Pollen Cell Wall Patterns Form from Modulated Phases.

The ornately geometric walls of pollen grains have inspired scientists for decades. We show that the evolved diversity of these patterns is entirely recapitulated by a biophysical model in which an initially uniform polysaccharide layer in the extracellular space, mechanically coupled to the cell membrane, phase separates to a spatially modulated state. Experiments reveal this process occurring in living cells. We observe that in ∼10% of extant species, this phase separation reaches equilibrium during development such that individual pollen grains are identical and perfectly reproducible. About 90% of species undergo an arrest of this process prior to equilibrium such that individual grains are similar but inexact copies. Equilibrium patterns have appeared multiple times during the evolution of seed plants, but selection does not favor these states. This framework for pattern development provides a route to rationalizing the surface textures of other secreted structures, such as cell walls and insect cuticle.

Violet-light suppression of thermogenesis by opsin 5 hypothalamic neurons.

The opsin family of G-protein-coupled receptors are used as light detectors in animals. Opsin 5 (also known as neuropsin or OPN5) is a highly conserved opsin that is sensitive to visible violet light1,2. In mice, OPN5 is a known photoreceptor in the retina3 and skin4 but is also expressed in the hypothalamic preoptic area (POA)5. Here we describe a light-sensing pathway in which POA neurons that express Opn5 regulate thermogenesis in brown adipose tissue (BAT). We show that Opn5 is expressed in glutamatergic warm-sensing POA neurons that receive synaptic input from several thermoregulatory nuclei. We further show that Opn5 POA neurons project to BAT and decrease its activity under chemogenetic stimulation. Opn5-null mice show overactive BAT, increased body temperature, and exaggerated thermogenesis when cold-challenged. Moreover, violet photostimulation during cold exposure acutely suppresses BAT temperature in wild-type mice but not in Opn5-null mice. Direct measurements of intracellular cAMP ex vivo show that Opn5 POA neurons increase cAMP when stimulated with violet light. This analysis thus identifies a violet light-sensitive deep brain photoreceptor that normally suppresses BAT thermogenesis.

Patchy particle insights into self-assembly of transparent, graded index squid lenses.

Squids have spherical, gradient index lenses that maximize optical sensitivity while minimizing light scattering and geometric aberration. Previous studies have shown that the constituent lens proteins behave like patchy particles, and that a density gradient of packing fraction ∼0.01 to 1 assembles from a gradient of average particle valence, 〈M〉 ≈ 2.1 to 〈M〉 > 6. A priori, transparency requires that all regions within the larger gradient must minimize density fluctuations at length scales close to the wavelength of visible light. It is not known how a material can achieve this at all possible packing fractions via attractive interactions. We also observe that the set of proteins making the lens is remarkably polydisperse (there are around 40 isoforms expressed). Why does nature employ so many geometrically similar isoforms when theory suggests a few would suffice, and what, if any, is the physical role of the polydispersity? This study focuses on answering these questions for the sparsest regions of the lens, where the patchy nature of the system will have the largest influence on the final structure. We first simulated mixtures of bi- and trivalent patchy particles and found a strong influence of patch angle on the percolation and gel structure of the system. We then investigated the influence of the interaction polydispersity on the structure of the M = 2.1 system. We find that increasing the variance in patch energies and single-patch angle appears to decrease the length scale of density fluctuations while also moving the percolation line to lower temperature. S-Crystallin geometry and polydispersity appear to promote regular percolation of a gel structure while also limiting density fluctuations to small length scales, thereby promoting transparency in the annealed structure.

Mimicry of a biophysical pathway leads to diverse pollen-like surface patterns.

