Choroid plexus mast cells drive tumor-associated hydrocephalus.

Tumor-associated hydrocephalus (TAH) is a common and lethal complication of brain metastases. Although other factors beyond mechanical obstructions have been suggested, the exact mechanisms are unknown. Using single-nucleus RNA sequencing and spatial transcriptomics, we find that a distinct population of mast cells locate in the choroid plexus and dramatically increase during TAH. Genetic fate tracing and intracranial mast-cell-specific tryptase knockout showed that choroid plexus mast cells (CPMCs) disrupt cilia of choroid plexus epithelia via the tryptase-PAR2-FoxJ1 pathway and consequently increase cerebrospinal fluid production. Mast cells are also found in the human choroid plexus. Levels of tryptase in cerebrospinal fluid are closely associated with clinical severity of TAH. BMS-262084, an inhibitor of tryptase, can cross the blood-brain barrier, inhibit TAH in vivo, and alleviate mast-cell-induced damage of epithelial cilia in a human pluripotent stem-cell-derived choroid plexus organoid model. Collectively, we uncover the function of CPMCs and provide an attractive therapy for TAH.

Sensing of ATP via the Purinergic Receptor P2RX7 Promotes CD8+ Trm Cell Generation by Enhancing Their Sensitivity to the Cytokine TGF-ß.

Tissue-resident memory (Trm) CD8+ T cells mediate protective immunity in barrier tissues, but the cues promoting Trm cell generation are poorly understood. Sensing of extracellular adenosine triphosphate (eATP) by the purinergic receptor P2RX7 is needed for recirculating CD8+ T cell memory, but its role for Trm cells is unclear. Here we showed that P2RX7 supported Trm cell generation by enhancing CD8+ T cell sensing of TGF-ß, which was necessary for tissue residency. P2RX7-deficient Trm cells progressively decayed in non-lymphoid tissues and expressed dysregulated Trm-specific markers. P2RX7 was required for efficient re-expression of the receptor TGF-ßRII through calcineurin signaling. Forced Tgfbr2 expression rescued P2RX7-deficient Trm cell generation, and TGF-ß sensitivity was dictated by P2RX7 agonists and antagonists. Forced Tgfbr2 also rescued P2RX7-deficient Trm cell mitochondrial function. Sustained P2RX7 signaling was required for long-term Trm cell maintenance, indicating that P2RX7 signaling drives induction and CD8+ T cell durability in barrier sites.

Efficacy and safety of tislelizumab plus lenvatinib as first-line treatment in patients with unresectable hepatocellular carcinoma: a multicenter, single-arm, phase 2 trial.

BACKGROUND: Lenvatinib is widely used in treatment of unresectable hepatocellular carcinoma (uHCC), but the benefit of its combination with immunotherapy needs to be verified. This study evaluated the efficacy and safety of tislelizumab plus lenvatinib in systemic treatment-naïve patients with uHCC. METHODS: In this multicenter, single-arm, phase 2 study, systemic treatment-naïve patients with uHCC received tislelizumab 200 mg every three weeks plus lenvatinib (bodyweight ≥ 60 kg: 12 mg; < 60 kg: 8 mg; once daily). Dose-limiting toxicities (DLTs) were evaluated in safety run-in phase to determine whether to enter the expansion phase. The primary endpoint was objective response rate (ORR) assessed by independent review committee (IRC) per Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1). Based on Simon's two-stage design, > 6 responders were needed in stage 1 (n = 30) to continue the study, and ≥ 18 responders were needed by the end of stage 2 (n = 60) to demonstrate statistical superiority to a historical control of lenvatinib monotherapy. RESULTS: Sixty-four patients were enrolled. No DLTs were reported. The study achieved statistical superiority (p = 0.0003) with 23 responders assessed by IRC per RECIST v1.1 in the first 60 patients of the efficacy evaluable analysis set (n = 62). After a median follow-up of 15.7 months, confirmed ORR and disease control rate were 38.7% (24/62, 95% confidence interval [CI], 26.6-51.9) and 90.3% (56/62, 95% CI, 80.1-96.4), respectively. Median progression-free survival was 8.2 months (95% CI, 6.8-not evaluable). Overall survival rate at 12 months was 88.6% (95% CI, 77.7-94.4). Grade ≥ 3 treatment-related adverse events occurred in 18 (28.1%) patients. CONCLUSIONS: Tislelizumab plus lenvatinib demonstrated promising antitumor activity with favourable tolerability as first-line therapy for patients with uHCC. TRIAL REGISTRATION: ClinicalTrials.gov (NCT04401800).

