320 research outputs found
A single exercise bout enhances the manufacture of viral-specific T-cells from healthy donors: implications for allogeneic adoptive transfer immunotherapy
Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections remain a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). The adoptive transfer of donor-derived viral-specific cytotoxic T-cells (VSTs) is an effective treatment for controlling CMV and EBV infections after HSCT; however, new practical methods are required to augment the ex vivo manufacture of multi-VSTs from healthy donors. This study investigated the effects of a single exercise bout on the ex vivo manufacture of multi-VSTs. PBMCs isolated from healthy CMV/EBV seropositive participants before (PRE) and immediately after (POST) 30-minutes of cycling exercise were stimulated with CMV (pp65 and IE1) and EBV (LMP2A and BMLF1) peptides and expanded over 8 days. The number (fold difference from PRE) of T-cells specific for CMV pp65 (2.6), EBV LMP2A (2.5), and EBV BMLF1 (4.4) was greater among the VSTs expanded POST. VSTs expanded PRE and POST had similar phenotype characteristics and were equally capable of MHC-restricted killing of autologous target cells. We conclude that a single exercise bout enhances the manufacture of multi-VSTs from healthy donors without altering their phenotype or function and may serve as a simple and economical adjuvant to boost the production of multi-VSTs for allogeneic adoptive transfer immunotherapy
Acute exercise enhances the expansion of cytotoxic T-cells specific to leukemia and melanoma antigens: implications for adoptive transfer immunotherapy?
INTRODUCTION: The ex vivo expansion of tumor-associated-antigen (TAA)-specific cytotoxic T-cells from healthy donors for adoptive transfer in cancer patients has been used successfully to prevent relapse after hematopoietic stem cell transplantation (HSCT). However, this therapy is limited by the difficulty in priming and expanding sufficient numbers of functional TAA-specific T-cells, as T-cells recognizing TAA are usually low in frequency and avidity in healthy donors. Furthermore, monocyte-derived dendritic cells (Mo-DC) are used for TAA-presentation, but their manufacture is limited by low blood monocyte numbers. Therefore, large and impractical numbers of blood cells are required to successfully expand TAA-specific T-cells. Acute exercise is well-known to transiently activate and increase the numbers of T-cells and monocytes in peripheral blood. We therefore hypothesized that the immune-enhancing effects of exercise could be harnessed to enhance the ex vivo expansion of TAA-specific T-cells for adoptive transfer immunotherapy. AIMS: To examine the effects of acute exercise on (1) the number and function of TAA-specific T-cells expanded ex vivo, and 2) the generation and function of mo-DC. METHODS: 12 healthy adults (mean ± SD: Age 27±2.6yrs) completed an acute bout of stair-running exercise (time: 104±17sec). Mo-DC generated from pre and post exercise blood samples were pulsed with the melanoma-associated-antigens MAGE-A4 and PRAME, the common tumor-antigen survivin, and the leukemia-associated-antigen WT-1. Autologous DC were used to expand TAA-specific T-cells obtained before and after exercise over 14-days. T-cells were enumerated and phenotyped by flow cytometry and function was assessed by ELISPOT and antigen-specific cytotoxicity. RESULTS: A greater number of mo-DC were generated from post-exercise blood samples (pre: 2.0±1.0 X106cells, post: 5.2±2.6 X106cells). This was due to the 1.7 fold increase in blood monocytes post-exercise, as the number of mo-DC generated per input CD14+cell did not differ (pre: 0.40±0.25, post: 0.59±0.36). Total T-cell expansion was increased post-exercise (fold-increase: pre: 2.48±0.75, post: 2.90±0.74). ELISPOT revealed that the majority of donors had enrichment in TAA-specific T-cells post-exercise, as T-cell lines expanded from post-exercise samples exhibited an increased interferon-gamma response to TAA compared to T-cell lines expanded from pre-exercise samples. Exercise had no effect on T-cell phenotype or antigen-specific cytotoxicity in the expanded cells. CONCLUSION: These data indicate that a single bout of exercise enhances mo-DC generation and the expansion of TAA-specific T-cells ex vivo. Exercise may therefore serve as an adjuvant to enhance the expansion of TAA-specific T-cells in healthy donors and improve the efficacy of adoptive transfer therapy in cancer patients
Cortical cells are altered by factors including bone morphogenetic protein released from a placental barrier model under altered oxygenation
Episodes of hypoxia and hypoxia/reoxygenation during foetal development have been associated with increased risk of neurodevelopmental conditions presenting in later life.
