266 research outputs found
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Intracellular \u3cem\u3eSalmonella\u3c/em\u3e delivery of an exogenous immunization antigen refocuses CD8 T cells against cancer cells, eliminates pancreatic tumors and forms antitumor immunity
Introduction: Immunotherapies have shown great promise, but are not effective for all tumors types and are effective in less than 3% of patients with pancreatic ductal adenocarcinomas (PDAC). To make an immune treatment that is effective for more cancer patients and those with PDAC specifically, we genetically engineered Salmonella to deliver exogenous antigens directly into the cytoplasm of tumor cells. We hypothesized that intracellular delivery of an exogenous immunization antigen would activate antigen-specific CD8 T cells and reduce tumors in immunized mice.
Methods: To test this hypothesis, we administered intracellular delivering (ID) Salmonella that deliver ovalbumin as a model antigen into tumor-bearing, ovalbumin-vaccinated mice. ID Salmonella delivers antigens by autonomously lysing in cells after the induction of cell invasion.
Results: We showed that the delivered ovalbumin disperses throughout the cytoplasm of cells in culture and in tumors. This delivery into the cytoplasm is essential for antigen cross-presentation. We showed that co-culture of ovalbumin-recipient cancer cells with ovalbumin-specific CD8 T cells triggered a cytotoxic T cell response. After the adoptive transfer of OT-I CD8 T cells, intracellular delivery of ovalbumin reduced tumor growth and eliminated tumors. This effect was dependent on the presence of the ovalbumin-specific T cells. Following vaccination with the exogenous antigen in mice, intracellular delivery of the antigen cleared 43% of established KPC pancreatic tumors, increased survival, and prevented tumor re-implantation.
Discussion: This response in the immunosuppressive KPC model demonstrates the potential to treat tumors that do not respond to checkpoint inhibitors, and the response to re-challenge indicates that new immunity was established against intrinsic tumor antigens. In the clinic, ID Salmonella could be used to deliver a protein antigen from a childhood immunization to refocus pre-existing T cell immunity against tumors. As an off-the-shelf immunotherapy, this bacterial system has the potential to be effective in a broad range of cancer patients
Early Indicators of Autism Spectrum Disorders in the Second Year of Life
Three groups of 18 children were selected for this study, one group with autism spectrum disorders (ASD), one group with developmental delays in which ASD was ruled out (DD), and one group with typical development (TD), from a pool of 3026 children who were screened with the Communication and Symbolic Behavior Scales Developmental Profile (CSBS DP, Wetherby & Prizant, 2002) Infant-Toddler Checklist under 24 months of age. The CSBS DP Behavior Sample was videotaped on selected children as a second-level evaluation during the second year of life. The Infant-Toddler Checklist had a sensitivity and specificity of 88.9% for this sample of children. Significant group differences were found on the Infant-Toddler Checklist and the Behavior Sample, however, these differences did not distinguish children with ASD and DD with high accuracy. The videotapes of the Behavior Sample were reanalyzed to identify red flags of ASD. Nine red flags differentiated children in the ASD group from both the DD and TD groups and four red flags differentiated children in the ASD Group from the TD group but not the DD group. These 13 red flags were found to discriminate the three groups with a correct classification rate of 94.4%.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44624/1/10803_2004_Article_492544.pd
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Intracellular delivery of protein drugs with an autonomously lysing bacterial system reduces tumor growth and metastases
Critical cancer pathways often cannot be targeted because of limited efficiency crossing cell membranes. Here we report the development of a Salmonella-based intracellular delivery system to address this challenge. We engineer genetic circuits that (1) activate the regulator flhDC to drive invasion and (2) induce lysis to release proteins into tumor cells. Released protein drugs diffuse from Salmonella containing vacuoles into the cellular cytoplasm where they interact with their therapeutic targets. Control of invasion with flhDC increases delivery over 500 times. The autonomous triggering of lysis after invasion makes the platform self-limiting and prevents drug release in healthy organs. Bacterial delivery of constitutively active caspase-3 blocks the growth of hepatocellular carcinoma and lung metastases, and increases survival in mice. This success in targeted killing of cancer cells provides critical evidence that this approach will be applicable to a wide range of protein drugs for the treatment of solid tumors
Large-scale associations between the leukocyte transcriptome and BOLD responses to speech differ in autism early language outcome subtypes.