TGF-ß signaling to T cells inhibits autoimmunity during lymphopenia-driven proliferation.

T cell-specific deletion of the receptor for transforming growth factor-ß (TGF-ß) mediated by Cre recombinase expressed early in T cell development leads to early-onset lethal autoimmune disease that cannot be controlled by regulatory T cells. However, when we deleted that receptor through the use of Cre driven by a promoter that is active much later in T cell development, adult mice in which most peripheral CD4(+) or CD8(+) T cells lacked the receptor for TGF-ß showed no signs of autoimmunity. Because of their enhanced responses to weak stimulation of the T cell antigen receptor, when transferred into lymphopenic recipients, naive TGF-ß-unresponsive T cells underwent much more proliferation and differentiation into effector cells and induced lymphoproliferative disease. We propose that TGF-ß signaling controls the self-reactivity of peripheral T cells but that in the absence of TGF-ß signals, an added trigger such as lymphopenia is needed to drive overt autoimmune disease.

A comparative study of diffusion kurtosis imaging and diffusion tensor imaging in detecting corticospinal tract impairment in diffuse glioma patients.

PURPOSE: This study aimed to investigate the diagnostic performance of diffusion kurtosis imaging (DKI) and diffusion tensor imaging (DTI) in identifying aberrations in the corticospinal tract (CST), whilst elucidating the relationship between abnormalities of CST and patients' motor function. METHODS: Altogether 21 patients with WHO grade II or grade IV glioma were enrolled and divided into Group 1 and Group 2, according to the presence or absence of preoperative paralysis. DKI and DTI metrics were generated and projected onto the CST. Histograms of the CST along x, y, and z axes were developed based on DKI and DTI metrics, and compared subsequently to determine regions of aberrations on the fibers. The receiver operating characteristic curve was performed to investigate the diagnostic efficacy of DKI and DTI metrics. RESULTS: In Group 1, a significantly lower fractional anisotropy, radial kurtosis and mean kurtosis, and a higher mean diffusivity were found in the ipsilateral CST as compared to the contralateral CST. Significantly higher relative axial diffusivity, relative radial diffusivity, and relative mean diffusivity (rMD) were found in Group 1, as compared to Group 2. The relative volume of ipsilateral CST abnormalities higher than the maximum value of mean kurtosis combined with rMD exhibited the best diagnostic performance in distinguishing dysfunction of CST with an AUC of 0.93. CONCLUSION: DKI is sensitive in detecting subtle changes of CST distal from the tumor. The combination of DKI and DTI is feasible for evaluating the impairment of the CST.

Circular MTHFD2L RNA-encoded CM-248aa inhibits gastric cancer progression by targeting the SET-PP2A interaction.

The available targeted therapies for gastric cancer (GC) are still limited, so it is important to discover novel molecules as potential treatment options. Proteins or peptides encoded by circular RNAs (circRNAs) are increasingly reported to play essential roles in malignancies. The aim of the present study was to identify an undiscovered protein encoded by circRNA and explore its key role and molecular mechanism in GC progression. CircMTHFD2L (hsa_circ_0069982) was screened and validated as a downregulated circRNA with coding potential. The protein encoded by circMTHFD2L, named CM-248aa, was identified for the first time by immunoprecipitation and mass spectrometry. CM-248aa was significantly downregulated in GC, while its low expression was associated with advanced tumor-node-metastasis (TNM) stage and histopathological grade. Low expression of CM-248aa could be an independent risk factor for poor prognosis. Functionally, CM-248aa, instead of circMTHFD2L suppressed the proliferation and metastasis of GC in vitro and in vivo. Mechanistically, CM-248aa competitively targeted the acidic domain of SET nuclear oncogene (SET) and acted as an endogenous inhibitor of the SET-protein phosphatase 2A interaction to promote dephosphorylation of AKT, extracellular signal-regulated kinase, and P65. Our discovery revealed that CM-248aa could be a potential prognostic biomarker and endogenous therapeutic option for GC.

