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:The pathogenesis of acne vulgaris is multifactorial and is influenced by the presence of Cutibacterium acnes. This study investigated how different strains of C. acnes, associated with either healthy skin (CH) or acne-prone skin (CA), selectively modulate the function of three dendritic cell (DC) subtypes: Langerhans cell-derived (LCDC), monocyte-derived (moDCs), and myeloid (mDCs). Our findings revealed that all DC subtypes secreted varying levels of TGF-β, IL-1β, IL-6, IL-12p70, and IL-23 in response to C. acnes stimulation. Notably, moDCs exhibited the highest cytokine secretion in response to CA-ribotypes, indicating their potent immune responsiveness. Conversely, LCDCs were the least responsive, regardless of the ribotypes. Principal component (PCA) and gene ontology (GO) analysis of bulk RNA sequencing data of DCs exposed to C. acnes identified extensive transcriptional changes, particularly in immune response pathways. moDCs showed the most pronounced transcriptional changes, aligning with their high cytokine secretion levels. Additionally, we identified specific genes upregulated by CA-ribotypes, with notable differences among the DC types, highlighting the unique contributions of each DC subtype to the skin's immune defense mechanisms against C. acnes. Overall, our study underscores the complexity of DC responses in the skin's immune environment and provides valuable insights into their roles in acne.
Project description:TRPV3 is highly expressed in human skin and is involved in the development of inflammatory dermatoses. However, it remains unclear whether TRPV3 influences inflammation in human sebaceous glands and its role in the pathogenesis of acne. Here, we showed that TRPV3 expression was increased in the sebaceous glands of facial acne lesions and acne-like mice. TRPV3 increased the secretion of pro-inflammatory cytokines and chemokines in human SZ95 sebocytes, as well as the chemotaxis of neutrophils, which were the major immune cells found in acne lesions. We demonstrated that P.acnes promoted TRPV3 expression through regulating lipid profile especially upregulated arachidonic acid levels in human sebocytes. TRPV3 further upregulated TLR2 expression by promoting transcriptional factor p-FOSL1 expression and its binding to the TLR2 promoter, leading to downstream NF-κB signaling activation. Importantly, either genetic silencing or pharmacological inhibition of TRPV3 alleviated acne-like inflammation in mice, showing reduced acne-characteristic cytokines and chemokines production and neutrophil infiltration by inhibiting the TLR2-NF-κB axis. Thus, our study revealed the critical role of TRPV3 in sebocytes inflammation, which was involved in the development of acne, indicating that TRPV3 is a potential therapeutic target for acne and other disorders of the pilosebaceous unit.
Project description:Staphylococcus epidermidis (S. epidermidis) ATCC 12228 was incubated with 2% polyethylene glycol (PEG)-8 Laurate to yield electricity which was measured by a voltage difference between electrodes. Production of electron was validated by a Ferrozine assay. The anti-Cutibacterium acnes (C. acnes) activity of electrogenic S. epidermidis was assessed in vitro and in vivo. The voltage change (~ 4.4 mV) reached a peak 60 min after pipetting S. epidermidis plus 2% PEG-8 Laurate onto anodes. The electricity produced by S. epidermidis caused significant growth attenuation and cell lysis of C. acnes. Intradermal injection of C. acnes and S. epidermidis plus PEG-8 Laurate into the mouse ear considerably suppressed the growth of C. acnes. This suppressive effect was noticeably reversed when cyclophilin A of S. epidermidis was inhibited, indicating the essential role of cyclophilin A in electricity production of S. epidermidis against C. acnes. In summary, we demonstrate for the first time that skin S. epidermidis, in the presence of PEG-8 Laurate, can mediate cyclophilin A to elicit an electrical current that has anti-C. acnes effects. Electricity generated by S. epidermidis may confer immediate innate immunity in acne lesions to rein in the overgrowth of C. acnes at the onset of acne vulgaris.
Project description:Cutibacterium acnes is an opportunistic pathogen involved in Bone and Prosthesis Infections (BPIs). In this study, we observed the behavior of commensal and BPI C. acnes strains in the bone environment through bacterial internalization by osteoblast-like cells and biofilm formation. For the commensal strains, less than 1% of the bacteria were internalized; among them, about 32.7 ± 3.9% persisted intracellularly for up to 48 h. C. acnes infection seems to have no cytotoxic effect on bone cells as detected by LDH assay. Interestingly, commensal C. acnes showed a significant increase in biofilm formation after osteoblast-like internalization for 50% of the strains (2.8-fold increase). This phenomenon is exacerbated on a titanium support, a material used for medical devices. For the BPI clinical strains, we did not notice any increase in biofilm formation after internalization despite a similar internalization rate by the osteoblast-like cells. Furthermore, fluorescent staining revealed more live bacteria within the biofilm after osteoblast-like cell interaction, for all strains (BPIs and commensal). The genomic study did not reveal any link between their clinical origin and phylotype. In conclusion, we have shown for the first time the possible influence of internalization by osteoblast-like cells on commensal C. acnes.
