Pathogens MDPI’s Post

New bacterial mechanism to stop viral infection Bacteria defend themselves from viral infection using diverse immune systems, some of which target and degrade foreign DNA, while others, including defense-associated reverse transcriptase (DRT) systems, take advantage of DNA synthesis. But how the latter approach leads to antiviral defense – including through DNA products produced – remains largely unknown. Focusing on a DRT system from the bacteria K. pneumoniae, the researchers discovered that when K. pneumoniae cells were infected with a phage, the DRT2 reverse transcriptases used RNA templates to synthesize a new gene, which the authors dubbed “neo.” Using mass spectrometry, the authors detected Neo peptides in phage-infected cells. The peptides’ presence halted cell growth and restricted viral spread, they say. “It is the Neo protein, we propose,” say the authors, “that acts as the effector arm of the immune system by rapidly arresting cell growth and inducing programmed dormancy, thus protecting the larger bacterial population from the spread of phage.” #ScienceMission #sciencenewshighlights https://lnkd.in/g3C_3iSf

Persistent COVID-19 Infection in an Immunocompromised Host: A Case Report Abstract This case report highlights the prolonged SARS-CoV-2 reverse transcriptase polymerase chain reaction positivity in a 32-year-old immunocompromised male with a history of kidney transplants and chronic kidney disease. The whole genome sequencing of nasopharyngeal samples for SARS-CoV-2 collected 12 days apart showed the presence of the BA.1.1 Omicron variant. It revealed evidence of intra-host viral evolution, showing the development and loss of specific mutations over time. This report emphasizes the need for continuous monitoring strategies for immunocompromised patients, as they may serve as reservoirs for viral evolution and potentially give rise to immune escape variants. Click on image in banner below to access entire study, the authors and their reference materials. Posted by Larry Cole @ Covid Impact 360°

Mechanism for Cellular RNA’s Role in Antiviral Immune Response Uncovered https://lnkd.in/gb-rkxQx Scientists from the University of Washington School of Medicine and Duke University have published a study that describes how RNA helps regulate antiviral signaling to help with the immune response to viral infections. The post [...]

Researchers at the University of Würzburg have combined click chemistry with pseudotyped vesicular stomatitis virus (VSV) to produce a highly fluorescent VSV, termed clickVSV. This was achieved by adding a unique chemical handle to the spike protein of SARS-CoV-2, which binds small tetrazine dyes, generating a fluorescent signal. Since clickVSV maintained infectivity after labelling, the process did not interfere with viral entry, allowing visualisation and tracking of cell binding and entry in living cells. Unlike conventional pseudotyped viruses, which carry a reporter gene expressed post-entry, this method expands the potential applications of pseudotyped viruses and enables more studies to be conducted outside high-containment laboratories. https://lnkd.in/exMVu3vc #pseudotyping #virology #Fluorescence  

Link between hepatitis and kidney damage The infected liver cells produce an excess of a viral protein that can bind with other viral proteins to form a viral envelope. Because the virus’s genetic material replicates to a far lesser extent, the vast majority of the envelopes remain empty when they are secreted by the liver cells. This is how they enter the bloodstream, where they are detected by the immune system, which then forms antibodies that stick to the viral proteins. These viral envelope-antibody complexes are then deposited in the filter structures of the kidneys, known as the glomeruli. If the complexes accumulate more quickly than they are removed, they can damage the glomeruli, triggering what is known as glomerulonephritis – a pattern of damage that in the worst case can lead to kidney failure. The researchers discovered this mechanism when they were examining the cause of death of a patient who had received a new kidney years earlier. #ScienceMission #sciencenewshighlights https://lnkd.in/gdEH-4Dt

JEM's July issue is out! https://hubs.la/Q02Djn3C0 Regulation of pulmonary plasma cell responses during secondary infection with influenza virus is largely independent of CD4+ and CD8+ T cells. The image shows a representative image from thick sections of lungs of BAT mice reinfected with influenza and depleted for CD4+ T cells, showing the positioning of alveoli-associated plasma cells (AlvPC) in rechallenged lungs. The mice were genetically engineered and labeled as follows: AID-tdTomato (red), Blimp-1mVenus (yellow), CFP-Flu (light blue), collagen (SH) (purple). From MacLean et al. (https://hubs.la/Q02DjBMP0).

By engineering human cytomegalovirus #HCMV to express single guide #RNAlibraries directly from the viral genome, investigators developed virus-encoded CRISPR-based direct readout screening (#VECOS), a sensitive, versatile, viral-centric approach that enables profiling of different stages of viral infection in a pooled format. https://lnkd.in/gbXEYGas

Single-cell RNA sequencing of peripheral blood links cell-type-specific regulation of splicing to autoimmune and inflammatory diseases This analysis of single-cell RNA sequencing data from peripheral blood mononuclear cells for 474 individuals of diverse Asian ancestries in the Asian Immune Diversity Atlas links cell-type-specific splicing variation with autoimmune and inflammatory disease risk. https://lnkd.in/gy6Q8PTx

A new study from the lab of Bruno Lemaitre finds that Drosophila's Turandot proteins protect against immune self-harm. It's the first identification of proteins that protect against antimicrobial peptides, and it can tell us a lot about cellular resilience mechanisms, with potential therapeutic applications. #immunity #immunesystem #proteins #autoimmunediseases #epfl #drosophila

This research sheds light on the possibility of revitalizing the aging immune system, offering hope for bolstering our defenses against infections and diseases. By targeting stem cells responsible for replenishing crucial blood cells, such as white and red blood cells, researchers have shown how antibodies can revitalize immune responses in aged mice. The findings suggest a potential avenue for enhancing vaccination and combating viral infections in older individuals. Stem cell biology offer promising prospects for future therapeutic interventions. https://lnkd.in/exxPPNaN