The protective effect of intranasal immunization with influenza virus recombinant adenovirus vaccine on mucosal and systemic immune response

Influenza virus is a kind of virus that poses several hazards of animal and human health. Therefore, it is important to develop an effective vaccine to prevent influenza. To this end we successfully packaged recombinant adenovirus rAd-NP-M2e-GFP expressing multiple copies of influenza virus conserved antigens NP and M2e and packaged empty vector adenovirus rAd-GFP. The effect of rAd-NP-M2e-GFP on the activation of dendritic cell (DC) in vitro and in vivo was detected by intranasal immunization. The results showed that rAd-NP-M2e-GFP promoted the activation of DC in vitro and in vivo. After the primary immunization and booster immunization of mice through the nasal immune way, the results showed that rAd-NP-M2e-GFP induced enhanced local mucosal-specific T cell responses, increased the content of SIgA in broncho alveolar lavage fluids (BALF) and triggered the differentiation of B cells in the germinal center. It is proved that rAd-NP-M2e-GFP can significantly elicit mucosal immunity and systemic immune response. In addition, rAd-NP-M2e-GFP could effectively protect mice after H1N1 influenza virus challenge. To lay the foundation and provide reference for further development of influenza virus mucosal vaccine in the future.

Immunogenicity of engineered probiotics expressing conserved antigens of influenza virus and FLIC flagellin against H9N2 AIVinfection in mice

Avian influenza virus (AIV)is easy to cause diseases in birds and humans.It causes great economic losses to the poultry farms and leads to public health problems. Using vaccines is the main approach to control the prevalence of AIV. In our previously published article, a recombinant Lactobacillus plantarum (L. plantarum) expressing the NP-M2 peptide ofH9N2 AIV was generated, and its protective effect was evaluated in a chicken model. In this study, the protective effect was estimated in mice model. Humoral and cellular immune response parameters were measured using flow cytometry adding to body weight loss, survival rate, virus load, and histopathological changes in the lung. The obtained results elucidated that, the recombinant L. plantarum can promote the activation of dendritic cells (DC), proliferation of T and B cells adding to eliciting protective secretory IgA (sIgA) and humeral IgG level in mice model. Accordingly, it could be used as a patent vaccine to control the AIV infection.

[Clinical and molecular pathological features of bronchopulmonary large cell neuroendocrine carcinoma]

Objective: To investigate the clinical manifestations, imaging, pathological and molecular features of bronchopulmonary large-cell neuroendocrine carcinoma (LCNEC). Methods: The clinical data of 216 LCNEC patients in the First Affiliated Hospital of Zhengzhou University from 2011 to 2021 were analyzed retrospectively. The clinical manifestations, tumor location and size, characteristics of CT images, immunohistochemical and molecular pathological features were analyzed and compared with 115 cases of mixed small cell carcinoma (M-SCLC) diagnosed in the same period. Results: Among the 216 LCNEC patients, there were 190 males and 26 females, with a median age of 65 years. The first symptoms of the patients were mainly cough (106 cases, 49.1%) and bloody sputum (48 cases, 22.2%). The median tumor length were 4.7cm, including 55 cases of nodular type (25.5%) and 161 cases of mass-forming type (74.5%). CT imaging results showed that LCNEC lesions had soft tissue density, and the proportion of slight enhancement lesions was significantly lower than that in M-SCLC group (52.3% vs 74.8%, P<0.001). In contrast, the proportion of necrosis (87.0% vs 58.3%, P<0.001) and calcification (26.9% vs 2.6%, P<0.001) in LCNEC patients was significantly higher than that in M-SCLC group. Immunohistochemical results showed that the positive rate of CK in LCNEC was significantly higher than that in M-SCLC (99.0 % vs 90.5%, P<0.05), while the positive rate of TTF-1 was significantly lower than that in M-SCLC (51.6% vs 67.0%, P<0.05). In LCNEC group, the proportion of patients with Ki-67 positive index between 50% and 80% was significantly higher than that of M-SCLC (41.2% vs 25.2%), while the proportion between 80% and 100% was lower than that of M-SCLC (51.9% vs 72.2%). There was no significant difference in the positive rates of CD56 (91.7% vs 94.6%, P=0.336), Syn (83.8% vs 84.7%, P=0.838) and CgA (54.8% vs 50.0%, P=0.632) in both tumor types. Molecular pathology results showed that frequent mutatios were TP53 (54.5%), RB1 (36.4%), KEAP1 (18.2%), MYC(18.2%), and PTEN (14.3%), and the rate of tumor mutation burden which is more than 25 mutation/Mb was 27.3%. Conclusions: LCNEC lacks specific clinical manifestations. CT imaging is powerful in distinguishing LCNEC from M-SCLC. LCNEC contains a specific mutation spectrum. Pathology combined with immunohistochemical staining is still the gold standard for LCNEC diagnosis, and the differentiation from M-SCLC mainly depends on cell size and nuclear chromatin pattern with light microscopy.

