Cellular and biochemical responses induced by Biotherapics prepared from intact influenza A (H3N2) and inactivated influenza A (H3N2) virus at 12x and 30x in the MDCK cells

Biotherapics are homeopathic remedies prepared from organic products that are chemically undefined and can be used for treatment of diseases like influenza. There are several classes of biotherapics and, among these, there are some called "living biotherapics" or "Roberto Costa’s Biotherapics". This study aimed to compare the cellular and biochemical effects of biotherapics prepared from intact influenza virus diluted in water and the one obtained from the same viral sample inactivated by ethanol 70% (v / v), both in the potencies of 12x and 30x. Transmission electron microscopy (TEM) analyses were performed on both preparations to assess the integrity of viral particles, which showed that ethanol 70% (v/v) induced a complete denaturation of viral particles. In contrast, the integrity of virus particles was preserved when water was used as the biotherapic solvent. Cellular and biochemical alterations induced by the preparations on MDCK cells were analyzed and compared with those induced by respective controls (water 30x-treated and untreated cells). Cellular viability analyzed by MTT method showed statistically significant differences (p

Biochemical responses induced by Biotherapics prepared from intact influenza A (H3N2) and inactivated influenza A (H3N2) virus at 12x and 30x in MDCK cells and RAW-264-7 macrophages

Background: "Roberto Costa’s Biotherapics" are homeopathic remedies prepared from intact microorganisms which have been proposed for treatment of diseases like influenza. Aim: This study aimed to compare the biochemical effects, in MDCK cells and RAW-264-7 macrophages, of biotherapics prepared from intact influenza virus diluted in water as well as from a sample of the same virus inactivated by ethanol 70% (v / v), both in the homeopathic potencies of 12x and 30x. Water 30x, non-dynamized water and cells without treatment (control cells) were used as control. Methodology: Treatments were performed by incubating MDCK cells with DMEM medium added in a 1:10 ratio for 6 times (3 different aliquots per day) or 18 times (up to 4 aliquots per day) in each experimental situation. Each aliquot was added with an interval of at least 2 hours. After that, the mitochondrial activity of MDCK cells was analyzed by MTT assay. The effects of treatments with intact biotherapics on MDCK cells respiratory parameters were studied using high resolution respirometry (Oroboros Oxygraph-O2K). RAW-264-7 macrophages were treated with intact and inactivated biotherapic 30x (4 treatments, 24 hours) to verify the nitric oxide production. These macrophages were also submitted to MTT assay. Results: Both biotherapic preparations 1x (intact and inactivated virus sample) were analyzed by transmission electronic microscopy. The presence of virus particles was detected when water was used as solvent. The use of ethanol as biotherapic solvent induced complete virus lysis. There was no alteration in cell osmolarity revealed by neutral red assay, when 10% of each test solution was used. Cellular viability analyzed by MTT method increased when MDCK cells were treated with 18 stimuli of inactivated biotherapic 30x when compared to intact biotherapic 30x (p0.05) were detected when these cells were compared to control cells. The maximum respiratory capacity of MDCK cells increased after treatment with 18 stimuli of intact biotherapic 30x when compared to control cells. However, no statistically significant differences (p>0.05) induced by biotherapics in macrophage cells were observed by MTT and nitric oxide assays. Moreover, a reduction in nitric oxide was observed in macrophages treated with dynamized water when compared to control cells. Conclusions: These results indicate that the method of biotherapic compounding (intact or inactivated virus as starting point) can modify the cellular parameters with the tendency to increase cellular response with longer treatments and higher potencies.

Antigenic evolution of human influenza H3N2 neuraminidase is constrained by charge balancing

As one of the main influenza antigens, neuraminidase (NA) in H3N2 virus has evolved extensively for more than 50 years due to continuous immune pressure. While NA has recently emerged as an effective vaccine target, biophysical constraints on the antigenic evolution of NA remain largely elusive. Here, we apply combinatorial mutagenesis and next-generation sequencing to characterize the local fitness landscape in an antigenic region of NA in six different human H3N2 strains that were isolated around 10 years apart. The local fitness landscape correlates well among strains and the pairwise epistasis is highly conserved. Our analysis further demonstrates that local net charge governs the pairwise epistasis in this antigenic region. In addition, we show that residue coevolution in this antigenic region is correlated with the pairwise epistasis between charge states. Overall, this study demonstrates the importance of quantifying epistasis and the underlying biophysical constraint for building a model of influenza evolution.

