Intragraft gene expression profile associated with the induction of tolerance

<p>Abstract</p> <p>Background</p> <p>Xenotransplantation holds the promise of providing an unlimited supply of donor organs for terminal patients with organ failure. Pre-existing natural antibodies to the Galα1,3Galβ1,4GlcNac-R (αGal) carbohydrate xenoantigen, however, bind rapidly to the graft endothelium and initiate hyperacute rejection of wild type pig grafts in humans. Experimental procedures designed to prevent xenoantibody-mediated rejection have been tested in gal knockout mice. These mice produce anti-gal xenoantibodies and are widely used as small animal models for xenotransplantation research. In this model, chimerism for cells expressing the gal carbohydrate can be achieved by transplantation of mixed cells or by transduction of bone marrow cells with viral vectors expressing a functional α1,3 galactosyltransferase gene. Chimerism induces tolerance to heart grafts expressing αGal. The mechanisms by which tolerance is achieved include systemic changes such as clonal deletion and/or anergy. Intragraft changes that occur during the early stages of tolerance induction have not been characterized.</p> <p>Results</p> <p>Cytoprotective genes heme oxygenase-1 (HO-1), Bcl2, and A20 that have been reported to contribute to long-term graft survival in various models of accommodation were not expressed at high levels in tolerant heart grafts. Intragraft gene expression at both early (Day 10) and late (>2 month) time points after heart transplant were examined by real-time PCR and microarray analysis was used to identify changes associated with the induction of tolerance. Intragraft gene expression profiling using microarray analysis demonstrated that genes identified in the functional categories of stress and immunity and signal transduction were significantly up-regulated in early tolerant grafts compared with syngeneic control grafts. Biological process classification showed lower binomial p-values in the categories of "response to biotic stimulus, defense response, and immune response" suggesting that up-regulated genes identified in these grafts promote survival in the presence of an immune response. The expression of the incompatible carbohydrate antigen (αGal) was reduced by 2 months post-transplant when compared with the expression of this gene at Day 10 post-transplant. These results suggest that the gal carbohydrate antigen is downmodulated over time in grafts that demonstrate tolerance.</p> <p>Conclusion</p> <p>Our study suggests that tolerance is associated with intragraft gene expression changes that render the heart resistant to immune-mediated rejection. Genes associated with stress and immunity are up-regulated, however cytoprotective genes HO-1, Bcl2 and A20 were not up-regulated. The expression of the gal carbohydrate, the key target initiating an immune response in this model, is down-regulated in the post-transplant period.</p

Gene Transfer of Heme Oxygenase-1 Using an Adeno-Associated Virus Serotype 6 Vector Prolongs Cardiac Allograft Survival

Introduction. Allograft survival can be prolonged by overexpression of cytoprotective genes such as heme oxygenase-1 (HO-1). Modifications in vector design and delivery have provided new opportunities to safely and effectively administer HO-1 into the heart prior to transplantation to improve long-term graft outcome. Methods. HO-1 was delivered to the donor heart using an adeno-associated virus vector (AAV) with a pseudotype 6 capsid and vascular endothelial growth factor (VEGF) to enhance myocardial tropism and microvascular permeability. Survival of mouse cardiac allografts, fully or partially mismatched at the MHC, was determined with and without cyclosporine A. Intragraft cytokine gene expression was examined by PCR. Results. The use of AAV6 to deliver HO-1 to the donor heart, combined with immunosuppression, prolonged allograft survival by 55.3% when donor and recipient were completely mismatched at the MHC and by 94.6% if partially mismatched. The combination of gene therapy and immunosuppression was more beneficial than treatment with either AAV6-HO-1 or CsA alone. IL-17a, b, e and f were induced in the heart at rejection. Conclusions. Pretreatment of cardiac allografts with AAV6-HO-1 plus cyclosporine A prolonged graft survival. HO-1 gene therapy represents a beneficial adjunct to immunosuppressive therapy in cardiac transplantation

Intragraft gene expression profile associated with the induction of tolerance-2

Ts (GalT BMT) compared to syngeneic control grafts. Nine functional subsets were identified using Gene Ontology Biological Process categories.<p><b>Copyright information:</b></p><p>Taken from "Intragraft gene expression profile associated with the induction of tolerance"</p><p>http://www.biomedcentral.com/1471-2172/9/5</p><p>BMC Immunology 2008;9():5-5.</p><p>Published online 11 Feb 2008</p><p>PMCID:PMC2275216.</p><p></p

Intragraft gene expression profile associated with the induction of tolerance-0

R, transduced bone marrow cells and bone marrow cells from GalT BMT mice at day 14 post-BMT express the galactosyltransferase gene as identified by real-time PCR. Relative cDNA expression levels were normalized with respect to GAPDH gene expression as an internal control. The samples were run in triplicate and the experiment was repeated twice. Standard deviations are shown for each experiment.<p><b>Copyright information:</b></p><p>Taken from "Intragraft gene expression profile associated with the induction of tolerance"</p><p>http://www.biomedcentral.com/1471-2172/9/5</p><p>BMC Immunology 2008;9():5-5.</p><p>Published online 11 Feb 2008</p><p>PMCID:PMC2275216.</p><p></p