Improved pathogenicity of H9N2 subtype of avian influenza virus induced by mutations occurred after serial adaptations in mice

H9N2 subtype, a low pathogenic avian influenza virus, is emerging as a major causative agent circulating poultry workplaces across China and other Asian countries. Increasing case number of interspecies transmissions to mammals reported recently provoked a great concern about its risks inducing global pandemics. In an attempt to understand the underlying mechanism of how the H9N2 virus disrupts the interspecies segregation to transmit to mammals. A mutant H9N2 strain was obtained by passaging the wildtype H9N2 A/chicken/Hong Kong/G9/1997 eight times from lung to lung in BALB/c mice. Our finding revealed that mice manifested severe clinical symptoms including losses of body weight, pathological damages in pulmonary sites and all died within two weeks after infected with the mutated H9N2, whereas all mice survived upon infected with wildtype strain in comparison, which suggested increased pathogenicity of the mutant strain. In addition, mice showed enhanced levels of proinflammatory cytokines in sera, including IL-6, TNF-α and IL-1β compared to those subjected to wildtype viral infections. Sequence analysis showed that five amino acid substitutions occurred at PB2₆₂₇, HA_87, HA₂₃₄, NP₃₈₇ and M₁₅₆, and a deletion mutation happened in the M gene (M₁₅₇). Of these mutations, PB2 E627K played key roles in modulating lethality in mice. Taken together, the mutant H9N2 strain obtained by serial passaging of its wildtype in mice significantly increased its virulence leading to death of mice, which might be associated the accumulated mutations occurred on its genome.

Design of an electric-driven nonvolatile low-energy-consumption phase change optical switch

Traditional optical switches relying on the weak, volatile thermo-optic or electro-optic effects of Si or SiN waveguides show a high consumption and large footprint. In this paper, we reported an electric-driven phase change optical switch consisting of a Si waveguide, Ge₂Sb₂Te₅(GST) thin film and graphene heater suitable for large-scale integration and high-speed switching. The reversible transition between the amorphous and crystalline states was achieved by applying two different voltage pulses of 1.4 V (SET) and 4 V (RESET). The optical performance of the proposed switch showed a high extinction ration of 44-46 dB in a wide spectral range (1525-1575 nm), an effective index variation of Δn_eff = 0.49 and a mode loss variation of Δα = 15 dBμm^-1at the wavelength of 1550 nm. In thermal simulations, thanks to the ultra-high thermal conductivity of graphene, the proposed switch showed that the consumption for the SET process was only 3.528 pJ with a 1.4 V pulse of 5 ns, while a 4 V pulse of 1.5 ns was needed for RESET process with a consumption of 1.05 nJ. Our work is helpful to analyze the thermal-conduction phase transition process of on-chip phase change optical switches, and the design of the low-energy-consumption switch is conducive to the integrated application of photonic chips.