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MMWR. Morbidity and Mortality Weekly... May 2024
Topics: Humans; Animals; United States; Influenza, Human; Cattle; Disease Outbreaks; Influenza A Virus, H5N1 Subtype; Cattle Diseases; Female; Male
PubMed: 38814843
DOI: 10.15585/mmwr.mm7321e1 -
Frontiers in Bioscience (Landmark... May 2024To investigate the immune responses and protection ability of ultraviolet light (UV)-inactivated recombinant vesicular stomatitis (rVSV)-based vectors that expressed a...
BACKGROUND
To investigate the immune responses and protection ability of ultraviolet light (UV)-inactivated recombinant vesicular stomatitis (rVSV)-based vectors that expressed a fusion protein consisting of four copies of the influenza matrix 2 protein ectodomain (tM2e) and the Dendritic Cell (DC)-targeting domain of the Ebola Glycoprotein (EΔM), (rVSV-EΔM-tM2e).
METHOD
In our previous study, we demonstrated the effectiveness of rVSV-EΔM-tM2e to induce robust immune responses against influenza M2e and protect against lethal challenges from H1N1 and H3N2 strains. Here, we used UV to inactivate rVSV-EΔM-tM2e and tested its immunogenicity and protection in BALB/c mice from a mouse-adapted H1N1 influenza challenge. Using Enzyme-Linked Immunosorbent Assay (ELISA) and Antibody-Dependent Cellular Cytotoxicity (ADCC), the influenza anti-M2e immune responses specific to human, avian and swine influenza strains induced were characterized. Likewise, the specificity of the anti-M2e immune responses induced in recognizing M2e antigen on the surface of the cell was investigated using Fluorescence-Activated Cell Sorting (FACS) analysis.
RESULTS
Like the live attenuated rVSV-EΔM-tM2e, the UV-inactivated rVSV-EΔM-tM2e was highly immunogenic against different influenza M2e from strains of different hosts, including human, swine, and avian, and protected against influenza H1N1 challenge in mice. The FACS analysis demonstrated that the induced immune responses can recognize influenza M2 antigens from human, swine and avian influenza strains. Moreover, the rVSV-EΔM-tM2e also induced ADCC activity against influenza M2e from different host strains.
CONCLUSIONS
These findings suggest that UV-inactivated rVSV-EΔM-tM2e could be used as an inactivated vaccine against influenza viruses.
Topics: Animals; Influenza Vaccines; Influenza A Virus, H1N1 Subtype; Ultraviolet Rays; Mice, Inbred BALB C; Orthomyxoviridae Infections; Female; Mice; Humans; Viral Matrix Proteins; Vesiculovirus; Vaccines, Inactivated
PubMed: 38812326
DOI: 10.31083/j.fbl2905195 -
Scientific Reports May 2024Catalytic antibodies possess a dual function that enables both antigen recognition and degradation. However, their time-consuming preparation is a significant drawback....
Catalytic antibodies possess a dual function that enables both antigen recognition and degradation. However, their time-consuming preparation is a significant drawback. This study developed a new method for quickly converting mice monoclonal antibodies into catalytic antibodies using site-directed mutagenesis. Three mice type monoclonal antibodies targeting hemagglutinin molecule of influenza A virus could be transformed into the catalytic antibodies by deleting Pro95 in CDR-3 of the light chain. No catalytic activity was observed for monoclonal antibodies and light chains. In contrast, the Pro95-deleted light chains exhibited a catalytic activity to cleave the antigenic peptide including the portion of conserved region of hemagglutinin molecule. The affinity of the Pro95-deleted light chains to the antigen increased approximately 100-fold compared to the wild-type light chains. In the mutants, three residues (Asp1, Ser92, and His93) come closer to the appropriate position to create the catalytic site and contributing to the enhancement of both catalytic function and immunoreactivity. Notably, the Pro95-deleted catalytic light chains could suppress influenza virus infection in vitro assay, whereas the parent antibody and the light chain did not. This strategy offers a rapid and efficient way to create catalytic antibodies from existing antibodies, accelerating the development for various applications in diagnostic and therapeutic applications.
