Surface exposure of antigens on bacterial cells can be critical for eliciting an effective antibody response. Therefore, we investigated the cellular localization of the fimbrial F17a-G receptor-binding domain, fused to the translocator domain of the AIDA-I autotransporter. Synthesis of the fusion protein, under the control of the L-arabinose-inducible PBAD promoter, was shown to permeabilize Escherichia coli K-12 and Salmonella enterica serovar Typhimurium cells. The presence of permeable cells interfered with several methods that are typically used to determine surface exposure of proteins, such as protease treatment and whole-cell ELISA. Double immunofluorescence microscopy, using a second antibody directed against beta-galactosidase, a bacterial protein expressed in the cytoplasm, allowed the simultaneous detection of antigen expression and permeability in individual cells.
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http://dx.doi.org/10.1099/mic.0.022327-0 | DOI Listing |
Adv Biotechnol (Singap)
February 2024
CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200030, China.
Pichia pastoris is a popular yeast host for high-level heterologous expression of proteins on an industrial scale owing to its reliable expression, robust growth, high fermentation density, and easy genetic manipulation and cultivation at a relatively low cost. Of particular interest is its high secretion efficiency for small proteins including insulin, human serum albumin, vaccines, enzymes, and llama-derived heavy-chain only antibodies (nanobodies) for pharmaceutical and research applications. However, a recurring challenge in using P.
View Article and Find Full Text PDFJ Control Release
January 2025
Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China. Electronic address:
Adeno-associated viruses (AAV) have significant potential as vaccine carriers due to their excellent biosafety and efficient antigen gene delivery. However, most AAV vaccines show limited capacity to transduce antigen-presenting cells (APCs) following intramuscular injection which may cause inadequate cellular immune responses and undesired side effects due to transducing other tissues or cells. Herein, we developed a soluble microneedle patch for targeting the AAV vaccines to the epidermal and dermal APCs.
View Article and Find Full Text PDFInfluenza Other Respir Viruses
January 2025
Área de Investigación en Vacunas, Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana, Valencia, Spain.
SARS-CoV-2, which originated in China in late 2019, quickly fueled the global COVID-19 pandemic, profoundly impacting health and the economy worldwide. A series of vaccines, mostly based on the full SARS-CoV-2 Spike protein, were rapidly developed, showing excellent humoral and cellular responses and high efficacy against both symptomatic infection and severe disease. However, viral evolution and the waning humoral neutralizing responses strongly challenged vaccine long term effectiveness, mainly against symptomatic infection, making necessary a strategy of repeated and updated booster shots.
View Article and Find Full Text PDFPept Sci (Hoboken)
November 2024
Department of Pediatrics, Section of Hematology/Oncology, The University of Chicago, Chicago, Illinois 60637, United States of America.
The COVID-19 pandemic drove a uniquely fervent pursuit to explore the potential of peptide, antibody, protein, and small-molecule based antiviral agents against severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). The interaction between the SARS-CoV2 spike protein with the angiotensin-converting enzyme 2 (ACE2) receptor that mediates viral cell entry was a particularly interesting target given its well described protein-protein interaction (PPI). This PPI is mediated by an α-helical portion of ACE2 binding to the receptor binding domain (RBD) of the spike protein and thought to be susceptible to blockade through molecular mimicry.
View Article and Find Full Text PDFCOVID-19 vaccination is the most effective strategy for preventing severe disease and death. Inactivated vaccines are the most accessible type of COVID-19 vaccines in developing countries. Several studies, including work from our group, have demonstrated that the third dose (booster vaccination) of inactivated COVID-19 vaccine induces robust humoral and cellular immune responses.
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