Endoplasmic Reticulum Stress Response Mediator IRE-1α Promotes Host Dendritic Cells in Graft-versus-Host Disease Development.

Allogeneic hematopoietic cell transplantation is an effective treatment for hematologic malignancies, but the complications such as graft-versus-host disease (GVHD) can limit its benefit. The conditioning regimens before transplant, including chemotherapy or irradiation, can trigger endoplasmic reticulum stress. IRE-1α is a major endoplasmic reticulum stress mediator that can further activate both spliced XBP-1 (XBP-1s) and regulated IRE-1-dependent decay (RIDD). IRE-1α-XBP-1s signaling controls dendritic cell (DC) differentiation and Ag presentation, crucial in GVHD progression. In this study, we used DC-specific XBP-1-deficient mice as donors or recipients and observed that XBP-1s was crucial for host DCs in the induction of GVHD but dispensable for the graft-versus-leukemia response. To specifically target IRE-1α in the host, we treated recipient mice with the IRE-1α inhibitor B-I09 for 3 d prior to bone marrow transplantation, which significantly suppressed GVHD development while maintaining the graft-versus-leukemia effect. XBP-1-deficient or BI09-treated recipients showed reduced DC survival after irradiation and bone marrow transplantation. Inhibition of IRE-1α also led to a reduction in DC alloreactivity, subsequently decreasing the proliferation and activation of allogeneic T cells. With further study using RIDD-deficient DCs, we observed that RIDD was also required for optimal DC activation. Taken together, XBP-1s and RIDD both promote host DC survival and alloreactivity that contribute to GVHD development.

The Absence of IL-12Rß2 Expression on Recipient Nonhematopoietic Cells Diminishes Acute Graft-versus-Host Disease in the Gastrointestinal Tract.

The gastrointestinal (GI) tract is a frequent target organ in acute graft-versus-host disease (aGVHD), which can determine the morbidity and nonrelapse mortality after allogeneic hematopoietic cell transplantation (allo-HCT). Donor T cells recognize allogeneic Ags presented by host APCs, proliferate, and differentiate into Th1 and Th17 cells that drive GVHD pathogenesis. IL-12 has been shown to play an important role in amplifying the allogeneic response in preclinical and clinical studies. This study demonstrates that IL-12Rß2 expression on recipient nonhematopoietic cells is required for optimal development of aGVHD in murine models of allo-HCT. aGVHD attenuation by genetic depletion of IL-12R signaling is associated with reduced MHC class II expression by intestinal epithelial cells and maintenance of intestinal integrity. We verified IL-12Rß2 expression on activated T cells and in the GI tract. This study, to our knowledge, reveals a novel function of IL-12Rß2 in GVHD pathogenesis and suggests that selectively targeting IL-12Rß2 on host nonhematopoietic cells may preserve the GI tract after allo-HCT.

Leukemia inhibitory factor protects against graft-versus-host disease while preserving graft-versus-leukemia activity.

Graft-versus-host disease (GVHD) remains a major complication after allogeneic hematopoietic stem cell transplantation, a widely used therapy for hematologic malignancies and blood disorders. Here, we report an unexpected role of cytokine leukemia inhibitory factor (LIF) in protecting against GVHD development. Administrating recombinant LIF protein (rLIF) protects mice from GVHD-induced tissue damage and lethality without compromising the graft-versus-leukemia activity, which is crucial to prevent tumor relapse. We found that rLIF decreases the infiltration and activation of donor immune cells and protects intestinal stem cells to ameliorate GVHD. Mechanistically, rLIF downregulates IL-12-p40 expression in recipient dendritic cells after irradiation through activating STAT1 signaling, which results in decreased major histocompatibility complex II levels on intestinal epithelial cells and decreased donor T-cell activation and infiltration. This study reveals a previously unidentified protective role of LIF for GVHD-induced tissue pathology and provides a potential effective therapeutic strategy to limit tissue pathology without compromising antileukemic efficacy.

Risk factors and management of gastrointestinal bleeding in patients with or without antiplatelet and anticoagulation therapy: a multicenter real-world prospective study.