Topics: Animals; Mice; Antibodies, Monoclonal; Antibodies, Catalytic; Hemagglutinin Glycoproteins, Influenza Virus; Mutagenesis, Site-Directed; Influenza A virus; Catalytic Domain; Humans; Immunoglobulin Light Chains; Antibodies, Viral; Mice, Inbred BALB C
PubMed: 38806597
DOI: 10.1038/s41598-024-63116-6 -
ELife May 2024Human H3N2 influenza viruses are subject to rapid antigenic evolution which translates into frequent updates of the composition of seasonal influenza vaccines. Despite...
Human H3N2 influenza viruses are subject to rapid antigenic evolution which translates into frequent updates of the composition of seasonal influenza vaccines. Despite these updates, the effectiveness of influenza vaccines against H3N2-associated disease is suboptimal. Seasonal influenza vaccines primarily induce hemagglutinin-specific antibody responses. However, antibodies directed against influenza neuraminidase (NA) also contribute to protection. Here, we analysed the antigenic diversity of a panel of N2 NAs derived from human H3N2 viruses that circulated between 2009 and 2017. The antigenic breadth of these NAs was determined based on the NA inhibition (NAI) of a broad panel of ferret and mouse immune sera that were raised by infection and recombinant N2 NA immunisation. This assessment allowed us to distinguish at least four antigenic groups in the N2 NAs derived from human H3N2 viruses that circulated between 2009 and 2017. Computational analysis further revealed that the amino acid residues in N2 NA that have a major impact on susceptibility to NAI by immune sera are in proximity of the catalytic site. Finally, a machine learning method was developed that allowed to accurately predict the impact of mutations that are present in our N2 NA panel on NAI. These findings have important implications for the renewed interest to develop improved influenza vaccines based on the inclusion of a protective NA antigen formulation.
Topics: Neuraminidase; Influenza A Virus, H3N2 Subtype; Humans; Animals; Ferrets; Antigens, Viral; Mice; Influenza, Human; Antibodies, Viral; Influenza Vaccines; Antigenic Variation; Viral Proteins; Orthomyxoviridae Infections
PubMed: 38805550
DOI: 10.7554/eLife.90782 -
Nature Communications May 2024Avian influenza A virus H7N9 causes severe human infections with >30% fatality. Currently, there is no H7N9-specific prevention or treatment for humans. Here, from a...
Avian influenza A virus H7N9 causes severe human infections with >30% fatality. Currently, there is no H7N9-specific prevention or treatment for humans. Here, from a 2013 H7N9 convalescent case in Hong Kong, we isolate four hemagglutinin (HA)-reactive monoclonal antibodies (mAbs), with three directed to the globular head domain (HA1) and one to the stalk domain (HA2). Two clonally related HA1-directed mAbs, H7.HK1 and H7.HK2, potently neutralize H7N9 and protect female mice from lethal H7N9/AH1 challenge. Cryo-EM structures reveal that H7.HK1 and H7.HK2 bind to a β14-centered surface and disrupt the 220-loop that makes hydrophobic contacts with sialic acid on an adjacent protomer, thereby blocking viral entry. Sequence analysis indicates the lateral patch targeted by H7.HK1 and H7.HK2 to be conserved among influenza subtypes. Both H7.HK1 and H7.HK2 retain HA1 binding and neutralization capacity to later H7N9 isolates from 2016-2017, consistent with structural data showing that the antigenic mutations during this timeframe occur at their epitope peripheries. The HA2-directed mAb H7.HK4 lacks neutralizing activity but when used in combination with H7.HK2 moderately augments female mouse protection. Overall, our data reveal antibodies to a conserved lateral HA1 supersite that confer neutralization, and when combined with a HA2-directed non-neutralizing mAb, augment protection.
Topics: Influenza A Virus, H7N9 Subtype; Animals; Antibodies, Neutralizing; Humans; Hemagglutinin Glycoproteins, Influenza Virus; Female; Influenza, Human; Mice; Antibodies, Viral; Antibodies, Monoclonal; Mice, Inbred BALB C; Cryoelectron Microscopy; Orthomyxoviridae Infections; Epitopes
PubMed: 38802413
DOI: 10.1038/s41467-024-48758-4 -
Nature Communications May 2024Jamaican fruit bats (Artibeus jamaicensis) naturally harbor a wide range of viruses of human relevance. These infections are typically mild in bats, suggesting unique...
