM/Hym mice were significantly lower than that in the infected BALB/c mice (2.17 × plaque-forming units mL-1).
CONCLUSIONS: Our results demonstrate that the KWM/Hym mice are resistant to influenza A virus infection. Further, these mice can be used as a model organism to understand the mechanism of influenza A virus susceptibility.

3-{[(1-Methyl-1H-tetrazol-5-yl)imino]methyl}quinoline-2-thiol and 3-{[(2-methyl-2H-tetrazol-5-yl)imino]methyl}quinoline-2-thiol were synthesized. The sequence of the thiol-Michael reaction and the (aza)-Morita-Baylis-Hillman reaction yielded 4-[(1-methyl-1H-tetrazol-5-yl)amino]-2-phenyl-4H-thiopyrano[2,3-b]quinoline-3-carbaldehyde, 4-[(2-methyl-2H-tetrazol-5-yl)amino]-2-phenyl-4H-thiopyrano[2,3-b]-quinoline-3-carbaldehyde, and 4-hydroxy-2-phenyl-4H-thiopyrano[2,3-b]quinoline-3-carbaldehyde. Cytotoxicity and antiviral activity against the A/Puerto Rico/8/34 (H1N1) influenza virus strain in MDCK cell culture were determined for the obtained compounds. The study showed that the replacement of the hydroxyl group in 4-hydroxy-2-phenyl-4H-thiopyrano[2,3-b]quinoline-3-carbaldehyde with a 1-methyl- or 5-amino-2-methyltetrazolyl fragment decreased antiviral activity. At the same time, 3-{[(1-methyl-1H-tetrazol-5-yl)imino]-methyl}quinoline-2-thiol has a higher activity than 3-{[(2-methyl-2H-tetrazol-5-yl)imino]methyl}quinoline-2-thiol. This fact indicates a possible relationship between the arrangement of substituents in the tetrazole ring and the antiviral activity of the tested heterocyclic system.
UNASSIGNED: The online version contains supplementary material available at 10.1007/s10593-022-03083-w.

The H1N1 subtype influenza viruses (H1N1) have been causing persistent epidemics in human, swine and poultry populations since 1918. This subtype has evolved into four relatively stable genetic lineages, including classical swine influenza virus lineage, seasonal human influenza virus lineage, avian influenza virus lineage and Eurasian avian-like swine influenza virus lineage. In this study, four pairs of primers, based on the relatively conserved HA nucleotide regions of each H1N1 genetic lineage, were designed to establish a SYBR Green-based real-time quantitative RT-PCR (qPCR) assay to differentiate between the H1N1 genetic lineages. The results of qPCR assay showed that the lineage-specific primers designed for each H1N1 lineage were intra-lineage-specific, without mismatch of inter-lineage or inter-subtype and there appeared specific amplification curves when the concentrations of H1N1 plasmids were greater than or equal to 1.0 × 101 copies/reaction. Thus, this qPCR assay can specifically differentiate between the four lineages of H1N1 with a good specificity and sensitivity, which would assist in recognizing the infection and epidemic status of different H1N1 genetic lineages.

A recurrent pandemic with unpredictable viral nature has implied the need for a rapid diagnostic technology to facilitate timely and appropriate countermeasures against viral infections. In this study, conductive polymer-based nanoparticles have been developed as a tool for rapid diagnosis of influenza A (H1N1) virus. The distinctive property of a conductive polymer that transduces stimulus to respond, enabled immediate optical signal processing for the specific recognition of H1N1 virus. Conductive poly(aniline-co-pyrrole)-encapsulated polymeric vesicles, functionalized with peptides, were fabricated for the specific recognition of H1N1 virus. The low solubility of conductive polymers was successfully improved by employing vesicles consisting of amphiphilic copolymers, facilitating the viral titer-dependent production of the optical response. The optical response of the detection system to the binding event with H1N1, a mechanical stimulation, was extensively analyzed and provided concordant information on viral titers of H1N1 virus in 15 min. The specificity toward the H1N1 virus was experimentally demonstrated via a negative optical response against the control group, H3N2. Therefore, the designed system that transduces the optical response to the target-specific binding can be a rapid tool for the diagnosis of H1N1.
UNASSIGNED: Supplementary material (Table S1 and Figs. S1-S8) is available in the online version of this article at 10.1007/s12274-021-3772-6.

Guillain-Barré syndrome (GBS) is an immune-mediated peripheral neuropathy characterized by a typical post-infectious profile. Some post-Zika virus and post-severe acute respiratory syndrome-related coronavirus-2 GBS cases have been reported to occur with very short intervals between the infection and GBS onset. Evaluating 161 GBS patients consecutively admitted to two Italian Regional Hospitals between 2003 and 2019, we found that the only three with an antecedent influenza A (H1N1) virus infection developed GBS within an interval of less than 10 days from the influenza illness. The two of them with a demyelinating subtype promptly recovered without therapy. Overall, the parainfectious cases add heterogeneity to the GBS category, warranting pathogenetic insights.