BACKGROUND: Antiplatelet and anticoagulation drugs complicate acute gastrointestinal bleeding (GIB) patients. Limited data about the risk factors and patient management has been presented. This study explored the association between previous antiplatelet or anticoagulant drug usage and clinical outcomes in GIB patients to improve awareness further and optimize treatment. METHODS: We conducted a multicenter, non-interventional, real-world prospective study in 106 hospitals in 23 provinces in China. GIB patients confirmed in the emergency department were included and were grouped according to previous drug histories. Univariate analysis, multivariate logistic regression, and multivariate stratification models were performed separately to investigate the associations. RESULTS: A total of 2299 patients (57.23 ± 17.21 years old, 68.3% male) were included, of whom 20.1% and 2.9% received antiplatelet and anticoagulation therapy, respectively. The all-cause 28-day mortality rates in patients without antiplatelet or anticoagulants, patients undergoing antiplatelet treatment, and patients with anticoagulation therapy were 2.8%, 4.6%, and 10.5%, respectively. After adjusting for confounding factors, both antiplatelet [odd ratio (OR), 2.92; 95% confidence interval (CI), 1.48-5.76; p = 0.002] and anticoagulation therapy (OR, 8.87; 95% CI, 3.02-26.02; p < 0.001) were associated with higher 28-day mortality. In the subgroup analysis, blood transfusion, especially red blood cell transfusion, in patients undergoing antiplatelet and anticoagulation therapy was associated with a decreased death risk. CONCLUSION: We confirmed an association between concurrent antiplatelet or anticoagulation therapy in GIB patients and elevated 28-day mortality. Blood transfusions could improve poor outcomes in such patients.

Relationship between glucocorticoids and viral load during the Omicron wave in mainland China.

BACKGROUND: Coronavirus disease 19 (COVID-19) is a major public health problem that cannot be ignored. As a widely used drug in the treatment of COVID-19, whether glucocorticoids may accelerate the clearance of COVID-19 is still not clear, and the glucocorticoids may improve the prognosis of patients is also controversial. Therefore, to explore the relationship between COVID-19 viral load and the use of glucocorticoids we designed this study. METHODS: Patients with COVID-19 infection who were admitted to the emergency department of Peking Union Medical College Hospital from the end of 2022 to early 2023 were enrolled in this study. Characteristics of baseline, clinical and laboratory evaluation especially immunological indicator and daily viral load were carefully collected. Kolmogorov-Smirnov test, Student's t test, Mann-Whitney U test and proportional-hazards model (Cox model) were chosen as appropriate for comparison of variables. RESULTS: By comparing the daily COVID-19 viral load and prognosis of patients with and without glucocorticoid therapy, we found that glucocorticoids did not statistically enhance the clearance or replication of COVID-19, nor did it change the 28-days and in-hospital mortality. However, glucocorticoid therapy may be a favorable factor for COVID-19 negative conversion in Cox model. The inflammatory factors in patients with glucocorticoid therapy were significantly decreased. CONCLUSIONS: We believe that the real effect of glucocorticoids may be to improve the destruction of host immune system caused by inflammatory storm through host immune regulation and then achieve the improvement of clinical symptoms.

Expression of GM-CSF Is Regulated by Fli-1 Transcription Factor, a Potential Drug Target.

Friend leukemia virus integration 1 (Fli-1) is an ETS transcription factor and a critical regulator of inflammatory mediators, including MCP-1, CCL5, IL-6, G-CSF, CXCL2, and caspase-1. GM-CSF is a regulator of granulocyte and macrophage lineage differentiation and a key player in the pathogenesis of inflammatory/autoimmune diseases. In this study, we demonstrated that Fli-1 regulates the expression of GM-CSF in both T cells and endothelial cells. The expression of GM-CSF was significantly reduced in T cells and endothelial cells when Fli-1 was reduced. We found that Fli-1 binds directly to the GM-CSF promoter using chromatin immunoprecipitation assay. Transient transfection assays indicated that Fli-1 drives transcription from the GM-CSF promoter in a dose-dependent manner, and mutation of the Fli-1 DNA binding domain resulted in a significant loss of transcriptional activation. Mutation of a known phosphorylation site within the Fli-1 protein led to a significant increase in GM-CSF promoter activation. Thus, direct binding to the promoter and phosphorylation are two important mechanisms behind Fli-1-driven activation of the GM-CSF promoter. In addition, Fli-1 regulates GM-CSF expression in an additive manner with another transcription factor Sp1. Finally, we demonstrated that a low dose of a chemotherapeutic drug, camptothecin, inhibited expression of Fli-1 and reduced GM-CSF production in human T cells. These results demonstrate novel mechanisms for regulating the expression of GM-CSF and suggest that Fli-1 is a critical druggable regulator of inflammation and immunity.