Application of a Novel Miniaturized Histopathologic Microscope for Ex Vivo Identifying Cerebral Glioma Margins Rapidly During Surgery: A Parallel Control Study.

PURPOSE: The purpose of our study is to assess the clinical performance of the DiveScope, a novel handheld histopathologic microscope in rapidly differentiating glioma from normal brain tissue during neurosurgery. METHODS: Thirty-two ex vivo specimens from 18 patients were included in the present study. The excised suspicious tissue was sequentially stained with sodium fluorescein and methylene blue and scanned with DiveScope during surgery. The adjacent tissue was sent to the department of pathology for frozen section examination. They would eventually be sent to the pathology department later for hematoxylin and eosin staining for final confirmation. The positive likelihood ratio, negative likelihood ratio, sensitivity, specificity, and area under the curve of the device were calculated. In addition, the difference in time usage between DiveScope and frozen sections was compared for the initial judgment. RESULTS: The sensitivity and specificity of the DiveScope after analyzing hematoxylin and eosin -staining sections, were 88.29% and 100%, respectively. In contrast, the sensitivity and specificity of the frozen sections histopathology were 100% and 75%, respectively. The area under the curve of the DiveScope and the frozen sections histopathology was not significant ( P =0.578). Concerning time usage, DiveScope is significantly much faster than the frozen sections histopathology no matter the size of tissue. CONCLUSION: Compared with traditional pathological frozen sections, DiveScope was faster and displayed an equal accuracy for judging tumor margins intraoperatively.

Induction of Transmucosal Protection by Oral Vaccination with an Attenuated Chlamydia.

Chlamydia muridarum has been used to study chlamydial pathogenesis because it induces mice to develop hydrosalpinx, a pathology observed in C. trachomatis-infected women. We identified a C. muridarum mutant that is no longer able to induce hydrosalpinx. In the current study, we evaluated the mutant as an attenuated vaccine. Following an intravaginal immunization with the mutant, mice were protected from hydrosalpinx induced by wild-type C. muridarum. However, the mutant itself productively colonized the mouse genital tract and produced infectious organisms in vaginal swabs. Nevertheless, the mutant failed to produce infectious shedding in the rectal swabs following an oral inoculation. Importantly, mice orally inoculated with the mutant mounted transmucosal immunity against challenge infection of wild-type C. muridarum in the genital tract. The protection was detected as early as day 3 following the genital challenge infection and the orally immunized mice were protected from any significant pathology in the upper genital tract. However, the same orally immunized mice failed to prevent the colonization of wild-type C. muridarum in the gastrointestinal tract. The transmucosal immunity induced by the oral mutant was further validated in the airway. The orally vaccinated mice were protected from both lung infection and systemic toxicity caused by intranasally inoculated wild-type C. muridarum although the same mice still permitted the gastrointestinal colonization by the wild-type C. muridarum. These observations suggest that the mutant C. muridarum may be developed into an intracellular oral vaccine vector (or IntrOv) for selectively inducing transmucosal immunity in extra-gut tissues.

Differential regulation of CD8+ CD86+ Vγ1.1+ γδT cell responses in skin barrier tissue protection and homeostatic maintenance.

Compared to αßT cells, γδT cells are more innate-like and preferentially function as the first line of defense in barrier tissues. Certain populations of γδT cells possess adaptive immune cell properties but their regulation is not well understood. We herein report that while innate-like γδT17 cells dominated in the skin of WT mice, Vγ1.1+ γδT cells with adaptive T cell-like properties predominantly expanded in the skin of TCRß-/- and B2m-/- mice. Commensal bacteria drove expansion of Vγ1.1+ skin γδT cells, functional properties of which correlated with local immune requirements. That is, Vγ1.1+ skin γδT cells in TCRß-/- mice were a heterogeneous population; while Vγ1.1+ skin γδT cells in B2m-/- mice were mostly CD8+ CD86+ cells that had a similar function of CD8+ CD86+ skin αßT cells in supporting local Treg cells. We also found that intrinsic TGF-ß receptor 2-derived signals in skin CD8+ αßT and γδT cells are required for their expression of CD86, a molecule important in supporting skin Treg cells. Our findings reveal broad functional potentials of γδT cells that are coordinately regulated with αßT cells to help maintain local tissue homeostasis.