A ubiquitous structural feature in biological systems is texture in extracellular matrix that gains functions when hardened, for example, cell walls, insect scales, and diatom tests. Here, we develop patterned liquid crystal elastomer (LCE) particles by recapitulating the biophysical patterning mechanism that forms pollen grain surfaces. In pollen grains, a phase separation of extracellular material into a pattern of condensed and fluid-like phases induces undulations in the underlying elastic cell membrane to form patterns on the cell surface. In this work, LCE particles with variable surface patterns were created through a phase separation of liquid crystal oligomers (LCOs) droplet coupled to homeotropic anchoring at the droplet interface, analogously to the pollen grain wall formation. Specifically, nematically ordered polydisperse LCOs and isotropic organic solvent (dichloromethane) phase-separate at the surface of oil-in-water droplets, while, different LCO chain lengths segregate to different surface curvatures simultaneously. This phase separation, which creates a distortion in the director field, is in competition with homeotropic anchoring induced by sodium dodecyl sulfate (SDS). By tuning the polymer chemistry of the system, we are able to influence this separation process and tune the types of surface patterns in these pollen-like microparticles. Our study reveals that the energetically favorable biological mechanism can be leveraged to offer simple yet versatile approaches to synthesize microparticles for mechanosensing, tissue engineering, drug delivery, energy storage, and displays.

Children and young people's experiences of living with rare diseases: An integrative review.

PROBLEM: Rare diseases are any disease affecting fewer than five people in 10,000. More than 8000 rare diseases and 50-75% of all rare diseases affect children. The purpose of this review was to critically appraise and synthesize existing literature relating to the impact of rare diseases on children's day-to-day lives. ELIGIBILITY CRITERIA: An integrative literature review was conducted using the CINAHL Plus, PsycINFO, and PubMed databases. Studies were included if they were a primary source was published between the years 2005 and 2019 and written in the English language. SAMPLE: Eight primary sources met the inclusion criteria. RESULTS: Seven main themes emerged from the review as follows: (i) the experience of stigmatisations, (ii) self-consciousness, (iii) restrictions in independent living, (iv) developing resilience/coping strategies, (v) psychological and emotional impact, (vi) social impact vs social connectedness and (vii) transition challenges. CONCLUSIONS: The experience of having a rare illness differed across different age groups. Children (typically aged 3-10) with rare diseases generally view themselves and their lives the same way like their healthy peers. They were more likely to report being adaptive and resilient than those aged 12 or older. Young people reported being different compared to young children, and they faced numerous challenges related to their illness. IMPLICATIONS FOR PRACTICE: To provide the best possible level of care for children and families with rare disorders, health services must be informed and equipped to provide the necessary supports specific to the unique needs of children and young people living with rare diseases.

First-order patterning transitions on a sphere as a route to cell morphology.

We propose a general theory for surface patterning in many different biological systems, including mite and insect cuticles, pollen grains, fungal spores, and insect eggs. The patterns of interest are often intricate and diverse, yet an individual pattern is robustly reproducible by a single species and a similar set of developmental stages produces a variety of patterns. We argue that the pattern diversity and reproducibility may be explained by interpreting the pattern development as a first-order phase transition to a spatially modulated phase. Brazovskii showed that for such transitions on a flat, infinite sheet, the patterns are uniform striped or hexagonal. Biological objects, however, have finite extent and offer different topologies, such as the spherical surfaces of pollen grains. We consider Brazovskii transitions on spheres and show that the patterns have a richer phenomenology than simple stripes or hexagons. We calculate the free energy difference between the unpatterned state and the many possible patterned phases, taking into account fluctuations and the system's finite size. The proliferation of variety on a sphere may be understood as a consequence of topology, which forces defects into perfectly ordered phases. The defects are then accommodated in different ways. We also argue that the first-order character of the transition is responsible for the reproducibility and robustness of the pattern formation.

Differences in testing for drugs of abuse amongst racial and ethnic groups at children's hospitals.