The mechanism for this is not understood; however, several authors have suggested that the placenta plays an important role. Previously we found both placentas from a maternal hypoxia model and pre-eclamptic placentas from patients release factors lead to a loss of dendrite complexity in rodent neurons. Here to further explore the nature and origin of these secretions we exposed a simple in vitro model of the placental barrier, consisting of a barrier of human cytotrophoblasts, to hypoxia or hypoxia/reoxygenation. We then exposed cortical cultures from embryonic rat brains to the conditioned media (CM) from below these exposed barriers and examined changes in cell morphology, number, and receptor presentation.
The barriers released factors that reduced dendrite and astrocyte process lengths, decreased GABAB1 staining, and increased astrocyte number. The changes in astrocytes required the presence of neurons and were prevented by inhibition of the SMAD pathway and by neutralising Bone Morphogenetic Proteins (BMPs) 2/4. Barriers exposed to hypoxia/reoxygenation also released factors that reduced dendrite lengths but increased GABAB1 staining. Both oxygen changes caused barriers to release factors that decreased GluN1, GABAAα1 staining and increased GluN3a staining. We find that hypoxia in particular will elicit the release of factors that increase astrocyte number and decrease process length as well as causing changes in the intensity of glutamate and GABA receptor staining. There is some evidence that BMPs are released and contribute to these changes
CMV-specific T-cells Mobilized with Exercise have Broad Epitope Specificity and a High-Differentiated Effector Memory Phenotype.
Introduction: Dynamic exercise evokes a rapid redeployment of cytotoxic T-cell subsets with high surface expression of b2 adrenergic receptors, presumably to enhance immunosurveillance during acute stress. As this response is affected by age and infection history, the main aim of this study was to examine latent CMV infection as a potential confounder to age-related differences in blood CD8+ T-cell responses to exercise. The second aim of this study was to examine the impact of acute exercise on the mobilization of CMV-specific T-cells in the peripheral blood compartment. Methods: Healthy young (n=16) and older (n=16) humans counterbalanced by CMV IgG serostatus (positive or negative) exercised for 30-minutes at ~80% peak cycling power. Isolated blood lymphocytes phenotypes were assessed by flow cytometry and Enzyme-linked immunospot (ELISPOT) analysis was used to determine the frequency and function of T-cells secreting IFN-g in response to CMV antigens. Maximum likelihood linear mixed models (LMM) were used to determine main effects of exercise (pre, post and 1h post-exercise), age (young or old) and CMV status (positive or negative) on total numbers of blood lymphocytes and their subsets. Results: Those with CMV redeployed ~2 times more CD8+ T-cells and ~6-times more KLRG1+/CD28- and CD45RA+/CCR7- CD8+ subsets than non-infected exercisers. Seronegative older exercisers had an impaired redeployment of total CD8+ T-cells, CD45RA+/CCR7+ and (KLRG1-/CD28+) CD8+ subsets. Redeployed CD8+ T-cell numbers were similar between infected young and old. CMVpp65 specific CD8+ cells in HLA/A2* subjects increased ~2.7 fold after exercise, a response that was driven by the KLRG1+/CD28-/CD8+ subset. Stimulating PBMCs before and after exercise with CMVpp65 and CMV IE-1 antigens and overlapping peptide pools revealed a 2.1 and 4.4 fold increases in CMVpp65 and CMV IE-1 IFN-g secreting cells respectively. The breadth