564 research outputs found
Genetically modified human CD4(+) T cells can be evaluated in vivo without lethal graft-versus-host disease
No full textAdoptive cell immunotherapy for human diseases, including the use of T cells modified to express an anti-tumour T-cell receptor (TCR) or chimeric antigen receptor, is showing promise as an effective treatment modality. Further advances would be accelerated by the availability of a mouse model that would permit human T-cell engineering protocols and proposed genetic modifications to be evaluated in vivo. NOD-scid IL2rγ(null) (NSG) mice accept the engraftment of mature human T cells; however, long-term evaluation of transferred cells has been hampered by the xenogeneic graft-versus-host disease (GVHD) that occurs soon after cell transfer. We modified human primary CD4(+) T cells by lentiviral transduction to express a human TCR that recognizes a pancreatic beta cell-derived peptide in the context of HLA-DR4. The TCR-transduced cells were transferred to NSG mice engineered to express HLA-DR4 and to be deficient for murine class II MHC molecules. CD4(+) T-cell-depleted peripheral blood mononuclear cells were also transferred to facilitate engraftment. The transduced cells exhibited long-term survival (up to 3 months post-transfer) and lethal GVHD was not observed. This favourable outcome was dependent upon the pre-transfer T-cell transduction and culture conditions, which influenced both the kinetics of engraftment and the development of GVHD. This approach should now permit human T-cell transduction protocols and genetic modifications to be evaluated in vivo, and it should also facilitate the development of human disease models that incorporate human T cells
Immunological mutants of the mouse.
No full textMutations at more than 30 loci in mice have been shown to cause deleterious effects on the immune system. Immunologic defects caused by certain of these mutations are determined at the level of hematopoietic progenitor cells or at the level of hematopoietic cell-stromal cell interactions. The immunological mutants described in this paper serve as experimental tools with which to increase our understanding of the development and regulation of the mammalian immune system
Antibody Repertoires in Humanized NOD-scid-IL2Rγnull Mice and Human B Cells Reveals Human-Like Diversification and Tolerance Checkpoints in the Mouse
No full textGregory C. Ippolito is with UT Austin; George Georgiou is with UT Austin; Kam Hon Hoi is with UT Austin; Sai T. Reddy is with Eidgenössische Technische Hochschule Zurich; Sean M. Carroll is with UT Austin; Xin Ge is with University of California, Riverside; Tobias Rogosch is with Philips-University; Michael Zemlin is with Philips-University; Leonard D. Shultz is with the Jackson Laboratory; Andrew D. Ellington is with UT Austin; Carla L. VanDenBerg is with UT Austin.Immunodeficient mice reconstituted with human hematopoietic stem cells enable the in vivo study of human hematopoiesis. In particular, NOD-scid-IL2Rγnull engrafted mice have been shown to have reasonable levels of T and B cell repopulation and can mount T-cell dependent responses; however, antigen-specific B-cell responses in this model are generally poor. We explored whether developmental defects in the immunoglobulin gene repertoire might be partly responsible for the low level of antibody responses in this model. Roche 454 sequencing was used to obtain over 685,000 reads from cDNA encoding immunoglobulin heavy (IGH) and light (IGK and IGL) genes isolated from immature, naïve, or total splenic B cells in engrafted NOD-scid-IL2Rγnull mice, and compared with over 940,000 reads from peripheral B cells of two healthy volunteers. We find that while naïve B-cell repertoires in humanized mice are chiefly indistinguishable from those in human blood B cells, and display highly correlated patterns of immunoglobulin gene segment use, the complementarity-determining region H3 (CDR-H3) repertoires are nevertheless extremely diverse and are specific for each individual. Despite this diversity, preferential DH-JH pairings repeatedly occur within the CDR-H3 interval that are strikingly similar across all repertoires examined, implying a genetic constraint imposed on repertoire generation. Moreover, CDR-H3 length, charged amino-acid content, and hydropathy are indistinguishable between humans and humanized mice, with no evidence of global autoimmune signatures. Importantly, however, a statistically greater usage of the inherently autoreactive IGHV4-34 and IGKV4-1 genes was observed in the newly formed immature B cells relative to naïve B or total splenic B cells in the humanized mice, a finding consistent with the deletion of autoreactive B cells in humans. Overall, our results provide evidence that key features of the primary repertoire are shaped by genetic factors intrinsic to human B cells and are principally unaltered by differences between mouse and human stromal microenvironments.Funding was provided by the Cancer Prevention and Research Institute of Texas; the Clayton Foundation; the Defense Advanced Research Projects Agency; Deutsche Forschungsgemeinschaft; and the National Institutes of Health. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Microbiolog
Development and Evaluation of Instrumented Soccer Equipment to Collect Ankle Joint Kinematics in the Field
No full textAnkle sprains commonly occur during athletic competition and result in traumatic injury to the lateral ligament complex. Ankle ligament sprains are the most common injury type for intercollegiate soccer players and athletes that sustain lateral ankle sprains may lose game and/or practice time, have recurrent sprains due to ankle instability, incur proprioceptive deficits, and be at an increased risk of ankle osteoarthritis. The high rate of ankle injuries among soccer athletes demonstrates a need for novel and advanced data collection methodologies to reduce the incidence of lateral ankle sprains and improve injury prevention interventions.