OBJECTIVES: Racial and ethnic differences in drug testing have been described among adults and newborns. Less is known regarding testing patterns among children and adolescents. We sought to describe the association between race and ethnicity and drug testing at US children's hospitals. We hypothesized that non-Hispanic White children undergo drug testing less often than children from other groups. METHODS: We conducted a retrospective cohort study of emergency department (ED)-only encounters and hospitalizations for children diagnosed with a condition for which drug testing may be indicated (abuse or neglect, burns, malnutrition, head injury, vomiting, altered mental status or syncope, psychiatric, self-harm, and seizure) at 41 children's hospitals participating in the Pediatric Health Information System during 2018 and 2021. We compared drug testing rates among (non-Hispanic) Asian, (non-Hispanic) Black, Hispanic, and (non-Hispanic) White children overall, by condition and patient cohort (ED-only vs. hospitalized) and across hospitals. RESULTS: Among 920,755 encounters, 13.6% underwent drug testing. Black children were tested at significantly higher rates overall (adjusted odds ratio [aOR]: 1.18; 1.05-1.33) than White children. Black-White testing differences were observed in the hospitalized cohort (aOR: 1.42; 1.18-1.69) but not among ED-only encounters (aOR: 1.07; 0.92-1.26). Asian, Hispanic, and White children underwent testing at similar rates. Testing varied by diagnosis and across hospitals. CONCLUSIONS: Hospitalized Black children were more likely than White children to undergo drug testing at US children's hospitals, though this varied by diagnosis and hospital. Our results support efforts to better understand and address healthcare disparities, including the contributions of implicit bias and structural racism.

Measurement system for marine animal reflectance functions.

Photonic structures in the skin of pelagic fishes and squids evolved specifically for hiding in the complex light field of the open ocean. To understand the principles under which these structures operate, a detailed characterization of their optical properties is required. An optical scatterometer has been developed to measure one important property, the bidirectional reflectance distribution function (BRDF). The instrument was used to collect reflectance functions from the squid Pterygioteuthis microlampas and fish Sternoptyx sp. Although the animals appear very different to a casual observer, the results reveal interesting similarities in their scattering patterns, suggesting a similar optical strategy for hiding in open water.

An Intra-Tissue Radiometry Microprobe for Measuring Radiance In Situ in Living Tissue.

Organisms appear opaque largely because their outer tissue layers are strongly scattering to incident light; strongly absorbing pigments, such as blood, typically have narrow absorbances, such that the mean free path of light outside the absorbance peaks can be quite long. As people cannot see through tissue, they generally imagine that tissues like the brain, fat, and bone contain little or no light. However, photoresponsive opsin proteins are expressed within many of these tissues, and their functions are poorly understood. Radiance internal to tissue is also important for understanding photosynthesis. For example, giant clams are strongly absorbing yet maintain a dense population of algae deep in the tissue. Light propagation through systems like sediments and biofilms can be complex, and these communities can be major contributors to ecosystem productivity. Therefore, a method for constructing optical micro-probes for measuring scalar irradiance (photon flux intersecting a point) and downwelling irradiance (photon flux crossing a plane perpendicularly) to better understand these phenomena inside living tissue has been developed. This technique is also tractable in field laboratories. These micro-probes are made from heat-pulled optical fibers that are then secured in pulled glass pipettes. To change the angular acceptance of the probe, a 10-100 µm sized sphere of UV-curable epoxy mixed with titanium dioxide is then secured to the end of a pulled, trimmed fiber. The probe is inserted into living tissue, and its position is controlled using a micromanipulator. These probes are capable of measuring in situ tissue radiance at spatial resolutions of 10-100 µm or on the scale of single cells. These probes were used to characterize the light reaching the adipose and brain cells 4 mm below the skin of a living mouse and to characterize the light reaching similar depths within living algae-rich giant clam tissue.

Evaluation of Patient Access to Spanish-Language-Concordant Care on a Postpartum Unit.

