Coxiella burnetii infects osteoclasts and alters their differentiation and function in a type IV secretion system-dependent manner

Lai C, Siddique MNAA, Asghar F, Su X, Schulze-Lührmann J, Jia Y, Escarrega EA, Bachmann E, Bozec A, Lang R, Lührmann A, Soulat D (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Frontiers in Immunology Frontiers Research Foundation / Frontiers Media

Book Volume: 16

Article Number: 1724684

DOI: 10.3389/fimmu.2025.1724684

Abstract

Chronic Q fever is caused by persistent infection with the Gram-negative bacterium Coxiella burnetii. The mechanisms underlying this persistence remain elusive, but the presence of the bacteria in the bone marrow of C. burnetii-infected patients has been demonstrated. Therefore, we investigated the potential role of osteoclasts, the bone-resorbing cells, in harboring C. burnetii during infection. The histological analysis of bones from a murine model of Q fever revealed the presence of C. burnetii inside osteoclasts. In vitro infection assays confirmed that osteoclasts can be infected with C. burnetii and supported bacterial replication in a type IVB secretion system (T4BSS)-dependent manner. Wild-type C. burnetii infection inhibited osteoclast differentiation and bone-resorbing activity, while the T4BSS mutant enhanced the differentiation and bone-degrading function of osteoclasts. Taken together, our findings identify osteoclasts as a potential host cell for C. burnetii. This opens new perspectives on the mechanisms that may underlie chronic Q fever as well as questioning the putative consequences on bone biology in chronically affected patients.

Authors with CRIS profile

Chaobo Lai Professur für Experimentelle Immuntherapie Md Nur A Alam Siddique Institute of Microbiology – Clinical Microbiology, Immunology and Hygiene Faiza Asghar Institute of Microbiology – Clinical Microbiology, Immunology and Hygiene Xudong Su Professur für Experimentelle Immuntherapie Jan Schulze-Lührmann Institute of Microbiology – Clinical Microbiology, Immunology and Hygiene Yewei Jia Professur für Experimentelle Immuntherapie Edith Alexandar Escarrega Payan Institute of Microbiology – Clinical Microbiology, Immunology and Hygiene Elke Bachmann Institute of Microbiology – Clinical Microbiology, Immunology and Hygiene Aline Bozec Roland Lang Professur für Angeborene Immunität und Pathogenerkennung Anja Lührmann Institute of Microbiology – Clinical Microbiology, Immunology and Hygiene Didier Soulat Institute of Microbiology – Clinical Microbiology, Immunology and Hygiene

How to cite

APA:

Lai, C., Siddique, M.N.A.A., Asghar, F., Su, X., Schulze-Lührmann, J., Jia, Y.,... Soulat, D. (2026). Coxiella burnetii infects osteoclasts and alters their differentiation and function in a type IV secretion system-dependent manner. Frontiers in Immunology, 16. https://doi.org/10.3389/fimmu.2025.1724684

MLA:

Lai, Chaobo, et al. "Coxiella burnetii infects osteoclasts and alters their differentiation and function in a type IV secretion system-dependent manner." Frontiers in Immunology 16 (2026).

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