Intragraft gene expression profile associated with the induction of tolerance-4

Tolerance group (GalT BMT) compared to syngeneic controls were analyzed by real-time PCR to determine whether the data obtained by microarray analysis could be validated using an alternative technique. Relative cDNA expression levels were normalized with respect to GAPDH gene expression as internal control. Results are shown as the logarithmic value of mean fold-change of gene expression.<p><b>Copyright information:</b></p><p>Taken from "Intragraft gene expression profile associated with the induction of tolerance"</p><p>http://www.biomedcentral.com/1471-2172/9/5</p><p>BMC Immunology 2008;9():5-5.</p><p>Published online 11 Feb 2008</p><p>PMCID:PMC2275216.</p><p></p

Intragraft gene expression profile associated with the induction of tolerance-5

R, transduced bone marrow cells and bone marrow cells from GalT BMT mice at day 14 post-BMT express the galactosyltransferase gene as identified by real-time PCR. Relative cDNA expression levels were normalized with respect to GAPDH gene expression as an internal control. The samples were run in triplicate and the experiment was repeated twice. Standard deviations are shown for each experiment.<p><b>Copyright information:</b></p><p>Taken from "Intragraft gene expression profile associated with the induction of tolerance"</p><p>http://www.biomedcentral.com/1471-2172/9/5</p><p>BMC Immunology 2008;9():5-5.</p><p>Published online 11 Feb 2008</p><p>PMCID:PMC2275216.</p><p></p

Factors Associated With Work Engagement of Nurses During the Fifth Wave of the COVID-19 Pandemic in Japan: Web-Based Cross-Sectional Study

BackgroundThe COVID-19 pandemic has brought to light the prevalence of mental health issues among nurses. Work engagement (WE) is a concept that describes work-related positive psychological states and is of importance within mental health measures. There is, however, a lack of research on factors associated with the WE of nurses during the COVID-19 pandemic. ObjectiveWe aimed to determine which factors are associated with WE among nurses during the COVID-19 pandemic using the job demands-resources (JD-R) model as a framework. MethodsA web-based cross-sectional survey was conducted among nurses working in acute care and psychiatric institutions in the prefectures of Chiba and Tokyo in Japan. The survey period occurred between August 8 and September 30, 2021, during a time when the number of patients with a positive COVID-19 infection increased. The 3-item version of the Utrecht Work Engagement Scale (UWES-3) was used to measure WE. Factors such as age, gender, years of experience, affiliated ward, COVID-19–related stress, financial rewards from the government and hospital, encouragement from the government and patients, and workplace social capital were assessed. A total of 187 participants were included in the final analysis. Multiple regression analysis was performed to examine the factors related to WE. Partial regression coefficients (B), 95% CI, and P values were calculated. ResultsThe mean overall score for the UWES-3 was 3.19 (SD 1.21). Factors negatively associated with UWES-3 were COVID-19–related stress on work motivation and escape behavior (Β –0.16, 95% CI –0.24 to –0.090; P<.001), and factors positively associated with UWES-3 were affiliation of intensive care units (Β 0.76, 95% CI 0.020-1.50; P=.045) and financial rewards from the government and hospital (Β 0.40, 95% CI 0.040-0.76; P=.03). ConclusionsThis study examined factors related to WE among nurses during the COVID-19 pandemic using the JD-R model. When compared with findings from previous studies, our results suggest that nurses’ WE was lower than before the COVID-19 pandemic. Negative motivation and escape behaviors related to COVID-19 were negatively associated with WE, while there were positive associations with financial rewards from the government and hospital and affiliation with an intensive care unit. Further research into larger populations is needed to confirm these findings

Efficacy of Recombinant Canine Distemper Virus Expressing Leishmania Antigen against Leishmania Challenge in Dogs

Canine distemper virus (CDV) vaccination confers long-term protection against CDV reinfection. To investigate the utility of CDV as a polyvalent vaccine vector for Leishmania, we generated recombinant CDVs, based on an avirulent Yanaka strain, that expressed Leishmania antigens: LACK, TSA, or LmSTI1 (rCDV–LACK, rCDV–TSA, and rCDV–LmSTI1, respectively). Dogs immunized with rCDV-LACK were protected against challenge with lethal doses of virulent CDV, in the same way as the parental Yanaka strain. To evaluate the protective effects of the recombinant CDVs against cutaneous leishmaniasis in dogs, dogs were immunized with one recombinant CDV or a cocktail of three recombinant CDVs, before intradermal challenge (in the ears) with infective-stage promastigotes of Leishmania major. Unvaccinated dogs showed increased nodules with ulcer formation after 3 weeks, whereas dogs immunized with rCDV–LACK showed markedly smaller nodules without ulceration. Although the rCDV–TSA- and rCDV–LmSTI1-immunized dogs showed little protection against L. major, the cocktail of three recombinant CDVs more effectively suppressed the progression of nodule formation than immunization with rCDV–LACK alone. These results indicate that recombinant CDV is suitable for use as a polyvalent live attenuated vaccine for protection against both CDV and L. major infections in dogs