OBJECTIVE: To evaluate patient access to Spanish-language-concordant care on a postpartum unit and to identify facilitators and barriers to the use of interpretation services. DESIGN: Mixed-methods research study, comprising a cross-sectional chart review from September to December 2019 and semistructured interviews from June to December 2020. SETTING/LOCAL PROBLEM: A tertiary academic medical center in the southeastern United States where individuals with limited English proficiency are at risk for poor health outcomes when they are unable to communicate with clinicians in their preferred language. PARTICIPANTS: We conducted a chart review of 50 randomly selected birthing parent-newborn couplets and interviews with 14 inpatient health care team members. MEASUREMENTS: The chart review examined patient characteristics, health care team composition including Spanish language proficiency, length of stay, number of interpreter requests, and time between clinician interpreter requests and interpreter arrival on the unit. Interviews evaluated facilitators and barriers to interpreter use. RESULTS: Access to a clinician certified in medical Spanish or an interpreter was offered to 12 of 50 (24%) couplets upon admission to the unit and to 7 of 50 (14%) of couplets for daily maternal and newborn medical rounds. Clinicians reported long and unpredictable wait times to access interpreters, which led them to rely on hand gestures, broken Spanish, and smartphone apps to "get by" when communicating with patients without certified interpretation services. Participants described low usage of interpreters for "noncritical" encounters. CONCLUSION: Interpreters and other forms of Spanish-language-concordant care were underused on the postpartum unit. This deviation from national standards may put families at risk for harm. Recommendations from this study include advancing a culture of respectful care, improving the interpreter request workflow, addressing safe staffing, facilitating direct patient access to interpreters, and providing ongoing evaluation and support.

Rheology of marine sponges reveals anisotropic mechanics and tuned dynamics.

Sponges are animals that inhabit many aquatic environments while filtering small particles and ejecting metabolic wastes. They are composed of cells in a bulk extracellular matrix, often with an embedded scaffolding of stiff, siliceous spicules. We hypothesize that the mechanical response of this heterogeneous tissue to hydrodynamic flow influences cell proliferation in a manner that generates the body of a sponge. Towards a more complete picture of the emergence of sponge morphology, we dissected a set of species and subjected discs of living tissue to physiological shear and uniaxial deformations on a rheometer. Various species exhibited rheological properties such as anisotropic elasticity, shear softening and compression stiffening, negative normal stress, and non-monotonic dissipation as a function of both shear strain and frequency. Erect sponges possessed aligned, spicule-reinforced fibres which endowed three times greater stiffness axially compared with orthogonally. By contrast, tissue taken from shorter sponges was more isotropic but time-dependent, suggesting higher flow sensitivity in these compared with erect forms. We explore ecological and physiological implications of our results and speculate about flow-induced mechanical signalling in sponge cells.

Characteristics and Outcomes of Children Discharged With Nasoenteral Feeding Tubes.

OBJECTIVES: To describe the characteristics and outcomes of children discharged from the hospital with new nasoenteral tube (NET) use after acute hospitalization. METHODS: Retrospective cohort study using multistate Medicaid data of children <18 years old with a claim for tube feeding supplies within 30 days after discharge from a nonbirth hospitalization between 2016 and 2019. Children with a gastrostomy tube (GT) or requiring home NET use in the 90 days before admission were excluded. Outcomes included patient characteristics and associated diagnoses, 30-day emergency department (ED-only) return visits and readmissions, and subsequent GT placement. RESULTS: We identified 1815 index hospitalizations; 77.8% were patients ≤5 years of age and 81.7% had a complex chronic condition. The most common primary diagnoses associated with index hospitalization were failure to thrive (11%), malnutrition (6.8%), and acute bronchiolitis (5.9%). Thirty-day revisits were common (49%), with 26.4% experiencing an ED-only return and 30.9% hospital readmission. Revisits with a primary diagnosis code for tube displacement/dysfunction (10.7%) or pneumonia/pneumonitis (0.3%) occurred less frequently. A minority (16.9%) of patients progressed to GT placement within 6 months, 22.3% by 1 year. CONCLUSIONS: Children with a variety of acute and chronic conditions are discharged from the hospital with NET feeding. All-cause 30-day revisits are common, though revisits coded for specific tube-related complications occurred less frequently. A majority of patients do not progress to GT within a year. Home NET feeding may be useful for facilitating discharge among patients unable to meet their oral nutrition goals but should be weighed against the high revisit rate.