Jamaican fruit bats (Artibeus jamaicensis) naturally harbor a wide range of viruses of human relevance. These infections are typically mild in bats, suggesting unique features of their immune system. To better understand the immune response to viral infections in bats, we infected male Jamaican fruit bats with the bat-derived influenza A virus (IAV) H18N11. Using comparative single-cell RNA sequencing, we generated single-cell atlases of the Jamaican fruit bat intestine and mesentery. Gene expression profiling showed that H18N11 infection resulted in a moderate induction of interferon-stimulated genes and transcriptional activation of immune cells. H18N11 infection was predominant in various leukocytes, including macrophages, B cells, and NK/T cells. Confirming these findings, human leukocytes, particularly macrophages, were also susceptible to H18N11, highlighting the zoonotic potential of this bat-derived IAV. Our study provides insight into a natural virus-host relationship and thus serves as a fundamental resource for future in-depth characterization of bat immunology.
Topics: Animals; Chiroptera; Male; Single-Cell Analysis; Humans; Orthomyxoviridae Infections; Macrophages; Influenza A virus; Gene Expression Profiling
PubMed: 38802391
DOI: 10.1038/s41467-024-48934-6 -
Influenza and Other Respiratory Viruses May 2024Novel influenza viruses pose a potential pandemic risk, and rapid detection of infections in humans is critical to characterizing the virus and facilitating the...
BACKGROUND
Novel influenza viruses pose a potential pandemic risk, and rapid detection of infections in humans is critical to characterizing the virus and facilitating the implementation of public health response measures.
METHODS
We use a probabilistic framework to estimate the likelihood that novel influenza virus cases would be detected through testing in different community and healthcare settings (urgent care, emergency department, hospital, and intensive care unit [ICU]) while at low frequencies in the United States. Parameters were informed by data on seasonal influenza virus activity and existing testing practices.
RESULTS
In a baseline scenario reflecting the presence of 100 novel virus infections with similar severity to seasonal influenza viruses, the median probability of detecting at least one infection per month was highest in urgent care settings (72%) and when community testing was conducted at random among the general population (77%). However, urgent care testing was over 15 times more efficient (estimated as the number of cases detected per 100,000 tests) due to the larger number of tests required for community testing. In scenarios that assumed increased clinical severity of novel virus infection, median detection probabilities increased across all healthcare settings, particularly in hospitals and ICUs (up to 100%) where testing also became more efficient.
CONCLUSIONS
Our results suggest that novel influenza virus circulation is likely to be detected through existing healthcare surveillance, with the most efficient testing setting impacted by the disease severity profile. These analyses can help inform future testing strategies to maximize the likelihood of novel influenza detection.
Topics: Humans; Influenza, Human; United States; Orthomyxoviridae; Epidemiological Monitoring
PubMed: 38798083
DOI: 10.1111/irv.13315 -
Influenza and Other Respiratory Viruses May 2024Seroepidemiological studies provide estimates of population-level immunity, prevalence/incidence of infections, and evaluation of vaccination programs. We assessed the...
BACKGROUND
Seroepidemiological studies provide estimates of population-level immunity, prevalence/incidence of infections, and evaluation of vaccination programs. We assessed the seroprevalence of protective antibodies against influenza and evaluated the correlation of seroprevalence with the cumulative annual influenza incidence rate.
METHODS
We conducted an annual repeated cross-sectional seroepidemiological survey, during June-August, from 2014 to 2019, in Portugal. A total of 4326 sera from all age groups, sex, and regions was tested by hemagglutination inhibition assay. Seroprevalence and geometric mean titers (GMT) of protective antibodies against influenza were assessed by age group, sex, and vaccine status (65+ years old). The association between summer annual seroprevalence and the difference of influenza incidence rates between one season and the previous one was measured by Pearson correlation coefficient (r).
RESULTS
Significant differences in seroprevalence of protective antibodies against influenza were observed in the population. Higher seroprevalence and GMT for A(H1N1)pdm09 and A(H3N2) were observed in children (5-14); influenza B seroprevalence in adults 65+ was 1.6-4.4 times than in children (0-4). Vaccinated participants (65+) showed significant higher seroprevalence/GMT for influenza. A strong negative and significant correlation was found between seroprevalence and ILI incidence rate for A(H1N1)pdm09 in children between 5 and 14 (r = -0.84; 95% CI, -0.98 to -0.07); a weak negative correlation was observed for A(H3N2) and B/Yamagata (r ≤ -0.1).
