Draining Lymph Node Metastasis Model for Assessing the Dynamics of Antigen-Specific CD8<sup>+</sup> T Cells During Tumorigenesis

Tumor antigen-specific CD8+ T cells from draining lymph nodes gain an accumulating importance in mounting anti-tumor immune response during tumorigenesis. ...

Qingdao Agricultural University

A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay has been developed to detect and differentiate between canine parvovirus (CPV) and mink enteritis virus (MEV). Eight CPV and three MEV epidemic strains isolated from 28 pathological samples from dogs and minks suspected of being infected with parvovirus were amplified by PCR using a pair of specific primers designed based on the CPV-N strain (M19296). PCR amplified a fragment of 1016bp from the genomic DNA of both MEV and CPV. The MEV-derived fragment could be digested with the restriction enzyme BSP1407I into three fragments of 102bp, 312bp and 602bp, while the fragment amplified from the CPV genomic DNA was digested into only two fragments of 414bp and 602bp. The lowest DNA concentration of CPV and MEV that could be detected using this assay was 0.004μg/ml and 0.03μg/ml, respectively. The PCR-RFLP assay developed in the present study can, therefore, be used to detect and differentiate MEV from CPV with high specificity and sensitivity.

Development of a PCR-RFLP assay for the detection and differentiation of canine parvovirus and mink enteritis virus.

The prevalence of avian H9N2 viruses throughout Asia, along with their demonstrated ability to infect mammals, puts them high on the list of influenza viruses with pandemic potential for humans. In this study, we investigated whether H9N2 viruses could infect farmed minks.

Avian influenza virus H9N2 infections in farmed minks.

The surge of patients in the pandemic of COVID-19 caused by the novel coronavirus SARS-CoV-2 may overwhelm the medical systems of many countries. Mask-wearing and handwashing can slow the spread of the virus, but currently, masks are in shortage in many countries, and timely handwashing is often impossible. In this study, the efficacy of three types of masks and instant hand wiping was evaluated using the avian influenza virus to mock the coronavirus. Virus quantification was performed using real-time reverse transcription-polymerase chain reaction. Previous studies on mask-wearing were reviewed. The results showed that instant hand wiping using a wet towel soaked in water containing 1.00% soap powder, 0.05% active chlorine, or 0.25% active chlorine from sodium hypochlorite removed 98.36%, 96.62%, and 99.98% of the virus from hands, respectively. N95 masks, medical masks, and homemade masks made of four-layer kitchen paper and one-layer cloth could block 99.98%, 97.14%, and 95.15% of the virus in aerosols. Medical mask-wearing which was supported by many studies was opposed by other studies possibly due to erroneous judgment. With these data, we propose the approach of mask-wearing plus instant hand hygiene (MIH) to slow the exponential spread of the virus. This MIH approach has been supported by the experiences of seven countries in fighting against COVID-19. Collectively, a simple approach to slow the exponential spread of SARS-CoV-2 was proposed with the support of experiments, literature review, and control experiences.

Potential utilities of mask-wearing and instant hand hygiene for fighting SARS-CoV-2.

Bp7 is a T-even phage with a broad host range specific to , including  K-12. The receptor binding protein (RBP) of bacteriophages plays an important role in the phage adsorption process and determines phage host range, but the molecular mechanism involved in host recognition of phage Bp7 remains unknown. In this study, the interaction between phage Bp7 and  K-12 was investigated. Based on homology alignment, amino acid sequence analysis, and a competitive assay, gp38, located at the tip of the long tail fiber, was identified as the RBP of phage Bp7. Using a combination of  and  approaches, including affinity chromatography, gene knockout mutagenesis, a phage plaque assay, and phage adsorption kinetics analysis, we identified the LamB and OmpC proteins on the surface of  K-12 as specific receptors involved in the first step of reversible phage adsorption. Genomic analysis of the phage-resistant mutant strain  K-12-R and complementation tests indicated that HepI of the inner core of polysaccharide acts as the second receptor recognized by phage Bp7 and is essential for successful phage infection. This observation provides an explanation of the broad host range of phage Bp7 and provides insight into phage-host interactions. The RBPs of T4-like phages are gp37 and gp38. The interaction between phage T4 RBP gp37 and its receptors has been clarified by many reports. However, the interaction between gp38 and its receptors during phage adsorption is still not completely understood. Here, we identified phage Bp7, which uses gp38 as an RBP, and provided a good model to study the phage-host interaction mechanisms in an enterobacteriophage. Our study revealed that gp38 of phage Bp7 recognizes the outer membrane proteins (OMPs) LamB and OmpC of  K-12 as specific receptors and binds with them reversibly. HepI of the inner-core oligosaccharide is the second receptor and binds with phage Bp7 irreversibly to begin the infection process. Determining the interaction between the phage and its receptors will help elucidate the mechanisms of phage with a broad host range and help increase understanding of the phage infection mechanism based on gp38.