Twilight spectral dynamics and the coral reef invertebrate spawning response.

There are dramatic and physiologically relevant changes in both skylight color and intensity during evening twilight as the pathlength of direct sunlight through the atmosphere increases, ozone increasingly absorbs long wavelengths and skylight becomes increasingly blue shifted. The moon is above the horizon at sunset during the waxing phase of the lunar cycle, on the horizon at sunset on the night of the full moon and below the horizon during the waning phase. Moonlight is red shifted compared with daylight, so the presence, phase and position of the moon in the sky could modulate the blue shifts during twilight. Therefore, the influence of the moon on twilight color is likely to differ somewhat each night of the lunar cycle, and to vary especially rapidly around the full moon, as the moon transitions from above to below the horizon during twilight. Many important light-mediated biological processes occur during twilight, and this lunar effect may play a role. One particularly intriguing biological event tightly correlated with these twilight processes is the occurrence of mass spawning events on coral reefs. Therefore, we measured downwelling underwater hyperspectral irradiance on a coral reef during twilight for several nights before and after the full moon. We demonstrate that shifts in twilight color and intensity on nights both within and between evenings, immediately before and after the full moon, are correlated with the observed times of synchronized mass spawning, and that these optical phenomena are a biologically plausible cue for the synchronization of these mass spawning events.

The use of music for children and adolescents living with rare diseases in the healthcare setting: a scoping review study protocol.

Background: Interest in the application of music in the health, social care and community contexts is growing worldwide. There is an emerging body of literature about the positive effects of music on the well-being and social relationships of children and adult populations. Music has also been found to promote social interaction, communication skills, and social-emotional behaviours of children with medically complex care needs. Despite significant advancements in the area, to the authors' knowledge, this is the first scoping review to investigate the evidence for using music therapy and music-based interventions for children living with rare diseases in the healthcare setting. Therefore, the purpose of this study is to conduct a scoping review of the literature to map out the existing studies about the use of music therapy and music-based interventions with children who have rare diseases in the healthcare setting. This review will also identify gaps in current knowledge and use of these interventions. Method: This study follows the Joanna Briggs Institute's methodology for scoping reviews, utilising Arksey and O'Malley's six-stage scoping review framework: 1) identifying the research question; 2) identifying relevant studies; 3) study selection; 4) charting the data; 5) collating, summarising and reporting results; and 6) consulting with relevant stakeholders step. A comprehensive search will be conducted in CINAHL Complete; MEDLINE Complete; Psychology and Behavioral Sciences Collection; and PubMed Central databases. A search strategy with selected inclusion and exclusion criteria will be used to reveal a wide range of evidence. This study will include quantitative, qualitative and mixed research methods studies published in English from 2010 to 2020.

Adaptive Thermogenesis in Mice Is Enhanced by Opsin 3-Dependent Adipocyte Light Sensing.

Almost all life forms can detect and decode light information for adaptive advantage. Examples include the visual system, in which photoreceptor signals are processed into virtual images, and the circadian system, in which light entrains a physiological clock. Here we describe a light response pathway in mice that employs encephalopsin (OPN3, a 480 nm, blue-light-responsive opsin) to regulate the function of adipocytes. Germline null and adipocyte-specific conditional null mice show a light- and Opn3-dependent deficit in thermogenesis and become hypothermic upon cold exposure. We show that stimulating mouse adipocytes with blue light enhances the lipolysis response and, in particular, phosphorylation of hormone-sensitive lipase. This response is Opn3 dependent. These data establish a key mechanism in which light-dependent, local regulation of the lipolysis response in white adipocytes regulates energy metabolism.

Catecholic Compounds in Ctenophore Colloblast and Nerve Net Proteins Suggest a Structural Role for DOPA-Like Molecules in an Early-Diverging Animal Lineage.