CONCLUSIONS
The study provides new insight into the anti-influenza antibodies seroprevalence measured in summer on the ILI incidence rate in the next season and the need for adjusted preventive health care measures to prevent influenza infection and transmission.
Topics: Humans; Seroepidemiologic Studies; Cross-Sectional Studies; Influenza, Human; Female; Male; Adult; Incidence; Antibodies, Viral; Child, Preschool; Child; Middle Aged; Adolescent; Young Adult; Aged; Portugal; Infant; Influenza Vaccines; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Hemagglutination Inhibition Tests; Influenza B virus; Seasons; Infant, Newborn; Aged, 80 and over
PubMed: 38798072
DOI: 10.1111/irv.13307 -
Viruses May 2024Influenza vaccines, which are recommended by the World Health Organization (WHO), are the most effective preventive measure against influenza virus infection....
Influenza vaccines, which are recommended by the World Health Organization (WHO), are the most effective preventive measure against influenza virus infection. Madin-Darby canine kidney (MDCK) cell culture is an emerging technology used to produce influenza vaccines. One challenge when purifying influenza vaccines using this cell culture system is to efficiently remove impurities, especially host cell double-stranded DNA (dsDNA) and host cell proteins (HCPs), for safety assurance. In this study, we optimized ion-exchange chromatography methods to harvest influenza viruses from an MDCK cell culture broth, the first step in influenza vaccine purification. Bind/elute was chosen as the mode of operation for simplicity. The anion-exchange Q chromatography method was able to efficiently remove dsDNA and HCPs, but the recovery rate for influenza viruses was low. However, the cation-exchange SP process was able to simultaneously achieve high dsDNA and HCP removal and high influenza virus recovery. For the SP process to work, the clarified cell culture broth needed to be diluted to reduce its ionic strength, and the optimal dilution rate was determined to be 1:2 with purified water. The SP process yielded a virus recovery rate exceeding 90%, as measured using a hemagglutination units (HAUs) assay, with removal efficiencies over 97% for HCPs and over 99% for dsDNA. Furthermore, the general applicability of the SP chromatography method was demonstrated with seven strains of influenza viruses recommended for seasonal influenza vaccine production, including H1N1, H3N2, B (Victoria), and B (Yamagata) strains, indicating that the SP process could be utilized as a platform process. The SP process developed in this study showed four advantages: (1) simple operation, (2) a high recovery rate for influenza viruses, (3) a high removal rate for major impurities, and (4) general applicability.
Topics: Animals; Dogs; Madin Darby Canine Kidney Cells; Virion; Chromatography, Ion Exchange; Influenza Vaccines; Virus Cultivation; Orthomyxoviridae; Cell Culture Techniques
PubMed: 38793649
DOI: 10.3390/v16050768 -
Viruses May 2024Avian influenza viruses (AIVs) of the H5 subtype rank among the most serious pathogens, leading to significant economic losses in the global poultry industry and posing...
Avian influenza viruses (AIVs) of the H5 subtype rank among the most serious pathogens, leading to significant economic losses in the global poultry industry and posing risks to human health. Therefore, rapid and accurate virus detection is crucial for the prevention and control of H5 AIVs. In this study, we established a novel detection method for H5 viruses by utilizing the precision of CRISPR/Cas12a and the efficiency of RT-RPA technologies. This assay facilitates the direct visualization of detection results through blue light and lateral flow strips, accurately identifying H5 viruses with high specificity and without cross-reactivity against other AIV subtypes, NDV, IBV, and IBDV. With detection thresholds of 1.9 copies/μL (blue light) and 1.9 × 10 copies/μL (lateral flow strips), our method not only competes with but also slightly surpasses RT-qPCR, demonstrating an 80.70% positive detection rate across 81 clinical samples. The RT-RPA/CRISPR-based detection method is characterized by high sensitivity, specificity, and independence from specialized equipment. The immediate field applicability of the RT-RPA/CRISPR approach underscores its importance as an effective tool for the early detection and management of outbreaks caused by the H5 subtype of AIVs.
Topics: Animals; Influenza in Birds; CRISPR-Cas Systems; Sensitivity and Specificity; Influenza A Virus, H5N1 Subtype; Influenza A virus; Poultry; Poultry Diseases; Chickens; Birds
PubMed: 38793634
DOI: 10.3390/v16050753