Project description:Recently the membrane vesicles (MVs) production has been observed in Gram-positive bacterium, Cutibacterium acnes (C. acnes). In order to explore the mechanism of antibiotic resistance and the virulent components within the C. acnes-derived MVs, we isolated MVs from the clinical C. acnes, which were sensitive or resistant to antibiotics erythromycin and clindamycin. With the LC-MS/MS method, we detected several lipases, virulent factors and cell division protein differentially expressed between the sensitive and the resistant C. acnes-derived MVs.
Project description:Cutibacterium acnes (C. acnes) is a ubiquitous skin commensal bacterium that is generally well tolerated by the immune system. Different strain-types of C. acnes have been reported to be enriched on patients with acne. To understand if these strain-types contribute to skin inflammation, we generated a library of over 200 C. acnes isolates from skin swabs of healthy and acne subjects and assessed their strain-level identity and inflammatory potential. Phylotype II K-type strains were more frequent on healthy and acne non-lesional skin compared to lesional. Phylotype IA-1 C-type strains were dominant on acne lesional skin but absent from healthy. Measurement of host cytokine responses from C. acnes supernatant revealed neither strain-type nor skin-type association predicted inflammatory potential. However, differential proinflammatory responses were induced from identical strain-types, but these differences were not attributable to protease, short chain fatty acid or porphyrin production. Instead, whole genome sequencing revealed the presence of a linear plasmid in high inflammatory strain-types. Intradermal injection of C. acnes in mouse skin revealed a plasmid-associated inflammatory response in dermal fibroblasts, revealed by single-cell RNA sequencing. We conclude that C. acnes strain-type is not sufficient to predict inflammation but other virulence factors including a plasmid may contribute to disease.
Project description:External insults can cause immune activation in immune cells, resulting in persistent molecular changes that can lead to innate immune memory (IIM) changes in these cells. This study investigated the potential for cellular reprogramming in response to Cutibacterium acnes in keratinocytes. We exposed normal human epidermal keratinocytes obtained by mammoplasty (NHEK-B) or abdominoplasty (NHEK-A) to C. acnes, followed by stimulation with Pam3CSK4 to assess immune activation and cellular responses. In NHEK-B cells, C. acnes and Pam3CSK4 treatment induced trained immunity-type responses, with higher expression of selected immune target genes, and a diminished response compared with that in nontrained but Pam3CSK4-induced NHEK-A cells. Total transcriptome analysis delineated regional differences, with the activation of immune-related pathways in NHEK-B cells and increased skin development in NHEK-A cells. We detected differences in metabolic regulation, and utilizing pharmacological inhibitors, we demonstrated the necessity of the optimal regulation of histone acetylation and DNA methylation for the aforementioned changes. This study demonstrated that C. acnes triggers IIM-like processes in keratinocytes, characterized by signaling, epigenetic, and metabolic reprogramming that influences cellular responses to subsequent stimuli. The observation that analogous insults might elicit skin region specific responses offers novel insights into the etiology and mechanisms underlying common inflammatory skin diseases.