Project description:Recently, the role of infection of the intervertebral disc (IVD) with Cutibacterium acnes (C. acnes) as a contributor to disc-related low back pain (LBP) has been discussed. The aim of this study was to investigate whether and how C. acnes contributes to the inflammatory processes during IVD disease. The prevalence of C. acnes infection in human IVD tissue was determined by aerobic and anaerobic culture. Thereafter, primary human IVD cells were infected with a reference and a clinical C. acnes strain and analyzed for pro-inflammatory markers (gene/protein level). In a subsequent experiment, the involvement of the Toll-like receptor (TLR) pathway was investigated by co-treatment with sparstolonin B, a TLR2/4 inhibitor. We detected C. acnes in 10% of IVD biopsies (with either herniation or degeneration). Stimulating IVD cells with both C. acnes strains strongly and significantly upregulated expression of Interleukin (IL)-1β, IL-6, IL-8, and inducible nitric oxide synthase (iNOS). IL-6, cyclooxygenase (COX)-2, and iNOS expression was reduced upon TLR2/4 inhibition in 3 out of 5 donors, whereby responders and non-responders could not be differentiated by their basal TLR2 or TLR4 expression levels. We demonstrate that exposure of IVD cells to C. acnes induces an inflammatory response that may contribute to the development of discogenic LBP by involving TLR2/4 activation, yet only in a subgroup of patients. Whether the same response will be observed in vivo and where lower inoculums are present remains to be proven in future studies.
Project description:Cutibacterium acnes (C. acnes) is a gram-positive bacterium and a member of the human skin microbiome. Despite being the most abundant skin commensal, certain members have been associated with common inflammatory disorders such as acne vulgaris. The availability of the complete genome sequences from various C. acnes clades have enabled the identification of putative methyltransferases, some of them potentially belonging to restriction-modification (R-M) systems which protect the host of invading DNA. However, little is known on whether these systems are functional in the different C. acnes strains. To investigate the activity of these putative R-M and their relevance in host protective mechanisms, we analyzed the methylome of six representative C. acnes strains by Oxford Nanopore Technologies (ONT) sequencing. We detected the presence of a 6-methyladenine modification at a defined DNA consensus sequence in strain KPA171202 and recombinant expression of this R-M system confirmed its methylation activity. Additionally, a R-M knockout mutant verified the loss of methylation properties of the strain. We studied the potential of one C. acnes bacteriophage (PAD20) in killing various C. acnes strains and linked an increase in its specificity to phage DNA methylation acquired upon infection of a methylation competent strain. We demonstrate a therapeutic application of this mechanism where phages propagated in R-M deficient strains selectively kill R-M deficient acne-prone clades while probiotic ones remain resistant to phage infection.
Project description:Cutibacterium acnes is a human skin-resident bacterium. Although C. acnes maintains skin health by inhibiting invasion from pathogens like Staphylococcus aureus, it also contributes to several diseases, including acne. Studies suggest that differences in genetic background may explain the diverse phenotypes of C. acnes strains. In this study, we investigated the effects of C. acnes strains on the Caenorhabditis elegans life span and observed that some strains shortened the life span, whereas other strains, such as strain HL110PA4, did not alter it. Next, we assessed the effects of C. acnes HL110PA4 on host resistance against S. aureus. The survival time of C. acnes HL110PA4-fed wild-type animals was significantly longer than that of Escherichia coli OP50 control bacterium-fed worms upon infection with S. aureus. Although the survival times of worms harboring mutations at the daf-16/FoxO and skn-1/Nrf2 loci were similar to those of wild-type worms after S. aureus infection, administration of C. acnes failed to improve survival times of tir-1/SARM1, nsy-1/mitogen-activated protein kinase kinase kinase (MAPKKK), sek-1/mitogen-activated protein kinase kinase (MAPKK), and pmk-1/p38 mitogen-activated protein kinase (MAPK) mutants. These results suggest that the TIR-1 and p38 MAPK pathways are involved in conferring host resistance against S. aureus in a C. acnes-mediated manner. IMPORTANCE Cutibacterium acnes is one of the most common bacterial species residing on the human skin. Although the pathogenic properties of C. acnes, such as its association with acne vulgaris, have been widely described, its beneficial aspects have not been well characterized. Our study classifies C. acnes strains based on its pathogenic potential toward the model host C. elegans and reveals that the life span of C. elegans worms fed on C. acnes was consistent with the clinical association of C. acnes ribotypes with acne or nonacne. Furthermore, nonpathogenic C. acnes confers host resistance against the opportunistic pathogen Staphylococcus aureus. Our study provides insights into the impact of C. acnes on the host immune system and its potential roles in the ecosystem of skin microbiota.