Explore the vast range of titles available.

Efficient repair of DNA double-strand breaks (DSBs) requires a coordinated DNA Damage Response (DDR), which includes phosphorylation of histone H2Ax, forming γH2Ax. This histone modification spreads beyond the DSB into neighboring chromatin, generating a DDR platform that protects against end disassociation and degradation, minimizing chromosomal rearrangements. However, mechanisms that determine the breadth and intensity of γH2Ax domains remain unclear. Here, we show that chromosomal contacts of a DSB site are the primary determinants for γH2Ax landscapes. DSBs that disrupt a topological border permit extension of γH2Ax domains into both adjacent compartments. In contrast, DSBs near a border produce highly asymmetric DDR platforms, with γH2Ax nearly absent from one broken end. Collectively, our findings lend insights into a basic DNA repair mechanism and how the precise location of a DSB may influence genome integrity. Formation of γH2Ax serves as a checkpoint for double-strand break (DSB) repair pathways. Here the authors reveal via integrated chromatin analysis that γH2Ax domains are established by chromosomal contacts with the DSB site.

Mycobacterium tuberculosis instigates interactions with host factors to promote its survival within the host inimical conditions. Among such factors, nuclear receptors (NRs) seem to be promising candidates owing to their role in bacterial pathogenesis. However, only few members of NR superfamily have been implicated in M. tuberculosis infection and there is a dearth of comprehensive knowledge about expression or function of the entire superfamily. In this study, we performed detailed expression analysis and identified key NRs getting differentially regulated in murine macrophages and dendritic cells (DC) upon infection with H37Rv . The murine macrophages and DCs infected with H37Rv entailed overlapping changes in the expression of certain NRs which reflect upon the possibility that both cells might utilize similar transcriptional programs upon M. tuberculosis infection. We identified Nr4a3 and Rora, which have not been implicated in M. tuberculosis pathogenesis, undergo similar changes in expression in macrophages and DCs upon H37Rv infection. Interestingly, a similar pattern in their expression was also observed in infected human monocyte derived macrophages and the findings corroborated well with PBMCs obtained from TB patients. This all-inclusive analysis provides the basis for a precise approach in identifying NRs that can be targeted therapeutically in intracellular bacterial infections.

Epigenetic scarring of terminally dysfunctional (TDysf) CD8+ T cells hinders long-term protection and response to immune checkpoint blockade during chronic infections and cancer. We developed a faithful in vitro model for CD8+ T cell terminal dysfunction as a platform to advance T cell immunotherapy. Using TCR-transgenic CD8+ T cells, we found that 1-week peptide stimulation, mimicking conditions in previous models, failed to induce a stable exhaustion program. In contrast, prolonged stimulation for 2-3 weeks induced T cell dysfunction but triggered activation-induced cell death, precluding long-term investigation of exhaustion programs. To better mimic in vivo exhaustion, we provided post-effector, chronic TGF-β1 signals, enabling survival of chronically stimulated CD8+ T cells for over 3 weeks. These conditions induced a state of terminal dysfunction, marked by a stable loss of effector, cytotoxicity, and memory programs, along with mitochondrial stress and impaired protein translation. Importantly, transcriptomic and epigenetic analyses verified the development of terminal exhaustion-specific signatures in TDysf cells. Adoptive transfer of TDysf cells revealed their inability to recall effector functions or proliferate after acute lymphocytic choriomeningitis virus rechallenge. This tractable model system enables investigation of molecular pathways driving T cell terminal dysfunction and discovery of therapeutic targets for cancer or chronic infections.

A set of D–A–π–A dyes containing a carbazole donor, linker composed of a naphthalimide auxiliary acceptor and spacers such as phenyl, oligothiophene, dithienopyrrole and cyanoacrylic acid acceptor have been synthesized and characterized. Influence of spacers on the optical and photovoltaic properties are analyzed. Nature of the spacer between naphthalimide and cyanoacrylic acid show significant effect on the absorption maximum. Elongation of conjugation and increment in electron richness gradually red shift the absorption. It also helps to tune the oxidation potential of the dyes. All dyes possess high-lying LUMO and low-lying HOMO when compared to CB of TiO 2 and reduction potential of iodide electrolyte, which facilitate the electron injection into TiO 2 , and regeneration of the oxidized dye by electrolyte, respectively. A dye containing dithienopyrrole led to maximum photocurrent density of 3.60 mA cm −2 and an open circuit voltage of 519 mV in the series. This is attributed to the diminished resistance for charge transfer and long-lived electron lifetime when compared to the other dyes. The electrochemical impedance spectroscopy revealed small charge recombination resistance at TiO 2 /dye/electrolyte interface for all the dyes attesting the low open circuit voltages of the devices.

Two new organic sensitizers featuring fluorenylidene decoration on the phenothiazine donor have been synthesized and characterized as sensitizers for nanocrystalline TiO 2 -based dye sensitized solar cells (DSSCs). The dyes possess cyanoacrylic acid as acceptor/anchoring group and a conjugation pathway composed of fluorene and thiophene. Introduction of the fluorenylidene moiety on phenothiazine enhances the optical density of the dyes while the extension of conjugation by thiophene insertion red-shifts the absorption peak originating from the intramolecular charge transfer from phenothiazine to cyanoacrylic acid. The ground and excited state oxidation potentials of the fluorenylidene-containing dyes are upwardly shifted when compared to the parent dyes indicating a π-delocalized donor segment. The electronic properties were supported by density functional theoretical computations. Among the DSSCs fabricated, the dye ( 5a ) having fluorene and thiophene in the spacer resulted higher power conversion efficiency (3.31 %) than the corresponding bithiophene analog ( 5b , 2.83 %) attributable to the relatively high electron life time and enhanced resistance for recombination in the former.

