{"doi":"10.3390/ijms24076693","title":"TLR9 Signaling Is Required for the Porphyromonas gingivalis-Induced Activation of IL-10-Expressing B Cells","abstract":"Immune cell pattern-recognition receptors such as Toll-like receptors (TLRs) play important roles in the regulation of host responses to periodontal pathogens. Our previous studies have demonstrated that immune regulatory B cells were activated by TLRs and alleviated periodontitis inflammation and bone loss. The purpose of this study is to determine the role of TLR9 signaling in the activation and IL-10 production of the primed-immune B cells in vitro. Wild-type (WT) and TLR9 knockout (TLR9KO) mice (C57BL/6 background, n = 5) were pre-immunized intraperitoneally with 1 × 108 formalin-fixed P. gingivalis and boosted once with 1 × 107 formalin-fixed P. gingivalis. Isolated splenocytes and purified B cells from each mouse were cultured with 1 × 108 formalin-fixed P. gingivalis for 48 h. Immunocytochemistry was performed to detect CD45+ IL-10+ cells. Levels of IL-10 expression and secretion in splenocytes and B cells were detected using qRT-PCR and ELISA, respectively. After stimulation with fixed P. gingivalis, the percentage of CD45+ IL-10+ B cells and the level of IL-10 expression were significantly increased (p < 0.01) in splenocytes and purified B cells isolated from WT mice. However, these changes were not observed in splenocytes and purified B cells from TLR9KO mice when the cells were treated with fixed P. gingivalis. The percentage of CD45+ IL-10+ B cells was significantly reduced in splenocytes and purified B cells from TLR9KO mice compared to those from WT mice when challenged with P. gingivalis. IL-10 expression in B cells from TLR9KO mice was significantly decreased compared to those from WT mice at both the mRNA and protein levels. Additionally, P. gingivalis-induced up-regulation of TNF-α mRNA expressions were consistently observed in B cells from both WT and TLR9KO mice. P. gingivalis-induced B10 activation and IL-10 production during adaptive responses by primed B cells requires TLR9 signaling and can be achieved independent of T-cell help.","journal":"International Journal of Molecular Sciences","year":2023,"id":370950,"datarank":0.31191623125197543,"base_score":2.0794415416798357,"endowment":2.0794415416798357,"self_citation_contribution":0.31191623125197543,"citation_network_contribution":0.0,"self_endowment_contribution":0.31191623125197543,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":7,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.953,"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":640109,"name":"Yang Hu","orcid":"0000-0002-4508-5365","position":1,"is_corresponding":false},{"id":807526,"name":"Shengyuan Huang","orcid":null,"position":2,"is_corresponding":false},{"id":982291,"name":"Sunniva Ruiz","orcid":"0000-0002-8218-5410","position":3,"is_corresponding":false},{"id":303716,"name":"Toshihisa Kawai","orcid":"0000-0003-3310-3818","position":4,"is_corresponding":false},{"id":415918,"name":"Xiaozhe Han","orcid":"0000-0001-8357-1471","position":5,"is_corresponding":false},{"id":1130628,"name":"Ali Alaqla","orcid":null,"position":0,"is_corresponding":true}],"reference_count":50,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-19T01:15:41.237096Z","pmid":"37047666","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":[]}