Local induction of bladder Th1 responses to combat urinary tract infections.

Given the high frequency of urinary tract infections (UTIs) and their recurrence, there is keen interest in developing effective UTI vaccines. Currently, most vaccine studies, including those in humans, involve parenteral vaccination aimed at evoking and sustaining elevated levels of systemic antibody directed at the uropathogens. In view of recent reports of aberrant Th2-biased bladder immune responses to infection, we hypothesized that immunizing mice intravesically with antigens from uropathogenic (UPEC) combined with a Th1-skewing adjuvant could correct this defect and promote protection against UTIs.

The Roles of T cells in Bladder Pathologies.

T lymphocytes play important roles in the skin and mucosal surfaces such as the gut and lung. Until recently the contributions of T cells to mammalian bladder immunity were largely unknown. With newer techniques, including single-cell RNA sequencing and reporter mice, an understanding is emerging of T cell roles in bladder diseases (bacterial infections, bladder cancer, chronic inflammation).

A mosaic analysis system with Cre or Tomato expression in the mouse.

Somatic mutations are major genetic contributors to cancers and many other age-related diseases. Many disease-causing somatic mutations can initiate clonal growth prior to the appearance of any disease symptoms, yet experimental models that can be used to examine clonal abnormalities are limited. We describe a mosaic analysis system with Cre or Tomato (MASCOT) for tracking mutant cells and demonstrate its utility for modeling clonal hematopoiesis.

A highly polarized T2 bladder response to infection promotes epithelial repair at the expense of preventing new infections.

Urinary tract infections (UTIs) typically evoke prompt and vigorous innate bladder immune responses, including extensive exfoliation of the epithelium. To explain the basis for the extraordinarily high recurrence rates of UTIs, we examined adaptive immune responses in mouse bladders. We found that, following each bladder infection, a highly T helper type 2 (T2)-skewed immune response directed at bladder re-epithelialization is observed, with limited capacity to clear infection.

Introducing a novel experimental model of bladder transplantation in mice.

Bladder dysfunction is a common clinical problem attributed to various conditions such as posterior urethral valves, neurogenic bladder, ureteral ectopy, or bladder exstrophy. Currently, the main therapeutic option for these dysfunctions is neobladder reconstruction with gastrointestinal tract segments. However, the latter was associated with significant long-term complications.

Collaboration between Distinct Rab Small GTPase Trafficking Circuits Mediates Bacterial Clearance from the Bladder Epithelium.

Rab small GTPases control membrane trafficking through effectors that recruit downstream mediators such as motor proteins. Subcellular trafficking typically involves multiple Rabs, with each specific step mediated by a distinct Rab protein. We describe a collaboration between two distinct Rab-protein-orchestrated trafficking circuits in bladder epithelial cells (BECs) that expels intracellular uropathogenic Escherichia coli (UPEC) from their intracellular niche.

The multiple antibacterial activities of the bladder epithelium.

The urinary tract is subject to frequent challenges from the gut microflora. Indeed, up to 40% of women will experience at least one urinary tract infection (UTI) during their lifetime. Uropathogenic (UPEC) contribute to an overwhelming majority of these cases and they typically initiate UTIs by invading the superficial epithelium that lines the bladder lumen.

BATF Modulates the Th2 Locus Control Region and Regulates CD4+ T Cell Fate during Antihelminth Immunity.

The AP-1 factor basic leucine zipper transcription factor, ATF-like (BATF) is important for CD4 Th17, Th9, and follicular Th cell development. However, its precise role in Th2 differentiation and function remains unclear, and the requirement for BATF in nonallergic settings of type-2 immunity has not been explored. In this article, we show that, in response to parasitic helminths, Batf mice are unable to generate follicular Th and Th2 cells.

Ubiquitination of Innate Immune Regulator TRAF3 Orchestrates Expulsion of Intracellular Bacteria by Exocyst Complex.

Although the intracellular trafficking system is integral to most physiologic activities, its role in mediating immune responses to infection has remained elusive. Here, we report that infected bladder epithelial cells (BECs) mobilized the exocyst complex, a powerful exporter of subcellular vesicles, to rapidly expel intracellular bacteria back for clearance. Toll-like receptor (TLR) 4 signals emanating from bacteria-containing vesicles (BCVs) were found to trigger K33-linked polyubiquitination of TRAF3 at Lys168, which was then detected by RalGDS, a guanine nucleotide exchange factor (GEF) that precipitated the assembly of the exocyst complex.

Differential Requirements of TCR Signaling in Homeostatic Maintenance and Function of Dendritic Epidermal T Cells.

Dendritic epidermal T cells (DETCs) are generated exclusively in the fetal thymus and maintained in the skin epithelium throughout postnatal life of the mouse. DETCs have restricted antigenic specificity as a result of their exclusive usage of a canonical TCR. Although the importance of the TCR in DETC development has been well established, the exact role of TCR signaling in DETC homeostasis and function remains incompletely defined.

Quantitatively relating gene expression to light intensity via the serial connection of blue light sensor and CRISPRi.

The ability to regulate endogenous gene expression is critical in biological research. Existing technologies, such as RNA interference, zinc-finger regulators, transcription-activator-like effectors, and CRISPR-mediated regulation, though proved to be competent in significantly altering expression levels, do not provide a quantitative adjustment of regulation effect. As a solution to this problem, we place CRISPR-mediated interference under the control of blue light: while dCas9 protein is constitutively expressed, guide RNA transcription is regulated by YF1-FixJ-PFixK2, a blue light responding system.