Characterization of Pathogenic CD8+ T cells in Chlamydia-Infected OT1 Mice.

Chlamydia trachomatis is a leading infectious cause of infertility in women due to its induction of lasting pathology such as hydrosalpinx. Chlamydia muridarum induces mouse hydrosalpinx because C. muridarum can both invade tubal epithelia directly (as a first hit) and induce lymphocytes to promote hydrosalpinx indirectly (as a second hit). In the current study, a critical role of CD8+ T cells in chlamydial induction of hydrosalpinx was validated in both wild type C57BL/6J mice and OT1 transgenic mice. OT1 mice failed to develop hydrosalpinx partially due to the failure of their lymphocytes to recognize chlamydial antigens. CD8+ T cells from naive C57BL/6J mice rescued the ability of recipient OT1 mice to develop hydrosalpinx when naive CD8+ T cells were transferred at the time of infection with Chlamydia. However, when the transfer was delayed for 2 weeks or longer after the Chlamydia infection, naive CD8+ T cells no longer promoted hydrosalpinx. Nevertheless, CD8+ T cells from mice immunized against Chlamydia still promoted significant hydrosalpinx in the recipient OT1 mice even when the transfer was delayed for 3 weeks. Thus, CD8+ T cells must be primed within 2 weeks after Chlamydia infection to be pathogenic, but, once primed, they can promote hydrosalpinx for >3 weeks. However, Chlamydia-primed CD4+ T cells failed to promote chlamydial induction of pathology in OT1 mice. This study optimized an OT1 mouse-based model for revealing the pathogenic mechanisms of Chlamydia-specific CD8+ T cells.

A novel peptide encoded by N6-methyladenosine modified circMAP3K4 prevents apoptosis in hepatocellular carcinoma.

BACKGROUND: Circular RNAs (circRNAs) regulate various biological activities and have been shown to play crucial roles in hepatocellular carcinoma (HCC) progression. However, only a few coding circRNAs have been identified in cancers, and their roles in HCC remain elusive. This study aimed to identify coding circRNAs and explore their function in HCC. METHODS: CircMAP3K4 was selected from the CIRCpedia database. We performed a series of experiments to determine the characteristics and coding capacity of circMAP3K4. We then used in vivo and in vitro assays to investigate the biological function and mechanism of circMAP3K4 and its protein product, circMAP3K4-455aa, in HCC. RESULTS: We found circMAP3K4 to be an upregulated circRNA with coding potential in HCC. IGF2BP1 recognized the circMAP3K4 N6-methyladenosine modification and promoted its translation into circMAP3K4-455aa. Functionally, circMAP3K4-455aa prevented cisplatin-induced apoptosis in HCC cells by interacting with AIF, thus protecting AIF from cleavage and decreasing its nuclear distribution. Moreover, circMAP3K4-455aa was degraded through the ubiquitin-proteasome E3 ligase MIB1 pathway. Clinically, a high level of circMAP3K4 is an independent prognostic factor for adverse overall survival and adverse disease-free survival of HCC patients. CONCLUSIONS: CircMAP3K4 is a highly expressed circRNA in HCC. Driven by m6A modification, circMAP3K4 encoded circMAP3K4-455aa, protected HCC cells from cisplatin exposure, and predicted worse prognosis of HCC patients. Targeting circMAP3K4-455aa may provide a new therapeutic strategy for HCC patients, especially for those with chemoresistance. CircMAP3K4 is a highly expressed circRNA in HCC. Driven by m6A modification, IGF2BP1 facilitates circMAP3K4 peptide translation, then the circMAP3K4 peptide inhibits AIF cleavage and nuclear distribution, preventing HCC cells from cell death under stress and promoting HCC progression.

Transforming growth factor-ß signaling controls the formation and maintenance of gut-resident memory T cells by regulating migration and retention.