Prospects of using conservative linear B-cell epitopes of influenza virus A neuraminidase for induction of cross-protective immune response

BACKGROUND: Influenza is a dangerous, widespread infectious disease that takes thousands of lives during annual epidemics, and also causes significant damage to the countrys economy. The most effective means of fighting the influenza virus is vaccination of the population. Due to the variability of influenza viruses, the strain composition of influenza vaccines must be updated annually. In this regard, an urgent task is to improve the existing influenza vaccines in order to expand their spectrum of action. One of the promising approaches is the targeted induction of the humoral immune response to the conservative linear epitopes of influenza A virus neuraminidase. AIM: This project is aimed at assessing the immunogenicity and cross-protective activity of conserved neuraminidase epitopes in order to select promising targets for the targeted design of broad-spectrum influenza vaccines. MATERIALS AND METHODS: Peptides corresponding to linear B-cell epitopes of neuraminidase were chemically synthesized de novo. The peptides were conjugated with keyhole limpet hemocyanin. CBA mice were immunized and challenged with A/PR/8/34 (H1N1) and A/Philippines/2/1982 (H3N2) viruses at a dose of 3 LD50. The survival rate of the animals was assessed within 14 days after infection. The immunogenicity of the peptides was assessed in a standard enzyme-linked immunosorbent assay using the recombinant neuraminidase proteins of the viruses A/California/07/2009 (H1N1) and A/Hong Kong/4801/2014 (H3N2) as antigen. RESULTS: Immunization of neuraminidase with peptides MNPNQKIITIGS and ILRTQESEC, but not DNWKGSNRP, protected mice from lethality caused by the H1N1 and/or H3N2 virus. The protective potential of the peptides correlated with the levels of antineuraminidase antibodies after immunization. CONCLUSIONS: The presence of a cross-protective potential in two conserved linear B-cell epitopes of influenza A neuraminidase (MNPNQKIITIGS and ILRTQESEC) allows them to be recommended as a target for the development of a broad-spectrum influenza vaccine.

Characterization of Canine Influenza Virus A (H3N2) Circulating in Dogs in China from 2016 to 2018

Avian H3N2 influenza virus follows cross-host transmission and has spread among dogs in Asia since 2005. After 2015–2016, a new H3N2 subtype canine influenza epidemic occurred in dogs in North America and Asia. The disease prevalence was assessed by virological and serological surveillance in dogs in China. Herein, five H3N2 canine influenza virus (CIV) strains were isolated from 1185 Chinese canine respiratory disease samples in 2017–2018; these strains were on the evolutionary branch of the North American CIVs after 2016 and genetically far from the classical canine H3N2 strain discovered in China before 2016. Serological surveillance showed an HI antibody positive rate of 6.68%. H3N2 was prevalent in the coastal areas and northeastern regions of China. In 2018, it became the primary epidemic strain in the country. The QK01 strain of H3N2 showed high efficiency in transmission among dogs through respiratory droplets. Nevertheless, the virus only replicated in the upper respiratory tract and exhibited low pathogenicity in mice. Furthermore, highly efficient transmission by direct contact other than respiratory droplet transmission was found in a guinea pig model. The low-level replication in avian species other than ducks could not facilitate contact and airborne transmission in chickens. The current results indicated that a novel H3N2 virus has become a predominant epidemic strain in dogs in China since 2016 and acquired highly efficient transmissibility but could not be replicated in avian species. Thus, further monitoring is required for designing optimal immunoprophylactic tools for dogs and estimating the zoonotic risk of CIV in China.

Simultaneous Infection With Porcine Reproductive and Respiratory Syndrome and Influenza Viruses Abrogates Clinical Protection Induced by Live Attenuated Porcine Reproductive and Respiratory Syndrome Vaccination

The porcine respiratory disease complex (PRDC) is responsible for significant economic losses in the pig industry worldwide. Porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza virus are major viral contributors to PRDC. Vaccines are cost-effective measures for controlling PRRS, however, their efficacy in the context of co-infections has been poorly investigated. In this study, we aimed to determine the effect of PRRSV-2 and swine influenza H3N2 virus co-infection on the efficacy of PRRSV modified live virus (MLV) vaccination, which is widely used in the field. Following simultaneous challenge with contemporary PRRSV-2 and H3N2 field isolates, we found that the protective effect of PRRS MLV vaccination on clinical disease and pathology was abrogated, although viral load was unaffected and antibody responses were enhanced. In contrast, co-infection in non-immunized animals reduced PRRSV-2 viremia and H3N2 virus load in the upper respiratory tract and potentiated T cell responses against both PRRSV-2 and H3N2 in the lung. Further analysis suggested that an upregulation of inhibitory cytokines gene expression in the lungs of vaccinated pigs may have influenced responses to H3N2 and PRRSV-2. These findings provide important insights into the effect of viral co-infections on PRRS vaccine efficacy that may help identify more effective vaccination strategies against PRDC in the field.