Ctenophores, or comb jellies, are among the earliest-diverging extant animal lineages. Several recent phylogenomic studies suggest that they may even be the sister group to all other animals. This unexpected finding remains difficult to contextualize, particularly given ctenophores' unique and sometimes poorly understood physiology. Colloblasts, a ctenophore-specific cell type found on the surface of these animals' tentacles, are emblematic of this difficulty. The exterior of the colloblast is dotted with granules that burst and release an adhesive on contact with prey, ensnaring it for consumption. To date, little is known about the fast-acting underwater adhesive that these cells secrete or its biochemistry. We present evidence that proteins in the colloblasts of the ctenophore Pleurobrachia bachei incorporate catecholic compounds similar to the amino acid l-3,4-dihydroxyphenylalanine. These compounds are associated with adhesive-containing granules on the surface of colloblasts, suggesting that they may play a role in prey capture, akin to dihydroxyphenylalanine-based adhesives in mussel byssus. We also present unexpected evidence of similar catecholic compounds in association with the subepithelial nerve net. There, catecholic compounds are present in spatial patterns similar to those of l-3,4-dihydroxyphenylalanine and its derivatives in cnidarian nerves, where they are associated with membranes and possess unknown functionality. This "structural" use of catecholic molecules in ctenophores represents the earliest-diverging animal lineage in which this trait has been observed, though it remains unclear whether structural catechols are deeply rooted in animals or whether they have arisen multiple times.

Brief cognitive behavioral therapy reduces suicidal ideation in veterans with chronic illnesses.

OBJECTIVE: We evaluated the effect of brief cognitive behavioral therapy (bCBT) on suicidal ideation among medically ill veterans receiving mental health treatment in primary care. METHODS: Secondary analysis was conducted on data collected during a multisite, patient-randomized trial investigating the impact of bCBT (n = 180) on depression and anxiety symptoms, relative to enhanced usual care (EUC; n = 122), in patients with congestive heart failure and/or chronic obstructive pulmonary disease. BCBT was delivered by primary care mental health providers over 4 months, with follow-up posttreatment assessments of suicidal ideation, measured by the Patient Health Questionnaire-9 (item 9) at 4, 8, and 12 months. Suicidal ideation was the primary outcome examined in the current analysis. Generalized estimating equations modeling suicidal ideation were used to compare the study arms. RESULTS: Participants receiving bCBT were less likely to have high suicidal ideation than participants receiving EUC posttreatment and at 8-month follow-up after accounting for baseline suicidal ideation. Within-group comparisons suggest participants receiving bCBT were less likely to have high suicidal ideation at 4, 8, and 12 months when compared with baseline. High suicidal ideation for EUC participants did not differ at 4, or 8 months, but they were less likely to have high suicidal ideation at 12 months. CONCLUSION: bCBT in primary care reduces suicidal ideation and may help prevent future suicidal ideation.

Systemic CTLA-4 blockade ameliorates glioma-induced changes to the CD4+ T cell compartment without affecting regulatory T-cell function.

PURPOSE: Patients with malignant glioma suffer global compromise of their cellular immunity, characterized by dramatic reductions in CD4(+) T cell numbers and function. We have previously shown that increased regulatory T cell (T(reg)) fractions in these patients explain T-cell functional deficits. Our murine glioma model recapitulates these findings. Here, we investigate the effects of systemic CTLA-4 blockade in this model. EXPERIMENTAL DESIGN: A monoclonal antibody (9H10) to CTLA-4 was employed against well-established glioma. Survival and risks for experimental allergic encephalomyelitis were assessed, as were CD4(+) T cell numbers and function in the peripheral blood, spleen, and cervical lymph nodes. The specific capacities for anti-CTLA-4 to modify the functions of regulatory versus CD4(+)CD25(-) responder T cells were evaluated. RESULTS: CTLA-4 blockade confers long-term survival in 80% of treated mice, without eliciting experimental allergic encephalomyelitis. Changes to the CD4 compartment were reversed, as anti-CTLA-4 reestablishes normal CD4 counts and abrogates increases in CD4(+)CD25(+)Foxp3(+)GITR(+) regulatory T cell fraction observed in tumor-bearing mice. CD4(+) T-cell proliferative capacity is restored and the cervical lymph node antitumor response is enhanced. Treatment benefits are bestowed exclusively on the CD4(+)CD25(-) T cell population and not T(regs), as CD4(+)CD25(-) T cells from treated mice show improved proliferative responses and resistance to T(reg)-mediated suppression, whereas T(regs) from the same mice remain anergic and exhibit no restriction of their suppressive capacity. CONCLUSIONS: CTLA-4 blockade is a rational means of reversing glioma-induced changes to the CD4 compartment and enhancing antitumor immunity. These benefits were attained through the conferment of resistance to T(reg)-mediated suppression, and not through direct effects on T(regs).