of the T cell response was maintained after exercise with the magnitude of the response being amplified across the entire epitope repertoire. Conclusion: We conclude that latent CMV infection overrides age-related impairments in CD8+ T-cell redeployment with exercise. We also show for the first time that many T-cells redeployed with exercise are specific to CMVpp65 and CMV IE-1 antigens, have broad epitope specificity, and are mostly of a high-differentiated effector memory phenotype. We anticipate that these findings may have clinical implications, with acute exercise serving as a simple strategy to increase numbers of available antigen-specific cells in blood that can be harvested for expansion and adoptive T-cell transfer in HSCT recipients
Toward a Rapid Production of Multivirus-Specific T Cells Targeting BKV, Adenovirus, CMV, and EBV from Umbilical Cord Blood
Umbilical cord blood (CB) has emerged as an effective alternative donor source for hematopoietic stem cell transplantation. Despite this success, the prolonged duration of immune suppression following CB transplantation and the naiveté of CB T cells leave patients susceptible to viral infections. Adoptive transfer of ex vivo-expanded virus-specific T cells from CB is both feasible and safe. However, the manufacturing process of these cells is complicated, lengthy, and labor-intensive. We have now developed a simplified method to manufacture a single culture of polyclonal multivirus-specific cytotoxic T cells in less than 30 days. It eliminates the need for a live virus or transduction with a viral vector, thus making this approach widely available and GMP-applicable to target multiple viruses. The use of overlapping PepMixes as a source of antigen stimulation enable expansion of the repertoire of the T cell product to any virus of interest and make it available as a third party “off the shelf” treatment for viral infections following transplantation
The Extratropical Transition of Tropical Cyclones: Forecast Challenges, Current Understanding, and Future Directions
A significant number of tropical cyclones move into the midlatitudes and transform into extratropical cyclones. This process is generally referred to as extratropical transition (ET). During ET a cyclone frequently produces intense rainfall and strong winds and has increased forward motion, so that such systems pose a serious threat to land and maritime activities. Changes in the structure of a system as it evolves from a tropical to an extratropical cyclone during ET necessitate changes in forecast strategies. In this paper a brief climatology of ET is given and the challenges associated with forecasting extratropical transition are described in terms of the forecast variables (track, intensity, surface winds, precipitation) and their impacts (flooding, bush fires, ocean response). The problems associated with the numerical prediction of ET are discussed. A comprehensive review of the current understanding of the processes involved in ET is presented. Classifications of extratropical transition are described and potential vorticity thinking is presented as an aid to understanding ET. Further sections discuss the interaction between a tropical cyclone and the midlatitude environment, the role of latent heat release, convection and the underlying surface in ET, the structural changes due to frontogenesis, the mechanisms responsible for precipitation, and the energy budget during ET. Finally, a summary of the future directions for research into ET is given
UK B.1.1.7 variant exhibits increased respiratory replication and shedding in nonhuman primates.