Tissue-resident memory T (Trm) cells represent a population of memory CD8⁺ T cells that can act as first responders to local infection. The mechanisms regulating the formation and maintenance of intestinal Trm cells remain elusive. Here we showed that transforming growth factor-ß (TGF-ß) controlled both stages of gut Trm cell differentiation through different mechanisms. During the formation phase of Trm cells, TGF-ß signaling inhibited the migration of effector CD8⁺ T cells from the spleen to the gut by dampening the expression of integrin α4ß7. During the maintenance phase, TGF-ß was required for the retention of intestinal Trm cells at least in part through the induction of integrins αEß7 and α1, as well as CD69. Thus, the cytokine acts to control cytotoxic T cell differentiation in lymphoid and peripheral organs.

Repetitive aeroallergen challenges elucidate maladaptive epithelial and inflammatory traits that underpin allergic airway diseases.

BACKGROUND: Signifying the 2-compartments/1-disease paradigm, allergic rhinoconjunctivitis (ARC) and asthma (AA) are prevalent, comorbid conditions triggered by environmental factors (eg, house dust mites [HDMs]). However, despite the ubiquity of triggers, progression to severe ARC/AA is infrequent, suggesting either resilience or adaptation. OBJECTIVE: We sought to determine whether ARC/AA severity relates to maladaptive responses to disease triggers. METHODS: Adults with HDM-associated ARC were challenged repetitively with HDMs in an aeroallergen challenge chamber. Mechanistic traits associated with disease severity were identified. RESULTS: HDM challenges evoked maladaptive (persistently higher ARC symptoms), adaptive (progressive symptom reduction), and resilient (resistance to symptom induction) phenotypes. Symptom severity in the natural environment was an imprecise correlate of the phenotypes. Nasal airway traits, defined by low inflammation-effectual epithelial integrity, moderate inflammation-effectual epithelial integrity, and higher inflammation-ineffectual epithelial integrity, were hallmarks of the resilient, adaptive, and maladaptive evoked phenotypes, respectively. Highlighting a crosstalk mechanism, peripheral blood inflammatory tone calibrated these traits: ineffectual epithelial integrity associated with CD8+ T cells, whereas airway inflammation associated with both CD8+ T cells and eosinophils. Hallmark peripheral blood maladaptive traits were increased natural killer and CD8+ T cells, lower CD4+ mucosal-associated invariant T cells, and deficiencies along the TLR-IRF-IFN antiviral pathway. Maladaptive traits tracking HDM-associated ARC also contributed to AA risk and severity models. CONCLUSIONS: Repetitive challenges with HDMs revealed that maladaptation to disease triggers may underpin ARC/AA disease severity. A combinatorial therapeutic approach may involve reversal of loss-of-beneficial-function traits (ineffectual epithelial integrity, TLR-IRF-IFN deficiencies), mitigation of gain-of-adverse-function traits (inflammation), and blocking of a detrimental crosstalk between the peripheral blood and airway compartments.

Immunologic resilience and COVID-19 survival advantage.

BACKGROUND: The risk of severe coronavirus disease 2019 (COVID-19) varies significantly among persons of similar age and is higher in males. Age-independent, sex-biased differences in susceptibility to severe COVID-19 may be ascribable to deficits in a sexually dimorphic protective attribute that we termed immunologic resilience (IR). OBJECTIVE: We sought to examine whether deficits in IR that antedate or are induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection independently predict COVID-19 mortality. METHODS: IR levels were quantified with 2 novel metrics: immune health grades (IHG-I [best] to IHG-IV) to gauge CD8+ and CD4+ T-cell count equilibrium, and blood gene expression signatures. IR metrics were examined in a prospective COVID-19 cohort (n = 522); primary outcome was 30-day mortality. Associations of IR metrics with outcomes in non-COVID-19 cohorts (n = 13,461) provided the framework for linking pre-COVID-19 IR status to IR during COVID-19, as well as to COVID-19 outcomes. RESULTS: IHG-I, tracking high-grade equilibrium between CD8+ and CD4+ T-cell counts, was the most common grade (73%) among healthy adults, particularly in females. SARS-CoV-2 infection was associated with underrepresentation of IHG-I (21%) versus overrepresentation (77%) of IHG-II or IHG-IV, especially in males versus females (P < .01). Presentation with IHG-I was associated with 88% lower mortality, after controlling for age and sex; reduced risk of hospitalization and respiratory failure; lower plasma IL-6 levels; rapid clearance of nasopharyngeal SARS-CoV-2 burden; and gene expression signatures correlating with survival that signify immunocompetence and controlled inflammation. In non-COVID-19 cohorts, IR-preserving metrics were associated with resistance to progressive influenza or HIV infection, as well as lower 9-year mortality in the Framingham Heart Study, especially in females. CONCLUSIONS: Preservation of immunocompetence with controlled inflammation during antigenic challenges is a hallmark of IR and associates with longevity and AIDS resistance. Independent of age, a male-biased proclivity to degrade IR before and/or during SARS-CoV-2 infection predisposes to severe COVID-19.

