Skip to main content

Structural basis of different #neutralization capabilities of #monoclonal #antibodies against #H7N9 virus

Image
By G.M.

ABSTRACT

Neutralizing antibodies (nAbs) are important for the treatment of emerging viral diseases and for effective vaccine development. In this study, we generated and evaluated three nAbs (1H9, 2D7, and C4H4) against H7N9 influenza viruses and found that they differ in their ability to inhibit viral attachment, membrane fusion, and egress. We resolved the cryo-electron microscopy (cryo-EM) structures of H7N9 hemagglutinin (HA) alone and in complex with the nAb antigen-binding fragments (Fabs) and identified the HA head-located epitope for each nAb, thereby revealing the molecular basis and key residues that determine the differences in these nAbs in neutralizing H7N9 viruses. Moreover, we found that the humanized nAb CC4H4 provided complete protection in mice against death caused by a lethal H7N9 virus infection, even when nAb was given 3 days after the mice were infected. These findings provide new insights into the neutralizing mechanism and structural basis for the rational design of H7N9 virus vaccines and therapeutics.

Source: Journal of Virology, https://journals.asm.org/doi/full/10.1128/jvi.01400-24?af=R

____

Labels:

Comments

Post a Comment

Popular posts from this blog

#USA, Two more #human cases of #H5N1 #birdflu reported in #California

By G.M.
Two cases of bird flu have been reported in San Joaquin County, California, local health officials said. According to a press release issued Friday and reported by the Sacramento Bee , health officials with San Joaquin County Public Health Services said both cases were farm workers who were exposed to infected animals . Both people are showing mild symptoms and are recovering, officials said, adding that there are 34 total confirmed cases across California. In a warning posted on Facebook, health officials said bird flu was “spreading in several farms such as poultry and cattle” and urged residents to take precautions to prevent the spread of the disease. Precautions include the use of protective equipment when handling poultry, dairy cattle or other animals that may be infected, and when handling raw and unpasteurized milk. (...) There are currently 60 confirmed cases of bird flu in the country . While most of the cases are in California , other states with confirmed cases include Col...
Post a Comment
Read more »

Viral #sepsis: #diagnosis, clinical #features, #pathogenesis, and #clinical considerations

By G.M.
Abstract Sepsis , characterized as life-threatening organ dysfunction resulting from dysregulated host responses to infection , remains a significant challenge in clinical practice . Despite advancements in understanding host-bacterial interactions , molecular responses, and therapeutic approaches, the mortality rate associated with sepsis has consistently ranged between 10 and 16%. This elevated mortality highlights critical gaps in our comprehension of sepsis etiology. Traditionally linked to bacterial and fungal pathogens, recent outbreaks of acute viral infections , including Middle East respiratory syndrome coronavirus ( MERS-CoV ), influenza virus, and severe acute respiratory syndrome coronavirus 2 ( SARS-CoV-2 ), among other regional epidemics, have underscored the role of viral pathogenesis in sepsis, particularly when critically ill patients exhibit classic symptoms indicative of sepsis. However, many cases of viral-induced sepsis are frequently underdiagnosed because standar...
Post a Comment
Read more »

Rapid #Surge of #Reassortant A(#H1N1) #Influenza Viruses in Danish #Swine and their #Zoonotic Potential

By G.M.
 Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2024.12.11.627926v1?rss=1  Abstract In 2018, a single detection of a novel reassortant swine influenza A virus (swIAV) was made in Denmark . The hemagglutinin (HA) of the virus was from the H1N1 pandemic 2009 (H1N1pdm09) lineage and the neuraminidase (NA) from the H1N1 Eurasian avian-like swine lineage (H1N1av). By 2022, the novel reassortant virus (H1pdm09N1av) constituted 27 % of swIAVs identified through the Danish passive swIAV surveillance program. Sequencing detected two H1pdm09N1av genotypes ; Genotype 1 contained an internal gene cassette of H1N1pdm09 origin , Genotype 2 differed by carrying an NS gene segment of H1N1av origin . The internal gene cassette of Genotype 2 became increasingly dominant, not only in the H1pdm09N1av population, but also in other Danish enzootic swIAV subtypes . Phylogenetic analysis of the HA genes from H1pdm09N1av viruses revealed a monophyletic source , a higher substitution rat...
Post a Comment
Read more »