Predictive Values of ADAMTS13, TBIL, and D-D for Prognosis of Patients with Thrombotic Thrombocytopenic Purpura.

BACKGROUND: The aim of the study was to investigate the levels of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13), total bilirubin (TBIL), and D-dimer (D-D) in thrombotic thrombocytopenic purpura (TTP) and their values for predicting the prognosis. METHODS: The clinical data of 89 TTP patients admitted from March 2018 to December 2021 were collected for retrospective analysis. They were assigned to remission group (n = 61) and death group (n = 28) according to clinical outcomes. General clinical data were compared between the two groups. Predictors with non-zero coefficients were screened by LASSO regression analysis, and influencing factors were identified by logistic regression analysis. Then the risk factors were incorporated to construct a nomogram model, which was validated subsequently. Bivariate Pearson's correlation analysis was employed to analyze the correlations. The receiver operating characteristic curves were plotted to analyze the values of ADAMTS13, TBIL, and D-D for predicting the prognosis of TTP. RESULTS: TBIL ≥ 72.74 µmol/L, D-D ≥ 4.17 mg/L, PLASMIC score < 6 points, and absence of plasma exchange (PEx) were risk factors affecting the prognosis, and ADAMTS13 ≤ 25.04% was a protective factor for the prognosis of TTP patients (p < 0.05). ADAMTS13, TBIL, and D-D were significantly associated with death (p < 0.05). The areas under the curves of TBIL, ADAMTS13, D-D and their combination were 0.796 (95% confidence interval CI: 0.729 - 0.860), 0.721 (95% CI: 0.648 - 0.788), 0.820 (95% CI: 0.756 - 0.880), and 0.872 (95% CI: 0.823 - 0.920), respectively. CONCLUSIONS: TBIL, D-D, ADAMTS13, PLASMIC score, and absence of PEx are factors influencing the prognosis of TTP patients, among which TBIL, D-D, and ADAMTS13 are of high predictive values.

A Retrospective, Nested Case-Control Study to Develop a Biomarker-Based Model for ARDS Diagnostics.

BACKGROUND: Several biomarkers could be intercalated with traditional measures to improve ARDS diagnostics. METHODS: There were 211 ICU patients enrolled in this retrospective, nested case-control study. Participants were divided into an ARDS (n = 79) and non-ARDS (n = 132) groups, according to the Berlin criteria. Patient characteristics, vital signs, and laboratory tests were collected within three hours of admission. CC16, Ang-2, sRAGE, HMGB1, and SPD were measured within three hours and again at 24 hours, after admission to ICU. Receiver Operating Characteristic curves and multivariate logistic regression analyses were applied for predictive purposes. RESULTS: C-reactive protein (CRP), NT-proBNP, and pH values were intercalated with five established ARDS indicators, and the PaO2/FiO2 ratio. Only four potential indicators were analyzed, with CRP having high diagnostic value. Areas under curve (AUC) were as follows: CC16 (AUC: 0.752; 95% CI 0.680 - 0.824), Ang-2 (AUC: 0.695; 95% CI 0.620 - 0.770), HMGB1 (AUC: 0.668; 95% CI 0.592 - 0.744), sRAGE (AUC: 0.665; 95% CI 0.588 - 0.743), CRP (AUC: 0.701; 95% CI 0.627 - 0.776). No single indicator improved upon the PaO2/FiO2 ratio which had an AUC: 0.844 (95% CI 0.789 - 0.898). However, when the binary logistic model was transformed and the model was constructed, the AUC increased from 0.647 (95% CI 0.568 - 0.726) to 0.911 (95% CI 0.864 - 0.946). Among the combinations tested, PaO2/FiO2 + CRP + Ang-2 + CC16 + HMGB1 resulted in the highest AUC of 0.910 (95% CI 0.863 - 0.945), although there are other factors which must be considered. CONCLUSIONS: A combination of biomarkers could enhance ARDS diagnostics, which has obvious ramifications for patient care and prognosis. It may be possible to develop a predictive ARDS nomogram; however, of the combinations tested here, we tentatively recommend PaO2/FiO2 + CRP + Ang-2 + CC16 + HMGB1. This is because of the cost implications in contrast with benefit involved in utilizing the more elaborate model. Further health economics research is required to consider the opportunity cost for emergency care policy.