Heterogeneity in early language development in autism spectrum disorder (ASD) is clinically important and may reflect neurobiologically distinct subtypes. Here, we identified a large-scale association between multiple coordinated blood leukocyte gene coexpression modules and the multivariate functional neuroimaging (fMRI) response to speech. Gene coexpression modules associated with the multivariate fMRI response to speech were different for all pairwise comparisons between typically developing toddlers and toddlers with ASD and poor versus good early language outcome. Associated coexpression modules were enriched in genes that are broadly expressed in the brain and many other tissues. These coexpression modules were also enriched in ASD-associated, prenatal, human-specific, and language-relevant genes. This work highlights distinctive neurobiology in ASD subtypes with different early language outcomes that is present well before such outcomes are known. Associations between neuroimaging measures and gene expression levels in blood leukocytes may offer a unique in vivo window into identifying brain-relevant molecular mechanisms in ASD
The potential for deep groundwater use by Acacia papyrocarpa (Western myall) in a water-limited environment
Knowledge regarding the use of groundwater by plants has implications for successful mine rehabilitation and revegetation programs in water-limited environments. In this study, we combined several approaches to investigate water sources used by Acacia papyrocarpa (Western myall) in the far west of South Australia, including stable isotopes, water potential, groundwater and soil chemistry, and root mapping techniques. Plant δ 18 O signatures and water potentials were compared against a range of possible sources: rainwater, surface soil water (≤1 m depth), and deep groundwater ( > 20 m depth). Our aim was to determine whether groundwater contributed to the mix of waters used by A. papyrocarpa. Overall, we found that trees did not source surface soil water (≤1 m), and probably sourced deep soil water (i.e. > 1 m) rather than deep groundwater. Groundwater, however, could not be dismissed as a potential source, as root mapping showed tree roots were capable of reaching groundwater at depths > 20 m, and isotope results indicated a potential contribution by groundwater to tree water use. However, low osmotic potentials and/or high acidity levels were shown to pose likely barriers to groundwater uptake, at least at the time of sampling. We conclude that because groundwater salinity and acidity are spatially variable in this region, plants with extensive root systems may be able to utilize zones of groundwater with lower salinity and pH levels. Overall, this study contributes to our limited understanding of groundwater use by trees occurring in water-limited environments where groundwater is extremely deep ( > 20 m depth)
Brief Report: Using Individualized Orienting Cues to Facilitate First-Word Acquisition in Non-Responders with Autism
Though considerable progress has been made in developing techniques for improving the acquisition of expressive verbal communication in children with autism, research has documented that 10–25% still fail to develop speech. One possible technique that could be significant in facilitating responding for this nonverbal subgroup of children is the use of orienting cues. Using a multiple baseline design, this study examined whether individualized orienting cues could be identified, and whether their presentation would result in verbal expressive words. The results suggest that using individualized orienting cues can increase correct responding to verbal models as well as subsequent word use. Theoretical and applied implications of orienting cues as they relate to individualized programming for children with autism are discussed
Brief Report: Question-Asking and Collateral Language Acquisition in Children with Autism
The literature suggests children with autism use communication primarily for requests and protests, and almost never for information-seeking. This study investigated whether teaching “Where” questions using intrinsic reinforcement procedures would produce the generalized use of the question, and whether concomitant improvements in related language structures, provided as answers to the children’s questions, would occur. In the context of a multiple baseline across participants design, data showed that the children could rapidly acquire and generalize the query, and that there were collateral improvements in the children’s use of language structures corresponding to the answers to the questions the children asked. The results are discussed in the context of teaching child initiations to improve linguistic competence in children with autism
Using video modeling to teach complex social sequences to children with autism
This study comprised of two experiments was designed to teach complex social sequences to children with autism. Experimental control was achieved by collecting data using means of within-system design methodology. Across a number of conditions children were taken to a room to view one of the four short videos of two people engaging in a simple sequence of activities. Then, each child’s behavior was assessed in the same room. Results showed that this video modeling procedure enhanced the social initiation skills of all children. It also facilitated reciprocal play engagement and imitative responding of a sequence of behaviors, in which social initiation was not included. These behavior changes generalized across peers and maintained after a 1- and 2-month follow-up period
In-Home Training for Fathers of Children with Autism: A Follow up Study and Evaluation of Four Individual Training Components
Literature regarding fathers of children with autism remains sparse, and because mothers are the more common intervening parent, few training methods have focused on fathers. Thus, we sought to evaluate effects of in-home training directed at fathers and their ability to train mothers in the same manner in which they were trained. Fathers were taught four skills commonly associated with in-home training interventions for parents of children with autism: following the child’s lead, imitation with animation, commenting on the child, and expectant waiting. Father skills were evaluated twice a week for 12 weeks during videotaped in-home father–child play sessions. Analyses included visual inspection of graphed data and statistical analyses of father skill acquisition, mother skill acquisition, and child behaviors with both parents. A multivariate repeated measures analysis of 18 dyads revealed significant increases in frequencies of fathers’ imitation with animation, expectant waiting, and commenting on the child. Child initiating rates increased significantly as did frequencies of child non-speech vocalizations. Analysis of mothers revealed significant increases in frequencies of imitation with animation, expectant waiting, and following the child’s lead. Child behaviors had similar results for father and mother sessions. Findings are consistent with those from our first study indicating that fathers can effectively implement skills that promote father–child social interactions and that children respond positively to this approach
Play and Developmental Outcomes in Infant Siblings of Children with Autism
We observed infant siblings of children with autism later diagnosed with ASD (ASD siblings; n = 17), infant siblings of children with autism with and without other delays (Other Delays and No Delays siblings; n = 12 and n = 19, respectively) and typically developing controls (TD controls; n = 19) during a free-play task at 18 months of age. Functional, symbolic, and repeated play actions were coded. ASD siblings showed fewer functional and more non-functional repeated play behaviors than TD controls. Other Delays and No Delays siblings showed more non-functional repeated play than TD controls. Group differences disappeared with the inclusion of verbal mental age. Play as an early indicator of autism and its relationship to the broader autism phenotype is discussed
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