The continuing emergence of SARS-CoV-2 variants calls for regular assessment to identify differences in viral replication, shedding and associated disease. In this study, African green monkeys were infected intranasally with either a contemporary D614G or the UK B.1.1.7 variant. Both variants caused mild respiratory disease with no significant differences in clinical presentation. Significantly higher levels of viral RNA and infectious virus were found in upper and lower respiratory tract samples and tissues from B.1.1.7 infected animals. Interestingly, D614G infected animals showed significantly higher levels of viral RNA and infectious virus in rectal swabs and gastrointestinal tract tissues. Our results indicate that B.1.1.7 infection in African green monkeys is associated with increased respiratory replication and shedding but no disease enhancement similar to human B.1.1.7 cases. ONE-SENTENCE SUMMARY: UK B.1.1.7 infection of African green monkeys exhibits increased respiratory replication and shedding but no disease enhancement
Privatization and State Capacity in Postcommunist Society
Economists have used cross-national regression analysis to argue that postcommunist economic failure is the result of inadequate adherence liberal economic policies. Sociologists have relied on case study data to show that postcommunist economic failure is the outcome of too close adherence to liberal policy recommendations, which has led to an erosion of state effectiveness, and thus produced poor economic performance. The present paper advances a version of this statist theory based on a quantitative analysis of mass privatization programs in the postcommunist world. We argue that rapid large-scale privatization creates severe supply and demand shocks for enterprises, thereby inducing firm failure. The resulting erosion of tax revenues leads to a fiscal crisis for the state, and severely weakens its capacity and bureaucratic character. This, in turn, reacts back on the enterprise sector, as the state can no longer support the institutions necessary for the effective functioning of a modern economy, thus resulting in deindustrialization. Using cross-national regression techniques we find that the implementation of mass privatization programs negatively impacts measures of economic growth, state capacity and the security of property rights.http://deepblue.lib.umich.edu/bitstream/2027.42/40192/3/wp806.pd
Mycobacteria-Specific T Cells May Be Expanded From Healthy Donors and Are Near Absent in Primary Immunodeficiency Disorders
Mycobacterial Infections can be severe in patients with T-cell deficiency or phagocyte disorders, and treatment is frequently complicated by antimicrobial resistance. Restoration of T-cell immunity via stem cell transplantation facilitates control of mycobacterial infections, but presence of active infections during transplantation is associated with a higher risk of mortality. Adoptive T cell immunotherapy has been successful in targeting viruses, but has not been attempted to treat mycobacterial infections. We sought to expand and characterize mycobacterial-specific T-cells derived from healthy donors in order to determine suitability for adoptive immunotherapy. Mycobacteria-specific T-cells (MSTs) were generated from 10 healthy donors using a rapid ex vivo expansion protocol targeting five known mycobacterial target proteins (AG85B, PPE68, ESXA, ESXB, and ADK). MSTs were compared to T-cells expanded from the same donors using lysate from M. tuberculosis or purified protein derivative from M. avium (sensitin). MST expansion from seven patients with primary immunodeficiency disorders (PID) and two patients with IFN-γ autoantibodies and invasive M. avium infections. MSTs expanded from healthy donors recognized a median of 3 of 5 antigens, with production of IFN-γ, TNF, and GM-CSF in CD4+ T cells. Comparison of donors who received BCG vaccine (n = 6) to those who did not (n = 4) showed differential responses to PPE68 (p = 0.028) and ADK (p = 0.015) by IFN-γ ELISpot. MSTs expanded from lysate or sensitin also recognized multiple mycobacterial antigens, with a statistically significant differences noted only in the response to PPE68 (p = 0.016). MSTs expanded from patients with primary immunodeficiency (PID) and invasive mycobacterial infections showed activity against mycobacterial antigens in only two of seven subjects, whereas both patients with IFN-γ autoantibodies recognized mycobacterial antigens. Thus, MSTs can be generated from donors using a rapid expansion protocol regardless of history of BCG immunization. Most tested PID patients had no detectable T-cell immunity to mycobacteria despite history of infection. MSTs may have clinical utility for adoptive immunotherapy in T-cell deficient patients with invasive mycobacterial infections
SARS-Like coronavirus WIV1-CoV does not replicate in Egyptian fruit bats (Rousettus aegyptiacus)
Severe acute respiratory syndrome (SARS)-like WIV1-coronavirus (CoV) was first isolated
from Rhinolophus sinicus bats and can use the human angiotensin converting enzyme 2 (ACE2) receptor.
In the current study, we investigate the ability of WIV1-CoV to infect Rousettus aegyptiacus bats. No
clinical signs were observed throughout the experiment. Furthermore, only four oropharyngeal swabs
and two respiratory tissues, isolated on day 3 post inoculation, were found positive for viral RNA.
Two out of twelve bats showed a modest increase in coronavirus specific antibodies post challenge.
In conclusion, WIV1-CoV was unable to cause a robust infection in Rousettus aegyptiacus bats
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