LamB, OmpC, and the Core Lipopolysaccharide of Escherichia coli K-12 Function as Receptors of Bacteriophage Bp7.

The coronavirus disease 2019 pandemic caused by the novel coronavirus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) has claimed many lives worldwide. Wearing medical masks (MMs) or N95 masks ([N95Ms] namely N95 respirators) can slow the virus spread and reduce the infection risk. Reuse of these masks can minimize waste, protect the environment, and help solve the current imminent shortage of masks. Disinfection of used masks is needed for their reuse with safety, but improper decontamination can damage the blocking structure of masks. In this study, we demonstrated using the avian coronavirus of infectious bronchitis virus to mimic SARS-CoV-2 that MMs and N95Ms retained their blocking efficacy even after being steamed on boiling water for 2 hours. We also demonstrated that three brands of MMs blocked over 99% viruses in aerosols. The avian coronavirus was completely inactivated after being steamed for 5 minutes. Altogether, this study suggested that MMs are adequate for use on most social occasions and both MMs and N95Ms can be reused for a few days with steam decontamination between use.

Decontamination of face masks with steam for mask reuse in fighting the pandemic COVID-19: Experimental supports.

Pseudorabies virus (PRV) is the causative agent of Aujeszky's disease and is communicable across species. In particular, the emergence of PRV variants in 2011 have resulted in serious economic losses to the Chinese pig industry. In this study, we used tandem mass tag (TMT) quantitative protein analysis to identify differentially expressed proteins between the PRV variant strain SD-2017 and the vaccine strain Bartha-K/61 in the swine kidney cell line PK15. Overall, we identified 4690 proteins for SD-2017 infection compared with the mock-infected control cells. We found 162 differentially expressed cellular proteins including 41 up- and 121 down-regulated proteins. SD-2017-infected PK15 cells differential proteins were primarily related to gap junctions, the phagosome, antigen processing and presentation, cell adhesion molecules and peroxisome pathways. Compared to Bartha-K/61-infected PK15 cells, SD-2017-infected cells displayed differentially expressed proteins involved in tryptophan metabolism, mitophagy and Notch signaling. Western blot analysis of MARK2, TSR1 and TMED1 three representative proteins validated the reliability of the TMT data. This study is an initial at-tempt to compare the proteomes of PK15 cells infected by a PRV variant and a vaccine strain using TMT technology to provide new insights into the mechanisms of PRV pathogenesis and immune evasion.

Comparative proteomic analysis of PK15 swine kidney cells infected with a pseudorabies pathogenic variant and the Bartha-K/61 vaccine strain.

Pseudorabies (PR) (also called Aujeszky's disease, AD) is a serious infectious disease affecting pigs and other animals worldwide. The emergence of variant strains of pseudorabies virus (PRV) since 2011 has led to PR outbreaks in China and a vaccine that antigenically more closely matches these PRV variants could represent an added value to control these infections.

Guimei Li

College of Veterinary Medicine

Qingdao Agricultural University

Draining Lymph Node Metastasis Model for Assessing the Dynamics of Antigen-Specific CD8⁺ T Cells During Tumorigenesis

Guimei Li

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Qingdao Agricultural University

Draining Lymph Node Metastasis Model for Assessing the Dynamics of Antigen-Specific CD8+ T Cells During Tumorigenesis

College of Veterinary Medicine

Draining Lymph Node Metastasis Model for Assessing the Dynamics of Antigen-Specific CD8⁺ T Cells During Tumorigenesis