Cereblon harnesses Myc-dependent bioenergetics and activity of CD8+ T lymphocytes.

Immunomodulatory drugs, such as thalidomide and related compounds, potentiate T-cell effector functions. Cereblon (CRBN), a substrate receptor of the DDB1-cullin-RING E3 ubiquitin ligase complex, is the only molecular target for this drug class, where drug-induced, ubiquitin-dependent degradation of known "neosubstrates," such as IKAROS, AIOLOS, and CK1α, accounts for their biological activity. Far less clear is whether these CRBN E3 ligase-modulating compounds disrupt the endogenous functions of CRBN. We report that CRBN functions in a feedback loop that harnesses antigen-specific CD8+ T-cell effector responses. Specifically, Crbn deficiency in murine CD8+ T cells augments their central metabolism manifested as elevated bioenergetics, with supraphysiological levels of polyamines, secondary to enhanced glucose and amino acid transport, and with increased expression of metabolic enzymes, including the polyamine biosynthetic enzyme ornithine decarboxylase. Treatment with CRBN-modulating compounds similarly augments central metabolism of human CD8+ T cells. Notably, the metabolic control of CD8+ T cells by modulating compounds or Crbn deficiency is linked to increased and sustained expression of the master metabolic regulator MYC. Finally, Crbn-deficient T cells have augmented antigen-specific cytolytic activity vs melanoma tumor cells, ex vivo and in vivo, and drive accelerated and highly aggressive graft-versus-host disease. Therefore, CRBN functions to harness the activation of CD8+ T cells, and this phenotype can be exploited by treatment with drugs.

Anti-N-methyl-D-aspartate receptor encephalitis: characteristics and rapid diagnostic approach in the emergency department.

BACKGROUND: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a common type of autoimmune encephalitis. Patients with this condition are frequently very ill but are often misdiagnosed in the Emergency Department (ED). The objective of this study was to analyze the clinical characteristics of anti-NMDAR patients in the ED and to identify any associations with a diagnosis of anti-NMDAR encephalitis. METHODS: We performed a retrospective analysis of a prospectively obtained cohort of ED patients from May 2011 to December 2017. We identified patients diagnosed with anti-NMDAR encephalitis in this cohort and extracted key patient characteristics and clinical data, including patient gender, age, presentation, modified Rank Score (m-RS), laboratory test results, significant treatments, and mortality. RESULTS: Eighty-seven patients with anti-NMDAR encephalitis were identified. 54 (62.1%) were female, 23 (26.4%) were < 18 years old, 14 (16.1%) had teratoma, and 45 (51.7%) had an m-RS ≥ 4. Fever, altered mental status, and seizures were the most common symptoms, with a > 50% incidence of each symptom in the cohort. The sensitivity of CSF oligoclonal band (OB) testing was 78.9%. 22 (25.3%) were admitted to the ICU, 20 (23.0%) patients were intubated, but only one patient died (1.1%). 47 (54.0%) were misdiagnosed prior to ED arrival. All patients underwent immunotherapy as first-line treatment for anti-NMDAR encephalitis. CONCLUSIONS: A majority of anti-NMDAR encephalitis patients presenting to the ED were female and were likely to be misdiagnosed prior to arrival. Patients with symptoms of fever, altered mental status, and seizures need a lumbar puncture, including CSF OB testing, for definitive diagnosis.

Assessment of a new volumetric capnography-derived parameter to reflect compression quality and to predict return of spontaneous circulation during cardiopulmonary resuscitation in a porcine model.