CircCD44 plays oncogenic roles in triple-negative breast cancer by modulating the miR-502-5p/KRAS and IGF2BP2/Myc axes.

BACKGROUND: Emerging studies have revealed the potent functions of circRNAs in breast cancer tumorigenesis. However, the biogenesis, biofunction and mechanism of circRNAs in triple-negative breast cancer (TNBC) are largely unknown. METHODS: High-throughput RNA sequencing was applied to identify dysregulated circRNAs in TNBCs and paired normal tissues. RNA pulldown and luciferase assays were performed to investigate the interaction between circular CD44 (circCD44, also annotated as hsa_circ_0021735) and miR-502-5p. RNA pulldown and RIP assays were used to investigate the interaction between circCD44 and IGF2BP2. Cell viability, colony formation, migration/invasion assays and in vivo tumorigenesis were used to investigate circCD44 biological functions. RESULTS: CircCD44 is an uncharacterized circRNA, which is highly expressed in TNBC, and its expression is negatively correlated with the prognosis of TNBC patients. CircCD44 promotes TNBC proliferation, migration, invasion and tumorigenesis at least partially by sponging miR-502-5p and interacting with IGF2BP2. CONCLUSION: Our data suggested that overexpressed circCD44 promotes TNBC progression. CircCD44 is potentially a novel diagnostic and therapeutic marker for TNBC patients.

Rapid Clot Reduction with Direct Aspiration via 8-F Guide Catheter for Cardioembolic Extracranial Carotid Artery Occlusion: A Guide Catheter Aspiration Technique.

This study reported data that were collected from 11 consecutive patients undergoing treatment for acute cardioembolic extracranial carotid artery (ECCA) occlusion with extensive clot burden via the guide catheter aspiration (GCA) technique. The GCA technique was performed as a direct aspiration using 2 60-mL syringes simultaneously through an 8-F guide catheter. Successful reperfusion was achieved in all 11 patients at the end of thrombectomy, and successful reperfusion was observed in 4 patients after a single GCA procedure pass. A favorable clinical outcome was achieved in 6 (54.5%) cases after 90 days. Thus, the GCA technique is efficacious for patients with cardioembolic ECCA occlusions.

Analysis of the effects of magnetic levitation to simulate microgravity environment on the Arp2/3 complex pathway in macrophage.

With dwindling natural resources on earth, current and future generations will need to explore space to new planets that will require travel under no or varying gravity conditions. Hence, long-term space missions and anticipated impacts on human biology such as changes in immune function are of growing research interest. Here, we reported new findings on mechanisms of immune response to microgravity with a focus on macrophage as a cellular model. We employed a superconducting magnet to generate a simulated microgravity environment and evaluated the effects of simulated microgravity on RAW 264.7 mouse macrophage cell line in three time frames: 8, 24, and 48 h. As study endpoints, we measured cell viability, phagocytosis, and used next-generation sequencing to explore its changing mechanism. Macrophage cell viability and phagocytosis both showed a marked decrease under microgravity. The differentially expressed genes (DEG) were identified in two ways: (1) gravity-dependent DEG, compared µg samples and 1 g samples at each time point; (2) time-dependent DEG, compared time-point samples within the same gravitational field. Through transcriptome analysis and confirmed by molecular biological verification, our findings firstly suggest that microgravity might affect macrophage phagocytosis by targeting Arp2/3 complex involved cytoskeleton synthesis and causing macrophage immune dysfunction. Our findings contribute to an emerging body of scholarship on biological effects of space travel.

Evasion of Innate Lymphoid Cell-Regulated Gamma Interferon Responses by Chlamydia muridarum To Achieve Long-Lasting Colonization in Mouse Colon.