The cytokines interleukin (IL)-22 and IL-17 are secreted by innate and adaptive immune cells to drive \"type III\" responses that protect against extracellular pathogens, promote mucosal barrier integrity, and foster microbiota homeostasis. However, dysregulation of IL-22 and/or IL-17 contributes to autoimmunity, chronic inflammation, and malignancy. Thus, a deeper understanding of mechanisms regulating type III cytokine production could provide new therapeutic targets for a spectrum of immune-mediated diseases. Toward this goal, we performed a genome-wide CRISPR inhibition (CRISPRi) screen to identify factors that regulate IL-22/IL-17 expression in a murine type III innate lymphoid cell (ILC3) model, MNK3, following stimulation with IL-23 and IL-1b. In addition to previously known regulators of type III cytokines, including IL-23 receptor components IL23R and IL12RB1, the screen identified a large set of new factors that either potentiate or attenuate expression of IL-22 and/or IL-17. A subset of these novel factors was chosen for validation, from which two were selected for further study. The nuclear protein, SON, which binds both DNA and RNA, impaired expression of IL12RB1 at the levels of de novo transcription and RNA processing. The second, MAP4K1 (HPK1), is a serine/threonine kinase that is required for IL-22 but not IL-17 expression. Depletion of MAP4K1 in MNK3 also enhanced expression of the type I cytokine, IFNg, which was co-expressed with IL-17, a phenotype reminiscent of pathogenic Th17 cells. Together, results from the CRISPRi screen broaden our understanding of the factors involved in type III immune responses and offer new targets for modulating IL-22/17 expression.

Epigenetic scarring of terminally dysfunctional CD8 T cells hinders long-term protection and response to immune checkpoint blockade during chronic infections and cancer. We developed a faithful model for CD8 T cell terminal dysfunction as a platform to advance T cell immunotherapy. Using TCR-transgenic CD8 T cells, we found that 1-week peptide stimulation, mimicking conditions in previous models, failed to induce a stable exhaustion program in CD8 T cells. In contrast, prolonged stimulation for 2-3 weeks induced T cell dysfunction but triggered activation-induced cell death, precluding long-term investigation of exhaustion programs. To better mimic exhaustion, we provided post-effector, chronic TGFβ1 signals, enabling survival of chronically stimulated CD8 T cells for over 3 weeks. These conditions induced a stable state of terminal dysfunction (T ), marked by a stable loss of effector, cytotoxicity, and memory programs, along with mitochondrial stress and impaired protein translation. Importantly, transcriptomic and epigenetic analyses confirmed the development of terminal exhaustion-specific signatures in T cells. Adoptive transfer of T cells revealed their inability to recall effector functions or proliferate after acute LCMV rechallenge. This novel tractable model system enables investigation of molecular pathways driving T cell terminal dysfunction and discovery of new therapeutic targets for cancer or chronic infections.

IL-22, a signature cytokine of type 3 lymphoid cells, mediates epithelial homeostasis and protective pathogen responses in barrier tissues, while its deregulated expression drives chronic inflammation associated with colitis and psoriasis. Despite its therapeutic value, little is known about regulatory elements for IL-22 expression. We identify two conserved enhancers, E22-1 and E22-2, which differentially regulate in type 3 lymphoid subsets. These enhancers are required for steady-state expression of gut antimicrobial peptides, protection from infection, and development of IL-22-mediated psoriasis. E22-1 resembles many known enhancers, functioning in both Th-ILC counterparts. However, E22-2 is only required for IL-22 expression in ILC3s. Its ILC3 restriction relies on multiple Runx3 sites, combined with the lack of a functional RORγt motif, which is present in E22-1. Thus, although responding to similar stimuli, type 3 lymphoid cells use distinct cis-elements for IL-22 expression, with E22-2 likely serving as a homeostatic enhancer in barrier tissues.

IntroductionThe revision of International Federation of Gynaecology and Obstetrics staging in 2018 with recommendations to include cross-sectional imaging and a separate stage for node positive disease have opened a lot of uncertainties in implementing the correct treatment approach in these patients. While studies have suggested higher chances of occult para-aortic lymph node (PALN) even with advanced imaging, especially in pelvic node positive disease which tend to recur after pelvic radiation therapy. This study intends to study these patients and isolate the subset who will benefit most from elective PALN irradiation.Methods and analysisThis is an ongoing multicentric phase III randomised controlled trial with a sample size of 274 subjects in two arms (137 in each arm) to determine the superiority of limited elective para-aortic irradiation compared with no irradiation. Arm one includes radiation to the lower PALN and pelvis; Arm two includes radiation to the pelvis. Concurrent chemotherapy followed by brachytherapy is standard in both arms. Patients with cervical cancer and radiologically positive pelvic LNs aged>18 years and<70 years are screened for the study. The primary endpoint of this study is 3-year disease-free survival. The secondary endpoints include 3-year para-aortic recurrence-free survival, 3-year distant metastasis-free survival, 3-year overall survival, acute and late toxicity, quality of life. Translational study to evaluate systemic immune response by FAPI-PETCT (fibroblast activator protein inhibitor positron emission tomography) and assessment of p16, L1 cell adhesion molecule (L1CAM) and protein death ligand-1 (PDL-1) expression by immunohistochemistry.Ethics and disseminationThe study has been approved by the institutional ethics committee and will be routinely monitored according to standard guidelines. The results of the study will be published in peer-reviewed scientific journals, presented at conferences and submitted to regulatory authorities.Trial registration numberThe study was registered on 17 January 2022 under CTRI/2022/01/039495 (http://ctri.nic.in).