We aimed to evaluate a volumetric capnography (Vcap)-derived parameter, the volume of CO2 eliminated per minute and per kg body weight (VCO2/kg), as an indicator of the quality of chest compression (CC) and to predict the return to spontaneous circulation (ROSC) under stable ventilation status. Twelve male domestic pigs were utilized for the randomized crossover study. After 4 min of untreated ventricular fibrillation (VF), mechanical cardiopulmonary resuscitation and ventilation were administered. Following 5-min washout periods, each animal underwent two sessions of experiments: three types of CC quality for 5 min stages in the first session, followed by advanced life support, consecutively in two sessions. Different CC quality had a significant effect on the partial pressure of end-tidal carbon dioxide (PetCO2), VCO2/kg, aortic pressure (mean), aortic systolic pressure, aortic diastolic pressure, right atrial pressure (mean), and carotid blood flow (P < 0.05). With the improvement in CC quality, the values of PetCO2 and VCO2/kg also increased, and the difference between the groups was statistically significant (P < 0.05). The Spearman rank test revealed a significant correlation between the Vcap-derived parameters and hemodynamics. PetCO2 and VCO2/kg have similar capabilities for discriminating survivors from non-survivors, and the area under the curve for both was 0.97. VCO2/kg had similar performance as PetCO2 in reflecting the quality of CC and prediction of achieving ROSC under stable ventilation status in a porcine model of VF-related cardiac arrest. However, VCO2/kg requires a longer time to achieve a stable state after adjusting for quality of CC than PetCO2.

Interleukin-23 receptor signaling by interleukin-39 potentiates T cell pathogenicity in acute graft-versus-host disease.

IL-12 (p35/p40) and IL-23 (p19/p40) signal through IL-12R (IL-12Rß2/ß1) and IL-23R (IL-23Rα/IL-12Rß1), respectively, which can promote pathogenic T lymphocyte activation, differentiation, and function in graft-versus-host disease (GVHD). With the use of murine models of allogeneic hematopoietic cell transplantation (HCT), we found that IL-12Rß1 on donor T cells was dispensable to induce acute GVHD development in certain circumstances, while IL-23Rα was commonly required. This observation challenges the current paradigm regarding IL-12Rß1 as a prerequisite to transmit IL-23 signaling. We hypothesized that p19/EBI3 (IL-39) may have an important role during acute GVHD. With the use of gene transfection and immunoprecipitation approaches, we verified that p19 and EBI3 can form biological heterodimers. We found that IL-39 levels in recipient serum positively correlated with development of acute GVHD in experimental models and in clinical settings, thereby implicating IL-39 in the pathogenesis of acute GVHD. Furthermore, we observed that human T cells can signal in response to IL-39. In chronic GVHD, IL-23Rα and IL-12Rß1 were similarly required for donor T cell pathogenicity, and IL-39 levels were not significantly different from controls without GVHD. Collectively, we identify a novel cytokine, IL-39, as a pathogenic factor in acute GVHD, which represents a novel potential therapeutic target to control GVHD and other inflammatory disorders.

Targeting Sirt-1 controls GVHD by inhibiting T-cell allo-response and promoting Treg stability in mice.

Graft-versus-host disease (GVHD) remains one of the major complications after allogeneic bone marrow transplantation (allo-BMT). Sirtuin-1 (Sirt-1) plays a crucial role in various biological processes including cellular senescence, metabolism, and inflammatory responses. Sirt-1 deacetylation regulates different transcription factors that are important for modulating immune responses. In the current study, we addressed the role of Sirt-1 in GVHD induction by employing Sirt-1 conditional knockout mice as well as a pharmacological Sirt-1 inhibitor. Using major histocompatibility complex (MHC)-mismatched and MHC-matched murine BMT models, we found that Sirt-1-/- T cells had a reduced ability to induce acute GVHD (aGVHD) via enhanced p53 acetylation. Sirt-1-deficient T cells also promoted induced regulatory T cell (iTreg) differentiation and inhibited interferon-γ production after allo-BMT. Sirt-1 deletion in iTregs increased Foxp3 stability and restrained iTreg conversion into pathogenic T cells. Furthermore, we found that administration with a Sirt-1 inhibitor, Ex-527, significantly improved recipient survival and clinical scores, with no signs of tumor relapse. These results indicate that Sirt-1 inhibition can attenuate GVHD while preserving the graft-versus-leukemia effect. Consistently, Sirt-1-deficient T cells also displayed a remarkably reduced ability to induce chronic GVHD (cGVHD). Mechanistic studies revealed that Sirt-1 deficiency in T cells enhanced splenic B-cell reconstitution and reduced follicular T helper cell development. Sirt-1 deficiency in T cells modulated donor B-cell responses reducing both B-cell activation and plasma cell differentiation. In addition, therapeutic Sirt-1 inhibition could both prevent cGVHD and reduce established cGVHD. In conclusion, Sirt-1 is a promising therapeutic target for the control of aGVHD and cGVHD pathogenesis and possesses high potential for clinical application.

