{"doi":"10.3389/fimmu.2023.1243164","title":"Pre-existing CD4 T cell help boosts antibody responses but has limited impact on germinal center, antigen-specific B cell frequencies after influenza infection","abstract":"The influenza virus is a persistent burden on global health, with seasonal vaccines providing incomplete protection. CD4 + T cells help shape B cell and antibody responses; however, the selectivity of help and the effect on various antigen-specific B cell populations have not been fully elucidated. Here, we studied the specificity, selectivity, and influence of nucleoprotein (NP) CD4 + T cells on the magnitude and quality of hemagglutinin (HA) and NP-specific B cells and antibody responses. We identified immunodominant peptides and showed that peptide immunization was sufficient to induce CD4 + cells with Th1 and Tfh phenotypes. Surprisingly, while preexisting CD4 + T cells enhanced the influx of total germinal center (GC) B cells in the mediastinal lymph node after infection, this was not reflected by an increase in the frequency of antigen-specific cells within the GC. Furthermore, we demonstrated that NP-specific help was able to accelerate the kinetics and magnitude of the Ab response for NP but not for HA. Overall, our results showed that pre-existing CD4 + T cells provide strong cognate help during immunization or infection to enhance Ab production but not antigen-specific GC or memory B cells.","journal":"Frontiers in Immunology","year":2023,"id":356345,"datarank":0.2565591281858937,"base_score":1.6094379124341003,"endowment":1.6094379124341003,"self_citation_contribution":0.24141568686511508,"citation_network_contribution":0.01514344132077864,"self_endowment_contribution":0.24141568686511508,"citer_contribution":0.01514344132077864,"corpus_percentile":null,"corpus_rank":null,"citation_count":4,"citer_count":2,"citers_with_citation_signal":2,"citers_with_endowment":2,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9516,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1105491,"name":"Laura Reusch","orcid":null,"position":1,"is_corresponding":false},{"id":1105492,"name":"Josue Enriquez","orcid":null,"position":2,"is_corresponding":false},{"id":481154,"name":"Karin Schön","orcid":"0009-0008-3613-5819","position":3,"is_corresponding":false},{"id":325928,"name":"Davide Angeletti","orcid":"0000-0002-5256-1972","position":4,"is_corresponding":false},{"id":1105490,"name":"Danica F. Besavilla","orcid":null,"position":0,"is_corresponding":true}],"reference_count":43,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-19T01:13:25.429924Z","pmid":"37711622","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}