Biology subjects

Hasturk, H.

Publications and source records attributed to Hasturk, H..

7 recordsLinked to original sources

bioRxiv2026

Clonally Convergent Tph/Tfh-like CD4+ T Cells are Shared Across Recovery and Recurrence in Experimental Periodontitis

Periodontitis is a chronic inflammatory disease of the tooth-supporting structures (periodontium) that requires life-long maintenance to prevent progression. Using a sensitized model of recurrent periodontitis in mice (SeRPD), in which regulatory breakdown was induced by temporary Treg depletion concurrent with disease, we mapped the gingival T cell imprint across each disease phase. Transient regulatory breakdown left a durable mucosal imprint after clinical recovery, characterized by enrichment of local and regional CD4 T cells. Paired single-cell RNA and TCR sequencing of gingival immune cells identified a convergent clonotype expanded from recovery into recurrence that carried a Tfh/Tph-like transcriptional identity. An analogous CD4 T cell population was detected in human periodontitis lesions by single-cell transcriptomics. Together, these findings support a paradigm in which clinical recovery does not ensure a local T cell repertoire reset; instead, a reservoir of antigen-experienced, tissue-adapted CD4 T cells persist in the mucosa and participate in recurrence.

immunology↗

bioRxiv2026

Profiling Gingival Inflammation in a 3D Oral Tissue Model Reveals Early Features of Disease Progression

Gingival health depends on a balanced interplay among the gingival epithelium, immune system, and oral microbiome. Disruption of this equilibrium through sustained biofilm accumulation and host inflammatory responses leads to gingivitis, a highly prevalent yet reversible condition which if left untreated could progress into more severe and irreversible condition called periodontitis. The early onset of gingivitis remains poorly defined due to subtle clinical presentation and pronounced interindividual variability. Current diagnostic approaches rely largely on clinical assessment and endpoint biomarkers, limiting insight into the early host-microbiome interactions that drive disease initiation. Here, we employ a previously validated, physiologically relevant oral tissue model (OTM) to longitudinally investigate epithelial-microbiome interactions following inoculation with patient-derived dysbiotic microbiomes from early-stage gingivitis. The OTM maintained host tissue integrity and microbial viability over a seven-day period, preserving epithelial barrier function, dynamic inflammatory responses, and disease-associated microbial signatures. Notably, we establish, for the first time in an in vitro platform, clinical calibration against gingival crevicular fluid (GCF), demonstrating that OTM responses recapitulate inoculum-dependent inflammatory signatures, increased microbial dissimilarity under dysbiotic conditions, and coordinated host-microbiome metabolic interactions. While pro-inflammatory responses were most pronounced at early time points, subsequent modulation toward anti-inflammatory states highlights the temporal complexity of host responses and suggests that longer culture durations may further resolve disease trajectories. Collectively, these findings validate the OTM as a robust, physiologically relevant platform that captures key features of periodontal health and inflammation. By integrating host viability, microbial ecology, and clinical benchmarking, this system enables mechanistic interrogation of early disease-driving processes and provides a translational framework for advancing predictive diagnostics and preventive therapeutic strategies in periodontal disease.

microbiology↗

bioRxiv2026

Estrogen Deprivation and Periodontitis Interact Across Multiple Tissues

The study investigated the interaction between estrogen deprivation and periodontitis, systemically, in the bone marrow, and locally in periodontal tissues using a mouse model. MethodsWe used the ligature-induced periodontitis (LIP) model concurrently with ovariectomy-induced estrogen deprivation. Bone marrow was assessed for myeloid cell proportion by flow cytometry. The femur metaphysis was examined histologically and by micro-CT. Cytokine responses of CD11b+ myeloid cells to lipopolysaccharide stimulation were investigated ex vivo across ovary-intact (Sham), ovariectomized (OVX), and estrogen-replaced (OVX+E2) mice with or without periodontitis. Estrogen-related alterations in periodontitis, including microbiome composition and transcriptomic changes in the gingiva and dentoalveolar complex, were investigated by 16S rRNA sequencing and bulk RNA sequencing, respectively. ResultsOvariectomy increased osteoblast-like and adipocyte-like cell numbers in femoral marrow, whereas LIP reduced both populations (p = 0.020 and p = 0.029, respectively). LIP increased the bone marrow CD45+ hematopoietic fraction in Sham mice. LPS-stimulated bone marrow CD11b+ cells from OVX mice showed lower Tnf, Ccl2, and Il10 expression than Sham mice (p = 0.003, p = 0.005, and p = 0.001, respectively). OVX exacerbated LIP-associated alveolar bone loss, reducing BV/TV (p = 0.003) and increasing osteoclast numbers (p = 0.012). Neither OVX nor E2 replacement significantly altered ligature-associated microbial composition in 16S rRNA sequencing. Bulk RNA sequencing demonstrated estrogen-responsive transcriptomic changes in both the gingiva and dentoalveolar complex, including OVX-associated gene-expression changes that returned toward Sham levels in OVX+E2 mice. These included genes related to stromal regulation (Acan, Igfbp3, Erbb3) and immunity (Gp2, Spib, B2m). ConclusionPeriodontitis and estrogen deprivation exert combined effects on the bone marrow niche. Estrogen deprivation modulates immune- and healing-related gene expression in the gingiva and remaining dentoalveolar tissues during periodontitis.

