{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Næss LM"],"funding":["Norwegian Institute of Public Health","ConserV Bioscience Ltd.","James Cook University"],"pagination":["1084"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC12656455"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["13(11)"],"pubmed_abstract":["<b>Background/Objectives:</b> FLU-v is a peptide-based broad-spectrum influenza vaccine proven to induce humoral and cellular immune responses in humans. In this study, FLU-v-specific IgG1 and IgG3 subclass antibodies, induced by adjuvanted or non-adjuvanted FLU-v vaccination in healthy adults participating in a phase II clinical study, were quantitated. The ability of these antibodies to induce NK cell activation was investigated. <b>Methods:</b> An ELISA was developed to quantify FLU-v-specific IgG1 and IgG3 antibodies in serum. A flowcytometric assay based on an NK cell line was used to evaluate NK cell activation by expression of degranulation marker CD107a. <b>Results:</b> In the adjuvanted FLU-v group, IgG1 and IgG3 seroconversion on day 42 was 88.5% and 86.5% compared to 53.4% and 29.3% in the non-adjuvanted FLU-v group, which was significantly different from the respective placebo groups (0-6.3%). Adjuvanted FLU-v vaccination induced a raise in median IgG1 and IgG3 levels from 435 and 167 ng/mL pre vaccination to 4422 and 2020 ng/mL 42 days post vaccination, representing a fold increase of 16.3 for IgG1 and 11.6 for IgG3, which was sustained on day 180 post vaccination (10.4-fold and 5.0-fold, respectively). Non-adjuvanted vaccination induced a more modest increase in IgG1 and IgG3 from 655 and 206 ng/mL pre vaccination to 1808 and 264 ng/mL 42 days post vaccination. A correlation between levels of FLU-v-specific IgG, IgG1, or IgG3 and their ability to induce NK cell activation was demonstrated. <b>Conclusions:</b> A single dose of adjuvanted FLU-v induced high levels of long-lasting antigen-specific IgG1 and IgG3 antibodies with NK cell-mediated effector functions relevant to protection against influenza disease."],"journal":["Vaccines"],"pubmed_title":["FLU-v, a Broad-Spectrum Peptide-Based Influenza Vaccine, Induces NK Cell Activating IgG1 and IgG3 Subclass Antibodies in Humans."],"pmcid":["PMC12656455"],"funding_grant_id":["Not applicable"],"pubmed_authors":["Næss LM","Laake I","Vanderven H","Oftung F","Pleguezuelos O","Bryant-Bratlie D"],"additional_accession":[]},"is_claimable":false,"name":"FLU-v, a Broad-Spectrum Peptide-Based Influenza Vaccine, Induces NK Cell Activating IgG1 and IgG3 Subclass Antibodies in Humans.","description":"<b>Background/Objectives:</b> FLU-v is a peptide-based broad-spectrum influenza vaccine proven to induce humoral and cellular immune responses in humans. In this study, FLU-v-specific IgG1 and IgG3 subclass antibodies, induced by adjuvanted or non-adjuvanted FLU-v vaccination in healthy adults participating in a phase II clinical study, were quantitated. The ability of these antibodies to induce NK cell activation was investigated. <b>Methods:</b> An ELISA was developed to quantify FLU-v-specific IgG1 and IgG3 antibodies in serum. A flowcytometric assay based on an NK cell line was used to evaluate NK cell activation by expression of degranulation marker CD107a. <b>Results:</b> In the adjuvanted FLU-v group, IgG1 and IgG3 seroconversion on day 42 was 88.5% and 86.5% compared to 53.4% and 29.3% in the non-adjuvanted FLU-v group, which was significantly different from the respective placebo groups (0-6.3%). Adjuvanted FLU-v vaccination induced a raise in median IgG1 and IgG3 levels from 435 and 167 ng/mL pre vaccination to 4422 and 2020 ng/mL 42 days post vaccination, representing a fold increase of 16.3 for IgG1 and 11.6 for IgG3, which was sustained on day 180 post vaccination (10.4-fold and 5.0-fold, respectively). Non-adjuvanted vaccination induced a more modest increase in IgG1 and IgG3 from 655 and 206 ng/mL pre vaccination to 1808 and 264 ng/mL 42 days post vaccination. A correlation between levels of FLU-v-specific IgG, IgG1, or IgG3 and their ability to induce NK cell activation was demonstrated. <b>Conclusions:</b> A single dose of adjuvanted FLU-v induced high levels of long-lasting antigen-specific IgG1 and IgG3 antibodies with NK cell-mediated effector functions relevant to protection against influenza disease.","dates":{"release":"2025-01-01T00:00:00Z","publication":"2025 Oct","modification":"2026-05-20T03:18:03.702Z","creation":"2026-05-20T03:13:22.512Z"},"accession":"S-EPMC12656455","cross_references":{"pubmed":["41295457"],"doi":["10.3390/vaccines13111084"]}}