The purposes of this study were to develop instrumented soccer equipment to collect ankle joint kinematics in the field; establish the reliability and validity of a kinematic assessment using instrumented equipment during athletic maneuvers; and identify laboratory maneuvers that elicited game-like demands from athletes. Wireless orientation sensors were integrated into soccer shin guards and turf shoes. The instrumented equipment collected ankle joint kinematics during simulated athletic maneuvers in the laboratory and field. The simulated athletic maneuvers in the laboratory are commonly performed by soccer players and have been previously studied. Maneuvers included drop landing, drop jump, stop jump, and jump-stop cut. Drop landing and drop jump maneuvers resulted in poor to excellent reliability and very good to excellent validity. The stop jump maneuver resulted in poor to fair reliability and excellent validity. The jump-stop cut maneuver resulted in poor to excellent reliability and very good validity. The soccer-specific field maneuvers were jump header, moving jump header, and slalom. All maneuvers resulted in poor to good reliability.
To identify laboratory maneuvers that elicited game-like demands, laboratory maneuvers of varied demand were compared to field maneuvers. Drop landing and drop jump maneuvers from a 60 cm platform elicited a similar response to the jump header maneuver. A jump distance recommendation for the stop jump maneuver was not warranted because jump distance did not significantly alter landing biomechanics. The instrumented equipment collected reliable and valid ankle joint kinematics in the sagittal plane and are a promising technology for in-game data collection and injury prevention
Personality, performance, and the effects of stress on checkered pufferfish (Sphoeroides testudineus)
No full textFew studies focus on the mechanisms that regulate consistent individual-level differences in behaviour (i.e., personality) in wild animals, despite their potential evolutionary and ecological implications. I examined whether wild checkered pufferfish (Sphoeroides testudineus) have consistent individual-level differences in locomotor activity, threat-response behaviour, swimming ability, and puffing performance. I also evaluated the relationships between these personality and performance traits. Personality and performance were compared to movements in the field. In addition, I tested whether a treatment of the stress hormone cortisol would alter personality and performance. Pufferfish exhibited personalities but these were not associated with performance or recapture in the field. Performance was consistent between the lab and the natural enclosure but activity was not. The cortisol treatment did not modify personality or performance, which suggests that these traits do not represent a stress-coping syndrome. I conclude by recommending future directions for research on stress and personality in wild animals
Generation of β cell-specific human cytotoxic T cells by lentiviral transduction and their survival in immunodeficient human leucocyte antigen-transgenic mice
No full textSeveral β cell antigens recognized by T cells in the non-obese diabetic (NOD) mouse model of type 1 diabetes (T1D) are also T cell targets in the human disease. While numerous antigen-specific therapies prevent diabetes in NOD mice, successful translation of rodent findings to patients has been difficult. A human leucocyte antigen (HLA)-transgenic mouse model incorporating human β cell-specific T cells might provide a better platform for evaluating antigen-specific therapies. The ability to study such T cells is limited by their low frequency in peripheral blood and the difficulty in obtaining islet-infiltrating T cells from patients. We have worked to overcome this limitation by using lentiviral transduction to 'reprogram' primary human CD8 T cells to express three T cell receptors (TCRs) specific for a peptide derived from the β cell antigen islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP265-273 ) and recognized in the context of the human class I major histocompatibility complex (MHC) molecule HLA-A2. The TCRs bound peptide/MHC multimers with a range of avidities, but all bound with at least 10-fold lower avidity than the anti-viral TCR used for comparison. One exhibited antigenic recognition promiscuity. The β cell-specific human CD8 T cells generated by lentiviral transduction with one of the TCRs released interferon (IFN)-γ in response to antigen and exhibited cytotoxic activity against peptide-pulsed target cells. The cells engrafted in HLA-A2-transgenic NOD-scid IL2rγ(null) mice and could be detected in the blood, spleen and pancreas up to 5 weeks post-transfer, suggesting the utility of this approach for the evaluation of T cell-modulatory therapies for T1D and other T cell-mediated autoimmune diseases
Understanding Normal and Malignant Human Hematopoiesis Using Next-Generation Humanized Mice.
No full textRodent models for human diseases contribute significantly to understanding human physiology and pathophysiology. However, given the accelerating pace of drug development, there is a crucial need for in vivo preclinical models of human biology and pathology. The humanized mouse is one tool to bridge the gap between traditional animal models and the clinic. The development of immunodeficient mouse strains with high-level engraftment of normal and diseased human immune/hematopoietic cells has made in vivo functional characterization possible. As a patient-derived xenograft (PDX) model, humanized mice functionally correlate putative mechanisms with in vivo behavior and help to reveal pathogenic mechanisms. Combined with single-cell genomics, humanized mice can facilitate functional precision medicine such as risk stratification and individually optimized therapeutic approaches
- …