Klebsiella pneumoniae-related invasive liver abscess syndrome complicated by purulent meningitis: a review of the literature and description of three cases.

BACKGROUND: Klebsiella pneumoniae (K. pneumoniae) invasive liver abscess syndrome (ILAS) with purulent meningitis was rarely identified the mainland of China. Last winter, we received 3 cases of K. pneumoniae meningitis and all of them died in a short time. We report these cases in order to find the reason of high mortality and discuss effective effort to improve these patients' prognosis. CASE PRESENTATION: Three patients with uncontrolled diabetes developed live abscess and purulent meningitis. Upon admission, the clinical manifestations, laboratory result of blood and cerebrospinal fluid (CSF) and imaging examinations were compatible with K. pneumoniae ILAS which had metastasis infection of meningitis. Even with timely adequate antibiotic therapy and strict glycemic control, all of the patients' condition deteriorated rapidly and died in a short time. CONCLUSION: The reason of patients' poor prognosis might be the absence of liver abscess drainage, high level of CSF protein which indicates severe inflammation and unknown special but stronger virulence factors of K. pneumoniae the patients' living place Zhangjiakou. Strict glycemic control, early drainage of liver abscess and appropriate antibiotic application are recommended for treating this condition, further progress on the pathogenesis and treatment of K. pneumoniae meningitis may help patients gain a better prognosis.

Klebsiella pneumoniae pneumonia in patients with rheumatic autoimmune diseases: clinical characteristics, antimicrobial resistance and factors associated with extended-spectrum ß-lactamase production.

BACKGROUND: Over the past decades, Klebsiella pneumoniae (K. pneumoniae) infections have been increasing and affected immunocompromised patients nosocomially and communally, with extended-spectrum ß-lactamase (ESBL) production becoming a major concern. Patients with rheumatic autoimmune diseases, mostly receiving immunosuppressive therapy, are vulnerable to various infections, including K. pneumoniae. However, few have investigated K. pneumoniae infections in this specific population. This study aimed to identify factors associated with ESBL production and mortality of K. pneumoniae pneumonia among patients with rheumatic autoimmune diseases in the Emergency Department. METHODS: We retrospectively investigated patients with rheumatic diseases who were diagnosed with K. pneumoniae pneumonia. The diagnosis of K. pneumoniae pneumonia was based on clinical manifestations, radiological findings and microbiological testing results. Prognostic factors and risk factors for ESBL production were determined with univariate and multivariate logistic regression analysis. Empirical therapy and antimicrobial susceptibility data were also collected. RESULTS: Of 477 K. pneumoniae pneumonia patients, 60 were enrolled into this study. The in-hospital mortality was 28.3%. Septic shock, ICU admission, the need for mechanical ventilation and change of antibiotics due to clinical deterioration, all related to mortality, were included as unfavorable clinical outcomes. Multivariate analysis suggested that ESBL production (OR, 6.793; p = 0.012), initial PCT ≥ 0.5 ng/ml (OR, 5.024; p = 0.033) and respiratory failure at admission (OR, 4.401; p = 0.046) predicted increased mortality. ESBL production was significantly associated with dose of corticosteroids (OR, 1.033; p = 0.008) and CMV viremia (OR, 4.836; p = 0.032) in patients with rheumatic autoimmune diseases. Abnormal leukocyte count (OR, 0.192; p = 0.036) was identified as a protective factor of ESBL-producing K. pneumoniae pneumonia. The most commonly used empirical antibiotic was ceftazidime, while most isolates showed less resistance to carbapenems and amikacin in susceptibility testing. CONCLUSIONS: K. pneumoniae pneumonia could be life-threatening in patients with rheumatic autoimmune diseases. Our findings suggested that ESBL production, initial PCT ≥ 0.5 ng/ml and respiratory failure at admission were independent factors associated with poor prognosis. Dose of corticosteroids and CMV viremia, predicting ESBL production in K. pneumoniae pneumonia, may help make individualized antibiotic decisions in clinical practice.

