Background: Antibodies play a major role in the protection against influenza virus in human. However, the antibody level is usually short-lived and the cellular mechanisms underlying influenza virus-specific antibody response to acute infection remain unclear.
Methods: We studied the kinetics and magnitude of influenza virus-specific B-cell and serum antibody responses in relation to virus replication during the course of influenza infection in healthy adult volunteers who were previously seronegative and experimentally infected with seasonal influenza H1N1 A/Brisbane/59/07 virus.
Results: Our data demonstrated a robust expansion of the virus-specific antibody-secreting cells (ASCs) and memory B cells in the peripheral blood, which correlated with both the throat viral load and the duration of viral shedding. The ASC response was obviously detected on day 7 post-infection when the virus was completely cleared from nasal samples, and serum hemagglutination-inhibition antibodies were still undetectable. On day 28 postinfection, influenza virus-specific B cells were further identified from the circulating compartment of isotype-switched B cells.
Conclusions: Virus-specific ASCs could be the earliest marker of B-cell response to a new flu virus infection, such as H7N9 in humans.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1093/infdis/jit650 | DOI Listing |
Viruses
December 2024
Department of Experimental and Clinical Medicine, University of Florence, Viale Morgagni 48, I-50134 Florence, Italy.
Background: Understanding the interference patterns of respiratory viruses could be important for shedding light on potential strategies to combat these human infectious agents.
Objective: To investigate the possible interactions between adenovirus type 2 (AdV2), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A/H1N1 pandemic (H1N1pdm09) using the A549 cell line.
Methods: Single infections, co-infections, and superinfections (at 3 and 24 h after the first virus infection) were performed by varying the multiplicity of infection (MOI).
Vaccines (Basel)
November 2024
Institute of Experimental Medicine, Saint Petersburg 197022, Russia.
Background/objectives: Influenza viruses and SARS-CoV-2 are currently cocirculating with similar seasonality, and both pathogens are characterized by a high mutational rate which results in reduced vaccine effectiveness and thus requires regular updating of vaccine compositions. Vaccine formulations combining seasonal influenza and SARS-CoV-2 strains can be considered promising and cost-effective tools for protection against both infections.
Methods: We used a licensed seasonal trivalent live attenuated influenza vaccine (3×LAIV) as a basis for the development of a modified 3×LAIV/CoV-2 vaccine, where H1N1 and H3N2 LAIV strains encoded an immunogenic cassette enriched with conserved T-cell epitopes of SARS-CoV-2, whereas a B/Victoria lineage LAIV strain was unmodified.
The risk of severe outcomes of influenza increases during pregnancy. Whether vaccine-induced T cell memory-primed prepregnancy retains the ability to mediate protection during pregnancy, when systemic levels of several hormones with putative immunomodulatory functions are increased, is unknown. Here, using murine adoptive transfer systems and a translationally relevant model of cold-adapted live-attenuated influenza A virus vaccination, we show that preexisting virus-specific memory T cell responses are largely unaltered and highly protective against heterotypic viral challenges during pregnancy.
View Article and Find Full Text PDFMol Ther
December 2024
Center for Inflammation, Immunity & Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA. Electronic address:
BMJ Open Respir Res
December 2024
The Kids Research Institute Australia, Nedlands, Western Australia, Australia.
Introduction: Acute lower respiratory infections (ALRIs) are a major contributor to the global infectious disease burden and a common cause of hospitalisation for children under 2 years. We compared clinical severity in children hospitalised with respiratory syncytial virus (RSV), parainfluenza virus (PIV), human metapneumovirus (hMPV) and influenza virus (IFV).
Methods: We used a probabilistically linked population cohort born in Western Australia between 2010 and 2020 and hospitalised before the age of 2 years.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!