immunology↗

bioRxiv2026

Capsular K-antigen Coats Outer Membrane Vesicles of Porphyromonas gingivalis

Periodontal disease is an inflammatory disorder that arises from dysbiosis of the subgingival microbiota, with Porphyromonas gingivalis acting as a keystone pathogen in the shift from health to disease. P. gingivalis employs multiple strategies to subvert host immune defenses, and its capsular K-antigen serves as a key virulence determinant. Here, a pre-adsorbed antiserum (pAds106) was generated by removing nonspecific antibodies using cells from a K-antigen-null mutant (W83{Delta}PG0106), resulting in exceptional specificity for the P. gingivalis K1-antigen. Immunofluorescence analysis revealed that the K-antigen preferentially coats outer membrane vesicles (OMVs), rather than attaching to the bacterial cell surface. This localization was further confirmed by ELISAs of density gradient ultracentrifuge-purified OMVs, with background signal detected in OMVs derived from K-antigen-deficient strains, non-K1-strains, and other oral Bacteroidetes. K-antigen-coated OMVs exhibited higher hydrophilicity and elicited weaker inflammatory responses compared to K-antigen-deficient OMVs, consistent with previously reported properties of encapsulated strains. Importantly, the antiserum detected K-antigen-coated OMVs in subgingival plaque from periodontal patients, suggesting that K-antigen is actively produced at diseased sites. These findings revise the prevailing view that K-antigen solely encapsulates the bacterial cell body and suggest that K-antigen-coated OMVs produced by P. gingivalis play distinct roles in immune evasion during periodontal disease.

microbiology↗

bioRxiv2024

Sustaining healthy long-term host-microbiome interactions in a physiologically relevant dynamic gingival tissue model

Host-oral microbiome interactions are known to be critical in maintaining local and systemic health of the human body, although they are difficult to study in both clinical and in vitro applications. Despite efforts, recapitulation of gingival architecture and physiological characteristics of the periodontal niche cannot be achieved by traditional tissue engineering strategies. Here, we advanced our humanized three-dimensional gingival model by co-culturing it with a healthy patient-derived microbiomes for seven days within an oral bioreactor that mimics native salivary dynamics. Our results indicated long-term host and microbiome viability, host barrier integrity and physiological response, and preservation of healthy microbial populations and interbacterial dialogues. The model has proven useful in successfully mimicking tissue homeostasis at the interface of the periodontal niche and suitable for the introduction of immune cells. Future studies will focus on using the model as a comparator of periodontal inflammation and identifying biomarkers associated with eubiotic/dysbiotic profiles. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=137 SRC="FIGDIR/small/577629v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@1bc808aorg.highwire.dtl.DTLVardef@9b0ef8org.highwire.dtl.DTLVardef@1f3fbb1org.highwire.dtl.DTLVardef@11135f5_HPS_FORMAT_FIGEXP M_FIG Created partially in biorender.com. C_FIG

bioengineering↗

bioRxiv2023

Persistent enrichment of multidrug resistant Klebsiella in oral and nasal communities during long-term starvation

The human oral and nasal cavities can act as reservoirs for opportunistic pathogens capable of causing acute infection. These microbes asymptomatically colonize the human oral and nasal cavities which facilitates transmission within human populations via the environment, and they routinely possess a clinically-significant antibiotic-resistance genes. Among these opportunistic pathogens, the Klebsiella genus stands out as a notable example, with its members frequently linked to nosocomial infections and multidrug resistance. As with many colonizing opportunistic pathogens, how Klebsiella transitions from an asymptomatic colonizer to a pathogen remains unclear. Here, we explored a possible explanation by investigating the ability of oral and nasal Klebsiella to outcompete their native microbial community members under in vitro starvation conditions, which could be analogous to external hospital environments. When Klebsiella was present within a healthy human oral or nasal sample, the bacterial community composition shifted dramatically under starvation conditions and typically became dominated by Klebsiella. Furthermore, introducing K. pneumoniae exogenously into a native microbial community lacking K. pneumoniae, even at low inoculum, led to repeated dominance under starvation. K.pneumoniae strains isolated from healthy individuals oral and nasal cavities also exhibited resistance to multiple classes of antibiotics and were genetically similar to clinical and gut isolates. In addition, we found that in the absence of Klebsiella, other understudied opportunistic pathogens, such as Peptostreptococcus, dominate under starvation conditions. Our findings establish an environmental circumstance that allows for the outgrowth of Klebsiella and other opportunistic pathogens. The ability to outcompete other commensal bacteria and to persist under harsh environmental conditions may contribute to the colonization-to-infection transition of these opportunistic pathogens.

microbiology↗

bioRxiv2022

Three-dimensional humanized gingival tissue model to study oral microbiome

The oral cavity contains different microenvironments, as the non-shedding surface of the teeth and the epithelial mucosa, where oral barriers and microbial communities coexist. The interactions and balances between these two communities are responsible for oral tissue homeostasis or dysbiosis, that ultimately dictate health or disease. Disruption of this equilibrium is the first necessary step towards chronic inflammation and permanent tissue damage in the case of chronic periodontitis. There are currently no experimental models able to mimic the structural, physical, and metabolic conditions present in the oral gingival tissue to support the long-term investigation of host-pathogens unbalances. Herein, we report a 3D anatomical gingival in vitro model based on human primary culture that recapitulates the native tissue organization, and a native oxygen gradient within the gingival pocket to support human microbiome persistence with a physiologically relevant level of microbial diversity as well as native spatial organization. The modulation of inflammatory markers in the presence of oral microbiome suggested the humanized functional response of this model. The model will be used in future studies to investigate host-pathogen unbalances in gingivitis and periodontal disease.

bioengineering↗