Targeting JAK2 reduces GVHD and xenograft rejection through regulation of T cell differentiation.

Janus kinase 2 (JAK2) signal transduction is a critical mediator of the immune response. JAK2 is implicated in the onset of graft-versus-host disease (GVHD), which is a significant cause of transplant-related mortality after allogeneic hematopoietic cell transplantation (allo-HCT). Transfer of JAK2-/- donor T cells to allogeneic recipients leads to attenuated GVHD yet maintains graft-versus-leukemia. Th1 differentiation among JAK2-/- T cells is significantly decreased compared with wild-type controls. Conversely, iTreg and Th2 polarization is significantly increased among JAK2-/- T cells. Pacritinib is a multikinase inhibitor with potent activity against JAK2. Pacritinib significantly reduces GVHD and xenogeneic skin graft rejection in distinct rodent models and maintains donor antitumor immunity. Moreover, pacritinib spares iTregs and polarizes Th2 responses as observed among JAK2-/- T cells. Collectively, these data clearly identify JAK2 as a therapeutic target to control donor alloreactivity and promote iTreg responses after allo-HCT or solid organ transplantation. As such, a phase I/II acute GVHD prevention trial combining pacritinib with standard immune suppression after allo-HCT is actively being investigated (https://clinicaltrials.gov/ct2/show/NCT02891603).

Pulse rate as an alternative, real-time feedback indicator for chest compression rate: a porcine model of cardiac arrest.

Feedback indicators can improve chest compression quality during cardiopulmonary resuscitation (CPR). However, the application of feedback indicators in the clinic practice is rare. Pulse oximetry has been widely used and reported to correlate spontaneous circulation restoration during CPR. However, it is unclear if pulse oximetry can monitor the quality of chest compression. We hypothesized that pulse rate monitored by pulse oximetry can be used as a feedback indicator of the chest compression rate during CPR in a porcine model of cardiac arrest. Seven domestic male pigs (30-35 kg) were utilized in this study. Eighteen intermittent chest compression periods of 2 min were performed on each animal. Chest compression and pulse oximetry plethysmographic waveforms were recorded simultaneously. Chest compression and pulse rates were calculated based on both waveforms. Compression interruption and synchronous pulse interruption times were also measured. Agreement was analyzed between pulse rates and synchronous chest compression rates, as well as between compression interruption times and synchronous pulse interruption times. A total of 126 compression periods of 2 min were performed on seven animals. Interclass correlation coefficients and Bland-Altman analysis revealed reliable agreement between pulse rates and synchronous chest compression rates. Similarly, compression interruption and synchronous pulse interruption times obtained also showed high agreement. Pulse rate can be used as an alternative indicator of chest compression rate during CPR in a porcine model of cardiac arrest. Pulse interruption time also can be used to reflect compression interruption time precisely in this model.

Thioredoxin-1 improves the immunometabolic phenotype of antitumor T cells.

Adoptive transfer of tumor epitope-reactive T cells has emerged as a promising strategy to control tumor growth. However, chronically-stimulated T cells expanded for adoptive cell transfer are susceptible to cell death in an oxidative tumor microenvironment. Because oxidation of cell-surface thiols also alters protein functionality, we hypothesized that increasing the levels of thioredoxin (Trx), an antioxidant molecule facilitating reduction of proteins through cysteine thiol-disulfide exchange, in T cells will promote their sustained antitumor function. Using pre-melanosome protein (Pmel)-Trx1 transgenic mouse-derived splenic T cells, flow cytometry, and gene expression analysis, we observed here that higher Trx expression inversely correlated with reactive oxygen species and susceptibility to T-cell receptor restimulation or oxidation-mediated cell death. These Trx1-overexpressing T cells exhibited a cluster of differentiation 62Lhi (CD62Lhi) central memory-like phenotype with reduced glucose uptake (2-NBDGlo) and decreased effector function (interferon γlo). Furthermore, culturing tumor-reactive T cells in the presence of recombinant Trx increased the dependence of T cells on mitochondrial metabolism and improved tumor control. We conclude that strategies for increasing the antioxidant capacity of antitumor T cells modulate their immunometabolic phenotype leading to improved immunotherapeutic control of established tumors.