Age-Specific Etiology of Severe Acute Respiratory Infections and Influenza Vaccine Effectivity in Prevention of Hospitalization in Russia, 2018–2019 Season

The expansion and standardization of clinical trials, as well as the use of sensitive and specific molecular diagnostics methods, provide new information on the age-specific roles of influenza and other respiratory viruses in development of severe acute respiratory infections (SARI). Here, we present the results of the multicenter hospital-based study aimed to detect age-specific impact of influenza and other respiratory viruses (ORV). The 2018–2019 influenza season in Russia was characterized by co-circulation of influenza A(H1N1)pdm09 and A(H3N2) virus subtypes which were detected among hospitalized patients with SARI in 19.3% and 16.4%, respectively. RSV dominated among ORV (15.1% of total cases and 26.8% in infants aged ≤ 2 years). The most significant SARI agents in intensive care units were RSV and influenza A(H1N1)pdm09 virus, (37.3% and 25.4%, respectively, of PCR-positive cases). Hyperthermia was the most frequently registered symptom for influenza cases. In contrast, hypoxia, decreased blood O2 concentration, and dyspnea were registered more often in RSV, rhinovirus, and metapneumovirus infection in young children. Influenza vaccine effectiveness (IVE) against hospitalization of patients with PCR-confirmed influenza was evaluated using test-negative case–control design. IVE for children and adults was estimated to be 57.0% and 62.0%, respectively. Subtype specific IVE was higher against influenza A(H1N1)pdm09, compared to influenza A(H3N2) (60.3% and 45.8%, respectively). This correlates with delayed antigenic drift of the influenza A(H1N1)pdm09 virus and genetic heterogeneity of the influenza A(H3N2) population. These studies demonstrate the need to improve seasonal influenza prevention and control in all countries as states by the WHO Global Influenza Strategy for 2019–2030 initiative.

Replication and transmission of an influenza A(H3N2) virus harboring the polymerase acidic I38T substitution, in guinea pigs.

The polymerase acidic (PA) I38T substitution is a dominant marker of resistance to baloxavir. We evaluated the impact of I38T on the fitness of a contemporary influenza A(H3N2) virus. Influenza A/Switzerland/9715293/2013 (H3N2) wild-type (WT) virus and its I38T mutant were rescued by reverse genetics. Replication kinetics were compared using ST6GalI-MDCK and A549 cells and infectivity/contact transmissibility were evaluated in guinea pigs. Nasal wash (NW) viral titres were determined by TCID50 ml−1 in ST6GalI-MDCK cells. Competition experiments were performed and the evolution of viral population was assessed by droplet digital RT-PCR. I38T did not alter in vitro replication. I38T induced comparable titres vs the WT in guinea pigs NWs and the two viruses transmitted equally by direct contact. However, a 50 %:50 % mixture inoculum evolved to mean WT/I38T ratios of 71 %:29 % and 66.4 %:33.6 % on days 4 and 6 p.i., respectively. Contemporary influenza A(H3N2)-I38T PA variants may conserve a significant level of viral fitness.

Changes in the Nasal Microbiota of Pigs Following Single or Co-Infection with Porcine Reproductive and Respiratory Syndrome and Swine Influenza A Viruses

Host-microbiota interactions are important in shaping immune responses that have the potential to influence the outcome of pathogen infection. However, most studies have focused on the gut microbiota and its possible association with disease outcome, while the role of the nasal microbiota and respiratory pathogen infection has been less well studied. Here we examined changes in the composition of the nasal microbiota of pigs following experimental infection with porcine reproductive and respiratory syndrome virus 2 (PRRSV-2), swine influenza A H3N2 virus (H3N2) or both viruses. DNA extracted from nasal swabs were subjected to 16S rRNA sequencing to study the composition of the nasal microbiota. Bacterial richness fluctuated in all groups, with a slight reduction in pigs singly infected with PRRSV-2 and H3N2 during the first 5 days of infection compared to uninfected controls. In contrast, nasal bacterial richness remained relatively stable after PRRSV-2/H3N2 co-infection. PRRSV-2 and H3N2, alone or in combination differentially altered the abundance and distribution of bacterial families. Single and co-infection with PRRSV-2 or H3N2 was associated with the expansion of the Neisseriaceae family. A positive correlation between H3N2 viral load and the relative abundance of the Neisseriaceae was observed. However, further mechanistic studies are required to understand the significance of the changes in specific bacterial families following these viral infections.

Local patterns of spread of influenza A(H3N2) virus in coastal Kenya over a one-year period revealed through virus sequence data

The patterns of spread of influenza A viruses in local populations in tropical and sub-tropical regions are unclear due to sparsity of representative spatiotemporal sequence data. We sequenced and analyzed 58 influenza A(H3N2) virus genomes sampled between December 2015 and December 2016 from nine health facilities within the Kilifi Health and Demographic Surveillance System (KHDSS), a predominantly rural region, covering approximately 891 km2 along the Kenyan coastline. The genomes were compared with 1,571 contemporaneous global sequences from 75 countries. We observed at least five independent introductions of A(H3N2) viruses into the region during the one-year period, with the importations originating from Africa, Europe, and North America. We also inferred 23 virus location transition events between the nine facilities included in the study. International virus imports into the study area were captured at the facilities of Chasimba, Matsangoni, Mtondia, and Mavueni, while all four exports from the region were captured from the Chasimba facility, all occurring to Africa destinations. A strong spatial clustering of virus strains at all locations was observed associated with local evolution. Our study shows that influenza A(H3N2) virus epidemics in local populations appear to be characterized by limited introductions followed by significant local spread and evolution.