The Proof Is in the Pidan: Generalizing Proteins as Patchy Particles.

The Chinese century egg, or pidan, is a traditional preparation of duck eggs that can be stored for months at room temperature without degradation. Raw eggs are soaked in a strong alkaline and salt solution, and the albumin gradually forms a stable, transparent gel. Here, we show that pidan gels belong to the class of materials formed from "patchy particles". We found that the ß-sheet structure of ovalbumin, the major protein constituent of egg white, is preserved during gelation, while α-helical regions undergo a degree of unfolding into unstructured random coils that may form attractive patches. Upon dilution in additional strong base, the phase behavior of pidan gels is consistent with patchy-particle thermodynamics. This protein gel is also physically and structurally similar to the protein gels that form the squid lens. Both systems exhibit patchy thermodynamics, and the constituent proteins share physical features including a structured, charged core, and polar, unstructured "arms" that form attractive patches. Our work provides a path toward rational design of proteins for precisely structured, volume-spanning materials.

Systemic anti-CD25 monoclonal antibody administration safely enhances immunity in murine glioma without eliminating regulatory T cells.

PURPOSE: Elevated proportions of regulatory T cells (T(reg)) are present in patients with a variety of cancers, including malignant glioma, yet recapitulative murine models are wanting. We therefore examined T(regs) in mice bearing malignant glioma and evaluated anti-CD25 as an immunotherapeutic adjunct. EXPERIMENTAL DESIGN: CD4+CD25+Foxp3+GITR+ T(regs) were quantified in the peripheral blood, spleens, cervical lymph nodes, and bone marrow of mice bearing malignant glioma. The capacities for systemic anti-CD25 therapy to deplete T(regs), enhance lymphocyte function, and generate antiglioma CTL responses were assessed. Lastly, survival and experimental allergic encephalitis risks were evaluated when anti-CD25 was combined with a dendritic cell-based immunization targeting shared tumor and central nervous system antigens. RESULTS: Similar to patients with malignant glioma, glioma-bearing mice show a CD4 lymphopenia. Additionally, CD4+CD25+Foxp3+GITR+ T(regs) represent an increased fraction of the remaining peripheral blood CD4+ T cells, despite themselves being reduced in number. Similar trends are observed in cervical lymph node and spleen, but not in bone marrow. Systemic anti-CD25 administration hinders detection of CD25+ cells but fails to completely eliminate T(regs), reducing their number only moderately, yet eliminating their suppressive function. This elimination of T(reg) function permits enhanced lymphocyte proliferative and IFN-gamma responses and up to 80% specific lysis of glioma cell targets in vitro. When combined with dendritic cell immunization, anti-CD25 elicits tumor rejection in 100% of challenged mice without precipitating experimental allergic encephalitis. CONCLUSIONS: Systemic anti-CD25 administration does not entirely eliminate T(regs) but does prevent T(reg) function. This leads to safe enhancement of tumor immunity in a murine glioma model that recapitulates the tumor-induced changes to the CD4 and T(reg) compartments seen in patients with malignant glioma.