Revealing the mechanisms by which bacteria establish long-lasting colonization in the gastrointestinal tract is an area of intensive investigation. The obligate intracellular bacterium Chlamydia is known to colonize mouse colon for long periods. A colonization-deficient mutant strain of this intracellular bacterium is able to regain long-lasting colonization in gamma interferon (IFN-γ) knockout mice following intracolon inoculation. We now report that mice deficient in conventional T lymphocytes or recombination-activating gene (Rag) failed to show rescue of mutant colonization. Nevertheless, antibody depletion of IFN-γ or genetic deletion of interleukin 2 (IL-2) receptor common gamma chain in Rag-deficient mice did rescue mutant colonization. These observations suggest that colonic IFN-γ, responsible for inhibiting the intracellular bacterial mutant, is produced by innate lymphoid cells (ILCs). Consistently, depletion of NK1.1+ cells in Rag-deficient mice both prevented IFN-γ production and rescued mutant colonization. Furthermore, mice deficient in transcriptional factor RORγt, but not chemokine receptor CCR6, showed full rescue of the long-lasting colonization of the mutant, indicating a role for group 3-like ILCs. However, the inhibitory function of the responsible group 3-like ILCs was not dependent on the natural killer cell receptor (NCR1), since NCR1-deficient mice still inhibited mutant colonization. Consistently, mice deficient in the transcriptional factor T-bet only delayed the clearance of the bacterial mutant without fully rescuing the long-lasting colonization of the mutant. Thus, we have demonstrated that the obligate intracellular bacterium Chlamydia maintains its long-lasting colonization in the colon by evading IFN-γ from group 3-like ILCs.

Gastrointestinal Coinfection Promotes Chlamydial Pathogenicity in the Genital Tract.

Sexually transmitted Chlamydia, which can cause fibrotic pathology in women's genital tracts, is also frequently detected in the gastrointestinal tract. However, the medical significance of the gastrointestinal Chlamydia remains unclear. A murine Chlamydia readily spreads from the mouse genital tract to the gastrointestinal tract while inducing oviduct fibrotic blockage or hydrosalpinx. We previously proposed a two-hit model in which the mouse gastrointestinal Chlamydia might induce the second hit to promote genital tract pathology, and we are now providing experimental evidence for testing the hypothesis. First, chlamydial mutants that are attenuated in inducing hydrosalpinx in the genital tract also reduce their colonization in the gastrointestinal tract, leading to a better correlation of chlamydial induction of hydrosalpinx with chlamydial colonization in the gastrointestinal tract than in the genital tract. Second, intragastric coinoculation with a wild-type Chlamydia rescued an attenuated Chlamydia mutant to induce hydrosalpinx, while the chlamydial mutant infection in the genital tract alone was unable to induce any significant hydrosalpinx. Finally, the coinoculated gastrointestinal Chlamydia failed to directly spread to the genital tract lumen, suggesting that gastrointestinal Chlamydia may promote genital pathology via an indirect mechanism. Thus, we have demonstrated a significant role of gastrointestinal Chlamydia in promoting pathology in the genital tract possibly via an indirect mechanism. This study provides a novel direction/dimension for further investigating chlamydial pathogenic mechanisms.

Profiles of immune-related genes and immune cell infiltration in the tumor microenvironment of diffuse lower-grade gliomas.

The tumor microenvironment is highly correlated with tumor occurrence, progress, and prognosis. We aimed to investigate the immune-related gene (IRG) expression and immune infiltration pattern in the tumor microenvironment of lower-grade glioma (LGG). We employed the Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) algorithm to calculate immune and stromal scores and identify prognostic IRG based on The Cancer Genome Atlas data set. The potential molecular functions of these genes were explored with the help of functional enrichment analysis and the protein-protein interaction network. Remarkably, three cohorts that were downloaded from the Chinese Glioma Genome Atlas database were analyzed to further verify the prognostic values of these genes. Moreover, the Tumor IMmune Estimation Resource (TIMER) algorithm was used to estimate the abundance of infiltrating immune cells and explore the immune infiltration pattern in LGG. And unsupervised cluster analysis determined three clusters of the immune infiltration pattern and indicated that CD8+ T cells and macrophages were significantly associated with LGG outcomes. Altogether, our study identified a list of prognostic IRGs and provided a perspective to explore the immune infiltration pattern in LGG.