MicroRNA-17-92 is required for T-cell and B-cell pathogenicity in chronic graft-versus-host disease in mice.

Chronic graft-versus-host disease (cGVHD) is characterized as autoimmune-like fibrosis and antibody production mediated by pathogenic T cells and B cells. MicroRNA-17-92 (miR-17-92) influences the survival, differentiation, and function of lymphocytes in cancer, infections, and autoimmunity. To determine whether miR-17-92 regulates T- and B-cell responses in cGVHD, we generated mice conditionally deficient for miR-17-92 in T cells, B cells, or both. Using murine models of allogeneic bone marrow transplantation, we demonstrate that expression of miR-17-92 in donor T and B cells is essential for the induction of both scleroderma and bronchiolitis obliterans in cGVHD. Mechanistically, miR-17-92 expressed in T cells not only enhances the differentiation of pathogenic T helper 1 (Th1) and Th17 cells, but also promotes the generation of follicular Th cells, germinal center (GC) B cells, and plasma cells. In B cells, miR-17-92 expression is required for autoantibody production and immunoglobulin G deposition in the skin. Furthermore, we evaluated a translational approach using antagomirs specific for either miR-17 or miR-19, key members in miR-17-92 cluster. In a lupus-like cGVHD model, systemic administration of anti-miR-17, but not anti-miR-19, alleviates clinical manifestations and proteinuria incidence in recipients through inhibiting donor lymphocyte expansion, B-cell activation, and GC responses. Blockade of miR-17 also ameliorates skin damage by reducing Th17 differentiation in a scleroderma-cGVHD model. Taken together, our work reveals that miR-17-92 is required for T-cell and B-cell differentiation and function, and thus for the development of cGVHD. Furthermore, pharmacological inhibition of miR-17 represents a potential therapeutic strategy for the prevention of cGVHD.

Stabilization of Foxp3 by Targeting JAK2 Enhances Efficacy of CD8 Induced Regulatory T Cells in the Prevention of Graft-versus-Host Disease.

CD8+ induced regulatory T cells (iTregs) have been identified to suppress alloreactive immune responses and expressed regulatory T cell (Treg) ontological markers as similar as CD4+ iTregs. However, adoptive transfer of CD8+ iTreg-based therapy is hampered by the instability of Treg specific-transcription factor, Foxp3. As CD8+ iTregs were previously demonstrated to possess superior tumor-killing ability to CD4+ iTregs, adoptive transfer of stabilized CD8+ iTregs would be a potential therapy to prevent tumor relapse during graft-versus-leukemia disease (GVHD) treatment. In the current study, we generated alloantigen reactive CD8+ iTregs from JAK2-/- T cells and adoptively transferred them to MHC-mismatched and haploidentical murine models of allogeneic bone marrow transplantation. JAK2-/- CD8+ iTregs not only attenuated GVHD but also preserved graft-versus-leukemia effect. Mechanistic analysis revealed that JAK2-/- CD8+ iTregs upregulated natural Treg marker (neuropilin-1), and augmented DNA demethylation of CNS2 region within Foxp3 gene. These properties licensed JAK2-/- CD8+ iTregs to retain high Foxp3 expression resulting in less conversion to type 1 CTLs; as a result, JAK2-/- CD8+ iTregs were able to maintain their suppressive and cytolytic function. Thus, our findings provide a strong rationale and means to stabilize CD8+ iTregs by targeting JAK2, and the stabilized CD8+ iTregs exhibit therapeutic potential for alleviating GVHD and preserving the graft-versus-leukemia effect.