Publications by authors named "Amy Kempf"

The naturally occurring mutation E484D in the spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can render viral entry ACE2 independent and imdevimab resistant. Here, we investigated whether the cellular proteins ASGR1, DC-SIGN, and TMEM106B, which interact with the viral S protein, can contribute to these processes. Employing S protein-pseudotyped particles, we found that expression of ASGR1 or DC-SIGN jointly with TMEM106B allowed for robust entry of mutant E484D into otherwise non-susceptible cells, while this effect was not observed upon separate expression of the single proteins and upon infection with SARS-CoV-2 wild type (WT).

View Article and Find Full Text PDF

Background/objectives: The efficacy of monovalent BNT162b2 Omicron XBB.1.5 booster vaccination in liver transplant recipients (LTRs) has yet to be described, particularly regarding the immune response to emerging variants like JN.

View Article and Find Full Text PDF

New SARS-CoV-2 lineages continue to evolve and may exhibit new characteristics regarding host cell entry efficiency and potential for antibody evasion. Here, employing pseudotyped particles, we compared the host cell entry efficiency, ACE2 receptor usage, and sensitivity to antibody-mediated neutralization of four emerging SARS-CoV-2 lineages, KP.2, KP.

View Article and Find Full Text PDF
Article Synopsis
  • Human-to-human transmission of MERS-CoV is inefficient, but there are worries it could mutate and become more transmissible.
  • A study examined if enhancing the S1/S2 cleavage site of the MERS-CoV spike protein could improve its entry into human lung cells, similar to SARS-CoV-2.
  • Results showed that changes to the cleavage site did not increase MERS-CoV's ability to infect lung cells, indicating it might not have the same transmission potential as SARS-CoV-2.
View Article and Find Full Text PDF

Multivalent lectin-glycan interactions (MLGIs) are widespread and vital for biology, making them attractive therapeutic targets. Unfortunately, the structural and biophysical mechanisms of several key MLGIs remain poorly understood, limiting our ability to design spatially matched glycoconjugates as potential therapeutics against specific MLGIs. We have recently demonstrated that natural oligomannose-coated nanoparticles are powerful probes for MLGIs.

View Article and Find Full Text PDF
Article Synopsis
  • Multivalent lectin-glycan interactions (MLGIs) play a key role in viral infections and immune response, making understanding their structure essential for developing new therapies.
  • Researchers have created glycosylated nanoparticles, specifically gold nanoparticles (GNPs), to study MLGIs and have established a method to assess their binding affinities and structural characteristics.
  • Findings indicate that larger GNPs enhance MLGI affinity and antiviral effectiveness, particularly a 27 nm GNP that significantly inhibits viral connections to the DC-SIGN receptors.
View Article and Find Full Text PDF

Transmissibility and immune evasion of the recently emerged, highly mutated SARS-CoV-2 BA.2.87.

View Article and Find Full Text PDF

SARS-CoV-2 mainly infects the respiratory tract but can also target other organs, including the central nervous system. While it was recently shown that cells of the blood-brain-barrier are permissive to SARS-CoV-2 infection in vitro, it remains debated whether neurons can be infected. In this study, we demonstrate that vesicular stomatitis virus particles pseudotyped with the spike protein of SARS-CoV-2 variants WT, Alpha, Delta and Omicron enter the neuronal model cell line SH-SY5Y.

View Article and Find Full Text PDF

BA.2.86, a recently identified descendant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron BA.

View Article and Find Full Text PDF

Mutations in spike (S) protein epitopes allow SARS-CoV-2 variants to evade antibody responses induced by infection and/or vaccination. In contrast, mutations in glycosylation sites across SARS-CoV-2 variants are very rare, making glycans a potential robust target for developing antivirals. However, this target has not been adequately exploited for SARS-CoV-2, mostly due to intrinsically weak monovalent protein-glycan interactions.

View Article and Find Full Text PDF

The SARS-CoV-2 Omicron subvariants BA.1 and BA.2 exhibit reduced lung cell infection relative to previously circulating SARS-CoV-2 variants, which may account for their reduced pathogenicity.

View Article and Find Full Text PDF

The COVID-19 pandemic remains a global health threat and novel antiviral strategies are urgently needed. SARS-CoV-2 employs the cellular serine protease TMPRSS2 for entry into lung cells, and TMPRSS2 inhibitors are being developed for COVID-19 therapy. However, the SARS-CoV-2 Omicron variant, which currently dominates the pandemic, prefers the endo/lysosomal cysteine protease cathepsin L over TMPRSS2 for cell entry, raising doubts as to whether TMPRSS2 inhibitors would be suitable for the treatment of patients infected with the Omicron variant.

View Article and Find Full Text PDF

Recently, a recombinant SARS-CoV-2 lineage, XD, emerged that harbors a spike gene that is largely derived from the Omicron variant BA.1 in the genetic background of the Delta variant. This finding raised concerns that the recombinant virus might exhibit altered biological properties as compared to the parental viruses and might pose an elevated threat to human health.

View Article and Find Full Text PDF

The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) facilitates viral entry into host cells and is the key target for neutralizing antibodies. The SARS-CoV-2 lineage B.1.

View Article and Find Full Text PDF

Synopsis of recent research by authors named "Amy Kempf"

  • - Amy Kempf's research primarily focuses on the viral mechanisms and immune responses related to coronaviruses, particularly SARS-CoV-2 and its variants, as well as MERS-CoV, examining how mutations may influence viral entry and transmissibility in human cells.
  • - Recent studies explored the structural and biophysical interactions of multivalent lectin-glycan systems, highlighting their potential as therapeutic targets against viral infections, demonstrating the significance of glycan display on nanoparticle interactions and antiviral properties.
  • - Additionally, Kempf's work investigates the immune responses generated by specific COVID-19 vaccinations, assessing their effectiveness against emerging variants, thus contributing valuable insights into vaccine efficacy and public health strategies.

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessiond5o0sic581f24qrop9qlpk3iot2sbc3p): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once